Indirect handle on the down-quark Yukawa coupling.
Goertz, Florian
2014-12-31
To measure the Yukawa couplings of the up and down quarks, Yu,d, seems to be far beyond the capabilities of current and (near) future experiments in particle physics. By performing a general analysis of the potential misalignment between quark masses and Yukawa couplings, we derive predictions for the magnitude of induced flavor-changing neutral currents (FCNCs), depending on the shift in the physical Yukawa coupling of first-generation quarks. We find that a change of more than 50% in Yd would generically result in ds transitions in conflict with kaon physics. This could already be seen as evidence for a nonvanishing direct coupling of the down quark to the newly discovered Higgs boson. The nonobservation of certain--already well-constrained--processes is thus turned into a powerful indirect measure of otherwise basically unaccessible physical parameters of the effective standard model. Similarly, improvements in limits on FCNCs in the up-type quark sector can lead to valuable information on Yu. PMID:25615309
Why should we care about the top quark Yukawa coupling?
Shapshnikov, Mikhail; Bezrukov, Fedor
2015-04-15
In the cosmological context, for the Standard Model to be valid up to the scale of inflation, the top quark Yukawa coupling yt should not exceed the critical value ytcrit , coinciding with good precision (about 0.2‰) with the requirement of the stability of the electroweak vacuum. So, the exact measurements of yt may give an insight on the possible existence and the energy scale of new physics above 100 GeV, which is extremely sensitive to yt. In this study, we overview the most recent theoretical computations of and the experimental measurements of ytcrit and the experimental measurements ofmore » yt. Within the theoretical and experimental uncertainties in yt, the required scale of new physics varies from 10⁷ GeV to the Planck scale, urging for precise determination of the top quark Yukawa coupling.« less
Why should we care about the top quark Yukawa coupling?
Bezrukov, F.; Shaposhnikov, M.
2015-03-15
In the cosmological context, for the Standard Model to be valid up to the scale of inflation, the top quark Yukawa coupling y{sub t} should not exceed the critical value y{sub t}{sup crit}, coinciding with good precision (about 0.2‰) with the requirement of the stability of the electroweak vacuum. So, the exact measurements of y{sub t} may give an insight on the possible existence and the energy scale of new physics above 100 GeV, which is extremely sensitive to y{sub t}. We overview the most recent theoretical computations of and the experimental measurements of y{sub t}{sup crit} and the experimental measurements of y{sub t}. Within the theoretical and experimental uncertainties in y{sub t}, the required scale of new physics varies from 10{sup 7} GeV to the Planck scale, urging for precise determination of the top quark Yukawa coupling.
Why should we care about the top quark Yukawa coupling?
Shapshnikov, Mikhail; Bezrukov, Fedor
2015-04-15
In the cosmological context, for the Standard Model to be valid up to the scale of inflation, the top quark Yukawa coupling y_{t} should not exceed the critical value y_{t}^{crit }, coinciding with good precision (about 0.2‰) with the requirement of the stability of the electroweak vacuum. So, the exact measurements of y_{t} may give an insight on the possible existence and the energy scale of new physics above 100 GeV, which is extremely sensitive to y_{t}. In this study, we overview the most recent theoretical computations of and the experimental measurements of y_{t}^{crit } and the experimental measurements of y_{t}. Within the theoretical and experimental uncertainties in y_{t}, the required scale of new physics varies from 10⁷ GeV to the Planck scale, urging for precise determination of the top quark Yukawa coupling.
Constraining the charm Yukawa and Higgs-quark coupling universality
NASA Astrophysics Data System (ADS)
Perez, Gilad; Soreq, Yotam; Stamou, Emmanuel; Tobioka, Kohsaku
2015-08-01
We introduce four different types of data-driven analyses with different levels of robustness that constrain the size of the Higgs-charm Yukawa coupling: (i) Recasting the vector-boson associated V h analyses that search for the bottom-pair final state. We use this mode to directly and model independently constrain the Higgs-to-charm coupling, yc/ycSM≲234 . (ii) The direct measurement of the total width, yc/ycSM≲120 - 140 . (iii) The search for h →J /ψ γ , yc/ycSM≲220 . (iv) A global fit to the Higgs signal strengths, yc/ycSM≲6.2 . A comparison with t t ¯h data allows us to show that the Higgs does not couple to quarks in a universal way, as is expected in the Standard Model. Finally, we demonstrate how the experimental collaborations can further improve our direct bound by roughly an order of magnitude by charm tagging, as is already used in new-physics searches.
Exclusive radiative Higgs decays as probes of light-quark Yukawa couplings
NASA Astrophysics Data System (ADS)
König, Matthias; Neubert, Matthias
2015-08-01
We present a detailed analysis of the rare exclusive Higgs boson decays into a single vector meson and a photon and investigate the possibility of using these processes to probe the light-quark Yukawa couplings. We work with an effective Lagrangian with modified Higgs couplings to account for possible new-physics effects in a model-independent way. The h → Vγ decay rate is governed by the destructive interference of two amplitudes, one of which involves the Higgs coupling to the quark anti-quark pair inside the vector meson. We derive this amplitude at next-to-leading order in α s using QCD factorization, including the resummation of large logarithmic corrections and accounting for the effects of flavor mixing. The high factorization scale μ ˜ m h ensures that our results are rather insensitive to the hadronic parameters characterizing the light-cone distribution amplitude of the vector meson. The second amplitude arises from the loop-induced effective hγγ * and hγZ * couplings, where the off-shell gauge boson converts into the vector meson. We devise a strategy to eliminate theoretical uncertainties related to this amplitude to almost arbitrary precision. This opens up the possibility to probe for modifications of the c- and b-quark Yukawa couplings and modifications of the s-quark Yukawa coupling in the high-luminosity LHC run. In particular, we show that measurements of the ratios Br( h → Υ( nS) γ)/Br( h → γγ) and can provide complementary information on the real and imaginary parts of the b-quark Yukawa coupling. More accurate measurements would be possible at a future 100 TeV proton-proton collider.
Towards a precise measurement of the top quark Yukawa coupling at the ILC
Juste, A.
2005-12-01
A precise measurement of the top quark Yukawa coupling is of great importance, since it may shed light on the mechanism of EWSB. We study the prospects of such measurement during the first phase of the ILC at {radical}s = 500 GeV, focusing in particular on recent theoretical developments as well as the potential benefits of beam polarization. It is shown that both yield improvements that could possibly lead to a measurement competitive with the LHC.
Probing the Charm Quark Yukawa Coupling in Higgs+Charm Production.
Brivio, Ilaria; Goertz, Florian; Isidori, Gino
2015-11-20
We propose a new method for determining the coupling of the Higgs boson to charm quarks, via Higgs production in association with a charm-tagged jet: pp→hc. As a first estimate, we find that at the LHC with 3000 fb^{-1}, it should be possible to derive a constraint of order one, relative to the standard model (SM) value of the charm Yukawa coupling. As a by-product of this analysis, we present an estimate of the exclusive pp→hD^{(*)} electroweak cross section. Within the SM, the latter turns out to be not accessible at the LHC even in the high-luminosity phase. PMID:26636844
Yukawa Couplings in Heterotic Compactification
NASA Astrophysics Data System (ADS)
Anderson, Lara B.; Gray, James; Grayson, Dan; He, Yang-Hui; Lukas, André
2010-07-01
We present a practical, algebraic method for efficiently calculating the Yukawa couplings of a large class of heterotic compactifications on Calabi-Yau three-folds with non-standard embeddings. Our methodology covers all of, though is not restricted to, the recently classified positive monads over favourable complete intersection Calabi-Yau three-folds. Since the algorithm is based on manipulating polynomials it can be easily implemented on a computer. This makes the automated investigation of Yukawa couplings for large classes of smooth heterotic compactifications a viable possibility.
Exclusive window onto Higgs Yukawa couplings.
Kagan, Alexander L; Perez, Gilad; Petriello, Frank; Soreq, Yotam; Stoynev, Stoyan; Zupan, Jure
2015-03-13
We show that both flavor-conserving and flavor-violating Yukawa couplings of the Higgs boson to first- and second-generation quarks can be probed by measuring rare decays of the form h→MV, where M denotes a vector meson and V indicates either γ, W or Z. We calculate the branching ratios for these processes in both the standard model and its possible extensions. We discuss the experimental prospects for their observation. The possibility of accessing these Higgs couplings appears to be unique to the high-luminosity LHC and future hadron colliders, providing further motivation for those machines. PMID:25815924
Holomorphic Yukawa couplings in heterotic string theory
NASA Astrophysics Data System (ADS)
Blesneag, Stefan; Buchbinder, Evgeny I.; Candelas, Philip; Lukas, Andre
2016-01-01
We develop techniques, based on differential geometry, to compute holomorphic Yukawa couplings for heterotic line bundle models on Calabi-Yau manifolds defined as complete intersections in projective spaces. It is shown explicitly how these techniques relate to algebraic methods for computing holomorphic Yukawa couplings. We apply our methods to various examples and evaluate the holomorphic Yukawa couplings explicitly as functions of the complex structure moduli. It is shown that the rank of the Yukawa matrix can decrease at specific loci in complex structure moduli space. In particular, we compute the up Yukawa coupling and the singlet-Higgs-lepton trilinear coupling in the heterotic standard model described in ref. [32].
Renormalization group invariant of lepton Yukawa couplings
NASA Astrophysics Data System (ADS)
Tsuyuki, Takanao
2015-04-01
By using quark Yukawa matrices only, we can construct renormalization invariants that are exact at the one-loop level in the standard model. One of them, Iq, is accidentally consistent with unity, even though quark masses are strongly hierarchical. We calculate a lepton version of the invariant Il for Dirac and Majorana neutrino cases and find that Il can also be close to unity. For the Dirac neutrino and inverted hierarchy case, if the lightest neutrino mass is 3.0 meV to 8.8 meV, an equality Iq=Il can be satisfied. These invariants are not changed even if new particles couple to the standard model particles, as long as those couplings are generation independent.
Nonstandard Yukawa couplings and Higgs portal dark matter
NASA Astrophysics Data System (ADS)
Bishara, Fady; Brod, Joachim; Uttarayat, Patipan; Zupan, Jure
2016-01-01
We study the implications of non-standard Higgs Yukawa couplings to light quarks on Higgs-portal dark matter phenomenology. Saturating the present experimental bounds on up-quark, down-quark, or strange-quark Yukawa couplings, the predicted direct dark matter detection scattering rate can increase by up to four orders of magnitude. The effect on the dark matter annihilation cross-section, on the other hand, is subleading unless the dark matter is very light — a scenario that is already excluded by measurements of the Higgs invisible decay width. We investigate the expected size of corrections in multi-Higgs-doublet models with natural flavor conservation, the type-II two-Higgs-doublet model, the Giudice-Lebedev model of light quark masses, minimal flavor violation new physics models, Randall-Sundrum, and composite Higgs models. We find that an enhancement in the dark matter scattering rate of an order of magnitude is possible. Finally, we point out that a discovery of Higgs-portal dark matter could lead to interesting bounds on the light-quark Yukawa couplings.
Nonstandard Yukawa couplings and Higgs portal dark matter
Bishara, Fady; Brod, Joachim; Uttayarat, Patipan; Zupan, Jure
2016-01-04
We study the implications of non-standard Higgs Yukawa couplings to light quarks on Higgs-portal dark matter phenomenology. Saturating the present experimental bounds on up-quark, down-quark, or strange-quark Yukawa couplings, the predicted direct dark matter detection scattering rate can increase by up to four orders of magnitude. The effect on the dark matter annihilation cross-section, on the other hand, is subleading unless the dark matter is very light — a scenario that is already excluded by measurements of the Higgs invisible decay width. We investigate the expected size of corrections in multi-Higgs-doublet models with natural flavor conservation, the type-II two-Higgs-doublet model,more » the Giudice-Lebedev model of light quark masses, minimal flavor violation new physics models, Randall-Sundrum, and composite Higgs models. We find that an enhancement in the dark matter scattering rate of an order of magnitude is possible. In conclusion, we point out that a discovery of Higgs-portal dark matter could lead to interesting bounds on the light-quark Yukawa couplings.« less
NASA Astrophysics Data System (ADS)
Aad, G.; Abbott, B.; Abdallah, J.; Abdel Khalek, S.; Abdinov, O.; Aben, R.; Abi, B.; Abolins, M.; AbouZeid, O. S.; Abramowicz, H.; Abreu, H.; Abreu, R.; Abulaiti, Y.; Acharya, B. S.; Adamczyk, L.; Adams, D. L.; Adelman, J.; Adomeit, S.; Adye, T.; Agatonovic-Jovin, T.; Aguilar-Saavedra, J. A.; Agustoni, M.; Ahlen, S. P.; Ahmadov, F.; Aielli, G.; Akerstedt, H.; Åkesson, T. P. A.; Akimoto, G.; Akimov, A. V.; Alberghi, G. L.; Albert, J.; Albrand, S.; Alconada Verzini, M. J.; Aleksa, M.; Aleksandrov, I. N.; Alexa, C.; Alexander, G.; Alexandre, G.; Alexopoulos, T.; Alhroob, M.; Alimonti, G.; Alio, L.; Alison, J.; Allbrooke, B. M. M.; Allison, L. J.; Allport, P. P.; Aloisio, A.; Alonso, A.; Alonso, F.; Alpigiani, C.; Altheimer, A.; Alvarez Gonzalez, B.; Alviggi, M. G.; Amako, K.; Amaral Coutinho, Y.; Amelung, C.; Amidei, D.; Amor Dos Santos, S. P.; Amorim, A.; Amoroso, S.; Amram, N.; Amundsen, G.; Anastopoulos, C.; Ancu, L. S.; Andari, N.; Andeen, T.; Anders, C. F.; Anders, G.; Anderson, K. J.; Andreazza, A.; Andrei, V.; Anduaga, X. S.; Angelidakis, S.; Angelozzi, I.; Anger, P.; Angerami, A.; Anghinolfi, F.; Anisenkov, A. V.; Anjos, N.; Annovi, A.; Antonaki, A.; Antonelli, M.; Antonov, A.; Antos, J.; Anulli, F.; Aoki, M.; Aperio Bella, L.; Apolle, R.; Arabidze, G.; Aracena, I.; Arai, Y.; Araque, J. P.; Arce, A. T. H.; Arguin, J.-F.; Argyropoulos, S.; Arik, M.; Armbruster, A. J.; Arnaez, O.; Arnal, V.; Arnold, H.; Arratia, M.; Arslan, O.; Artamonov, A.; Artoni, G.; Asai, S.; Asbah, N.; Ashkenazi, A.; Åsman, B.; Asquith, L.; Assamagan, K.; Astalos, R.; Atkinson, M.; Atlay, N. B.; Auerbach, B.; Augsten, K.; Aurousseau, M.; Avolio, G.; Azuelos, G.; Azuma, Y.; Baak, M. A.; Baas, A. E.; Bacci, C.; Bachacou, H.; Bachas, K.; Backes, M.; Backhaus, M.; Backus Mayes, J.; Badescu, E.; Bagiacchi, P.; Bagnaia, P.; Bai, Y.; Bain, T.; Baines, J. T.; Baker, O. K.; Balek, P.; Balli, F.; Banas, E.; Banerjee, Sw.; Bannoura, A. A. E.; Bansal, V.; Bansil, H. S.; Barak, L.; Baranov, S. P.; Barberio, E. L.; Barberis, D.; Barbero, M.; Barillari, T.; Barisonzi, M.; Barklow, T.; Barlow, N.; Barnett, B. M.; Barnett, R. M.; Barnovska, Z.; Baroncelli, A.; Barone, G.; Barr, A. J.; Barreiro, F.; Barreiro Guimarães da Costa, J.; Bartoldus, R.; Barton, A. E.; Bartos, P.; Bartsch, V.; Bassalat, A.; Basye, A.; Bates, R. L.; Batley, J. R.; Battaglia, M.; Battistin, M.; Bauer, F.; Bawa, H. S.; Beattie, M. D.; Beau, T.; Beauchemin, P. H.; Beccherle, R.; Bechtle, P.; Beck, H. P.; Becker, K.; Becker, S.; Beckingham, M.; Becot, C.; Beddall, A. J.; Beddall, A.; Bedikian, S.; Bednyakov, V. A.; Bee, C. P.; Beemster, L. J.; Beermann, T. A.; Begel, M.; Behr, K.; Belanger-Champagne, C.; Bell, P. J.; Bell, W. H.; Bella, G.; Bellagamba, L.; Bellerive, A.; Bellomo, M.; Belotskiy, K.; Beltramello, O.; Benary, O.; Benchekroun, D.; Bendtz, K.; Benekos, N.; Benhammou, Y.; Benhar Noccioli, E.; Benitez Garcia, J. A.; Benjamin, D. P.; Bensinger, J. R.; Benslama, K.; Bentvelsen, S.; Berge, D.; Bergeaas Kuutmann, E.; Berger, N.; Berghaus, F.; Beringer, J.; Bernard, C.; Bernat, P.; Bernius, C.; Bernlochner, F. U.; Berry, T.; Berta, P.; Bertella, C.; Bertoli, G.; Bertolucci, F.; Bertsche, C.; Bertsche, D.; Besana, M. I.; Besjes, G. J.; Bessidskaia, O.; Bessner, M.; Besson, N.; Betancourt, C.; Bethke, S.; Bhimji, W.; Bianchi, R. M.; Bianchini, L.; Bianco, M.; Biebel, O.; Bieniek, S. P.; Bierwagen, K.; Biesiada, J.; Biglietti, M.; Bilbao De Mendizabal, J.; Bilokon, H.; Bindi, M.; Binet, S.; Bingul, A.; Bini, C.; Black, C. W.; Black, J. E.; Black, K. M.; Blackburn, D.; Blair, R. E.; Blanchard, J.-B.; Blazek, T.; Bloch, I.; Blocker, C.; Blum, W.; Blumenschein, U.; Bobbink, G. J.; Bobrovnikov, V. S.; Bocchetta, S. S.; Bocci, A.; Bock, C.; Boddy, C. R.; Boehler, M.; Boek, T. T.; Bogaerts, J. A.; Bogdanchikov, A. G.; Bogouch, A.; Bohm, C.; Bohm, J.; Boisvert, V.; Bold, T.; Boldea, V.; Boldyrev, A. S.; Bomben, M.; Bona, M.; Boonekamp, M.; Borisov, A.; Borissov, G.; Borri, M.; Borroni, S.; Bortfeldt, J.; Bortolotto, V.; Bos, K.; Boscherini, D.; Bosman, M.; Boterenbrood, H.; Boudreau, J.; Bouffard, J.; Bouhova-Thacker, E. V.; Boumediene, D.; Bourdarios, C.; Bousson, N.; Boutouil, S.; Boveia, A.; Boyd, J.; Boyko, I. R.; Bozic, I.; Bracinik, J.; Brandt, A.; Brandt, G.; Brandt, O.; Bratzler, U.; Brau, B.; Brau, J. E.; Braun, H. M.; Brazzale, S. F.; Brelier, B.; Brendlinger, K.; Brennan, A. J.; Brenner, R.; Bressler, S.; Bristow, K.; Bristow, T. M.; Britton, D.; Brochu, F. M.; Brock, I.; Brock, R.; Bromberg, C.; Bronner, J.; Brooijmans, G.; Brooks, T.; Brooks, W. K.; Brosamer, J.; Brost, E.; Brown, J.; Bruckman de Renstrom, P. A.; Bruncko, D.; Bruneliere, R.; Brunet, S.; Bruni, A.; Bruni, G.; Bruschi, M.; Bryngemark, L.; Buanes, T.; Buat, Q.; Bucci, F.; Buchholz, P.; Buckingham, R. M.; Buckley, A. G.; Buda, S. I.; Budagov, I. A.; Buehrer, F.; Bugge, L.; Bugge, M. K.; Bulekov, O.; Bundock, A. C.; Burckhart, H.; Burdin, S.; Burghgrave, B.; Burke, S.; Burmeister, I.; Busato, E.; Büscher, D.; Büscher, V.; Bussey, P.; Buszello, C. P.; Butler, B.; Butler, J. M.; Butt, A. I.; Buttar, C. M.; Butterworth, J. M.; Butti, P.; Buttinger, W.; Buzatu, A.; Byszewski, M.; Cabrera Urbán, S.; Caforio, D.; Cakir, O.; Calafiura, P.; Calandri, A.; Calderini, G.; Calfayan, P.; Calkins, R.; Caloba, L. P.; Calvet, D.; Calvet, S.; Camacho Toro, R.; Camarda, S.; Cameron, D.; Caminada, L. M.; Caminal Armadans, R.; Campana, S.; Campanelli, M.; Campoverde, A.; Canale, V.; Canepa, A.; Cano Bret, M.; Cantero, J.; Cantrill, R.; Cao, T.; Capeans Garrido, M. D. M.; Caprini, I.; Caprini, M.; Capua, M.; Caputo, R.; Cardarelli, R.; Carli, T.; Carlino, G.; Carminati, L.; Caron, S.; Carquin, E.; Carrillo-Montoya, G. D.; Carter, J. R.; Carvalho, J.; Casadei, D.; Casado, M. P.; Casolino, M.; Castaneda-Miranda, E.; Castelli, A.; Castillo Gimenez, V.; Castro, N. F.; Catastini, P.; Catinaccio, A.; Catmore, J. R.; Cattai, A.; Cattani, G.; Cavaliere, V.; Cavalli, D.; Cavalli-Sforza, M.; Cavasinni, V.; Ceradini, F.; Cerio, B. C.; Cerny, K.; Cerqueira, A. S.; Cerri, A.; Cerrito, L.; Cerutti, F.; Cerv, M.; Cervelli, A.; Cetin, S. A.; Chafaq, A.; Chakraborty, D.; Chalupkova, I.; Chang, P.; Chapleau, B.; Chapman, J. D.; Charfeddine, D.; Charlton, D. G.; Chau, C. C.; Chavez Barajas, C. A.; Cheatham, S.; Chegwidden, A.; Chekanov, S.; Chekulaev, S. V.; Chelkov, G. A.; Chelstowska, M. A.; Chen, C.; Chen, H.; Chen, K.; Chen, L.; Chen, S.; Chen, X.; Chen, Y.; Chen, Y.; Cheng, H. C.; Cheng, Y.; Cheplakov, A.; Cherkaoui El Moursli, R.; Chernyatin, V.; Cheu, E.; Chevalier, L.; Chiarella, V.; Chiefari, G.; Childers, J. T.; Chilingarov, A.; Chiodini, G.; Chisholm, A. S.; Chislett, R. T.; Chitan, A.; Chizhov, M. V.; Chouridou, S.; Chow, B. K. B.; Chromek-Burckhart, D.; Chu, M. L.; Chudoba, J.; Chwastowski, J. J.; Chytka, L.; Ciapetti, G.; Ciftci, A. K.; Ciftci, R.; Cinca, D.; Cindro, V.; Ciocio, A.; Cirkovic, P.; Citron, Z. H.; Citterio, M.; Ciubancan, M.; Clark, A.; Clark, P. J.; Clarke, R. N.; Cleland, W.; Clemens, J. C.; Clement, C.; Coadou, Y.; Cobal, M.; Coccaro, A.; Cochran, J.; Coffey, L.; Cogan, J. G.; Coggeshall, J.; Cole, B.; Cole, S.; Colijn, A. P.; Collot, J.; Colombo, T.; Colon, G.; Compostella, G.; Conde Muiño, P.; Coniavitis, E.; Conidi, M. C.; Connell, S. H.; Connelly, I. A.; Consonni, S. M.; Consorti, V.; Constantinescu, S.; Conta, C.; Conti, G.; Conventi, F.; Cooke, M.; Cooper, B. D.; Cooper-Sarkar, A. M.; Cooper-Smith, N. J.; Copic, K.; Cornelissen, T.; Corradi, M.; Corriveau, F.; Corso-Radu, A.; Cortes-Gonzalez, A.; Cortiana, G.; Costa, G.; Costa, M. J.; Costanzo, D.; Côté, D.; Cottin, G.; Cowan, G.; Cox, B. E.; Cranmer, K.; Cree, G.; Crépé-Renaudin, S.; Crescioli, F.; Cribbs, W. A.; Crispin Ortuzar, M.; Cristinziani, M.; Croft, V.; Crosetti, G.; Cuciuc, C.-M.; Cuhadar Donszelmann, T.; Cummings, J.; Curatolo, M.; Cuthbert, C.; Czirr, H.; Czodrowski, P.; Czyczula, Z.; D'Auria, S.; D'Onofrio, M.; Da Cunha Sargedas De Sousa, M. J.; Da Via, C.; Dabrowski, W.; Dafinca, A.; Dai, T.; Dale, O.; Dallaire, F.; Dallapiccola, C.; Dam, M.; Daniells, A. C.; Dano Hoffmann, M.; Dao, V.; Darbo, G.; Darmora, S.; Dassoulas, J. A.; Dattagupta, A.; Davey, W.; David, C.; Davidek, T.; Davies, E.; Davies, M.; Davignon, O.; Davison, A. R.; Davison, P.; Davygora, Y.; Dawe, E.; Dawson, I.; Daya-Ishmukhametova, R. K.; De, K.; de Asmundis, R.; De Castro, S.; De Cecco, S.; De Groot, N.; de Jong, P.; De la Torre, H.; De Lorenzi, F.; De Nooij, L.; De Pedis, D.; De Salvo, A.; De Sanctis, U.; De Santo, A.; De Vivie De Regie, J. B.; Dearnaley, W. J.; Debbe, R.; Debenedetti, C.; Dechenaux, B.; Dedovich, D. V.; Deigaard, I.; Del Peso, J.; Del Prete, T.; Deliot, F.; Delitzsch, C. M.; Deliyergiyev, M.; Dell'Acqua, A.; Dell'Asta, L.; Dell'Orso, M.; Della Pietra, M.; della Volpe, D.; Delmastro, M.; Delsart, P. A.; Deluca, C.; Demers, S.; Demichev, M.; Demilly, A.; Denisov, S. P.; Derendarz, D.; Derkaoui, J. E.; Derue, F.; Dervan, P.; Desch, K.; Deterre, C.; Deviveiros, P. O.; Dewhurst, A.; Dhaliwal, S.; Di Ciaccio, A.; Di Ciaccio, L.; Di Domenico, A.; Di Donato, C.; Di Girolamo, A.; Di Girolamo, B.; Di Mattia, A.; Di Micco, B.; Di Nardo, R.; Di Simone, A.; Di Sipio, R.; Di Valentino, D.; Dias, F. A.; Diaz, M. A.; Diehl, E. B.; Dietrich, J.; Dietzsch, T. A.; Diglio, S.; Dimitrievska, A.; Dingfelder, J.; Dionisi, C.; Dita, P.; Dita, S.; Dittus, F.; Djama, F.; Djobava, T.; do Vale, M. A. B.; Do Valle Wemans, A.; Dobos, D.; Doglioni, C.; Doherty, T.; Dohmae, T.; Dolejsi, J.; Dolezal, Z.; Dolgoshein, B. A.; Donadelli, M.; Donati, S.; Dondero, P.; Donini, J.; Dopke, J.; Doria, A.; Dova, M. T.; Doyle, A. T.; Dris, M.; Dubbert, J.; Dube, S.; Dubreuil, E.; Duchovni, E.; Duckeck, G.; Ducu, O. A.; Duda, D.; Dudarev, A.; Dudziak, F.; Duflot, L.; Duguid, L.; Dührssen, M.; Dunford, M.; Duran Yildiz, H.; Düren, M.; Durglishvili, A.; Dwuznik, M.; Dyndal, M.; Ebke, J.; Edson, W.; Edwards, N. C.; Ehrenfeld, W.; Eifert, T.; Eigen, G.; Einsweiler, K.; Ekelof, T.; El Kacimi, M.; Ellert, M.; Elles, S.; Ellinghaus, F.; Ellis, N.; Elmsheuser, J.; Elsing, M.; Emeliyanov, D.; Enari, Y.; Endner, O. C.; Endo, M.; Engelmann, R.; Erdmann, J.; Ereditato, A.; Eriksson, D.; Ernis, G.; Ernst, J.; Ernst, M.; Ernwein, J.; Errede, D.; Errede, S.; Ertel, E.; Escalier, M.; Esch, H.; Escobar, C.; Esposito, B.; Etienvre, A. I.; Etzion, E.; Evans, H.; Ezhilov, A.; Fabbri, L.; Facini, G.; Fakhrutdinov, R. M.; Falciano, S.; Falla, R. J.; Faltova, J.; Fang, Y.; Fanti, M.; Farbin, A.; Farilla, A.; Farooque, T.; Farrell, S.; Farrington, S. M.; Farthouat, P.; Fassi, F.; Fassnacht, P.; Fassouliotis, D.; Favareto, A.; Fayard, L.; Federic, P.; Fedin, O. L.; Fedorko, W.; Fehling-Kaschek, M.; Feigl, S.; Feligioni, L.; Feng, C.; Feng, E. J.; Feng, H.; Fenyuk, A. B.; Fernandez Perez, S.; Ferrag, S.; Ferrando, J.; Ferrari, A.; Ferrari, P.; Ferrari, R.; Ferreira de Lima, D. E.; Ferrer, A.; Ferrere, D.; Ferretti, C.; Ferretto Parodi, A.; Fiascaris, M.; Fiedler, F.; Filipčič, A.; Filipuzzi, M.; Filthaut, F.; Fincke-Keeler, M.; Finelli, K. D.; Fiolhais, M. C. N.; Fiorini, L.; Firan, A.; Fischer, A.; Fischer, J.; Fisher, W. C.; Fitzgerald, E. A.; Flechl, M.; Fleck, I.; Fleischmann, P.; Fleischmann, S.; Fletcher, G. T.; Fletcher, G.; Flick, T.; Floderus, A.; Flores Castillo, L. R.; Florez Bustos, A. C.; Flowerdew, M. J.; Formica, A.; Forti, A.; Fortin, D.; Fournier, D.; Fox, H.; Fracchia, S.; Francavilla, P.; Franchini, M.; Franchino, S.; Francis, D.; Franconi, L.; Franklin, M.; Franz, S.; Fraternali, M.; French, S. T.; Friedrich, C.; Friedrich, F.; Froidevaux, D.; Frost, J. A.; Fukunaga, C.; Fullana Torregrosa, E.; Fulsom, B. G.; Fuster, J.; Gabaldon, C.; Gabizon, O.; Gabrielli, A.; Gabrielli, A.; Gadatsch, S.; Gadomski, S.; Gagliardi, G.; Gagnon, P.; Galea, C.; Galhardo, B.; Gallas, E. J.; Gallo, V.; Gallop, B. J.; Gallus, P.; Galster, G.; Gan, K. K.; Gao, J.; Gao, Y. S.; Garay Walls, F. M.; Garberson, F.; García, C.; García Navarro, J. E.; Garcia-Sciveres, M.; Gardner, R. W.; Garelli, N.; Garonne, V.; Gatti, C.; Gaudio, G.; Gaur, B.; Gauthier, L.; Gauzzi, P.; Gavrilenko, I. L.; Gay, C.; Gaycken, G.; Gazis, E. N.; Ge, P.; Gecse, Z.; Gee, C. N. P.; Geerts, D. A. A.; Geich-Gimbel, Ch.; Gellerstedt, K.; Gemme, C.; Gemmell, A.; Genest, M. H.; Gentile, S.; George, M.; George, S.; Gerbaudo, D.; Gershon, A.; Ghazlane, H.; Ghodbane, N.; Giacobbe, B.; Giagu, S.; Giangiobbe, V.; Giannetti, P.; Gianotti, F.; Gibbard, B.; Gibson, S. M.; Gilchriese, M.; Gillam, T. P. S.; Gillberg, D.; Gilles, G.; Gingrich, D. M.; Giokaris, N.; Giordani, M. P.; Giordano, R.; Giorgi, F. M.; Giorgi, F. M.; Giraud, P. F.; Giugni, D.; Giuliani, C.; Giulini, M.; Gjelsten, B. K.; Gkaitatzis, S.; Gkialas, I.; Gladilin, L. K.; Glasman, C.; Glatzer, J.; Glaysher, P. C. F.; Glazov, A.; Glonti, G. L.; Goblirsch-Kolb, M.; Goddard, J. R.; Godlewski, J.; Goeringer, C.; Goldfarb, S.; Golling, T.; Golubkov, D.; Gomes, A.; Gomez Fajardo, L. S.; Gonçalo, R.; Goncalves Pinto Firmino Da Costa, J.; Gonella, L.; González de la Hoz, S.; Gonzalez Parra, G.; Gonzalez-Sevilla, S.; Goossens, L.; Gorbounov, P. A.; Gordon, H. A.; Gorelov, I.; Gorini, B.; Gorini, E.; Gorišek, A.; Gornicki, E.; Goshaw, A. T.; Gössling, C.; Gostkin, M. I.; Gouighri, M.; Goujdami, D.; Goulette, M. P.; Goussiou, A. G.; Goy, C.; Gozpinar, S.; Grabas, H. M. X.; Graber, L.; Grabowska-Bold, I.; Grafström, P.; Grahn, K.-J.; Gramling, J.; Gramstad, E.; Grancagnolo, S.; Grassi, V.; Gratchev, V.; Gray, H. M.; Graziani, E.; Grebenyuk, O. G.; Greenwood, Z. D.; Gregersen, K.; Gregor, I. M.; Grenier, P.; Griffiths, J.; Grillo, A. A.; Grimm, K.; Grinstein, S.; Gris, Ph.; Grishkevich, Y. V.; Grivaz, J.-F.; Grohs, J. P.; Grohsjean, A.; Gross, E.; Grosse-Knetter, J.; Grossi, G. C.; Groth-Jensen, J.; Grout, Z. J.; Guan, L.; Guescini, F.; Guest, D.; Gueta, O.; Guicheney, C.; Guido, E.; Guillemin, T.; Guindon, S.; Gul, U.; Gumpert, C.; Gunther, J.; Guo, J.; Gupta, S.; Gutierrez, P.; Gutierrez Ortiz, N. G.; Gutschow, C.; Guttman, N.; Guyot, C.; Gwenlan, C.; Gwilliam, C. B.; Haas, A.; Haber, C.; Hadavand, H. K.; Haddad, N.; Haefner, P.; Hageböck, S.; Hajduk, Z.; Hakobyan, H.; Haleem, M.; Hall, D.; Halladjian, G.; Hamacher, K.; Hamal, P.; Hamano, K.; Hamer, M.; Hamilton, A.; Hamilton, S.; Hamity, G. N.; Hamnett, P. G.; Han, L.; Hanagaki, K.; Hanawa, K.; Hance, M.; Hanke, P.; Hanna, R.; Hansen, J. B.; Hansen, J. D.; Hansen, P. H.; Hara, K.; Hard, A. S.; Harenberg, T.; Hariri, F.; Harkusha, S.; Harper, D.; Harrington, R. D.; Harris, O. M.; Harrison, P. F.; Hartjes, F.; Hasegawa, M.; Hasegawa, S.; Hasegawa, Y.; Hasib, A.; Hassani, S.; Haug, S.; Hauschild, M.; Hauser, R.; Havranek, M.; Hawkes, C. M.; Hawkings, R. J.; Hawkins, A. D.; Hayashi, T.; Hayden, D.; Hays, C. P.; Hayward, H. S.; Haywood, S. J.; Head, S. J.; Heck, T.; Hedberg, V.; Heelan, L.; Heim, S.; Heim, T.; Heinemann, B.; Heinrich, L.; Hejbal, J.; Helary, L.; Heller, C.; Heller, M.; Hellman, S.; Hellmich, D.; Helsens, C.; Henderson, J.; Henderson, R. C. W.; Heng, Y.; Hengler, C.; Henrichs, A.; Henriques Correia, A. M.; Henrot-Versille, S.; Herbert, G. H.; Hernández Jiménez, Y.; Herrberg-Schubert, R.; Herten, G.; Hertenberger, R.; Hervas, L.; Hesketh, G. G.; Hessey, N. P.; Hickling, R.; Higón-Rodriguez, E.; Hill, E.; Hill, J. C.; Hiller, K. H.; Hillert, S.; Hillier, S. J.; Hinchliffe, I.; Hines, E.; Hirose, M.; Hirschbuehl, D.; Hobbs, J.; Hod, N.; Hodgkinson, M. C.; Hodgson, P.; Hoecker, A.; Hoeferkamp, M. R.; Hoenig, F.; Hoffman, J.; Hoffmann, D.; Hofmann, J. I.; Hohlfeld, M.; Holmes, T. R.; Hong, T. M.; Hooft van Huysduynen, L.; Hopkins, W. H.; Horii, Y.; Hostachy, J.-Y.; Hou, S.; Hoummada, A.; Howard, J.; Howarth, J.; Hrabovsky, M.; Hristova, I.; Hrivnac, J.; Hryn'ova, T.; Hsu, C.; Hsu, P. J.; Hsu, S.-C.; Hu, D.; Hu, X.; Huang, Y.; Hubacek, Z.; Hubaut, F.; Huegging, F.; Huffman, T. B.; Hughes, E. W.; Hughes, G.; Huhtinen, M.; Hülsing, T. A.; Hurwitz, M.; Huseynov, N.; Huston, J.; Huth, J.; Iacobucci, G.; Iakovidis, G.; Ibragimov, I.; Iconomidou-Fayard, L.; Ideal, E.; Idrissi, Z.; Iengo, P.; Igonkina, O.; Iizawa, T.; Ikegami, Y.; Ikematsu, K.; Ikeno, M.; Ilchenko, Y.; Iliadis, D.; Ilic, N.; Inamaru, Y.; Ince, T.; Ioannou, P.; Iodice, M.; Iordanidou, K.; Ippolito, V.; Irles Quiles, A.; Isaksson, C.; Ishino, M.; Ishitsuka, M.; Ishmukhametov, R.; Issever, C.; Istin, S.; Iturbe Ponce, J. M.; Iuppa, R.; Ivarsson, J.; Iwanski, W.; Iwasaki, H.; Izen, J. M.; Izzo, V.; Jackson, B.; Jackson, M.; Jackson, P.; Jaekel, M. R.; Jain, V.; Jakobs, K.; Jakobsen, S.; Jakoubek, T.; Jakubek, J.; Jamin, D. O.; Jana, D. K.; Jansen, E.; Jansen, H.; Janssen, J.; Janus, M.; Jarlskog, G.; Javadov, N.; Javůrek, T.; Jeanty, L.; Jejelava, J.; Jeng, G.-Y.; Jennens, D.; Jenni, P.; Jentzsch, J.; Jeske, C.; Jézéquel, S.; Ji, H.; Jia, J.; Jiang, Y.; Jimenez Belenguer, M.; Jin, S.; Jinaru, A.; Jinnouchi, O.; Joergensen, M. D.; Johansson, K. E.; Johansson, P.; Johns, K. A.; Jon-And, K.; Jones, G.; Jones, R. W. L.; Jones, T. J.; Jongmanns, J.; Jorge, P. M.; Joshi, K. D.; Jovicevic, J.; Ju, X.; Jung, C. A.; Jungst, R. M.; Jussel, P.; Juste Rozas, A.; Kaci, M.; Kaczmarska, A.; Kado, M.; Kagan, H.; Kagan, M.; Kajomovitz, E.; Kalderon, C. W.; Kama, S.; Kamenshchikov, A.; Kanaya, N.; Kaneda, M.; Kaneti, S.; Kantserov, V. A.; Kanzaki, J.; Kaplan, B.; Kapliy, A.; Kar, D.; Karakostas, K.; Karastathis, N.; Kareem, M. J.; Karnevskiy, M.; Karpov, S. N.; Karpova, Z. M.; Karthik, K.; Kartvelishvili, V.; Karyukhin, A. N.; Kashif, L.; Kasieczka, G.; Kass, R. D.; Kastanas, A.; Kataoka, Y.; Katre, A.; Katzy, J.; Kaushik, V.; Kawagoe, K.; Kawamoto, T.; Kawamura, G.; Kazama, S.; Kazanin, V. F.; Kazarinov, M. Y.; Keeler, R.; Kehoe, R.; Keil, M.; Keller, J. S.; Kempster, J. J.; Keoshkerian, H.; Kepka, O.; Kerševan, B. P.; Kersten, S.; Kessoku, K.; Keung, J.; Khalil-zada, F.; Khandanyan, H.; Khanov, A.; Khodinov, A.; Khomich, A.; Khoo, T. J.; Khoriauli, G.; Khoroshilov, A.; Khovanskiy, V.; Khramov, E.; Khubua, J.; Kim, H. Y.; Kim, H.; Kim, S. H.; Kimura, N.; Kind, O.; King, B. T.; King, M.; King, R. S. B.; King, S. B.; Kirk, J.; Kiryunin, A. E.; Kishimoto, T.; Kisielewska, D.; Kiss, F.; Kittelmann, T.; Kiuchi, K.; Kladiva, E.; Klein, M.; Klein, U.; Kleinknecht, K.; Klimek, P.; Klimentov, A.; Klingenberg, R.; Klinger, J. A.; Klioutchnikova, T.; Klok, P. F.; Kluge, E.-E.; Kluit, P.; Kluth, S.; Kneringer, E.; Knoops, E. B. F. G.; Knue, A.; Kobayashi, D.; Kobayashi, T.; Kobel, M.; Kocian, M.; Kodys, P.; Koevesarki, P.; Koffas, T.; Koffeman, E.; Kogan, L. A.; Kohlmann, S.; Kohout, Z.; Kohriki, T.; Koi, T.; Kolanoski, H.; Koletsou, I.; Koll, J.; Komar, A. A.; Komori, Y.; Kondo, T.; Kondrashova, N.; Köneke, K.; König, A. C.; König, S.; Kono, T.; Konoplich, R.; Konstantinidis, N.; Kopeliansky, R.; Koperny, S.; Köpke, L.; Kopp, A. K.; Korcyl, K.; Kordas, K.; Korn, A.; Korol, A. A.; Korolkov, I.; Korolkova, E. V.; Korotkov, V. A.; Kortner, O.; Kortner, S.; Kostyukhin, V. V.; Kotov, V. M.; Kotwal, A.; Kourkoumelis, C.; Kouskoura, V.; Koutsman, A.; Kowalewski, R.; Kowalski, T. Z.; Kozanecki, W.; Kozhin, A. S.; Kral, V.; Kramarenko, V. A.; Kramberger, G.; Krasnopevtsev, D.; Krasny, M. W.; Krasznahorkay, A.; Kraus, J. K.; Kravchenko, A.; Kreiss, S.; Kretz, M.; Kretzschmar, J.; Kreutzfeldt, K.; Krieger, P.; Kroeninger, K.; Kroha, H.; Kroll, J.; Kroseberg, J.; Krstic, J.; Kruchonak, U.; Krüger, H.; Kruker, T.; Krumnack, N.; Krumshteyn, Z. V.; Kruse, A.; Kruse, M. C.; Kruskal, M.; Kubota, T.; Kuday, S.; Kuehn, S.; Kugel, A.; Kuhl, A.; Kuhl, T.; Kukhtin, V.; Kulchitsky, Y.; Kuleshov, S.; Kuna, M.; Kunkle, J.; Kupco, A.; Kurashige, H.; Kurochkin, Y. A.; Kurumida, R.; Kus, V.; Kuwertz, E. S.; Kuze, M.; Kvita, J.; La Rosa, A.; La Rotonda, L.; Lacasta, C.; Lacava, F.; Lacey, J.; Lacker, H.; Lacour, D.; Lacuesta, V. R.; Ladygin, E.; Lafaye, R.; Laforge, B.; Lagouri, T.; Lai, S.; Laier, H.; Lambourne, L.; Lammers, S.; Lampen, C. L.; Lampl, W.; Lançon, E.; Landgraf, U.; Landon, M. P. J.; Lang, V. S.; Lankford, A. J.; Lanni, F.; Lantzsch, K.; Laplace, S.; Lapoire, C.; Laporte, J. F.; Lari, T.; Lasagni Manghi, F.; Lassnig, M.; Laurelli, P.; Lavrijsen, W.; Law, A. T.; Laycock, P.; Le Dortz, O.; Le Guirriec, E.; Le Menedeu, E.; LeCompte, T.; Ledroit-Guillon, F.; Lee, C. A.; Lee, H.; Lee, J. S. H.; Lee, S. C.; Lee, L.; Lefebvre, G.; Lefebvre, M.; Legger, F.; Leggett, C.; Lehan, A.; Lehmacher, M.; Lehmann Miotto, G.; Lei, X.; Leight, W. A.; Leisos, A.; Leister, A. G.; Leite, M. A. L.; Leitner, R.; Lellouch, D.; Lemmer, B.; Leney, K. J. C.; Lenz, T.; Lenzen, G.; Lenzi, B.; Leone, R.; Leone, S.; Leonidopoulos, C.; Leontsinis, S.; Leroy, C.; Lester, C. G.; Lester, C. M.; Levchenko, M.; Levêque, J.; Levin, D.; Levinson, L. J.; Levy, M.; Lewis, A.; Lewis, G. H.; Leyko, A. M.; Leyton, M.; Li, B.; Li, B.; Li, H.; Li, H. L.; Li, L.; Li, L.; Li, S.; Li, Y.; Liang, Z.; Liao, H.; Liberti, B.; Lichard, P.; Lie, K.; Liebal, J.; Liebig, W.; Limbach, C.; Limosani, A.; Lin, S. C.; Lin, T. H.; Linde, F.; Lindquist, B. E.; Linnemann, J. T.; Lipeles, E.; Lipniacka, A.; Lisovyi, M.; Liss, T. M.; Lissauer, D.; Lister, A.; Litke, A. M.; Liu, B.; Liu, D.; Liu, J. B.; Liu, K.; Liu, L.; Liu, M.; Liu, M.; Liu, Y.; Livan, M.; Livermore, S. S. A.; Lleres, A.; Llorente Merino, J.; Lloyd, S. L.; Lo Sterzo, F.; Lobodzinska, E.; Loch, P.; Lockman, W. S.; Loddenkoetter, T.; Loebinger, F. K.; Loevschall-Jensen, A. E.; Loginov, A.; Lohse, T.; Lohwasser, K.; Lokajicek, M.; Lombardo, V. P.; Long, B. A.; Long, J. D.; Long, R. E.; Lopes, L.; Lopez Mateos, D.; Lopez Paredes, B.; Lopez Paz, I.; Lorenz, J.; Lorenzo Martinez, N.; Losada, M.; Loscutoff, P.; Lou, X.; Lounis, A.; Love, J.; Love, P. A.; Lowe, A. J.; Lu, F.; Lu, N.; Lubatti, H. J.; Luci, C.; Lucotte, A.; Luehring, F.; Lukas, W.; Luminari, L.; Lundberg, O.; Lund-Jensen, B.; Lungwitz, M.; Lynn, D.; Lysak, R.; Lytken, E.; Ma, H.; Ma, L. L.; Maccarrone, G.; Macchiolo, A.; Machado Miguens, J.; Macina, D.; Madaffari, D.; Madar, R.; Maddocks, H. J.; Mader, W. F.; Madsen, A.; Maeno, M.; Maeno, T.; Maevskiy, A.; Magradze, E.; Mahboubi, K.; Mahlstedt, J.; Mahmoud, S.; Maiani, C.; Maidantchik, C.; Maier, A. A.; Maio, A.; Majewski, S.; Makida, Y.; Makovec, N.; Mal, P.; Malaescu, B.; Malecki, Pa.; Maleev, V. P.; Malek, F.; Mallik, U.; Malon, D.; Malone, C.; Maltezos, S.; Malyshev, V. M.; Malyukov, S.; Mamuzic, J.; Mandelli, B.; Mandelli, L.; Mandić, I.; Mandrysch, R.; Maneira, J.; Manfredini, A.; Manhaes de Andrade Filho, L.; Manjarres Ramos, J. A.; Mann, A.; Manning, P. M.; Manousakis-Katsikakis, A.; Mansoulie, B.; Mantifel, R.; Mapelli, L.; March, L.; Marchand, J. F.; Marchiori, G.; Marcisovsky, M.; Marino, C. P.; Marjanovic, M.; Marques, C. N.; Marroquim, F.; Marsden, S. P.; Marshall, Z.; Marti, L. F.; Marti-Garcia, S.; Martin, B.; Martin, B.; Martin, T. A.; Martin, V. J.; Martin dit Latour, B.; Martinez, H.; Martinez, M.; Martin-Haugh, S.; Martyniuk, A. C.; Marx, M.; Marzano, F.; Marzin, A.; Masetti, L.; Mashimo, T.; Mashinistov, R.; Masik, J.; Maslennikov, A. L.; Massa, I.; Massa, L.; Massol, N.; Mastrandrea, P.; Mastroberardino, A.; Masubuchi, T.; Mättig, P.; Mattmann, J.; Maurer, J.; Maxfield, S. J.; Maximov, D. A.; Mazini, R.; Mazzaferro, L.; Mc Goldrick, G.; Mc Kee, S. P.; McCarn, A.; McCarthy, R. L.; McCarthy, T. G.; McCubbin, N. A.; McFarlane, K. W.; Mcfayden, J. A.; Mchedlidze, G.; McMahon, S. J.; McPherson, R. A.; Mechnich, J.; Medinnis, M.; Meehan, S.; Mehlhase, S.; Mehta, A.; Meier, K.; Meineck, C.; Meirose, B.; Melachrinos, C.; Mellado Garcia, B. R.; Meloni, F.; Mengarelli, A.; Menke, S.; Meoni, E.; Mercurio, K. M.; Mergelmeyer, S.; Meric, N.; Mermod, P.; Merola, L.; Meroni, C.; Merritt, F. S.; Merritt, H.; Messina, A.; Metcalfe, J.; Mete, A. S.; Meyer, C.; Meyer, C.; Meyer, J.-P.; Meyer, J.; Middleton, R. P.; Migas, S.; Mijović, L.; Mikenberg, G.; Mikestikova, M.; Mikuž, M.; Milic, A.; Miller, D. W.; Mills, C.; Milov, A.; Milstead, D. A.; Milstein, D.; Minaenko, A. A.; Minami, Y.; Minashvili, I. A.; Mincer, A. I.; Mindur, B.; Mineev, M.; Ming, Y.; Mir, L. M.; Mirabelli, G.; Mitani, T.; Mitrevski, J.; Mitsou, V. A.; Mitsui, S.; Miucci, A.; Miyagawa, P. S.; Mjörnmark, J. U.; Moa, T.; Mochizuki, K.; Mohapatra, S.; Mohr, W.; Molander, S.; Moles-Valls, R.; Mönig, K.; Monini, C.; Monk, J.; Monnier, E.; Montejo Berlingen, J.; Monticelli, F.; Monzani, S.; Moore, R. W.; Morange, N.; Moreno, D.; Moreno Llácer, M.; Morettini, P.; Morgenstern, M.; Morii, M.; Moritz, S.; Morley, A. K.; Mornacchi, G.; Morris, J. D.; Morvaj, L.; Moser, H. G.; Mosidze, M.; Moss, J.; Motohashi, K.; Mount, R.; Mountricha, E.; Mouraviev, S. V.; Moyse, E. J. W.; Muanza, S.; Mudd, R. D.; Mueller, F.; Mueller, J.; Mueller, K.; Mueller, T.; Mueller, T.; Muenstermann, D.; Munwes, Y.; Murillo Quijada, J. A.; Murray, W. J.; Musheghyan, H.; Musto, E.; Myagkov, A. G.; Myska, M.; Nackenhorst, O.; Nadal, J.; Nagai, K.; Nagai, R.; Nagai, Y.; Nagano, K.; Nagarkar, A.; Nagasaka, Y.; Nagel, M.; Nairz, A. M.; Nakahama, Y.; Nakamura, K.; Nakamura, T.; Nakano, I.; Namasivayam, H.; Nanava, G.; Narayan, R.; Nattermann, T.; Naumann, T.; Navarro, G.; Nayyar, R.; Neal, H. A.; Nechaeva, P. Yu.; Neep, T. J.; Nef, P. D.; Negri, A.; Negri, G.; Negrini, M.; Nektarijevic, S.; Nellist, C.; Nelson, A.; Nelson, T. K.; Nemecek, S.; Nemethy, P.; Nepomuceno, A. A.; Nessi, M.; Neubauer, M. S.; Neumann, M.; Neves, R. M.; Nevski, P.; Newman, P. R.; Nguyen, D. H.; Nickerson, R. B.; Nicolaidou, R.; Nicquevert, B.; Nielsen, J.; Nikiforou, N.; Nikiforov, A.; Nikolaenko, V.; Nikolic-Audit, I.; Nikolics, K.; Nikolopoulos, K.; Nilsson, P.; Ninomiya, Y.; Nisati, A.; Nisius, R.; Nobe, T.; Nodulman, L.; Nomachi, M.; Nomidis, I.; Norberg, S.; Nordberg, M.; Novgorodova, O.; Nowak, S.; Nozaki, M.; Nozka, L.; Ntekas, K.; Nunes Hanninger, G.; Nunnemann, T.; Nurse, E.; Nuti, F.; O'Brien, B. J.; O'grady, F.; O'Neil, D. C.; O'Shea, V.; Oakham, F. G.; Oberlack, H.; Obermann, T.; Ocariz, J.; Ochi, A.; Ochoa, M. I.; Oda, S.; Odaka, S.; Ogren, H.; Oh, A.; Oh, S. H.; Ohm, C. C.; Ohman, H.; Okamura, W.; Okawa, H.; Okumura, Y.; Okuyama, T.; Olariu, A.; Olchevski, A. G.; Olivares Pino, S. A.; Oliveira Damazio, D.; Oliver Garcia, E.; Olszewski, A.; Olszowska, J.; Onofre, A.; Onyisi, P. U. E.; Oram, C. J.; Oreglia, M. J.; Oren, Y.; Orestano, D.; Orlando, N.; Oropeza Barrera, C.; Orr, R. S.; Osculati, B.; Ospanov, R.; Otero y Garzon, G.; Otono, H.; Ouchrif, M.; Ouellette, E. A.; Ould-Saada, F.; Ouraou, A.; Oussoren, K. P.; Ouyang, Q.; Ovcharova, A.; Owen, M.; Ozcan, V. E.; Ozturk, N.; Pachal, K.; Pacheco Pages, A.; Padilla Aranda, C.; Pagáčová, M.; Pagan Griso, S.; Paganis, E.; Pahl, C.; Paige, F.; Pais, P.; Pajchel, K.; Palacino, G.; Palestini, S.; Palka, M.; Pallin, D.; Palma, A.; Palmer, J. D.; Pan, Y. B.; Panagiotopoulou, E.; Panduro Vazquez, J. G.; Pani, P.; Panikashvili, N.; Panitkin, S.; Pantea, D.; Paolozzi, L.; Papadopoulou, Th. D.; Papageorgiou, K.; Paramonov, A.; Paredes Hernandez, D.; Parker, M. A.; Parodi, F.; Parsons, J. A.; Parzefall, U.; Pasqualucci, E.; Passaggio, S.; Passeri, A.; Pastore, F.; Pastore, Fr.; Pásztor, G.; Pataraia, S.; Patel, N. D.; Pater, J. R.; Patricelli, S.; Pauly, T.; Pearce, J.; Pedersen, L. E.; Pedersen, M.; Pedraza Lopez, S.; Pedro, R.; Peleganchuk, S. V.; Pelikan, D.; Peng, H.; Penning, B.; Penwell, J.; Perepelitsa, D. V.; Perez Codina, E.; Pérez García-Estañ, M. T.; Perez Reale, V.; Perini, L.; Pernegger, H.; Perrella, S.; Perrino, R.; Peschke, R.; Peshekhonov, V. D.; Peters, K.; Peters, R. F. Y.; Petersen, B. A.; Petersen, T. C.; Petit, E.; Petridis, A.; Petridou, C.; Petrolo, E.; Petrucci, F.; Pettersson, N. E.; Pezoa, R.; Phillips, P. W.; Piacquadio, G.; Pianori, E.; Picazio, A.; Piccaro, E.; Piccinini, M.; Piegaia, R.; Pignotti, D. T.; Pilcher, J. E.; Pilkington, A. D.; Pina, J.; Pinamonti, M.; Pinder, A.; Pinfold, J. L.; Pingel, A.; Pinto, B.; Pires, S.; Pitt, M.; Pizio, C.; Plazak, L.; Pleier, M.-A.; Pleskot, V.; Plotnikova, E.; Plucinski, P.; Poddar, S.; Podlyski, F.; Poettgen, R.; Poggioli, L.; Pohl, D.; Pohl, M.; Polesello, G.; Policicchio, A.; Polifka, R.; Polini, A.; Pollard, C. S.; Polychronakos, V.; Pommès, K.; Pontecorvo, L.; Pope, B. G.; Popeneciu, G. A.; Popovic, D. S.; Poppleton, A.; Portell Bueso, X.; Pospisil, S.; Potamianos, K.; Potrap, I. N.; Potter, C. J.; Potter, C. T.; Poulard, G.; Poveda, J.; Pozdnyakov, V.; Pralavorio, P.; Pranko, A.; Prasad, S.; Pravahan, R.; Prell, S.; Price, D.; Price, J.; Price, L. E.; Prieur, D.; Primavera, M.; Proissl, M.; Prokofiev, K.; Prokoshin, F.; Protopapadaki, E.; Protopopescu, S.; Proudfoot, J.; Przybycien, M.; Przysiezniak, H.; Ptacek, E.; Puddu, D.; Pueschel, E.; Puldon, D.; Purohit, M.; Puzo, P.; Qian, J.; Qin, G.; Qin, Y.; Quadt, A.; Quarrie, D. R.; Quayle, W. B.; Queitsch-Maitland, M.; Quilty, D.; Qureshi, A.; Radeka, V.; Radescu, V.; Radhakrishnan, S. K.; Radloff, P.; Rados, P.; Ragusa, F.; Rahal, G.; Rajagopalan, S.; Rammensee, M.; Randle-Conde, A. S.; Rangel-Smith, C.; Rao, K.; Rauscher, F.; Rave, T. C.; Ravenscroft, T.; Raymond, M.; Read, A. L.; Readioff, N. P.; Rebuzzi, D. M.; Redelbach, A.; Redlinger, G.; Reece, R.; Reeves, K.; Rehnisch, L.; Reisin, H.; Relich, M.; Rembser, C.; Ren, H.; Ren, Z. L.; Renaud, A.; Rescigno, M.; Resconi, S.; Rezanova, O. L.; Reznicek, P.; Rezvani, R.; Richter, R.; Ridel, M.; Rieck, P.; Rieger, J.; Rijssenbeek, M.; Rimoldi, A.; Rinaldi, L.; Ritsch, E.; Riu, I.; Rizatdinova, F.; Rizvi, E.; Robertson, S. H.; Robichaud-Veronneau, A.; Robinson, D.; Robinson, J. E. M.; Robson, A.; Roda, C.; Rodrigues, L.; Roe, S.; Røhne, O.; Rolli, S.; Romaniouk, A.; Romano, M.; Romero Adam, E.; Rompotis, N.; Ronzani, M.; Roos, L.; Ros, E.; Rosati, S.; Rosbach, K.; Rose, M.; Rose, P.; Rosendahl, P. L.; Rosenthal, O.; Rossetti, V.; Rossi, E.; Rossi, L. P.; Rosten, R.; Rotaru, M.; Roth, I.; Rothberg, J.; Rousseau, D.; Royon, C. R.; Rozanov, A.; Rozen, Y.; Ruan, X.; Rubbo, F.; Rubinskiy, I.; Rud, V. I.; Rudolph, C.; Rudolph, M. S.; Rühr, F.; Ruiz-Martinez, A.; Rurikova, Z.; Rusakovich, N. A.; Ruschke, A.; Rutherfoord, J. P.; Ruthmann, N.; Ryabov, Y. F.; Rybar, M.; Rybkin, G.; Ryder, N. C.; Saavedra, A. F.; Sabato, G.; Sacerdoti, S.; Saddique, A.; Sadeh, I.; Sadrozinski, H. F.-W.; Sadykov, R.; Safai Tehrani, F.; Sakamoto, H.; Sakurai, Y.; Salamanna, G.; Salamon, A.; Saleem, M.; Salek, D.; Sales De Bruin, P. H.; Salihagic, D.; Salnikov, A.; Salt, J.; Salvatore, D.; Salvatore, F.; Salvucci, A.; Salzburger, A.; Sampsonidis, D.; Sanchez, A.; Sánchez, J.; Sanchez Martinez, V.; Sandaker, H.; Sandbach, R. L.; Sander, H. G.; Sanders, M. P.; Sandhoff, M.; Sandoval, T.; Sandoval, C.; Sandstroem, R.; Sankey, D. P. C.; Sansoni, A.; Santoni, C.; Santonico, R.; Santos, H.; Santoyo Castillo, I.; Sapp, K.; Sapronov, A.; Saraiva, J. G.; Sarrazin, B.; Sartisohn, G.; Sasaki, O.; Sasaki, Y.; Sauvage, G.; Sauvan, E.; Savard, P.; Savu, D. O.; Sawyer, C.; Sawyer, L.; Saxon, D. H.; Saxon, J.; Sbarra, C.; Sbrizzi, A.; Scanlon, T.; Scannicchio, D. A.; Scarcella, M.; Scarfone, V.; Schaarschmidt, J.; Schacht, P.; Schaefer, D.; Schaefer, R.; Schaepe, S.; Schaetzel, S.; Schäfer, U.; Schaffer, A. C.; Schaile, D.; Schamberger, R. D.; Scharf, V.; Schegelsky, V. A.; Scheirich, D.; Schernau, M.; Scherzer, M. I.; Schiavi, C.; Schieck, J.; Schillo, C.; Schioppa, M.; Schlenker, S.; Schmidt, E.; Schmieden, K.; Schmitt, C.; Schmitt, S.; Schneider, B.; Schnellbach, Y. J.; Schnoor, U.; Schoeffel, L.; Schoening, A.; Schoenrock, B. D.; Schorlemmer, A. L. S.; Schott, M.; Schouten, D.; Schovancova, J.; Schramm, S.; Schreyer, M.; Schroeder, C.; Schuh, N.; Schultens, M. J.; Schultz-Coulon, H.-C.; Schulz, H.; Schumacher, M.; Schumm, B. A.; Schune, Ph.; Schwanenberger, C.; Schwartzman, A.; Schwarz, T. A.; Schwegler, Ph.; Schwemling, Ph.; Schwienhorst, R.; Schwindling, J.; Schwindt, T.; Schwoerer, M.; Sciacca, F. G.; Scifo, E.; Sciolla, G.; Scott, W. G.; Scuri, F.; Scutti, F.; Searcy, J.; Sedov, G.; Sedykh, E.; Seidel, S. C.; Seiden, A.; Seifert, F.; Seixas, J. M.; Sekhniaidze, G.; Sekula, S. J.; Selbach, K. E.; Seliverstov, D. M.; Sellers, G.; Semprini-Cesari, N.; Serfon, C.; Serin, L.; Serkin, L.; Serre, T.; Seuster, R.; Severini, H.; Sfiligoj, T.; Sforza, F.; Sfyrla, A.; Shabalina, E.; Shamim, M.; Shan, L. Y.; Shang, R.; Shank, J. T.; Shapiro, M.; Shatalov, P. B.; Shaw, K.; Shehu, C. Y.; Sherwood, P.; Shi, L.; Shimizu, S.; Shimmin, C. O.; Shimojima, M.; Shiyakova, M.; Shmeleva, A.; Shochet, M. J.; Short, D.; Shrestha, S.; Shulga, E.; Shupe, M. A.; Shushkevich, S.; Sicho, P.; Sidiropoulou, O.; Sidorov, D.; Sidoti, A.; Siegert, F.; Sijacki, Dj.; Silva, J.; Silver, Y.; Silverstein, D.; Silverstein, S. B.; Simak, V.; Simard, O.; Simic, Lj.; Simion, S.; Simioni, E.; Simmons, B.; Simoniello, R.; Simonyan, M.; Sinervo, P.; Sinev, N. B.; Sipica, V.; Siragusa, G.; Sircar, A.; Sisakyan, A. N.; Sivoklokov, S. Yu.; Sjölin, J.; Sjursen, T. B.; Skottowe, H. P.; Skovpen, K. Yu.; Skubic, P.; Slater, M.; Slavicek, T.; Sliwa, K.; Smakhtin, V.; Smart, B. H.; Smestad, L.; Smirnov, S. Yu.; Smirnov, Y.; Smirnova, L. N.; Smirnova, O.; Smith, K. M.; Smizanska, M.; Smolek, K.; Snesarev, A. A.; Snidero, G.; Snyder, S.; Sobie, R.; Socher, F.; Soffer, A.; Soh, D. A.; Solans, C. A.; Solar, M.; Solc, J.; Soldatov, E. Yu.; Soldevila, U.; Solodkov, A. A.; Soloshenko, A.; Solovyanov, O. V.; Solovyev, V.; Sommer, P.; Song, H. Y.; Soni, N.; Sood, A.; Sopczak, A.; Sopko, B.; Sopko, V.; Sorin, V.; Sosebee, M.; Soualah, R.; Soueid, P.; Soukharev, A. M.; South, D.; Spagnolo, S.; Spanò, F.; Spearman, W. R.; Spettel, F.; Spighi, R.; Spigo, G.; Spiller, L. A.; Spousta, M.; Spreitzer, T.; Spurlock, B.; St. Denis, R. D.; Staerz, S.; Stahlman, J.; Stamen, R.; Stamm, S.; Stanecka, E.; Stanek, R. W.; Stanescu, C.; Stanescu-Bellu, M.; Stanitzki, M. M.; Stapnes, S.; Starchenko, E. A.; Stark, J.; Staroba, P.; Starovoitov, P.; Staszewski, R.; Stavina, P.; Steinberg, P.; Stelzer, B.; Stelzer, H. J.; Stelzer-Chilton, O.; Stenzel, H.; Stern, S.; Stewart, G. A.; Stillings, J. A.; Stockton, M. C.; Stoebe, M.; Stoicea, G.; Stolte, P.; Stonjek, S.; Stradling, A. R.; Straessner, A.; Stramaglia, M. E.; Strandberg, J.; Strandberg, S.; Strandlie, A.; Strauss, E.; Strauss, M.; Strizenec, P.; Ströhmer, R.; Strom, D. M.; Stroynowski, R.; Strubig, A.; Stucci, S. A.; Stugu, B.; Styles, N. A.; Su, D.; Su, J.; Subramaniam, R.; Succurro, A.; Sugaya, Y.; Suhr, C.; Suk, M.; Sulin, V. V.; Sultansoy, S.; Sumida, T.; Sun, S.; Sun, X.; Sundermann, J. E.; Suruliz, K.; Susinno, G.; Sutton, M. R.; Suzuki, Y.; Svatos, M.; Swedish, S.; Swiatlowski, M.; Sykora, I.; Sykora, T.; Ta, D.; Taccini, C.; Tackmann, K.; Taenzer, J.; Taffard, A.; Tafirout, R.; Taiblum, N.; Takai, H.; Takashima, R.; Takeda, H.; Takeshita, T.; Takubo, Y.; Talby, M.; Talyshev, A. A.; Tam, J. Y. C.; Tan, K. G.; Tanaka, J.; Tanaka, R.; Tanaka, S.; Tanaka, S.; Tanasijczuk, A. J.; Tannenwald, B. B.; Tannoury, N.; Tapprogge, S.; Tarem, S.; Tarrade, F.; Tartarelli, G. F.; Tas, P.; Tasevsky, M.; Tashiro, T.; Tassi, E.; Tavares Delgado, A.; Tayalati, Y.; Taylor, F. E.; Taylor, G. N.; Taylor, W.; Teischinger, F. A.; Teixeira Dias Castanheira, M.; Teixeira-Dias, P.; Temming, K. K.; Ten Kate, H.; Teng, P. K.; Teoh, J. J.; Terada, S.; Terashi, K.; Terron, J.; Terzo, S.; Testa, M.; Teuscher, R. J.; Therhaag, J.; Theveneaux-Pelzer, T.; Thomas, J. P.; Thomas-Wilsker, J.; Thompson, E. N.; Thompson, P. D.; Thompson, P. D.; Thompson, R. J.; Thompson, A. S.; Thomsen, L. A.; Thomson, E.; Thomson, M.; Thong, W. M.; Thun, R. P.; Tian, F.; Tibbetts, M. J.; Tikhomirov, V. O.; Tikhonov, Yu. A.; Timoshenko, S.; Tiouchichine, E.; Tipton, P.; Tisserant, S.; Todorov, T.; Todorova-Nova, S.; Toggerson, B.; Tojo, J.; Tokár, S.; Tokushuku, K.; Tollefson, K.; Tolley, E.; Tomlinson, L.; Tomoto, M.; Tompkins, L.; Toms, K.; Topilin, N. D.; Torrence, E.; Torres, H.; Torró Pastor, E.; Toth, J.; Touchard, F.; Tovey, D. R.; Tran, H. L.; Trefzger, T.; Tremblet, L.; Tricoli, A.; Trigger, I. M.; Trincaz-Duvoid, S.; Tripiana, M. F.; Trischuk, W.; Trocmé, B.; Troncon, C.; Trottier-McDonald, M.; Trovatelli, M.; True, P.; Trzebinski, M.; Trzupek, A.; Tsarouchas, C.; Tseng, J. C.-L.; Tsiareshka, P. V.; Tsionou, D.; Tsipolitis, G.; Tsirintanis, N.; Tsiskaridze, S.; Tsiskaridze, V.; Tskhadadze, E. G.; Tsukerman, I. I.; Tsulaia, V.; Tsuno, S.; Tsybychev, D.; Tudorache, A.; Tudorache, V.; Tuna, A. N.; Tupputi, S. A.; Turchikhin, S.; Turecek, D.; Turk Cakir, I.; Turra, R.; Tuts, P. M.; Tykhonov, A.; Tylmad, M.; Tyndel, M.; Uchida, K.; Ueda, I.; Ueno, R.; Ughetto, M.; Ugland, M.; Uhlenbrock, M.; Ukegawa, F.; Unal, G.; Undrus, A.; Unel, G.; Ungaro, F. C.; Unno, Y.; Unverdorben, C.; Urbaniec, D.; Urquijo, P.; Usai, G.; Usanova, A.; Vacavant, L.; Vacek, V.; Vachon, B.; Valencic, N.; Valentinetti, S.; Valero, A.; Valery, L.; Valkar, S.; Valladolid Gallego, E.; Vallecorsa, S.; Valls Ferrer, J. A.; Van Den Wollenberg, W.; Van Der Deijl, P. C.; van der Geer, R.; van der Graaf, H.; Van Der Leeuw, R.; van der Ster, D.; van Eldik, N.; van Gemmeren, P.; Van Nieuwkoop, J.; van Vulpen, I.; van Woerden, M. C.; Vanadia, M.; Vandelli, W.; Vanguri, R.; Vaniachine, A.; Vankov, P.; Vannucci, F.; Vardanyan, G.; Vari, R.; Varnes, E. W.; Varol, T.; Varouchas, D.; Vartapetian, A.; Varvell, K. E.; Vazeille, F.; Vazquez Schroeder, T.; Veatch, J.; Veloso, F.; Veneziano, S.; Ventura, A.; Ventura, D.; Venturi, M.; Venturi, N.; Venturini, A.; Vercesi, V.; Verducci, M.; Verkerke, W.; Vermeulen, J. C.; Vest, A.; Vetterli, M. C.; Viazlo, O.; Vichou, I.; Vickey, T.; Vickey Boeriu, O. E.; Viehhauser, G. H. A.; Viel, S.; Vigne, R.; Villa, M.; Villaplana Perez, M.; Vilucchi, E.; Vincter, M. G.; Vinogradov, V. B.; Virzi, J.; Vivarelli, I.; Vives Vaque, F.; Vlachos, S.; Vladoiu, D.; Vlasak, M.; Vogel, A.; Vogel, M.; Vokac, P.; Volpi, G.; Volpi, M.; von der Schmitt, H.; von Radziewski, H.; von Toerne, E.; Vorobel, V.; Vorobev, K.; Vos, M.; Voss, R.; Vossebeld, J. H.; Vranjes, N.; Vranjes Milosavljevic, M.; Vrba, V.; Vreeswijk, M.; Vu Anh, T.; Vuillermet, R.; Vukotic, I.; Vykydal, Z.; Wagner, P.; Wagner, W.; Wahlberg, H.; Wahrmund, S.; Wakabayashi, J.; Walder, J.; Walker, R.; Walkowiak, W.; Wall, R.; Waller, P.; Walsh, B.; Wang, C.; Wang, C.; Wang, F.; Wang, H.; Wang, H.; Wang, J.; Wang, J.; Wang, K.; Wang, R.; Wang, S. M.; Wang, T.; Wang, X.; Wanotayaroj, C.; Warburton, A.; Ward, C. P.; Wardrope, D. R.; Warsinsky, M.; Washbrook, A.; Wasicki, C.; Watkins, P. M.; Watson, A. T.; Watson, I. J.; Watson, M. F.; Watts, G.; Watts, S.; Waugh, B. M.; Webb, S.; Weber, M. S.; Weber, S. W.; Webster, J. S.; Weidberg, A. R.; Weigell, P.; Weinert, B.; Weingarten, J.; Weiser, C.; Weits, H.; Wells, P. S.; Wenaus, T.; Wendland, D.; Weng, Z.; Wengler, T.; Wenig, S.; Wermes, N.; Werner, M.; Werner, P.; Wessels, M.; Wetter, J.; Whalen, K.; White, A.; White, M. J.; White, R.; White, S.; Whiteson, D.; Wicke, D.; Wickens, F. J.; Wiedenmann, W.; Wielers, M.; Wienemann, P.; Wiglesworth, C.; Wiik-Fuchs, L. A. M.; Wijeratne, P. A.; Wildauer, A.; Wildt, M. A.; Wilkens, H. G.; Will, J. Z.; Williams, H. H.; Williams, S.; Willis, C.; Willocq, S.; Wilson, A.; Wilson, J. A.; Wingerter-Seez, I.; Winklmeier, F.; Winter, B. T.; Wittgen, M.; Wittig, T.; Wittkowski, J.; Wollstadt, S. J.; Wolter, M. W.; Wolters, H.; Wosiek, B. K.; Wotschack, J.; Woudstra, M. J.; Wozniak, K. W.; Wright, M.; Wu, M.; Wu, S. L.; Wu, X.; Wu, Y.; Wulf, E.; Wyatt, T. R.; Wynne, B. M.; Xella, S.; Xiao, M.; Xu, D.; Xu, L.; Yabsley, B.; Yacoob, S.; Yakabe, R.; Yamada, M.; Yamaguchi, H.; Yamaguchi, Y.; Yamamoto, A.; Yamamoto, K.; Yamamoto, S.; Yamamura, T.; Yamanaka, T.; Yamauchi, K.; Yamazaki, Y.; Yan, Z.; Yang, H.; Yang, H.; Yang, U. K.; Yang, Y.; Yanush, S.; Yao, L.; Yao, W.-M.; Yasu, Y.; Yatsenko, E.; Yau Wong, K. H.; Ye, J.; Ye, S.; Yeletskikh, I.; Yen, A. L.; Yildirim, E.; Yilmaz, M.; Yoosoofmiya, R.; Yorita, K.; Yoshida, R.; Yoshihara, K.; Young, C.; Young, C. J. S.; Youssef, S.; Yu, D. R.; Yu, J.; Yu, J. M.; Yu, J.; Yuan, L.; Yurkewicz, A.; Yusuff, I.; Zabinski, B.; Zaidan, R.; Zaitsev, A. M.; Zaman, A.; Zambito, S.; Zanello, L.; Zanzi, D.; Zeitnitz, C.; Zeman, M.; Zemla, A.; Zengel, K.; Zenin, O.; Ženiš, T.; Zerwas, D.; Zevi della Porta, G.; Zhang, D.; Zhang, F.; Zhang, H.; Zhang, J.; Zhang, L.; Zhang, X.; Zhang, Z.; Zhao, Z.; Zhemchugov, A.; Zhong, J.; Zhou, B.; Zhou, L.; Zhou, N.; Zhu, C. G.; Zhu, H.; Zhu, J.; Zhu, Y.; Zhuang, X.; Zhukov, K.; Zibell, A.; Zieminska, D.; Zimine, N. I.; Zimmermann, C.; Zimmermann, R.; Zimmermann, S.; Zimmermann, S.; Zinonos, Z.; Ziolkowski, M.; Zobernig, G.; Zoccoli, A.; zur Nedden, M.; Zurzolo, G.; Zutshi, V.; Zwalinski, L.
2015-01-01
A search is performed for Higgs bosons produced in association with top quarks using the diphoton decay mode of the Higgs boson. Selection requirements are optimized separately for leptonic and fully hadronic final states from the top quark decays. The dataset used corresponds to an integrated luminosity of 4.5 fb-1 of proton-proton collisions at a center-of-mass energy of 7 TeV and 20.3 fb-1 at 8 TeV recorded by the ATLAS detector at the CERN Large Hadron Collider. No significant excess over the background prediction is observed and upper limits are set on the t t bar H production cross section. The observed exclusion upper limit at 95% confidence level is 6.7 times the predicted Standard Model cross section value. In addition, limits are set on the strength of the Yukawa coupling between the top quark and the Higgs boson, taking into account the dependence of the t t bar H and tH cross sections as well as the H → γγ branching fraction on the Yukawa coupling. Lower and upper limits at 95% confidence level are set at -1.3 and +8.0 times the Yukawa coupling strength in the Standard Model.
Nonperturbative Yukawa Couplings from String Instantons
Blumenhagen, Ralph; Cvetic, Mirjam; Richter, Robert; Weigand, Timo; Luest, Dieter
2008-02-15
Nonperturbative D-brane instantons can generate perturbatively absent though phenomenologically relevant couplings for type II orientifold compactifications with D-branes. We discuss the generation of the perturbatively vanishing SU(5) GUT Yukawa coupling of type <10 10 5{sub H}>. Moreover, for a simple globally consistent intersecting D6-brane model, we discuss the generation of mass terms for matter fields. This can serve as a mechanism for decoupling exotic matter.
Remarkable coincidence for the top Yukawa coupling and an approximately massless bound state
Froggatt, C. D.; Nielsen, H. B.
2009-08-01
We calculate, with several corrections, the nonrelativistic binding by Higgs exchange and gluon exchange between six top and six antitop quarks (actually replaced by left-handed b quarks from time to time). The remarkable result is that, within our calculational accuracy of the order of 14% in the top-quark Yukawa coupling g{sub t}, the experimental running top-quark Yukawa coupling g{sub t}=0.935 happens to have just that value which gives a perfect cancellation of the unbound mass=12 top-quark masses by this binding energy. In other words the bound state is massless to the accuracy of our calculation. Our calculation is in disagreement with a similar calculation by Kuchiev et al., but this deviation may be explained by a phase transition. We and Kuchiev et al. compute on different sides of this phase transition.
Running of the Yukawa Couplings in a Two Higgs Doublet Model
Montes de Oca Y, J. H.; Juarez W, S. R.; Kielanowski, P.
2008-07-02
We solve the one loop Renormalization Group Equations (RGE) for the Yukawa couplings in the Standard Model with two Higgs doublets. In the RGE we include the contributions of the up and down quarks. In this approximation we explore universality and unification assumptions to study the mass-hierarchy problem through the running of the vacuum expectation values.
Measuring the top Yukawa coupling at 100 TeV
NASA Astrophysics Data System (ADS)
Mangano, Michelangelo L.; Plehn, Tilman; Reimitz, Peter; Schell, Torben; Shao, Hua-Sheng
2016-04-01
We propose a measurement of the top Yukawa coupling at a 100 TeV hadron collider, based on boosted Higgs and top decays. We find that the top Yukawa coupling can be measured to 1%, with excellent handles for reducing systematic and theoretical uncertainties, both from side bands and from t\\bar{t}H/t\\bar{t}Z ratios.
Examining the identity of Yukawa with gauge couplings in supersymmetric QCD at LHC
Freitas, Ayres; Skands, Peter Z.; Spira, M.; Zerwas, P.M.; /DESY
2007-03-01
The identity of the quark-squark-gluino Yukawa coupling with the corresponding quark-quark-gluon QCD coupling in supersymmetric theories can be examined experimentally at the Large Hadron Collider (LHC). Extending earlier investigations of like-sign di-lepton final states, we include jets in the analysis of the minimal supersymmetric standard model, adding squark-gluino and gluino-pair production to squark-pair production. Moreover we expand the method towards model-independent analyses which cover more general scenarios. In all cases, squark decays to light charginos and neutralinos persist to play a dominant role.
Yukawa couplings in string theory: the case for F-theory GUT's
NASA Astrophysics Data System (ADS)
Font, Anamaría
2015-11-01
We study the pattern of Yukawa couplings in local F-theory SU(5) GUT's. Couplings for the third family of quarks and leptons appear at the perturbative level, but to reproduce the observed couplings for the lighter families requires non-perturbative dynamics. We show that corrections due to instanton effects do lead to a Yukawa matrix with a hierarchical structure. Our results apply to both down-like and up- like 10 × 10 × 5 couplings. The models include magnetic fluxes needed for a chiral spectrum and for symmetry breaking down to the Standard Model. We compute the holomorphic couplings via residues and then obtain the physical couplings taking into account the normalization of wavefunction profiles. Combining non-perturbative corrections and magnetic fluxes allows to fit the measured masses and hierarchies of the third and second generations in the Standard Model.
Top Yukawa coupling measurement with indefinite CP Higgs in e+e-→tt¯Φ
NASA Astrophysics Data System (ADS)
Ananthanarayan, B.; Garg, Sumit K.; Kim, C. S.; Lahiri, Jayita; Poulose, P.
2014-07-01
We consider the issue of the top quark Yukawa coupling measurement in a model-independent and general case with the inclusion of CP violation in the coupling. Arguably the best process to study this coupling is the associated production of the Higgs boson along with a tt¯ pair in a machine like the International Linear Collider (ILC). While detailed analyses of the sensitivity of the measurement—assuming a Standard Model (SM)-like coupling is available in the context of the ILC—conclude that the coupling could be pinned down to about a 10% level with modest luminosity, our investigations show that the scenario could be different in the case of a more general coupling. The modified Lorentz structure resulting in a changed functional dependence of the cross section on the coupling, along with the difference in the cross section itself leads to considerable deviation in the sensitivity. Our studies of the ILC with center-of-mass energies of 500 GeV, 800 GeV, and 1000 GeV show that moderate CP mixing in the Higgs sector could change the sensitivity to about 20%, while it could be worsened to 75% in cases which could accommodate more dramatic changes in the coupling. Detailed considerations of the decay distributions point to a need for a relook at the analysis strategy followed for the case of the SM, such as for a model-independent analysis of the top quark Yukawa coupling measurement. This study strongly suggests that a joint analysis of the CP properties and the Yukawa coupling measurement would be the way forward at the ILC and that caution must be exercised in the measurement of the Yukawa couplings and the conclusions drawn from it.
Masses of third family vectorlike quarks and leptons in Yukawa-unified E6
NASA Astrophysics Data System (ADS)
Hebbar, Aditya; Leontaris, George K.; Shafi, Qaisar
2016-06-01
In supersymmetric E6 the masses of the third family quarks and charged lepton, t -b -τ , as well as the masses of the vectorlike quarks and leptons, D -D ¯ and L -L ¯, may arise from the coupling 2 73×2 73×2 7H, where 2 73 and 2 7H denote the third family matter and Higgs multiplets, respectively. We assume that the SO(10) singlet component in 2 7H acquires a TeV-scale vacuum expectation value that spontaneously breaks U (1 )ψ and provides masses to the vectorlike particles in 2 73, while the Minimal Supersymmetric Standard Model doublets in 2 7H provide masses to t , b , and τ . Imposing Yukawa coupling unification ht=hb=hτ=hD=hL at MGUT and employing the ATLAS and CMS constraints on the Zψ' boson mass, we estimate the lower bounds on the third family vectorlike particles D -D ¯ and L -L ¯ masses to be around 5.85 TeV and 2.9 TeV, respectively. These bounds apply in the supersymmetric limit.
Prospects for measuring the Higgs boson coupling to light quarks
NASA Astrophysics Data System (ADS)
Perez, Gilad; Soreq, Yotam; Stamou, Emmanuel; Tobioka, Kohsaku
2016-01-01
We discuss the prospects to probe the light-quark Yukawa couplings to the Higgs boson. The Higgs coupling to the charm quark can be probed both via inclusive and exclusive approaches. On the inclusive frontier, we use our recently proposed method together with published experimental studies for the sensitivity of the Higgs coupling to bottom quarks to find that the high-luminosity LHC can be sensitive to modifications of the charm Yukawa of the order of a few times its standard model (SM) value. We also present a preliminary study of this mode for a 100 TeV hadronic machine (with similar luminosity) and find that the bound can be further improved, possibly within the reach of the expected signal in the SM. On the exclusive frontier, we use the recent ATLAS search for charmonia and photon final state. This study yields the first measurement of the background relevant to these modes. Using this background measurement we project that at the high-luminosity LHC, unless the analysis strategy is changed, the sensitivity of the exclusive final state to the charm Yukawa to the charm Yukawa will be rather poor, of the order of 50 times the SM coupling. We then use a Monte-Carlo study to rescale the above backgrounds to the h →ϕ γ case and obtain a much weaker sensitivity to the strange Yukawa, of order of 3000 times the SM value. We briefly speculate what would be required to improve the prospects of the exclusive modes.
Scalar decay constant and Yukawa coupling in walking gauge theories
Hashimoto, Michio
2011-05-01
We propose an approach for the calculation of the Yukawa coupling through the scalar decay constant and the chiral condensate in the context of the extended technicolor . We perform the nonperturbative computation of the Yukawa coupling based on the improved ladder Schwinger-Dyson equation. It turns out that the Yukawa coupling can be larger or smaller than the standard model value, depending on the number N{sub D} of the weak doublets for each technicolor (TC) index. It is thus nontrivial whether or not the huge enhancement of the production of the scalar via the gluon fusion takes place even for a walking TC model with a colored techni-fermion. For the typical one-family TC model near conformality, it is found that the Yukawa coupling is slightly larger than the standard model one, where the expected mass of the scalar bound state is around 500 GeV. In this case, the production cross section via the gluon fusion is considerably enhanced, as naively expected, and hence such a scalar can be discovered/excluded at the early stage of the LHC.
Practical thermodynamics of Yukawa systems at strong coupling
Khrapak, Sergey A.; Kryuchkov, Nikita P.; Yurchenko, Stanislav O.; Thomas, Hubertus M.
2015-05-21
Simple practical approach to estimate thermodynamic properties of strongly coupled Yukawa systems, in both fluid and solid phases, is presented. The accuracy of the approach is tested by extensive comparison with direct computer simulation results (for fluids and solids) and the recently proposed shortest-graph method (for solids). Possible applications to other systems of softly repulsive particles are briefly discussed.
Practical thermodynamics of Yukawa systems at strong coupling.
Khrapak, Sergey A; Kryuchkov, Nikita P; Yurchenko, Stanislav O; Thomas, Hubertus M
2015-05-21
Simple practical approach to estimate thermodynamic properties of strongly coupled Yukawa systems, in both fluid and solid phases, is presented. The accuracy of the approach is tested by extensive comparison with direct computer simulation results (for fluids and solids) and the recently proposed shortest-graph method (for solids). Possible applications to other systems of softly repulsive particles are briefly discussed. PMID:26001480
Anderson, G.W.
1992-12-01
The effect of large third generation Yukawa couplings on radiative electroweak symmetry breaking in N = 1 SUSY-GUTS is reported. Limits on tan {beta}, and on the amount of fine tuning necessary for consistent symmetry breaking in the MSSM are derived. Predictions for fermion masses and mixing angles from GUT scale textures are also discussed. The effect of large Yukawa couplings on the running of the DHR texture is used to determine limits on the top quark valid for all values of tan {beta}.
Infrared fixed point of the top Yukawa coupling in split supersymmetry
Huitu, Katri; Laamanen, Jari; Roy, Probir; Roy, Sourov
2005-09-01
The severe constraints imposed on the parameter space of the minimal split supersymmetry model by the infrared fixed point solution of the top Yukawa coupling Y{sub t} are studied in detail in terms of the value of the top-quark mass measured at the Tevatron together with the lower bound on the lightest Higgs mass established by LEP. The dependence of the Higgsino mass parameter {mu}, the gaugino coupling strengths g-tilde{sub u,d}, g-tilde{sub u,d}{sup '} and of the Higgs quartic self-coupling {lambda} on the value of Y{sub t} in the vicinity of the Landau pole is discussed. A few interesting features emerge, though the model is found to be disfavored within the infrared fixed point scenario because of the need to have several unnatural cancellations at work on account of the requirement of a low upper bound on tan{beta}.
Nonlinear mode coupling and vibrational energy transfer in Yukawa clusters
NASA Astrophysics Data System (ADS)
Qiao, Ke; Kong, Jie; Matthews, Lorin; Hyde, Truell
2015-11-01
Nonlinear mode coupling and the subsequent vibrational energy transfer that results is an important topic in chemical physics research, ranging from small molecules consisting of several atoms to macromolecules such as those found in proteins and DNA. Nonlinear mode coupling is recognized as the mechanism leading to ergodicity, which is a foundational tenet of statistical mechanics. Over the past two decades, Yukawa systems of particles such as those found in complex plasma, have been shown to be an effective model across a large number of physical systems. In this research, nonlinear mode coupling in Yukawa clusters consisting of 3-10 particles is examined via numerical simulation of the vibrational energy transfer between modes starting from an initial excited state. The relationship between the energy transfer process and the internal resonance between modes having a specified frequency ratio and the temporal evolution of the system to a state of equal energy across all modes, i.e., the state of ergodicity, will be discussed. Support from the NSF and the DOE (award numbers PHY-1262031 and PHY-1414523) is gratefully acknowledged.
Absence of Rapid Proton Decay and Origin of Low-Energy Particlesand Yukawa Couplings
Tatar, Radu; Watari, Taizan
2006-01-01
In string theory, massless particles often originate from a symmetry breaking of a large gauge symmetry G to its subgroup H. The absence of dimension-4 proton decay in supersymmetric theories suggests that ({bar D},L) are different from {bar H}({bar 5}) in their origins. In this article, we consider a possibility that they come from different irreducible components in g/h. Requiring that all the Yukawa coupling constants of quarks and leptons be generated from the super Yang-Mills interactions of G, we found in the context of Georgi-Glashow H = SU(5) unification that the minimal choice of G is E{sub 7} and E{sub 8} is the only alternative. This idea is systematically implemented in Heterotic String, M theory and F theory, confirming the absence of dimension 4 proton decay operators. Not only H = SU(5) but also G constrain operators of effective field theories, providing non-trivial information.
Aspect of Fermion Mass Hierarchy within Flavor Democracy for Yukawa Couplings
NASA Astrophysics Data System (ADS)
Higuchi, Katsuichi; Yamamoto, Katsuji
We discuss the fermion mass hierarchy by including vector-like fermions which are accommodated in E6 GUTs within flavor democracy for Yukawa couplings. In this framework, all Yukawa couplings for the standard Higgs doublet have the same strength, and all Yukawa couplings for the singlet Higgs have the same strength (New ansatz). In addition, singlet Higgs and right-handed neutrinos exist. Under this condition, the mass hierarchy mt ≫ mb ˜ mτ as well as mt ≫ mc, mu can be naturally explained.
Instanton induced Yukawa couplings from distant E3 and E(-1) instantons
NASA Astrophysics Data System (ADS)
Goodsell, Mark D.; Witkowski, Lukas T.
2016-01-01
We calculate non-perturbative contributions to Yukawa couplings on D3-branes at orbifold singularities due to E3 and fractional E(-1) instantons which do not intersect the visible sector branes. While distant E3 instantons on bulk cycles typically contribute to Yukawa couplings, we find that distant fractional E(-1) can also give rise to new Yukawa couplings. However, fractional E(-1) instantons only induce Yukawa couplings if they are located at a singularity which shares a collapsed homologous two-cycle with the singularity supporting the visible sector. The non-perturbative contributions to Yukawa couplings exhibit a different flavour structure than the tree-level Yukawa couplings and, as a result, they can be sources of flavour violation. This is particularly relevant for schemes of moduli stabilisation which rely on superpotential contributions from E3 instantons, such as KKLT or the Large Volume Scenario. As a byproduct of our analysis, we shed some new light on the properties of annulus diagrams with matter field insertions in stringy instanton calculus.
Gomez-Bock, M.; Lopez-Castro, G.; Lopez-Lozano, L.; Rosado, A.
2009-09-01
We study flavor-violating processes in the production or decay of a neutral pseudoscalar meson P{sup 0} in the framework of a type-III two Higgs doublet model with four-texture Yukawa couplings. We use a version of the model where Yukawa interactions of neutral Higgs bosons allow for flavor change at the tree-level, but conserve CP symmetry. The physical Yukawa couplings respect CP-invariance due to the Hermiticity conditions that we impose on the fermion mass matrices. We focus on all possible {tau}{sup {+-}}{yields}l{sup {+-}}P{sup 0} and P{sup 0}{yields}l{sup +}l{sup '-} decay channels, where l, l{sup '} are charged leptons. We find that these processes provide complementary information on quark and lepton flavor-changing neutral current Yukawa couplings. In particular flavor-violating parameters in the quark sector, {chi}{sub sb} and {chi}{sub db}, are significantly constrained by present experimental data, whereas the corresponding parameters in the leptonic sector are less constrained.
Non-minimal coupling in Higgs–Yukawa model with asymptotically safe gravity
NASA Astrophysics Data System (ADS)
Oda, Kin-ya; Yamada, Masatoshi
2016-06-01
We study the fixed-point structure of the Higgs–Yukawa model, with its scalar being non-minimally coupled to the asymptotically safe gravity, using the functional renormalization group. We have obtained the renormalization group equations for the cosmological and Newton constants, the scalar mass squared and quartic coupling constant, and the Yukawa and non-minimal coupling constants, taking into account all the scalar, fermion, and graviton loops. We find that switching on the fermionic quantum fluctuations makes the non-minimal coupling constant irrelevant around the Gaussian-matter fixed point with asymptotically safe gravity.
Flavor constraints on two-Higgs-doublet models with general diagonal Yukawa couplings
Mahmoudi, F.
2010-02-01
We consider constraints from flavor physics on two-Higgs-doublet models (2HDM) with general, flavor-diagonal, Yukawa couplings. Analyzing the charged Higgs contribution to different observables, we find that b{yields}s{gamma} transitions and {Delta}M{sub B{sub d}} restrict the coupling {lambda}{sub tt} of the top quark (corresponding to cot{beta} in models with a Z{sub 2} symmetry) to |{lambda}{sub tt}|<1 for m{sub H}{sup +} < or approx. 500 GeV. Stringent constraints from B meson decays are obtained also on the other third generation couplings {lambda}{sub bb} and {lambda}{sub {tau}{tau},} but with stronger dependence on m{sub H}{sup +}. For the second generation, we obtain constraints on combinations of {lambda}{sub ss}, {lambda}{sub cc}, and {lambda}{sub {mu}{mu}}from leptonic K and D{sub s} decays. The limits on the general couplings are translated to the common 2HDM types I-IV with a Z{sub 2} symmetry, and presented on the (m{sub H}{sup +},tan{beta}) plane. The flavor constraints are most excluding in the type II model which lacks a decoupling limit in tan{beta}. We obtain a lower limit m{sub H}{sup +} > or approx. 300 GeV in models of type II and III, while no lower bound on m{sub H}{sup +} is found for types I and IV.
Quasi-localized wavefunctions on magnetized tori and tiny neutrino Yukawa couplings
NASA Astrophysics Data System (ADS)
Sumita, Keigo
2016-01-01
This paper shows that, a quasi-localization of wavefunctions in toroidal compactifications with magnetic fluxes can lead to a strong suppression for relevant Yukawa couplings, and it is applicable to obtain tiny neutrino masses. Although it is known that magnetic fluxes lead to a Gaussian profile of zero-modes on a torus and that can yield a suppressed coupling in higher-dimensional supersymmetric Yang-Mills (SYM) theories, the largest (diagonal) entry of Yukawa matrices is always of O(1) . In this paper, we propose a way to induce an absolutely tiny global factor of Yukawa matrices. In two SYM theories defined in different dimensional spacetime, their bifundamental representations must be localized as a point in some directions. Overlaps of such point-like localized wavefunctions and Gaussian zero-modes give a global factor of Yukawa matrices, and it can be a strong suppression factor or a usual O(1) factor, corresponding to their distance. Our numerical analysis shows that it is possible to obtain a suppression strong enough to realize the tiny neutrino masses without a fine-tuning. Furthermore, we propose a concrete model in a magnetized SYM system and demonstrate the mechanism to generate the tiny neutrino Yukawa couplings.
Yukawa coupling and anomalous magnetic moment of the muon: An update for the LHC era
Crivellin, Andreas; Girrbach, Jennifer; Nierste, Ulrich
2011-03-01
We study the interplay between a soft muon Yukawa coupling generated radiatively with the trilinear A-terms of the minimal supersymmetric standard model (MSSM) and the anomalous magnetic moment of the muon. In the absence of a tree-level muon Yukawa coupling the lightest smuon mass is predicted to be in the range between 600 GeV and 2200 GeV at 2{sigma}, if the bino mass M{sub 1} is below 1 TeV. Therefore, a detection of a smuon (in conjunction with a sub-TeV bino) at the LHC would directly imply a nonzero muon Yukawa coupling in the MSSM superpotential. Inclusion of slepton flavor mixing could in principle lower the mass of one smuonlike slepton below 600 GeV. However, the experimental bounds on radiative lepton decays instead strengthen the lower mass bound, with larger effects for smaller M{sub 1}, We also extend the analysis to the electron case and find that a light selectron close to the current experimental search limit may prove the MSSM electron Yukawa coupling to be nonzero.
Minimal SUSY SO(10) and Yukawa unification
Okada, Nobuchika
2013-05-23
The minimal supersymmetric (SUSY) SO(10) model, where only two Higgs multiplets {l_brace}10 Circled-Plus 126-bar{r_brace} are utilized for Yukawa couplings with matter fields, can nicely fit the neutrino oscillation parameters as well as charged fermion masses and mixing angles. In the fitting of the fermion mass matrix data, the largest element in the Yukawa coupling with the 126-bar -plet Higgs (Y{sup 126}) is found to be of order one, so that the right see-saw scale should be provided by Higgs vacuum expectation values (VEVs) of {beta}(10{sup 14}GeV). This fact causes a serious problem, namely, the gauge coupling unification is spoiled because of the presence of many exotic Higgs multiples emerging at the see-saw scale. In order to solve this problem, we consider a unification between bottom-quark and tau Yukawa couplings (b - {tau} Yukawa coupling unification) at the grand unified theory (GUT) scale, due to threshold corrections of superpartners to the Yukawa couplings at the 1 TeV scale. When the b - {tau} Yukawa coupling unification is very accurate, the largest element in Y{sub 126} can become {beta}(0.01), so that the right see-saw scale is realized by the GUT scale VEV and the usual gauge coupling unification is maintained. Since the b - {tau} Yukawa unification alters the Yukawa coupling data at the GUT scale, we re-analyze the fitting of the fermion mass matrix data by taking all the relevant free parameters into account. Unfortunately, we find that no parameter region shows up to give a nice fit for the current neutrino oscillation data and therefore, the usual picture of the gauge coupling unification cannot accommodate the fermion mass matrix data fitting in our procedure.
Blowup results for the KGS system with higher order Yukawa coupling
Shi, Qi-Hong; Li, Wan-Tong; Wang, Shu
2015-10-15
In this paper, we investigate the Klein-Gordon-Schrödinger (KGS) system with higher order Yukawa coupling in spatial dimensions N ≥ 3. We establish a perturbed virial type identity and prove blowup results relied on Lyapunov functionals for KGS system with a negative energy level. Additionally, we give a result with respect to the blowup rate in finite time for the radial solution in 3 spatial dimensions.
Dependence of Yukawa couplings on the axionic background moduli of ZN orbifolds
NASA Astrophysics Data System (ADS)
Erler, J.; Jungnickel, D.; Lauer, J.
1992-05-01
The metrical and axionic background moduli which determine a general symmetric ZN orbifold model are chosen in such a way that the rotational twist leaves the underlying σ model action invariant. A thorough analysis of this condition is given. We notice that it plays a key role in the evaluation of the four-point correlation functions of ground states which belong to the lowest twisted sectors. Having fixed the normalization of these functions we factorize them with respect to the twisted intermediate channel. This method yields the moduli-dependent part of the twisted sector Yukawa couplings of an orbifoldized heterotic string model. We then perform various discrete mappings (axionic shifts, duality) on the space of background moduli and recognize that the induced linear transformations of the Yukawa couplings are essentially independent of the choice of a specific background. If compensating unitary redefinitions of the twist fields are applied then orbifold models whose backgrounds are related by one of the above mappings cannot be distinguished. For many twist orders we arrive at an explicit form of the phase factors needed to redefine twist fields in order that a general discrete axionic shift can be undone. The requirement of duality invariance is sufficient to determine the moduli dependence of the Yukawa couplings. Hence one may even bypass the evaluation of instanton actions.
Weak quark couplings induced by gluon corrections
NASA Astrophysics Data System (ADS)
Gavela, M. B.; Le Yaouanc, A.; Oliver, L.; Pène, O.; Raynal, J. C.
1980-12-01
We compute the quark couplings in flavor-changing semileptonic transitions induced by lowest-order gluon corrections. We investigate the consequences of these radiative corrections for the quark axial-vector coupling, the deviations from Cabibbo universality for the axial-vector relative to the vector current, and the induced couplings (first-class pseudoscalar and anomalous magnetic moment, and second-class scalar and pseudotensor). The correction lowers the axial-vector coupling and increases the magnetic moment. We study the dependence of the couplings on the quark mass difference. Some of these results, true to all orders in αs, generalize the theorem of Ademollo and Gatto. The effective current is pure V-A to a very good approximation for transitions of heavy quarks (m>~5 GeV).
NASA Astrophysics Data System (ADS)
Ganesh, Rajaraman; Charan, Harish
2016-07-01
Understanding vortical flows under external forcing in two dimensional (2D) fluids is a fundamental paradigm for structure formation in driven, dissipative systems. Considering Yukawa liquid as a prototype for strongly correlated or strongly coupled plasmas characterized by coupling strength (Γ, the ratio of average potential to kinetic energy per particle) and screening parameter (κ, ratio of mean inter-particle distance to shielding length), we address two important problems: 1. Onset of Rayleigh Benard convection cell (RBCC) in 2D Yukawa liquids subject to gravity and external temperature gradient 2. Onset of von Karman vortices in 2D Yukawa liquid under external pressure head, using large scale, first principles molecular dynamics simulations. For typical values of (Γ,κ), existence of a critical external temperature difference is demonstrated, beyond which RBCC are seen to set in. Beyond this critical external temperature difference, the strength of the maximum convective flow velocity is shown to exhibit a new, hitherto unsuspected linear relationship with external temperature difference and with a slope independent of (Γ,κ). The time taken for the transients to settle down to a steady state RBCC τ_s, is found to be maximum close to the above said critical external temperature difference and is seen to reduce with increasing external temperature difference. For the range of values of (Γ, κ) considered here, τ_s ≃ 10 000-20 000;ω^{-1}_{pd}, where ω_{pd} is dust plasma frequency. As Γ is increased to very high values, due to strong coupling effects, RBC cells are seen to be in a transient state without attaining a steady state for as long as 100 000;ω^{-1}_{pd}, even for a very high external temperature difference. In the second part, we address the existence of universal relation between Strouhal (St) and Rayleigh (Ry) numbers for Yukawa liquid using first principles based classical molecular dynamics. The flow past an obstacle is seen to indeed
Full simulation study of the top Yukawa coupling at the ILC at TeV
NASA Astrophysics Data System (ADS)
Price, T.; Roloff, P.; Strube, J.; Tanabe, T.
2015-07-01
We present a study of the expected precision for the measurement of the top Yukawa coupling, , in collisions at a center-of-mass energy of 1 TeV. Independent analyses of final states containing at least six hadronic jets are performed, based on detailed simulations of SiD and ILD, the two candidate detector concepts for the ILC. We estimate that a statistical precision on of 4.5 % can be obtained with an integrated luminosity of 1 that is split equally between two configurations for the beam polarization , and . This estimate improves to if the 1 sample is assumed to be fully in the configuration.
Effective Yukawa couplings and flavor-changing Higgs boson decays at linear colliders
Gabrielli, E.; Mele, B.
2011-04-01
We analyze the advantages of a linear-collider program for testing a recent theoretical proposal where the Higgs boson Yukawa couplings are radiatively generated, keeping unchanged the standard-model mechanism for electroweak-gauge-symmetry breaking. Fermion masses arise at a large energy scale through an unknown mechanism, and the standard model at the electroweak scale is regarded as an effective field theory. In this scenario, Higgs boson decays into photons and electroweak gauge-boson pairs are considerably enhanced for a light Higgs boson, which makes a signal observation at the LHC straightforward. On the other hand, the clean environment of a linear collider is required to directly probe the radiative fermionic sector of the Higgs boson couplings. Also, we show that the flavor-changing Higgs boson decays are dramatically enhanced with respect to the standard model. In particular, we find a measurable branching ratio in the range (10{sup -4}-10{sup -3}) for the decay H{yields}bs for a Higgs boson lighter than 140 GeV, depending on the high-energy scale where Yukawa couplings vanish. We present a detailed analysis of the Higgs boson production cross sections at linear colliders for interesting decay signatures, as well as branching-ratio correlations for different flavor-conserving/nonconserving fermionic decays.
NASA Astrophysics Data System (ADS)
Mankoč Borštnik, Norma Susana
2015-03-01
Most physicists declare the Higgs as the last missing particle to be confirmed. But can this at all be true? Shouldn't we understand the origin of families before being able to understand the origin of the Yukawa couplings, for the explanation of which additional scalar fields are needed? The spin-charge-family theory is offering a possible explanation for the origin of families, for several scalar fields manifesting effectively at low energies as the Higgs and the Yukawa couplings, for the fact that the scalar fields are doublets with respect to the weak charge, while they are triplets with respect to the family groups, and also for other assumptions of the standard model. The theory predicts at the observable regime two decoupled groups of four families. The fourth family, coupled to the measured three, will be observed at the LHC. The fifth family is explaining the dark matter. The accuracy with which the fourth family masses can in this theory be predicted depends strongly on the accuracy with which the mixing 3 × 3 sub matrices of the quark and lepton mixing matrices are measured.
Alignment, reverse alignment, and wrong sign Yukawa couplings in two Higgs doublet models
NASA Astrophysics Data System (ADS)
Biswas, Ambalika; Lahiri, Amitabha
2016-06-01
We consider two Higgs doublet models with a softly broken U(1) symmetry, for various limiting values of the scalar mixing angles α and β . These correspond to the Standard Model Higgs particle being the lighter C P -even scalar (alignment) or the heavier C P -even scalar (reverse alignment), and also the limit in which some of the Yukawa couplings of this particle are the opposite sign of the vector boson couplings (wrong sign). In these limits we impose a criterion for naturalness by demanding that quadratic divergences cancel at one loop. We plot the allowed masses of the remaining physical scalars based on naturalness, stability, perturbative unitarity, and constraints coming from the ρ parameter. We also calculate the h →γ γ decay width in the wrong sign limit.
Quark mean field approach with derivative coupling for nuclear matter
Kawabata, M.; Akiyama, S.; Futami, Y.; Nakasone, T.; Yukino, T.
2008-05-15
We propose the quark mean field model including derivative coupling between quarks and scalar mesons in nuclear matter. This model concisely interprets an increasing size of the nucleon as well as a modification of coupling constant in the nuclear environment.
Constraining the Higgs boson coupling to light quarks in the H →Z Z final states
NASA Astrophysics Data System (ADS)
Zhou, Yaofu
2016-01-01
We constrain the Higgs boson (Yukawa) coupling to quarks in the first two generations in the H →Z Z final states. Deviation of these couplings from the Standard Model values leads to changes in the Higgs boson width and in the cross sections of relevant processes. In the Higgs boson resonance region, an increased light Yukawa coupling leads to an increased Higgs boson width, which in turn leads to a decreased cross section. In the off-shell region, increased Yukawa couplings result in an enhancement of the Higgs boson signal through q q ¯ annihilation. With the assumption of scaling one Yukawa coupling at a time, this study is conceptually simple and yields results with the same order of magnitude as the tightest in the literature. The study is based on results published by the CMS experiment at the LHC in 2014, corresponding to integrated luminosities of 5.1 fb-1 at a centre-of-mass energy √{s }=7 TeV and 19.7 fb-1 at 8 TeV.
NASA Astrophysics Data System (ADS)
Kjellander, Roland; Ramirez, Rosa
2008-12-01
An exact treatment of screened electrostatics in electrolyte solutions is presented. In electrolytes the anisotropy of the exponentially decaying electrostatic potential from a molecule extends to the far field region. The full directional dependence of the electrostatic potential from a charged or uncharged molecule remains in the longest range tail (i.e. from all multipole moments). In particular, the range of the potential from an ion and that from an electroneutral polar particle is generally exactly the same. This is in contrast to the case in vacuum or pure polar liquids, where the potential from a single charge is longer ranged than that from a dipole, which is, itself, longer ranged than the one from a quadrupole etc. The orientational dependence of the exponentially screened electrostatic interaction between two molecules in electrolytes is therefore rather complex even at long distances. These facts are formalized in Yukawa multipole expansions of the electrostatic potential and the pair interaction free energy based on the Yukawa function family exp(-κr)/rm, where r is the distance, κ is a decay parameter and m is a positive integer. The expansion is formally exact for electrolytes with molecular solvent and in the primitive model, provided the non-Coulombic interactions between the particles are sufficiently short ranged. The results can also be applied in the Poisson-Boltzmann approximation. Differences and similarities to the ordinary multipole expansion of electrostatics are pointed out. On the other hand, when the non-Coulombic interactions between the constituent particles of the electrolyte solution contain a dispersion 1/r6 potential, the electrostatic potential from a molecule decays like a power law for long distances rather than as a Yukawa function. This is due to nontrivial coupling between the electrostatic and dispersion interactions. There remains an exponentially decaying component in the electrostatic potential, but it becomes
Strongly coupled quark gluon plasma (SCQGP)
NASA Astrophysics Data System (ADS)
Bannur, Vishnu M.
2006-07-01
We propose that the reason for the non-ideal behaviour seen in lattice simulation of quark gluon plasma (QGP) and ultrarelativistic heavy ion collision experiments is that the QGP near Tc and above is a strongly coupled plasma (SCP), i.e., a strongly coupled quark gluon plasma (SCQGP). It is remarkable that the widely used equation of state of SCP in QED (quantum electrodynamics) very nicely fits lattice results on all QGP systems, with proper modifications to include colour degrees of freedom and the running coupling constant. Results on pressure in pure gauge, 2-flavours and 3-flavours QGP can all be explained by treating QGP as SCQGP, as demonstrated here. Energy density and speed of sound are also presented for all three systems. We further extend the model to systems with finite quark mass and reasonably good fits to lattice results are obtained for (2+1)-flavours and 4-flavours QGP. Hence it is a unified model, namely SCQGP, to explain the non-ideal QGP seen in lattice simulations with just two system dependent parameters.
Dzhumagulova, K N; Masheyeva, R U; Ott, T; Hartmann, P; Ramazanov, T S; Bonitz, M; Donkó, Z
2016-06-01
The influence of an external homogeneous magnetic field on the quasilocalization of the particles-characterized quantitatively by cage correlation functions-in strongly coupled three-dimensional Yukawa systems is investigated via molecular dynamics computer simulations over a wide domain of the system parameters (coupling and screening strengths, and magnetic field). The caging time is found to be enhanced by the magnetic field B. The anisotropic migration of the particles in the presence of magnetic field is quantified via computing directional correlation functions, which indicate a more significant increase of localization in the direction perpendicular to B, while a moderate increase is also found along the B field lines. Associating the particles' escapes from the cages with jumps of a characteristic length, a connection is found with the diffusion process: the diffusion coefficients derived from the decay time of the directional correlation functions in both the directions perpendicular to and parallel with B are in very good agreement with respective diffusion coefficients values obtained from their usual computation based on the mean-squared displacement of the particles. PMID:27415379
NASA Astrophysics Data System (ADS)
Dzhumagulova, K. N.; Masheyeva, R. U.; Ott, T.; Hartmann, P.; Ramazanov, T. S.; Bonitz, M.; Donkó, Z.
2016-06-01
The influence of an external homogeneous magnetic field on the quasilocalization of the particles—characterized quantitatively by cage correlation functions—in strongly coupled three-dimensional Yukawa systems is investigated via molecular dynamics computer simulations over a wide domain of the system parameters (coupling and screening strengths, and magnetic field). The caging time is found to be enhanced by the magnetic field B . The anisotropic migration of the particles in the presence of magnetic field is quantified via computing directional correlation functions, which indicate a more significant increase of localization in the direction perpendicular to B , while a moderate increase is also found along the B field lines. Associating the particles' escapes from the cages with jumps of a characteristic length, a connection is found with the diffusion process: the diffusion coefficients derived from the decay time of the directional correlation functions in both the directions perpendicular to and parallel with B are in very good agreement with respective diffusion coefficients values obtained from their usual computation based on the mean-squared displacement of the particles.
Evidence for the Higgs-boson Yukawa coupling to tau leptons with the ATLAS detector
Aad, G.
2015-04-21
Results of a search for H → ττ decays are presented, based on the full set of proton-proton collision data recorded by the ATLAS experiment at the LHC during 2011 and 2012. The data correspond to integrated luminosities of 4.5 fb–1 and 20.3 fb–1 at centre-of-mass energies of √s=7 TeV and √s=8 TeV respectively. All combinations of leptonic (τ → ℓνν¯ with ℓ = e, μ) and hadronic (τ → hadrons ν) tau decays are considered. An excess of events over the expected background from other Standard Model processes is found with an observed (expected) significance of 4.5 (3.4) standardmore » deviations. This excess provides evidence for the direct coupling of the recently discovered Higgs boson to fermions. The measured signal strength, normalized to the Standard Model expectation, of μ = 1.43–0.37+0.43 is consistent with the predicted Yukawa coupling strength in the Standard Model.« less
Evidence for the Higgs-boson Yukawa coupling to tau leptons with the ATLAS detector
Aad, G.
2015-04-21
Results of a search for H → ττ decays are presented, based on the full set of proton-proton collision data recorded by the ATLAS experiment at the LHC during 2011 and 2012. The data correspond to integrated luminosities of 4.5 fb^{–1} and 20.3 fb^{–1} at centre-of-mass energies of √s=7 TeV and √s=8 TeV respectively. All combinations of leptonic (τ → ℓνν¯ with ℓ = e, μ) and hadronic (τ → hadrons ν) tau decays are considered. An excess of events over the expected background from other Standard Model processes is found with an observed (expected) significance of 4.5 (3.4) standard deviations. This excess provides evidence for the direct coupling of the recently discovered Higgs boson to fermions. The measured signal strength, normalized to the Standard Model expectation, of μ = 1.43_{–0.37}^{+0.43} is consistent with the predicted Yukawa coupling strength in the Standard Model.
Quark and pion effective couplings from polarization effects
NASA Astrophysics Data System (ADS)
Braghin, Fábio L.
2016-05-01
A flavor SU(2) effective model for pions and quarks is derived by considering polarization effects departing from the usual quark-quark effective interaction induced by dressed gluon exchange, i.e. a global color model for QCD. For that, the quark field is decomposed into a component that yields light mesons and the quark-antiquark condensate, being integrated out by means of the auxiliary field method, and another component which yields constituent quarks, which is basically a background quark field. Within a long-wavelength and weak quark field expansion (or large quark effective mass expansion) of a quark determinant, the leading terms are found up to the second order in a zero-order derivative expansion, by neglecting vector mesons that are considerably heavier than the pion. Pions are considered in the structureless limit and, besides the chiral invariant terms that reproduce previously derived expressions, symmetry breaking terms are also presented. The leading chiral quark-quark effective couplings are also found corresponding to a NJL and a vector-NJL couplings. All the resulting effective coupling constants and parameters are expressed in terms of the current and constituent quark masses and of the coupling g.
Generalized Yukawa PPPM for molecular dynamics simulation of strongly coupled plasmas
NASA Astrophysics Data System (ADS)
Dharuman, Gautham; Stanton, Liam; Glosli, James; Verboncoeur, John; Christlieb, Andrew; Murillo, Michael
2015-11-01
The Particle-Particle-Particle-Mesh (PPPM) method is an efficient way of treating the Ewald sum for long range interactions in a periodic system. It makes use of the Fast-Fourier-Transform algorithm that scales as O(N logN). In this work we have applied the PPPM method to long range interactions in the weak screening limit of generalized Yukawa interaction to identify the range of screening over which PPPM is computationally more efficient than the minimum image method which is usually usedfor the well-known Yukawa interactions. Generalized Yukawa interaction is obtained by including arbitrary linear dielectric screening in the Yukawa model. In the PPPM method the Fourier space part of the Ewald sum is treated by assigning charges to a mesh and computing the potential using an optimized Green's function that minimizes the discretization errors introduced in the forces.
3D dust clouds (Yukawa Balls) in strongly coupled dusty plasmas
Melzer, A.; Passvogel, M.; Miksch, T.; Ikkurthi, V. R.; Schneider, R.; Block, D.; Piel, A.
2010-06-16
Three-dimensional finite systems of charged dust particles confined to concentric spherical shells in a dusty plasma, so-called 'Yukawa balls', have been studied with respect to their static and dynamic properties. Here, we review the charging of particles in a dusty plasma discharge by computer simulations and the respective particle arrangements. The normal mode spectrum of Yukawa balls is measured from the 3D thermal Brownian motion of the dust particles around their equilibrium positions.
Ashwin, J.; Ganesh, R.
2010-10-15
Using a generalized hydrodynamic (GH) model, the growth rate spectra of Kelvin-Helmholtz (KH) instability has been obtained analytically for a step shear profile in strongly coupled Yukawa liquids. The class of shear flows studied is assumed to be incompressible in nature. The growth rate spectra calculated exhibit viscous damping at high mode numbers, destabilization at stronger coupling, and in the limit {tau}{sub m} (viscoelastic relaxation time){yields}0, reduce to the regular Navier-Stokes growth rate spectra. A direct comparison is made with previous molecular dynamics (MD) simulations [Ashwin J. and R. Ganesh, Phys. Rev. Lett. 104, 215003 (2010)] of KH instability. We find that for a given value of Reynolds number R and coupling parameter 1<{Gamma}<100, the GH and MD growth rates are in a qualitative agreement. The inclusion of the effect of shear heating as an effective coupling parameter {Gamma}{sub e} appears to improve the quantitative comparison as well.
Shear viscosity of strongly coupled Yukawa systems on finite length scales.
Sanbonmatsu, K Y; Murillo, M S
2001-02-12
The Yukawa shear viscosity has been calculated using nonequilibrium molecular dynamics. Near the viscosity minimum, we find exponential decay consistent with the Navier-Stokes equation, with significant deviations on finite length scales for larger viscosity values. The viscosity is determined to be nonlocal on a scale length consistent with the correlation length, revealing the length scales necessary for obtaining transport coefficients in the hydrodynamic limit by nonequilibrium molecular dynamics methods. Our results are quasiuniversal with respect to excess entropy for excess entropies well below unity. PMID:11178047
Full simulation study of the top Yukawa coupling at the ILC at √s = 1 TeV
Price, T.; Roloff, P.; Strube, J.; Tanabe, T.
2015-07-04
We present a study of the expected precision for the measurement of the top Yukawa coupling, y_{t}, in e^{+}e^{-} collisions at a center-of-mass energy of 1 TeV. Independent analyses of tt-barH final states containing at least six hadronic jets are performed, based on detailed simulations of SiD and ILD, the two candidate detector concepts for the ILC. We estimate that a statistical precision on y_{t} of 4.5 % can be obtained with an integrated luminosity of 1 ab^{-1} that is split equally between two configurations for the beam polarization P(e^{-},e^{+}), (-80 %,+20 %) and (+80 %,-20 %). This estimate improves to 4 % if the 1 ab^{-1} sample is assumed to be fully in the P(e^{-},e^{+})=(-80 %,+20 %) configuration.
Full simulation study of the top Yukawa coupling at the ILC at √s = 1 TeV
Price, T.; Roloff, P.; Strube, J.; Tanabe, T.
2015-07-04
We present a study of the expected precision for the measurement of the top Yukawa coupling, yt, in e+e- collisions at a center-of-mass energy of 1 TeV. Independent analyses of tt-barH final states containing at least six hadronic jets are performed, based on detailed simulations of SiD and ILD, the two candidate detector concepts for the ILC. We estimate that a statistical precision on yt of 4.5 % can be obtained with an integrated luminosity of 1 ab-1 that is split equally between two configurations for the beam polarization P(e-,e+), (-80 %,+20 %) and (+80 %,-20 %). This estimate improvesmore » to 4 % if the 1 ab-1 sample is assumed to be fully in the P(e-,e+)=(-80 %,+20 %) configuration.« less
Textures of Yukawa coupling matrices in the 2HDM type III
Carcamo, A. E.; Martinez, R.; Rodriguez, J.-Alexis
2008-07-02
The quark mass matrices ansatze proposed by Fritzsch, Du-Xing and Fukuyama-Nishiura in the framework of the general two Higgs doublet model are studied. The corresponding Cabbibo-Kobayashi-Maskawa matrix elements are computed in all cases and compared with their experimental values. The complex phases of the anstaze are taken into account and the CP violating phase {delta} is computed. Finally some phenomenology is discussed.
Determination of the quark coupling strength |Vub| using baryonic decays
NASA Astrophysics Data System (ADS)
LHCb Collaboration; Aaij, R.; Adeva, B.; Adinolfi, M.; Affolder, A.; Ajaltouni, Z.; Akar, S.; Albrecht, J.; Alessio, F.; Alexander, M.; Ali, S.; Alkhazov, G.; Cartelle, P. Alvarez; Alves, A. A., Jr.; Amato, S.; Amerio, S.; Amhis, Y.; An, L.; Anderlini, L.; Anderson, J.; Andreotti, M.; Andrews, J. E.; Appleby, R. B.; Gutierrez, O. Aquines; Archilli, F.; Artamonov, A.; Artuso, M.; Aslanides, E.; Auriemma, G.; Baalouch, M.; Bachmann, S.; Back, J. J.; Badalov, A.; Baesso, C.; Baldini, W.; Barlow, R. J.; Barschel, C.; Barsuk, S.; Barter, W.; Batozskaya, V.; Battista, V.; Bay, A.; Beaucourt, L.; Beddow, J.; Bedeschi, F.; Bediaga, I.; Bel, L. J.; Belyaev, I.; Ben-Haim, E.; Bencivenni, G.; Benson, S.; Benton, J.; Berezhnoy, A.; Bernet, R.; Bertolin, A.; Bettler, M.-O.; van Beuzekom, M.; Bien, A.; Bifani, S.; Bird, T.; Birnkraut, A.; Bizzeti, A.; Blake, T.; Blanc, F.; Blouw, J.; Blusk, S.; Bocci, V.; Bondar, A.; Bondar, N.; Bonivento, W.; Borghi, S.; Borsato, M.; Bowcock, T. J. V.; Bowen, E.; Bozzi, C.; Braun, S.; Brett, D.; Britsch, M.; Britton, T.; Brodzicka, J.; Brook, N. H.; Bursche, A.; Buytaert, J.; Cadeddu, S.; Calabrese, R.; Calvi, M.; Calvo Gomez, M.; Campana, P.; Campora Perez, D.; Capriotti, L.; Carbone, A.; Carboni, G.; Cardinale, R.; Cardini, A.; Carniti, P.; Carson, L.; Akiba, K. Carvalho; Mohr, R. Casanova; Casse, G.; Cassina, L.; Garcia, L. Castillo; Cattaneo, M.; Cauet, Ch.; Cavallero, G.; Cenci, R.; Charles, M.; Charpentier, Ph.; Chefdeville, M.; Chen, S.; Cheung, S.-F.; Chiapolini, N.; Chrzaszcz, M.; Vidal, X. Cid; Ciezarek, G.; Clarke, P. E. L.; Clemencic, M.; Cliff, H. V.; Closier, J.; Coco, V.; Cogan, J.; Cogneras, E.; Cogoni, V.; Cojocariu, L.; Collazuol, G.; Collins, P.; Comerma-Montells, A.; Contu, A.; Cook, A.; Coombes, M.; Coquereau, S.; Corti, G.; Corvo, M.; Couturier, B.; Cowan, G. A.; Craik, D. C.; Crocombe, A.; Torres, M. Cruz; Cunliffe, S.; Currie, R.; D'Ambrosio, C.; Dalseno, J.; David, P. N. Y.; Davis, A.; de Bruyn, K.; de Capua, S.; de Cian, M.; de Miranda, J. M.; de Paula, L.; de Silva, W.; de Simone, P.; Dean, C.-T.; Decamp, D.; Deckenhoff, M.; Del Buono, L.; Déléage, N.; Derkach, D.; Deschamps, O.; Dettori, F.; Dey, B.; di Canto, A.; di Ruscio, F.; Dijkstra, H.; Donleavy, S.; Dordei, F.; Dorigo, M.; Suárez, A. Dosil; Dossett, D.; Dovbnya, A.; Dreimanis, K.; Dufour, L.; Dujany, G.; Dupertuis, F.; Durante, P.; Dzhelyadin, R.; Dziurda, A.; Dzyuba, A.; Easo, S.; Egede, U.; Egorychev, V.; Eidelman, S.; Eisenhardt, S.; Eitschberger, U.; Ekelhof, R.; Eklund, L.; El Rifai, I.; Elsasser, Ch.; Ely, S.; Esen, S.; Evans, H. M.; Evans, T.; Falabella, A.; Färber, C.; Farinelli, C.; Farley, N.; Farry, S.; Fay, R.; Ferguson, D.; Albor, V. Fernandez; Ferrari, F.; Rodrigues, F. Ferreira; Ferro-Luzzi, M.; Filippov, S.; Fiore, M.; Fiorini, M.; Firlej, M.; Fitzpatrick, C.; Fiutowski, T.; Fol, P.; Fontana, M.; Fontanelli, F.; Forty, R.; Francisco, O.; Frank, M.; Frei, C.; Frosini, M.; Fu, J.; Furfaro, E.; Gallas Torreira, A.; Galli, D.; Gallorini, S.; Gambetta, S.; Gandelman, M.; Gandini, P.; Gao, Y.; Pardiñas, J. García; Garofoli, J.; Garra Tico, J.; Garrido, L.; Gascon, D.; Gaspar, C.; Gastaldi, U.; Gauld, R.; Gavardi, L.; Gazzoni, G.; Geraci, A.; Gerick, D.; Gersabeck, E.; Gersabeck, M.; Gershon, T.; Ghez, Ph.; Gianelle, A.; Gianì, S.; Gibson, V.; Giubega, L.; Gligorov, V. V.; Göbel, C.; Golubkov, D.; Golutvin, A.; Gomes, A.; Gotti, C.; Gándara, M. Grabalosa; Diaz, R. Graciani; Granado Cardoso, L. A.; Graugés, E.; Graverini, E.; Graziani, G.; Grecu, A.; Greening, E.; Gregson, S.; Griffith, P.; Grillo, L.; Grünberg, O.; Gui, B.; Gushchin, E.; Guz, Yu.; Gys, T.; Hadjivasiliou, C.; Haefeli, G.; Haen, C.; Haines, S. C.; Hall, S.; Hamilton, B.; Hampson, T.; Han, X.; Hansmann-Menzemer, S.; Harnew, N.; Harnew, S. T.; Harrison, J.; He, J.; Head, T.; Heijne, V.; Hennessy, K.; Henrard, P.; Henry, L.; Morata, J. A. Hernando; van Herwijnen, E.; Heß, M.; Hicheur, A.; Hill, D.; Hoballah, M.; Hombach, C.; Hulsbergen, W.; Humair, T.; Hussain, N.; Hutchcroft, D.; Hynds, D.; Idzik, M.; Ilten, P.; Jacobsson, R.; Jaeger, A.; Jalocha, J.; Jans, E.; Jawahery, A.; Jing, F.; John, M.; Johnson, D.; Jones, C. R.; Joram, C.; Jost, B.; Jurik, N.; Kandybei, S.; Kanso, W.; Karacson, M.; Karbach, T. M.; Karodia, S.; Kelsey, M.; Kenyon, I. R.; Kenzie, M.; Ketel, T.; Khanji, B.; Khurewathanakul, C.; Klaver, S.; Klimaszewski, K.; Kochebina, O.; Kolpin, M.; Komarov, I.; Koopman, R. F.; Koppenburg, P.; Korolev, M.; Kravchuk, L.; Kreplin, K.; Kreps, M.; Krocker, G.; Krokovny, P.; Kruse, F.; Kucewicz, W.; Kucharczyk, M.; Kudryavtsev, V.; Kurek, K.; Kvaratskheliya, T.; La Thi, V. N.; Lacarrere, D.; Lafferty, G.; Lai, A.; Lambert, D.; Lambert, R. W.; Lanfranchi, G.; Langenbruch, C.; Langhans, B.; Latham, T.; Lazzeroni, C.; Le Gac, R.; van Leerdam, J.; Lees, J.-P.; Lefèvre, R.; Leflat, A.; Lefrançois, J.; Leroy, O.; Lesiak, T.; Leverington, B.; Li, Y.; Likhomanenko, T.; Liles, M.; Lindner, R.; Linn, C.; Lionetto, F.; Liu, B.; Lohn, S.; Longstaff, I.; Lopes, J. H.; Lowdon, P.; Lucchesi, D.; Luo, H.; Lupato, A.; Luppi, E.; Lupton, O.; Machefert, F.; Maciuc, F.; Maev, O.; Maguire, K.; Malde, S.; Malinin, A.; Manca, G.; Mancinelli, G.; Manning, P.; Mapelli, A.; Maratas, J.; Marchand, J. F.; Marconi, U.; Benito, C. Marin; Marino, P.; Märki, R.; Marks, J.; Martellotti, G.; Martinelli, M.; Santos, D. Martinez; Vidal, F. Martinez; Tostes, D. Martins; Massafferri, A.; Matev, R.; Mathad, A.; Mathe, Z.; Matteuzzi, C.; Mauri, A.; Maurin, B.; Mazurov, A.; McCann, M.; McCarthy, J.; McNab, A.; McNulty, R.; Meadows, B.; Meier, F.; Meissner, M.; Merk, M.; Milanes, D. A.; Minard, M.-N.; Mitzel, D. S.; Rodriguez, J. Molina; Monteil, S.; Morandin, M.; Morawski, P.; Mordà, A.; Morello, M. J.; Moron, J.; Morris, A.-B.; Mountain, R.; Muheim, F.; Müller, J.; Müller, K.; Müller, V.; Mussini, M.; Muster, B.; Naik, P.; Nakada, T.; Nandakumar, R.; Nasteva, I.; Needham, M.; Neri, N.; Neubert, S.; Neufeld, N.; Neuner, M.; Nguyen, A. D.; Nguyen, T. D.; Nguyen-Mau, C.; Niess, V.; Niet, R.; Nikitin, N.; Nikodem, T.; Ninci, D.; Novoselov, A.; O'Hanlon, D. P.; Oblakowska-Mucha, A.; Obraztsov, V.; Ogilvy, S.; Okhrimenko, O.; Oldeman, R.; Onderwater, C. J. G.; Rodrigues, B. Osorio; Goicochea, J. M. Otalora; Otto, A.; Owen, P.; Oyanguren, A.; Palano, A.; Palombo, F.; Palutan, M.; Panman, J.; Papanestis, A.; Pappagallo, M.; Pappalardo, L. L.; Parkes, C.; Passaleva, G.; Patel, G. D.; Patel, M.; Patrignani, C.; Pearce, A.; Pellegrino, A.; Penso, G.; Altarelli, M. Pepe; Perazzini, S.; Perret, P.; Pescatore, L.; Petridis, K.; Petrolini, A.; Petruzzo, M.; Olloqui, E. Picatoste; Pietrzyk, B.; Pilař, T.; Pinci, D.; Pistone, A.; Playfer, S.; Casasus, M. Plo; Poikela, T.; Polci, F.; Poluektov, A.; Polyakov, I.; Polycarpo, E.; Popov, A.; Popov, D.; Popovici, B.; Potterat, C.; Price, E.; Price, J. D.; Prisciandaro, J.; Pritchard, A.; Prouve, C.; Pugatch, V.; Navarro, A. Puig; Punzi, G.; Qian, W.; Quagliani, R.; Rachwal, B.; Rademacker, J. H.; Rakotomiaramanana, B.; Rama, M.; Rangel, M. S.; Raniuk, I.; Rauschmayr, N.; Raven, G.; Redi, F.; Reichert, S.; Reid, M. M.; Dos Reis, A. C.; Ricciardi, S.; Richards, S.; Rihl, M.; Rinnert, K.; Molina, V. Rives; Robbe, P.; Rodrigues, A. B.; Rodrigues, E.; Lopez, J. A. Rodriguez; Perez, P. Rodriguez; Roiser, S.; Romanovsky, V.; Vidal, A. Romero; Rotondo, M.; Rouvinet, J.; Ruf, T.; Ruiz, H.; Valls, P. Ruiz; Saborido Silva, J. J.; Sagidova, N.; Sail, P.; Saitta, B.; Guimaraes, V. Salustino; Mayordomo, C. Sanchez; Sedes, B. Sanmartin; Santacesaria, R.; Rios, C. Santamarina; Santimaria, M.; Santovetti, E.; Sarti, A.; Satriano, C.; Satta, A.; Saunders, D. M.; Savrina, D.; Schiller, M.; Schindler, H.; Schlupp, M.; Schmelling, M.; Schmelzer, T.; Schmidt, B.; Schneider, O.; Schopper, A.; Schune, M.-H.; Schwemmer, R.; Sciascia, B.; Sciubba, A.; Semennikov, A.; Sepp, I.; Serra, N.; Serrano, J.; Sestini, L.; Seyfert, P.; Shapkin, M.; Shapoval, I.; Shcheglov, Y.; Shears, T.; Shekhtman, L.; Shevchenko, V.; Shires, A.; Coutinho, R. Silva; Simi, G.; Sirendi, M.; Skidmore, N.; Skillicorn, I.; Skwarnicki, T.; Smith, E.; Smith, E.; Smith, J.; Smith, M.; Snoek, H.; Sokoloff, M. D.; Soler, F. J. P.; Soomro, F.; Souza, D.; Souza de Paula, B.; Spaan, B.; Spradlin, P.; Sridharan, S.; Stagni, F.; Stahl, M.; Stahl, S.; Steinkamp, O.; Stenyakin, O.; Sterpka, F.; Stevenson, S.; Stoica, S.; Stone, S.; Storaci, B.; Stracka, S.; Straticiuc, M.; Straumann, U.; Stroili, R.; Sun, L.; Sutcliffe, W.; Swientek, K.; Swientek, S.; Syropoulos, V.; Szczekowski, M.; Szczypka, P.; Szumlak, T.; T'Jampens, S.; Tekampe, T.; Teklishyn, M.; Tellarini, G.; Teubert, F.; Thomas, C.; Thomas, E.; van Tilburg, J.; Tisserand, V.; Tobin, M.; Todd, J.; Tolk, S.; Tomassetti, L.; Tonelli, D.; Topp-Joergensen, S.; Torr, N.; Tournefier, E.; Tourneur, S.; Trabelsi, K.; Tran, M. T.; Tresch, M.; Trisovic, A.; Tsaregorodtsev, A.; Tsopelas, P.; Tuning, N.; Ukleja, A.; Ustyuzhanin, A.; Uwer, U.; Vacca, C.; Vagnoni, V.; Valenti, G.; Vallier, A.; Gomez, R. Vazquez; Regueiro, P. Vazquez; Sierra, C. Vázquez; Vecchi, S.; Velthuis, J. J.; Veltri, M.; Veneziano, G.; Vesterinen, M.; Barbosa, J. V. Viana; Viaud, B.; Vieira, D.; Diaz, M. Vieites; Vilasis-Cardona, X.; Vollhardt, A.; Volyanskyy, D.; Voong, D.; Vorobyev, A.; Vorobyev, V.; Voß, C.; de Vries, J. A.; Waldi, R.; Wallace, C.; Wallace, R.; Walsh, J.; Wandernoth, S.; Wang, J.; Ward, D. R.; Watson, N. K.; Websdale, D.; Weiden, A.; Whitehead, M.; Wiedner, D.; Wilkinson, G.; Wilkinson, M.; Williams, M.; Williams, M. P.; Williams, M.; Wilson, F. F.; Wimberley, J.; Wishahi, J.; Wislicki, W.; Witek, M.; Wormser, G.; Wotton, S. A.; Wright, S.; Wyllie, K.; Xie, Y.; Xu, Z.; Yang, Z.; Yuan, X.; Yushchenko, O.; Zangoli, M.; Zavertyaev, M.; Zhang, L.; Zhang, Y.; Zhelezov, A.; Zhokhov, A.; Zhong, L.
2015-09-01
In the Standard Model of particle physics, the strength of the couplings of the b quark to the u and c quarks, |Vub| and |Vcb|, are governed by the coupling of the quarks to the Higgs boson. Using data from the LHCb experiment at the Large Hadron Collider, the probability for the Λb0 baryon to decay into the p final state relative to the final state is measured. Combined with theoretical calculations of the strong interaction and a previously measured value of |Vcb|, the first |Vub| measurement to use a baryonic decay is performed. This measurement is consistent with previous determinations of |Vub| using B meson decays to specific final states and confirms the existing incompatibility with those using an inclusive sample of final states.
Quark-meson coupling model with the cloudy bag
Nagai, S.; Miyatsu, T.; Saito, Kenji; Tsushima, Kazuo
2008-07-01
Using the volume coupling version of the cloudy bag model, the quark-meson coupling model is extended to study the role of pion field and the properties of nuclear matter. The extended model includes the effect of gluon exchange as well as the pion-cloud effect, and provides a good description of the nuclear matter properties. The relationship between the extended model and the EFT approach to nuclear matter is also discussed.
NASA Astrophysics Data System (ADS)
Hollik, Wolfgang Gregor
2016-01-01
Testing the stability of the electroweak vacuum in any extension of the Standard Model Higgs sector is of great importance to verify the consistency of the theory. Multi-scalar extensions as the Minimal Supersymmetric Standard Model generically lead to unstable configurations in certain regions of parameter space. An exact minimization of the scalar potential is rather an impossible analytic task. To give handy analytic constraints, a specific direction in field space has to be considered which is a simplification that tends to miss excluded regions, however good to quickly check parameter points. We describe a yet undescribed class of charge and color breaking minima as they appear in the Minimal Supersymmetric Standard Model, exemplarily for the case of non-vanishing bottom squark vacuum expectation values constraining the combination μYb in a non-trivial way. Contrary to famous A-parameter bounds, we relate the bottom Yukawa coupling with the supersymmetry breaking masses. Another bound can be found relating soft breaking masses and μ only. The exclusions follow from the tree-level minimization and can change dramatically using the one-loop potential. Estimates of the lifetime of unstable configurations show that they are either extremely short- or long-lived.
Light colored scalar as messenger of up-quark flavor dynamics in grand unified theories
Dorsner, Ilja; Fajfer, Svjetlana; Kamenik, Jernej F.; Kosnik, Nejc
2010-11-01
The measured forward-backward asymmetry in the tt production at the Tevatron might be explained by the additional exchange of a colored weak singlet scalar. Such state appears in some of the grand unified theories, and its interactions with the up-quarks are purely antisymmetric in flavor space. We systematically investigate the resulting impact on charm and top quark physics. The constraints on the relevant Yukawa couplings come from the experimentally measured observables related to D{sup 0}-D{sup 0} oscillations, as well as dijet and single-top production measurements at the Tevatron. After fully constraining the relevant Yukawa couplings, we predict possible signatures of this model in rare top quark decays. In a class of grand unified models we demonstrate how the obtained information enables to constrain the Yukawa couplings of the up-quarks at very high energy scale.
B *B π coupling using relativistic heavy quarks
NASA Astrophysics Data System (ADS)
Flynn, J. M.; Fritzsch, P.; Kawanai, T.; Lehner, C.; Sachrajda, C. T.; Samways, B.; van de Water, R. S.; Witzel, O.; Rbc; Ukqcd Collaborations
2016-01-01
We report on a calculation of the B*B π coupling in three-flavor lattice QCD. This coupling, defined from the strong-interaction matrix element ⟨B π |B*⟩, is related to the leading order low-energy constant in heavy meson chiral perturbation theory. We carry out our calculation directly at the b -quark mass using a nonperturbatively tuned clover action that controls discretization effects of order |p →a | and (m a )n for all n . Our analysis is performed on RBC/UKQCD gauge configurations using domain-wall fermions and the Iwasaki gauge action at two lattice spacings of a-1=1.729 (25 ) GeV , a-1=2.281 (28 ) GeV , and unitary pion masses down to 290 MeV. We achieve good statistical precision and control all systematic uncertainties, giving a final result for the coupling gb=0.56 (3 )stat(7)sys in the continuum and at the physical light-quark masses. This is the first calculation performed directly at the physical b -quark mass and lies in the region one would expect from carrying out an interpolation between previous results at the charm mass and at the static point.
B*Bπ coupling using relativistic heavy quarks
Flynn, J. M.; Fritzsch, P.; Kawanai, T.; Lehner, C.; Sachrajda, C. T.; Samways, B.; Van de Water, R. S.; Witzel, O.
2016-01-27
Here, we report on a calculation of the B*Bπ coupling in three-flavor lattice QCD. This coupling, defined from the strong-interaction matrix element , is related to the leading order low-energy constant in heavy meson chiral perturbation theory. We carry out our calculation directly at the b-quark mass using a nonperturbatively tuned clover action that controls discretization effects of order |more » $$\\vec{p}$$a| and (ma)n for all n. Our analysis is performed on RBC/UKQCD gauge configurations using domain-wall fermions and the Iwasaki gauge action at two lattice spacings of a-1=1.729(25) GeV, a-1=2.281(28) GeV, and unitary pion masses down to 290 MeV. We achieve good statistical precision and control all systematic uncertainties, giving a final result for the coupling gb=0.56(3)stat(7)sys in the continuum and at the physical light-quark masses. Moreover, this is the first calculation performed directly at the physical b-quark mass and lies in the region one would expect from carrying out an interpolation between previous results at the charm mass and at the static point.« less
Top Quark Anomalous Couplings at the International Linear Collider
Devetak, Erik; Nomerotski, Andrei; Peskin, Michael; /SLAC
2011-08-15
We present a study of the experimental determination of the forward-backward asymmetry in the process e{sup +}e{sup -} {yields} t{bar t} and in the subsequent t {yields} Wb decay, studied in the context of the International Linear Collider. This process probes the elementary couplings of the top quark to the photon, the Z and the W bosons at a level of precision that is difficult to achieve at hadron colliders. Measurement of the forward-backward asymmetry requires excellent b quark identification and determination of the quark charge. The study reported here is performed in the most challenging all-hadronic channel e{sup +}e{sup -} {yields} b{bar b}q{bar q}q{bar q}. It includes realistic details of the experimental environment, a full Monte Carlo simulation of the detector, based on the Silicon Detector concept, and realistic event reconstruction. The forward-backward asymmetries are determined to a precision of approximately 1% for each of two choices of beam polarization. We analyze the implications for the determination of the t{bar t}Z and Wt{bar b} couplings.
B*Bπ coupling using relativistic heavy quarks
Flynn, J. M.; Fritzsch, P.; Kawanai, T.; Lehner, C.; Samways, B.; Sachrajda, C. T.; Van de Water, R. S.; Witzel, O.
2016-01-27
We report on a calculation of the B*Bπ coupling in lattice QCD. The strong matrix element (Bπ|B*) is directly related to the leading order low-energy constant in heavy meson chiral perturbation theory (HMΧPT) for B mesons. We carry out our calculation directly at the b-quark mass using a non-perturbatively tuned clover action that controls discretization effects of order |p→a| and (ma)n for all n. Our analysis is performed on RBC/UKQCD gauge configurations using domain-wall fermions and the Iwasaki gauge action at two lattice spacings of a–1 = 1.729(25) GeV, a–1 = 2.281 (28) GeV, and unitary pion masses down tomore » 290 MeV. We achieve good statistical precision and control all systematic uncertainties, giving a final result for the HMΧPT coupling gb = 0.56(3)stat(7)sys in the continuum and at the physical light-quark masses. Furthermore, this is the first calculation performed directly at the physical b-quark mass and lies in the region one would expect from carrying out an interpolation between previous results at the charm mass and at the static point.« less
The B*Bπ coupling using relativistic heavy quarks
Flynn, J. M.; Fritzsch, P.; Kawanai, T.; Lehner, C.; Samways, B.; Sachrajda, C. T.; Van de Water, R. S.; Witzel, O.
2015-06-23
We report on a calculation of the B*Bπ coupling in lattice QCD. The strong matrix element (Bπ|B*) is directly related to the leading order low-energy constant in heavy meson chiral perturbation theory (HM_{Χ}PT) for B mesons. We carry out our calculation directly at the b-quark mass using a non-perturbatively tuned clover action that controls discretization effects of order |p^{→}a| and (ma)^{n} for all n. Our analysis is performed on RBC/UKQCD gauge configurations using domain-wall fermions and the Iwasaki gauge action at two lattice spacings of a^{–1} = 1.729(25) GeV, a^{–1} = 2.281 (28) GeV, and unitary pion masses down to 290 MeV. We achieve good statistical precision and control all systematic uncertainties, giving a final result for the HM_{Χ}PT coupling g_{b} = 0.56(3)_{stat}(7)_{sys} in the continuum and at the physical light-quark masses. Furthermore, this is the first calculation performed directly at the physical b-quark mass and lies in the region one would expect from carrying out an interpolation between previous results at the charm mass and at the static point.
Quantum simulations of strongly coupled quark-gluon plasma
Filinov, V. S.; Ivanov, Yu. B.; Bonitz, M.; Levashov, P. R.; Fortov, V. E.
2011-09-15
A strongly coupled quark-gluon plasma (QGP) of heavy constituent quasiparticles is studied by a path-integral Monte-Carlo method. This approach is a quantum generalization of the model developed by B.A. Gelman, E.V. Shuryak, and I. Zahed. It is shown that this method is able to reproduce the QCD lattice equation of state and also yields valuable insight into the internal structure of the QGP. The results indicate that the QGP reveals liquid-like rather than gas-like properties. At temperatures just above the critical one it was found that bound quark-antiquark states still survive. These states are bound by effective string-like forces and turn out to be colorless. At the temperature as large as twice the critical one no bound states are observed. Quantum effects turned out to be of prime importance in these simulations.
Yukawa unification: The good, the bad, and the ugly
Rattazzi, R.; Sarid, U.; Hall, L.J.
1993-05-01
We analyze some consequences of grand unification of the third-generation Yukawa couplings, in the context of the minimal supersymmetric standard model. We address two issues: the prediction of the top quark mass, and the generation of the top-bottom mass hierarchy through a hierarchy of Higgs vacuum expectation values. The top mass is strongly dependent on a certain ratio of superpartner masses. And the VEV hierarchy always entails some tuning of the GUT-scale parameters. We study the RG equations and their semi-analytic solutions, which exhibit several interesting features, such as a focusing effect for a large Yukawa coupling in the limit of certain symmetries and a correlation between the A terms (which contribute to b {yields} s{gamma}) and the gaugino masses. This study shows that non-universal soft-SUSY-breaking masses are favored (in particular for splitting the Higgs-doublets via D-terms and for allowing more natural scenarios of symmetry breaking), and hints at features desired in Yukawa-unified models. Several phenomenological implications are also revealed.
Warm stellar matter within the quark-meson-coupling model
NASA Astrophysics Data System (ADS)
Panda, P. K.; Providência, C.; Menezes, D. P.
2010-10-01
In the present article, we investigate stellar matter obtained within the quark-meson-coupling (QMC) model for fixed temperature and with the entropy of the order of 1 or 2 Boltzmann units per baryon for neutrino-free matter and matter with trapped neutrinos. A new prescription for the calculation of the baryon effective masses in terms of the free energy is used. Comparing the results of the present work with those obtained from the nonlinear Walecka model, smaller strangeness and neutrino fractions are predicted within QMC. As a consequence, QMC has a smaller window of metastability for conversion into a low-mass blackhole during cooling.
Warm stellar matter within the quark-meson-coupling model
Panda, P. K.; Providencia, C.; Menezes, D. P.
2010-10-15
In the present article, we investigate stellar matter obtained within the quark-meson-coupling (QMC) model for fixed temperature and with the entropy of the order of 1 or 2 Boltzmann units per baryon for neutrino-free matter and matter with trapped neutrinos. A new prescription for the calculation of the baryon effective masses in terms of the free energy is used. Comparing the results of the present work with those obtained from the nonlinear Walecka model, smaller strangeness and neutrino fractions are predicted within QMC. As a consequence, QMC has a smaller window of metastability for conversion into a low-mass blackhole during cooling.
Hypernuclei in the quark-meson coupling model
K. Tsushima, P. A. M. Guichon
2010-07-01
We present results of hypernuclei calculated in the latest quark-meson coupling (QMC) model, where the effect of the mean scalar field in-medium on the one-gluon exchange hyperfine interaction, is also included self-consistently. The extra repulsion associated with this increased hyperfine interaction in-medium completely changes the predictions for {\\Sigma} hypernuclei. Whereas in the earlier version of QMC they were bound by an amount similar to {\\Lambda} hypernuclei, they are unbound in the latest version of QMC, in qualitative agreement with the experimental absence of such states.
Ahmadov, A.; Azuelos, G.; Bauer, U.; Belyaev, A.; Berger, E. L.; Sullivan, Z.; Tait, T. M. P.
2000-03-24
The top quark, when it was finally discovered at Fermilab in 1995 completed the three-generation structure of the Standard Model (SM) and opened up the new field of top quark physics. Viewed as just another SM quark, the top quark appears to be a rather uninteresting species. Produced predominantly, in hadron-hadron collisions, through strong interactions, it decays rapidly without forming hadrons, and almost exclusively through the single mode t {r_arrow} Wb. The relevant CKM coupling V{sub tb} is already determined by the (three-generation) unitarity of the CKM matrix. Rare decays and CP violation are unmeasurable small in the SM. Yet the top quark is distinguished by its large mass, about 35 times larger than the mass of the next heavy quark, and intriguingly close to the scale of electroweak (EW) symmetry breaking. This unique property raises a number of interesting questions. Is the top quark mass generated by the Higgs mechanism as the SM predicts and is its mass related to the top-Higgs-Yukawa coupling? Or does it play an even more fundamental role in the EW symmetry breaking mechanism? If there are new particles lighter than the top quark, does the top quark decay into them? Could non-SM physics first manifest itself in non-standard couplings of the top quark which show up as anomalies in top quark production and decays? Top quark physics tries to answer these questions. Several properties of the top quark have already been examined at the Tevatron. These include studies of the kinematical properties of top production, the measurements of the top mass, of the top production cross-section, the reconstruction of t{bar t}pairs in the fully hadronic final states, the study of {tau} decays of the top quark, the reconstruction of hadronic decays of the W boson from top decays, the search for flavor changing neutral current decays, the measurement of the W helicity in top decays, and bounds on t{bar t} spin correlations. Most of these measurements are limited by
Quark spectral density and a strongly-coupled quark-gluon plasma.
Qin, S.; Chang, L.; Liu, Y.; Roberts, C. D.
2011-07-13
The maximum entropy method is used to compute the dressed-quark spectral density from the self-consistent numerical solution of a rainbow truncation of QCD's gap equation at temperatures above that for which chiral symmetry is restored. In addition to the normal and plasmino modes, the spectral function also exhibits an essentially nonperturbative zero mode for temperatures extending to 1.4-1.8 times the critical temperature, T{sub c}. In the neighborhood of T{sub c}, this long-wavelength mode contains the bulk of the spectral strength and as long as this mode persists, the system may fairly be described as a strongly-coupled state of matter.
Finite Nuclei in the Quark-Meson Coupling Model
NASA Astrophysics Data System (ADS)
Stone, J. R.; Guichon, P. A. M.; Reinhard, P. G.; Thomas, A. W.
2016-03-01
We report the first use of the effective quark-meson coupling (QMC) energy density functional (EDF), derived from a quark model of hadron structure, to study a broad range of ground state properties of even-even nuclei across the periodic table in the nonrelativistic Hartree-Fock+BCS framework. The novelty of the QMC model is that the nuclear medium effects are treated through modification of the internal structure of the nucleon. The density dependence is microscopically derived and the spin-orbit term arises naturally. The QMC EDF depends on a single set of four adjustable parameters having a clear physics basis. When applied to diverse ground state data the QMC EDF already produces, in its present simple form, overall agreement with experiment of a quality comparable to a representative Skyrme EDF. There exist, however, multiple Skyrme parameter sets, frequently tailored to describe selected nuclear phenomena. The QMC EDF set of fewer parameters, derived in this work, is not open to such variation, chosen set being applied, without adjustment, to both the properties of finite nuclei and nuclear matter.
Finite Nuclei in the Quark-Meson Coupling Model.
Stone, J R; Guichon, P A M; Reinhard, P G; Thomas, A W
2016-03-01
We report the first use of the effective quark-meson coupling (QMC) energy density functional (EDF), derived from a quark model of hadron structure, to study a broad range of ground state properties of even-even nuclei across the periodic table in the nonrelativistic Hartree-Fock+BCS framework. The novelty of the QMC model is that the nuclear medium effects are treated through modification of the internal structure of the nucleon. The density dependence is microscopically derived and the spin-orbit term arises naturally. The QMC EDF depends on a single set of four adjustable parameters having a clear physics basis. When applied to diverse ground state data the QMC EDF already produces, in its present simple form, overall agreement with experiment of a quality comparable to a representative Skyrme EDF. There exist, however, multiple Skyrme parameter sets, frequently tailored to describe selected nuclear phenomena. The QMC EDF set of fewer parameters, derived in this work, is not open to such variation, chosen set being applied, without adjustment, to both the properties of finite nuclei and nuclear matter. PMID:26991171
Particle production within the quark meson coupling model
Panda, P. K.; Menezes, D. P.; Providencia, C.
2009-07-15
Quark-meson coupling (QMC) models can be successfully applied to the description of compact star properties in nuclear astrophysics as well as to nuclear matter. In the regime of hot hadronic matter very few calculations exist using the QMC model, in particular when applied to particle yields in heavy ion collisions. In the present work, we identify the free energy of the bag with the effective mass of the baryons and we calculate the particle production yields on a Au+Au collision at the BNL Relativistic Heavy Ion Collider (RHIC) with the QMC model and compare them with results obtained previously with other relativistic models. A smaller temperature for the fireball, T=132 MeV, is obtained because of the smaller effective baryon masses predicted by QMC. QMC was also applied to the description of particle yields at the CERN Super Proton Synchrotron (SPS) in Pb+Pb collisions.
Finite Hypernuclei in the Latest Quark-Meson Coupling Model
Pierre A. M. Guichon; Anthony W. Thomas; Kazuo Tsushima
2007-12-12
The most recent development of the quark-meson coupling (QMC) model, in which the effect of the mean scalar field in-medium on the hyperfine interaction is also included self-consistently, is used to compute the properties of finite hypernuclei. The calculations for $\\Lambda$ and $\\Xi$ hypernuclei are of comparable quality to earlier QMC results without the additional parameter needed there. Even more significantly, the additional repulsion associated with the increased hyperfine interaction in-medium completely changes the predictions for $\\Sigma$ hypernuclei. Whereas in the earlier work they were bound by an amount similar to $\\Lambda$ hypernuclei, here they are unbound, in qualitative agreement with the experimental absence of such states. The equivalent non-relativistic potential felt by the $\\Sigma$ is repulsive inside the nuclear interior and weakly attractive in the nuclear surface, as suggested by the analysis of $\\Sigma$-atoms.
NASA Astrophysics Data System (ADS)
Cvetič, G.; Kim, C. S.
We assume that the standard model (SM) breaks down around some energy Λ and is replaced there by a new (Higgsless) flavor gauge theory (FGT) with fewer input parameters in the interactions corresponding to the Yukawa sector of SM. This would imply more symmetry for the values of the Yukawa (running) parameters of SM at E Λ, possibly by a (approximate) flavor democracy (for the quark mass sector). We investigate this possibility by studying the renormalization group equations (RGE's) for the quark Yukawa couplings of SM with one and two Higgs doublets, by running them from the known physical values at low energies (E 1 GeV) to Λ (> 1 TeV) and comparing the resulting quark masses mq (E Λ) for various mt and υU/υD. Unlike previous investigations of these RGE's, we do not implement the requirement mt(Λpole) = ∞. We found that SM with two Higgs doublets (type 2) is most likely to experience a gradual transition to FGT. Our results also shed more light on the adequacy and deficiencies of the usual RGE approaches within TMSM and related models. We also found that, independent of the assumption of a transition mechanism to FGT, mt phy< ˜ 200 GeV for Λpole≪ ΛPlanck in most cases of SM with two Higgs doublets.
Yukawa sector in minimal D-brane models
NASA Astrophysics Data System (ADS)
Ennadifi, Salah Eddine
2015-07-01
We investigate the Yukawa couplings sector in the minimal gauge theory U(3) × U(2) × U(1) with the Standard Model chiral and Higgs spectrum based on three stacks of intersecting D-branes. In this model, stringy corrections are required to induce the missing Yukawa couplings and generate hierarchical pattern. Under the known data, we assign the realistic Yukawa texture and then bound their strengths.
rule, and in and models with FCNC quark couplings
NASA Astrophysics Data System (ADS)
Buras, Andrzej J.; De Fazio, Fulvia; Girrbach, Jennifer
2014-07-01
The experimental value for the isospin amplitude in decays has been successfully explained within the standard model (SM), both within the large approach to QCD and by QCD lattice calculations. On the other hand within the large approach the value of is by at least below the data. While this deficit could be the result of theoretical uncertainties in this approach and could be removed by future precise QCD lattice calculations, it cannot be excluded that the missing piece in comes from new physics (NP). We demonstrate that this deficit can be significantly softened by tree-level FCNC transitions mediated by a heavy colourless gauge boson with a flavour-violating left-handed coupling and an approximately universal flavour diagonal right-handed coupling to the quarks. The approximate flavour universality of the latter coupling assures negligible NP contributions to . This property, together with the breakdown of the GIM mechanisms at tree level, allows one to enhance significantly the contribution of the leading QCD-penguin operator to . A large fraction of the missing piece in the rule can be explained in this manner for in the reach of the LHC, while satisfying the constraints from , , , LEP-II and the LHC. The presence of a small right-handed flavour-violating coupling and of enhanced matrix elements of left-right operators allows one to satisfy simultaneously the constraints from and , although this requires some fine-tuning. We identify the quartic correlation between contributions to , , and . The tests of this proposal will require much improved evaluations of and within the SM, of as well as precise tree-level determinations of and . We present correlations between , and with and without the rule constraint and generalise the whole analysis to with colour () and with FCNC couplings. In the latter case no improvement on can be achieved without destroying the agreement of the SM with the data on . Moreover, this scenario is very tightly constrained by . On the
Quarkonium in a weakly-coupled quark-gluon plasma
Vairo, Antonio
2010-12-22
We report about a recent calculation of the heavy quarkonium mass and decay width in a quark-gluon plasma, whose temperature T and screening mass m{sub D} satisfy the hierarchy m{alpha}{sub s}>>T>>m{alpha}{sub s}{sup 2}>>m{sub D}, m being the heavy-quark mass, up to order m{alpha}{sub s}{sup 5}. The calculation may be relevant to understand the behavior of the {Upsilon}(1S) in a quark-gluon plasma at present-day colliders.
NASA Astrophysics Data System (ADS)
Pesando, Igor
2016-09-01
We consider the simplest possible setting of non-abelian twist fields which corresponds to SU (2) monodromies. We first review the theory of hypergeometric function and of the solutions of the most general Fuchsian second order equation with three singularities. Then we solve the problem of writing the general solution with prescribed U (2) monodromies. We use this result to compute the classical string solution corresponding to three D2 branes in R4. Despite the fact that the configuration is supersymmetric the classical string solution is not holomorphic. Using the equation of motion and not the KLT approach we give a very simple expression for the classical action of the string. We find that the classical action is not proportional to the area of the triangle determined by the branes intersection points since the solution is not holomorphic. Phenomenologically this means that the Yukawa couplings for these supersymmetric configurations on non-factorized tori are suppressed with respect to the factorized case.
{lambda}{sub c} Enhancement from Strongly Coupled Quark-Gluon Plasma
Lee, Su Houng; Ohnishi, Kazuaki; Yasui, Shigehiro; Yoo, In-Kwon; Ko, Che Ming
2008-06-06
We propose the enhancement of {lambda}{sub c} as a novel quark-gluon plasma signal in heavy ion collisions at the BNL Relativistic Heavy Ion Collider and the CERN Large Hadron Collider. Assuming a stable bound diquark state in the strongly coupled quark-gluon plasma near the critical temperature, we argue that the direct two-body collision between a c quark and a [ud] diquark would lead to an enhanced {lambda}{sub c} production in comparison with the normal three-body collision among independent c, u, and d quarks. In the coalescence model, we find that the {lambda}{sub c}/D yield ratio is enhanced substantially due to the diquark correlation.
Isovector channel of quark-meson-coupling model and its effect on symmetry energy
NASA Astrophysics Data System (ADS)
Wang, X. B.; Qi, C.; Xu, F. R.
2011-08-01
The non-relativistic approximation of the quark-meson-coupling model has been discussed and compared with the Skyrme-Hartree-Fock model which includes spin exchanges. Calculations show that the spin-exchange interaction has important effect on the descriptions of finite nuclei and nuclear matter through the Fock exchange. Also in the quark-meson-coupling model, it is the Fock exchange that leads to a nonlinear density-dependent isovector channel and changes the density-dependent behavior of the symmetry energy.
Vectorlike W± -boson coupling at TeV and third family fermion masses
NASA Astrophysics Data System (ADS)
Xue, She-Sheng
2016-04-01
In the third fermion family and gauge symmetry of the Standard Model, we study the quark-quark, lepton-lepton and quark-lepton four-fermion operators in an effective theory at high energies. These operators have nontrivial contributions to the Schwinger-Dyson equations for fermion self-energy functions and the W±-boson coupling vertex. As a result, the top-quark mass is generated via the spontaneous symmetry breaking of ⟨t ¯t ⟩-condensate and the W±-boson coupling becomes approximately vectorlike at TeV scale. The bottom-quark, tau-lepton and tau-neutrino masses are generated via the explicit symmetry breaking of W±-contributions and quark-lepton interactions. Their masses and Yukawa couplings are functions of the top-quark mass and Yukawa coupling. We qualitatively show the hierarchy of fermion masses and Yukawa couplings of the third fermion family. We also discuss the possible collider signatures due to the vectorlike (parity-restoration) feature of W±-boson coupling at high energies.
Heavy quark diffusion in strong magnetic fields at weak coupling and implications for elliptic flow
Fukushima, Kenji; Hattori, Koichi; Yee, Ho -Ung; Yin, Yi
2016-04-20
In this paper, we compute the momentum diffusion coefficients of heavy quarks, κ∥ and κ⊥, in a strong magnetic field B along the directions parallel and perpendicular to B, respectively, at the leading order in QCD coupling constant αs. We consider a regime relevant for the relativistic heavy ion collisions, αseB << T2 << eB, so that thermal excitations of light quarks are restricted to the lowest Landau level (LLL) states. In the vanishing light-quark mass limit, we find κLO⊥ ∝ α2sTeB in the leading order that arises from screened Coulomb scatterings with (1+1)-dimensional LLL quarks, while κ∥ gets nomore » contribution from the scatterings with LLL quarks due to kinematic restrictions. We show that the first nonzero leading order contributions to κLO∥ come from the two separate effects: 1) the screened Coulomb scatterings with thermal gluons, and 2) a finite light-quark mass mq. The former leads to κLO,gluon∥ ∝ α2sT3 and the latter to κLO,massive∥ ∝ αs(αseB)1/2m2q. Based on our results, we propose a new scenario for the large value of heavy-quark elliptic flow observed in RHIC and LHC. Namely, when κ⊥ >> κ∥, an anisotropy in drag forces gives rise to a sizable amount of the heavy-quark elliptic flow even if heavy quarks do not fully belong to an ellipsoidally expanding background fluid.« less
Heavy quark diffusion in strong magnetic fields at weak coupling and implications for elliptic flow
NASA Astrophysics Data System (ADS)
Fukushima, Kenji; Hattori, Koichi; Yee, Ho-Ung; Yin, Yi
2016-04-01
We compute the momentum diffusion coefficients of heavy quarks, κ∥ and κ⊥ , in a strong magnetic field B along the directions parallel and perpendicular to B , respectively, at the leading order in QCD coupling constant αs . We consider a regime relevant for the relativistic heavy ion collisions, αse B ≪T2≪e B , so that thermal excitations of light quarks are restricted to the lowest Landau level (LLL) states. In the vanishing light-quark mass limit, we find κ⊥LO∝αs2T e B in the leading order that arises from screened Coulomb scatterings with (1 +1 )-dimensional LLL quarks, while κ∥ gets no contribution from the scatterings with LLL quarks due to kinematic restrictions. We show that the first nonzero leading order contributions to κ∥LO come from the two separate effects: (1) the screened Coulomb scatterings with thermal gluons, and (2) a finite light-quark mass mq . The former leads to κ∥LO ,gluon∝αs2T3 and the latter to κ∥LO ,massive∝αs(αse B )1 /2mq2 . Based on our results, we propose a new scenario for the large value of heavy-quark elliptic flow observed in RHIC and LHC. Namely, when κ⊥≫κ∥, an anisotropy in drag forces gives rise to a sizable amount of the heavy-quark elliptic flow even if heavy quarks do not fully belong to an ellipsoidally expanding background fluid.
Yukawa unification predictions for the LHC
NASA Astrophysics Data System (ADS)
Anandakrishnan, Archana; Raby, Stuart; Wingerter, Akın
2013-03-01
This paper is divided into two parts. In the first part we analyze the consequences, for the LHC, of gauge and third-family Yukawa coupling unification with a particular set of boundary conditions defined at the grand unification scale. We perform a global χ2 analysis including the observables MW, MZ, GF, αem-1, αs(MZ), Mt, mb(mb), Mτ, BR(B→Xsγ), BR(Bs→μ+μ-), and Mh. The fit is performed in the minimal supersymmetric Standard Model in terms of nine grand unification-scale parameters, while tanβ and μ are fixed at the weak scale. Good fits suggest an upper bound on the gluino mass, Mg˜≲2TeV. This constraint comes predominantly from fitting the bottom-quark and Higgs masses (assuming a 125 GeV Higgs). Gluinos should be visible at the LHC in the 14 TeV run but they cannot be described by the typical simplified models. This is because the branching ratios for g˜→tt¯χ˜1,20, bb¯χ˜1,20, tb¯χ˜1,2-, bt¯χ˜1,2+, gχ˜1,2,3,40 are comparable. Top squarks and sbottoms may also be visible. Charginos and neutralinos can be light, with the lightest supersymmetric particle predominantly bino-like. In the second part of the paper we analyze a complete three-family model and discuss the quality of the global χ2 fits and the differences between the third-family analysis and the full three-family analysis for overlapping observables. We note that the light Higgs in our model couples to matter like the Standard Model Higgs. Any deviation from this would rule out this model.
Constraints on anomalous top quark couplings at the LHC
Rizzo, T.G.
1996-09-01
Measurements of distributions associated with the pair production of top quarks at the LHC can be used to constrain (or observe) the anomalous chromomagnetic dipole moment(k) of the top. For example, using either the tt(bar) invariant mass or the Pt distribution of top we find that sensitivities to ; k; of order 0.05 are obtainable with 100 /fb of integrated luminosity. This is similar in magnitude to what can be obtained at a 500 GeV NLC with an integrated luminosity of 50 /fb through an examination of the e(+)e(-) right arrow tt(bar)g process.
Ion sphere model for Yukawa systems (dusty plasmas)
NASA Astrophysics Data System (ADS)
Khrapak, S. A.; Khrapak, A. G.; Ivlev, A. V.; Thomas, H. M.
2014-12-01
Application of the ion sphere model (ISM), well known in the context of the one-component-plasma, to estimate thermodynamic properties of model Yukawa systems is discussed. It is shown that the ISM approximation provides fairly good estimate of the internal energy of the strongly coupled Yukawa systems, in both fluid and solid phases. Simple expressions for the excess pressure and isothermal compressibility are derived, which can be particularly useful in connection to wave phenomena in strongly coupled dusty plasmas. It is also shown that in the regime of strong screening a simple consideration of neighboring particles interactions can be sufficient to obtain quite accurate estimates of thermodynamic properties of Yukawa systems.
Massive quark scattering at strong coupling from AdS/CFT
Barnes, Edwin; Vaman, Diana
2010-06-15
We extend the analysis of Alday and Maldacena for obtaining gluon scattering amplitudes at strong coupling to include external massive quark states. Our quarks are actually the N=2 hypermultiplets which arise when D7-brane probes are included in the AdS{sub 5}xS{sup 5} geometry. We work in the quenched approximation, treating the N=2 matter multiplets as external sources coupled to the N=4 supersymmetric Yang-Mills fields. We first derive appropriate massive-particle boundary conditions for the string scattering world sheets. We then find an exact world sheet which corresponds to the scattering of two massive quarks and two massless gluons and extract from this the associated scattering amplitude. We also find the world sheet and amplitude for the scattering of four massive quarks. Our world sheet solutions reduce to the four massless gluon solution of Alday and Maldacena in the limit of zero quark mass. The amplitudes we compute can also be interpreted in terms of 2-2 scattering involving gluons and massive W bosons.
Duck, I. )
1993-04-01
Second-order radiative corrections to the nucleon axial vector coupling constant from gluon, pion, and sigma meson exchange are calculated in the chiral soliton quark model. Many apparent processes are found not to contribute. The soliton is elastically decoupled from meson radiative corrections which are dominated by a gluon exchange contribution equivalent to a gluonic hybrid component of the nucleon. A 30% radiative reduction of the axial coupling strength is indicated.
Quark CP-phase and Froggatt-Nielsen mechanism
NASA Astrophysics Data System (ADS)
Hattori, Chuichiro; Matsuda, Masahisa; Matsunaga, Mamoru; Matsuoka, Takeo
2016-08-01
On the basis of the Froggatt-Nielsen mechanism, we study quark flavor mixings in the SU (6) × SU (2)R model. The characteristic structure of the CKM matrix is attributed to the hierarchical effective Yukawa couplings due to the Froggatt-Nielsen mechanism and also to the state-mixings beyond the MSSM. We elucidate the detailed form of the CKM matrix elements and find interesting relations between the CP violating phase and three mixing angles. Taking the existing data of three mixing angles, we estimate the quark CP-phase at δ = (75 ± 3) °. This result is in accord with observations.
NASA Astrophysics Data System (ADS)
Sato, Humitaka
2008-06-01
Life history of Hideki Yukawa is described, together with that of Sin-itiro Tomonaga. They grew upiin Kyoto city and were classmate. Their independency and collaboration had contributed to the growth of physics research in Japan after the end of WWII.
Energy Loss of Heavy Quarks in a QGP with a Running Coupling Constant Approach
NASA Astrophysics Data System (ADS)
Gossiaux, P. B.; Aichelin, J.
2009-11-01
We show that the effective running coupling constant, α, and the effective regulator, κm˜D2, which we used recently to calculate the energy loss, dEdx, and the elliptic flow, v, of heavy quarks in an expanding quark gluon plasma plasma (QGP) [P. B. Gossiaux and J. Aichelin, Phys. Rev. C78, 014904 (2008), [arXiv:0802.2525], P. B. Gossiaux and J. Aichelin, J. Phys. G36 (2009) 064028, [arXiv:0901.2462], P. B. Gossiaux, R. Bierkandt and J. Aichelin, Phys. Rev. C79 (2009) 044906 [arXiv:0901.0946
Yukawa particles in a confining potential
Girotto, Matheus Levin, Yan; Santos, Alexandre P. dos; Colla, Thiago
2014-07-07
We study the density distribution of repulsive Yukawa particles confined by an external potential. In the weak coupling limit, we show that the mean-field theory is able to accurately account for the particle distribution. In the strong coupling limit, the correlations between the particles become important and the mean-field theory fails. For strongly correlated systems, we construct a density functional theory which provides an excellent description of the particle distribution, without any adjustable parameters.
Classical strongly coupled quark-gluon plasma. I. Model and molecular dynamics simulations
Gelman, Boris A.; Shuryak, Edward V.; Zahed, Ismail
2006-10-15
We propose a model for the description of strongly interacting quarks and gluon quasiparticles at T=(1-3)T{sub c} as a classical and nonrelativistic colored Coulomb gas. The sign and strength of the interparticle interactions are fixed by the scalar product of their classical color vectors subject to Wong's equations. The model displays a number of phases as the Coulomb coupling is increased ranging from a gas, to a liquid, to a crystal with antiferromagnetic-like color ordering. We analyze the model using molecular dynamics simulations and discuss the density-density correlator in real time. We extract pertinent decorrelation times, diffusion, and viscosity constants for all phases. The classical results when extrapolated to the strongly coupled quark-gluon plasma suggest that the phase is liquid-like, with a diffusion constant D{approx_equal}0.1/T and a shear viscosity to entropy density ratio {eta}/s{approx_equal}1/3.
Complex spectrum of finite-density lattice QCD with static quarks at strong coupling
NASA Astrophysics Data System (ADS)
Nishimura, Hiromichi; Ogilvie, Michael C.; Pangeni, Kamal
2016-05-01
We calculate the spectrum of transfer matrix eigenvalues associated with Polyakov loops in finite-density lattice QCD with static quarks. These eigenvalues determine the spatial behavior of Polyakov loop correlation functions. Our results are valid for all values of the gauge coupling in 1 +1 dimensions and in the strong-coupling region for any number of dimensions. When the quark chemical potential μ is nonzero, the spatial transfer matrix Ts is non-Hermitian. The appearance of complex eigenvalues in Ts is a manifestation of the sign problem in finite-density QCD. The invariance of finite-density QCD under the combined action of charge conjugation C and complex conjugation K implies that the eigenvalues of Ts are either real or part of a complex pair. Calculation of the spectrum confirms the existence of complex pairs in much of the temperature-chemical potential plane. Many features of the spectrum for static quarks are determined by a particle-hole symmetry. For μ that is small compared to the quark mass M , we typically find real eigenvalues for the lowest-lying states. At somewhat larger values of μ , pairs of eigenvalues may form complex-conjugate pairs, leading to damped oscillatory behavior in Polyakov loop correlation functions. However, near μ =M , the low-lying spectrum becomes real again. This is a direct consequence of the approximate particle-hole symmetry at μ =M for heavy quarks. This behavior of the eigenvalues should be observable in lattice simulations and can be used as a test of lattice algorithms. Our results provide independent confirmation of results we have previously obtained in Polyakov-Nambu-Jona-Lasinio models using complex saddle points.
Density functional theory for Yukawa fluids
NASA Astrophysics Data System (ADS)
Hatlo, Marius M.; Banerjee, Priyanka; Forsman, Jan; Lue, Leo
2012-08-01
We develop an approximate field theory for particles interacting with a generalized Yukawa potential. This theory improves and extends a previous splitting field theory, originally developed for counterions around a fixed charge distribution. The resulting theory bridges between the second virial approximation, which is accurate at low particle densities, and the mean-field approximation, accurate at high densities. We apply this theory to charged, screened ions in bulk solution, modeled to interact with a Yukawa potential; the theory is able to accurately reproduce the thermodynamic properties of the system over a broad range of conditions. The theory is also applied to "dressed counterions," interacting with a screened electrostatic potential, contained between charged plates. It is found to work well from the weak coupling to the strong coupling limits. The theory is able to reproduce the counterion profiles and force curves for closed and open systems obtained from Monte Carlo simulations.
Constraining couplings of top quarks to the Z boson in + Z production at the LHC
NASA Astrophysics Data System (ADS)
Röntsch, Raoul; Schulze, Markus
2014-07-01
We study top quark pair production in association with a Z boson at the Large Hadron Collider (LHC) and investigate the prospects of measuring the couplings of top quarks to the Z boson. To date these couplings have not been constrained in direct measurements. Such a determination will be possible for the first time at the LHC. Our calculation improves previous coupling studies through the inclusion of next-to-leading order (NLO) QCD corrections in production and decays of all unstable particles. We treat top quarks in the narrow-width approximation and retain all NLO spin correlations. To determine the sensitivity of a coupling measurement we perform a binned log-likelihood ratio test based on normalization and shape information of the angle between the leptons from the Z boson decay. The obtained limits account for statistical uncertainties as well as leading theoretical systematics from residual scale dependence and parton distribution functions. We use current CMS data to place the first direct constraints on the couplings. We also consider the upcoming high-energy LHC run and find that with 300 fb-1 of data at an energy of 13 TeV the vector and axial coupling can be constrained at the 95% confidence level to and , where the central values are the Standard Model predictions. This is a reduction of uncertainties by 25% and 42%, respectively, compared to an analysis based on leading-order predictions. We also translate these results into limits on dimension-six operators contributing to the interactions beyond the Standard Model.
NASA Astrophysics Data System (ADS)
Aad, G.; Abbott, B.; Abdallah, J.; Abdel Khalek, S.; Abdelalim, A. A.; Abdesselam, A.; Abdinov, O.; Abi, B.; Abolins, M.; Abouzeid, O. S.; Abramowicz, H.; Abreu, H.; Acerbi, E.; Acharya, B. S.; Adamczyk, L.; Adams, D. L.; Addy, T. N.; Adelman, J.; Aderholz, M.; Adomeit, S.; Adragna, P.; Adye, T.; Aefsky, S.; Aguilar-Saavedra, J. A.; Aharrouche, M.; Ahlen, S. P.; Ahles, F.; Ahmad, A.; Ahsan, M.; Aielli, G.; Akdogan, T.; Åkesson, T. P. A.; Akimoto, G.; Akimov, A. V.; Akiyama, A.; Alam, M. S.; Alam, M. A.; Albert, J.; Albrand, S.; Aleksa, M.; Aleksandrov, I. N.; Alessandria, F.; Alexa, C.; Alexander, G.; Alexandre, G.; Alexopoulos, T.; Alhroob, M.; Aliev, M.; Alimonti, G.; Alison, J.; Aliyev, M.; Allbrooke, B. M. M.; Allport, P. P.; Allwood-Spiers, S. E.; Almond, J.; Aloisio, A.; Alon, R.; Alonso, A.; Alvarez Gonzalez, B.; Alviggi, M. G.; Amako, K.; Amaral, P.; Amelung, C.; Ammosov, V. V.; Amorim, A.; Amorós, G.; Amram, N.; Anastopoulos, C.; Ancu, L. S.; Andari, N.; Andeen, T.; Anders, C. F.; Anders, G.; Anderson, K. J.; Andreazza, A.; Andrei, V.; Andrieux, M.-L.; Anduaga, X. S.; Angerami, A.; Anghinolfi, F.; Anisenkov, A.; Anjos, N.; Annovi, A.; Antonaki, A.; Antonelli, M.; Antonov, A.; Antos, J.; Anulli, F.; Aoun, S.; Aperio Bella, L.; Apolle, R.; Arabidze, G.; Aracena, I.; Arai, Y.; Arce, A. T. H.; Archambault, J. P.; Arfaoui, S.; Arguin, J.-F.; Arik, E.; Arik, M.; Armbruster, A. J.; Arnaez, O.; Arnal, V.; Arnault, C.; Artamonov, A.; Artoni, G.; Arutinov, D.; Asai, S.; Asfandiyarov, R.; Ask, S.; Åsman, B.; Asquith, L.; Assamagan, K.; Astbury, A.; Astvatsatourov, A.; Aubert, B.; Auge, E.; Augsten, K.; Aurousseau, M.; Avolio, G.; Avramidou, R.; Axen, D.; Ay, C.; Azuelos, G.; Azuma, Y.; Baak, M. A.; Baccaglioni, G.; Bacci, C.; Bach, A. M.; Bachacou, H.; Bachas, K.; Bachy, G.; Backes, M.; Backhaus, M.; Badescu, E.; Bagnaia, P.; Bahinipati, S.; Bai, Y.; Bailey, D. C.; Bain, T.; Baines, J. T.; Baker, O. K.; Baker, M. D.; Baker, S.; Banas, E.; Banerjee, P.; Banerjee, Sw.; Banfi, D.; Bangert, A.; Bansal, V.; Bansil, H. S.; Barak, L.; Baranov, S. P.; Barashkou, A.; Barbaro Galtieri, A.; Barber, T.; Barberio, E. L.; Barberis, D.; Barbero, M.; Bardin, D. Y.; Barillari, T.; Barisonzi, M.; Barklow, T.; Barlow, N.; Barnett, B. M.; Barnett, R. M.; Baroncelli, A.; Barone, G.; Barr, A. J.; Barreiro, F.; Barreiro Guimarães da Costa, J.; Barrillon, P.; Bartoldus, R.; Barton, A. E.; Bartsch, V.; Bates, R. L.; Batkova, L.; Batley, J. R.; Battaglia, A.; Battistin, M.; Bauer, F.; Bawa, H. S.; Beale, S.; Beare, B.; Beau, T.; Beauchemin, P. H.; Beccherle, R.; Bechtle, P.; Beck, H. P.; Becker, A. K.; Becker, S.; Beckingham, M.; Becks, K. H.; Beddall, A. J.; Beddall, A.; Bedikian, S.; Bednyakov, V. A.; Bee, C. P.; Begel, M.; Behar Harpaz, S.; Behera, P. K.; Beimforde, M.; Belanger-Champagne, C.; Bell, P. J.; Bell, W. H.; Bella, G.; Bellagamba, L.; Bellina, F.; Bellomo, M.; Belloni, A.; Beloborodova, O.; Belotskiy, K.; Beltramello, O.; Benami, S.; Benary, O.; Benchekroun, D.; Benchouk, C.; Bendel, M.; Bendtz, K.; Benekos, N.; Benhammou, Y.; Benhar Noccioli, E.; Benitez Garcia, J. A.; Benjamin, D. P.; Benoit, M.; Bensinger, J. R.; Benslama, K.; Bentvelsen, S.; Berge, D.; Bergeaas Kuutmann, E.; Berger, N.; Berghaus, F.; Berglund, E.; Beringer, J.; Bernat, P.; Bernhard, R.; Bernius, C.; Berry, T.; Bertella, C.; Bertin, A.; Bertinelli, F.; Bertolucci, F.; Besana, M. I.; Besson, N.; Bethke, S.; Bhimji, W.; Bianchi, R. M.; Bianco, M.; Biebel, O.; Bieniek, S. P.; Bierwagen, K.; Biesiada, J.; Biglietti, M.; Bilokon, H.; Bindi, M.; Binet, S.; Bingul, A.; Bini, C.; Biscarat, C.; Bitenc, U.; Black, K. M.; Blair, R. E.; Blanchard, J.-B.; Blanchot, G.; Blazek, T.; Blocker, C.; Blocki, J.; Blondel, A.; Blum, W.; Blumenschein, U.; Bobbink, G. J.; Bobrovnikov, V. B.; Bocchetta, S. S.; Bocci, A.; Boddy, C. R.; Boehler, M.; Boek, J.; Boelaert, N.; Bogaerts, J. A.; Bogdanchikov, A.; Bogouch, A.; Bohm, C.; Bohm, J.; Boisvert, V.; Bold, T.; Boldea, V.; Bolnet, N. M.; Bomben, M.; Bona, M.; Bondarenko, V. G.; Bondioli, M.; Boonekamp, M.; Boorman, G.; Booth, C. N.; Bordoni, S.; Borer, C.; Borisov, A.; Borissov, G.; Borjanovic, I.; Borri, M.; Borroni, S.; Bortolotto, V.; Bos, K.; Boscherini, D.; Böser, S.; Bosman, M.; Boterenbrood, H.; Botterill, D.; Bouchami, J.; Boudreau, J.; Bouhova-Thacker, E. V.; Boumediene, D.; Bourdarios, C.; Bousson, N.; Boveia, A.; Boyd, J.; Boyko, I. R.; Bozhko, N. I.; Bozovic-Jelisavcic, I.; Bracinik, J.; Braem, A.; Branchini, P.; Brandenburg, G. W.; Brandt, A.; Brandt, G.; Brandt, O.; Bratzler, U.; Brau, B.; Brau, J. E.; Braun, H. M.; Brelier, B.; Bremer, J.; Brendlinger, K.; Brenner, R.; Bressler, S.; Breton, D.; Britton, D.; Brochu, F. M.; Brock, I.; Brock, R.; Brodbeck, T. J.; Brodet, E.; Broggi, F.; Bromberg, C.; Bronner, J.; Brooijmans, G.; Brooks, W. K.; Brown, G.; Brown, H.; Bruckman de Renstrom, P. A.; Bruncko, D.; Bruneliere, R.; Brunet, S.; Bruni, A.; Bruni, G.; Bruschi, M.; Buanes, T.; Buat, Q.; Bucci, F.; Buchanan, J.; Buchanan, N. J.; Buchholz, P.; Buckingham, R. M.; Buckley, A. G.; Buda, S. I.; Budagov, I. A.; Budick, B.; Büscher, V.; Bugge, L.; Bulekov, O.; Bundock, A. C.; Bunse, M.; Buran, T.; Burckhart, H.; Burdin, S.; Burgess, T.; Burke, S.; Busato, E.; Bussey, P.; Buszello, C. P.; Butin, F.; Butler, B.; Butler, J. M.; Buttar, C. M.; Butterworth, J. M.; Buttinger, W.; Cabrera Urbán, S.; Caforio, D.; Cakir, O.; Calafiura, P.; Calderini, G.; Calfayan, P.; Calkins, R.; Caloba, L. P.; Caloi, R.; Calvet, D.; Calvet, S.; Camacho Toro, R.; Camarri, P.; Cambiaghi, M.; Cameron, D.; Caminada, L. M.; Campana, S.; Campanelli, M.; Canale, V.; Canelli, F.; Canepa, A.; Cantero, J.; Cantrill, R.; Capasso, L.; Capeans Garrido, M. D. M.; Caprini, I.; Caprini, M.; Capriotti, D.; Capua, M.; Caputo, R.; Caramarcu, C.; Cardarelli, R.; Carli, T.; Carlino, G.; Carminati, L.; Caron, B.; Caron, S.; Carquin, E.; Carrillo Montoya, G. D.; Carter, A. A.; Carter, J. R.; Carvalho, J.; Casadei, D.; Casado, M. P.; Cascella, M.; Caso, C.; Castaneda Hernandez, A. M.; Castaneda-Miranda, E.; Castillo Gimenez, V.; Castro, N. F.; Cataldi, G.; Cataneo, F.; Catastini, P.; Catinaccio, A.; Catmore, J. R.; Cattai, A.; Cattani, G.; Caughron, S.; Cauz, D.; Cavalleri, P.; Cavalli, D.; Cavalli-Sforza, M.; Cavasinni, V.; Ceradini, F.; Cerqueira, A. S.; Cerri, A.; Cerrito, L.; Cerutti, F.; Cetin, S. A.; Cevenini, F.; Chafaq, A.; Chakraborty, D.; Chalupkova, I.; Chan, K.; Chapleau, B.; Chapman, J. D.; Chapman, J. W.; Chareyre, E.; Charlton, D. G.; Chavda, V.; Chavez Barajas, C. A.; Cheatham, S.; Chekanov, S.; Chekulaev, S. V.; Chelkov, G. A.; Chelstowska, M. A.; Chen, C.; Chen, H.; Chen, S.; Chen, T.; Chen, X.; Cheng, S.; Cheplakov, A.; Chepurnov, V. F.; Cherkaoui El Moursli, R.; Chernyatin, V.; Cheu, E.; Cheung, S. L.; Chevalier, L.; Chiefari, G.; Chikovani, L.; Childers, J. T.; Chilingarov, A.; Chiodini, G.; Chisholm, A. S.; Chislett, R. T.; Chizhov, M. V.; Choudalakis, G.; Chouridou, S.; Christidi, I. A.; Christov, A.; Chromek-Burckhart, D.; Chu, M. L.; Chudoba, J.; Ciapetti, G.; Ciba, K.; Ciftci, A. K.; Ciftci, R.; Cinca, D.; Cindro, V.; Ciobotaru, M. D.; Ciocca, C.; Ciocio, A.; Cirilli, M.; Citterio, M.; Ciubancan, M.; Clark, A.; Clark, P. J.; Cleland, W.; Clemens, J. C.; Clement, B.; Clement, C.; Clifft, R. W.; Coadou, Y.; Cobal, M.; Coccaro, A.; Cochran, J.; Coe, P.; Cogan, J. G.; Coggeshall, J.; Cogneras, E.; Colas, J.; Colijn, A. P.; Collins, N. J.; Collins-Tooth, C.; Collot, J.; Colombo, T.; Colon, G.; Conde Muiño, P.; Coniavitis, E.; Conidi, M. C.; Consonni, M.; Consonni, S. M.; Consorti, V.; Constantinescu, S.; Conta, C.; Conti, G.; Conventi, F.; Cook, J.; Cooke, M.; Cooper, B. D.; Cooper-Sarkar, A. M.; Copic, K.; Cornelissen, T.; Corradi, M.; Corriveau, F.; Cortes-Gonzalez, A.; Cortiana, G.; Costa, G.; Costa, M. J.; Costanzo, D.; Costin, T.; Côté, D.; Coura Torres, R.; Courneyea, L.; Cowan, G.; Cowden, C.; Cox, B. E.; Cranmer, K.; Crescioli, F.; Cristinziani, M.; Crosetti, G.; Crupi, R.; Crépé-Renaudin, S.; Cuciuc, C.-M.; Cuenca Almenar, C.; Cuhadar Donszelmann, T.; Curatolo, M.; Curtis, C. J.; Cuthbert, C.; Cwetanski, P.; Czirr, H.; Czodrowski, P.; Czyczula, Z.; D'Auria, S.; D'Onofrio, M.; D'Orazio, A.; da Silva, P. V. M.; da Via, C.; Dabrowski, W.; Dafinca, A.; Dai, T.; Dallapiccola, C.; Dam, M.; Dameri, M.; Damiani, D. S.; Danielsson, H. O.; Dannheim, D.; Dao, V.; Darbo, G.; Darlea, G. L.; Daum, C.; Davey, W.; Davidek, T.; Davidson, N.; Davidson, R.; Davies, E.; Davies, M.; Davison, A. R.; Davygora, Y.; Dawe, E.; Dawson, I.; Dawson, J. W.; Daya-Ishmukhametova, R. K.; de, K.; de Asmundis, R.; de Castro, S.; de Castro Faria Salgado, P. E.; de Cecco, S.; de Graat, J.; de Groot, N.; de Jong, P.; de La Taille, C.; de la Torre, H.; de Lorenzi, F.; de Lotto, B.; de Mora, L.; de Nooij, L.; de Pedis, D.; de Salvo, A.; de Sanctis, U.; de Santo, A.; de Vivie de Regie, J. B.; de Zorzi, G.; Dean, S.; Dearnaley, W. J.; Debbe, R.; Debenedetti, C.; Dechenaux, B.; Dedovich, D. V.; Degenhardt, J.; Dehchar, M.; Del Papa, C.; Del Peso, J.; Del Prete, T.; Delemontex, T.; Deliyergiyev, M.; Dell'Acqua, A.; Dell'Asta, L.; Della Pietra, M.; Della Volpe, D.; Delmastro, M.; Delruelle, N.; Delsart, P. A.; Deluca, C.; Demers, S.; Demichev, M.; Demirkoz, B.; Deng, J.; Denisov, S. P.; Derendarz, D.; Derkaoui, J. E.; Derue, F.; Dervan, P.; Desch, K.; Devetak, E.; Deviveiros, P. O.; Dewhurst, A.; Dewilde, B.; Dhaliwal, S.; Dhullipudi, R.; di Ciaccio, A.; di Ciaccio, L.; di Girolamo, A.; di Girolamo, B.; di Luise, S.; di Mattia, A.; di Micco, B.; di Nardo, R.; di Simone, A.; di Sipio, R.; Diaz, M. A.; Diblen, F.; Diehl, E. B.; Dietrich, J.; Dietzsch, T. A.; Diglio, S.; Dindar Yagci, K.; Dingfelder, J.; Dionisi, C.; Dita, P.; Dita, S.; Dittus, F.; Djama, F.; Djobava, T.; Do Vale, M. A. B.; Do Valle Wemans, A.; Doan, T. K. O.; Dobbs, M.; Dobinson, R.; Dobos, D.; Dobson, E.; Dodd, J.; Doglioni, C.; Doherty, T.; Doi, Y.; Dolejsi, J.; Dolenc, I.; Dolezal, Z.; Dolgoshein, B. A.; Dohmae, T.; Donadelli, M.; Donega, M.; Donini, J.; Dopke, J.; Doria, A.; Dos Anjos, A.; Dosil, M.; Dotti, A.; Dova, M. T.; Dowell, J. D.; Doxiadis, A. D.; Doyle, A. T.; Drasal, Z.; Drees, J.; Dressnandt, N.; Drevermann, H.; Driouichi, C.; Dris, M.; Dubbert, J.; Dube, S.; Duchovni, E.; Duckeck, G.; Dudarev, A.; Dudziak, F.; Dührssen, M.; Duerdoth, I. P.; Duflot, L.; Dufour, M.-A.; Dunford, M.; Duran Yildiz, H.; Duxfield, R.; Dwuznik, M.; Dydak, F.; Düren, M.; Ebenstein, W. L.; Ebke, J.; Eckweiler, S.; Edmonds, K.; Edwards, C. A.; Edwards, N. C.; Ehrenfeld, W.; Ehrich, T.; Eifert, T.; Eigen, G.; Einsweiler, K.; Eisenhandler, E.; Ekelof, T.; El Kacimi, M.; Ellert, M.; Elles, S.; Ellinghaus, F.; Ellis, K.; Ellis, N.; Elmsheuser, J.; Elsing, M.; Emeliyanov, D.; Engelmann, R.; Engl, A.; Epp, B.; Eppig, A.; Erdmann, J.; Ereditato, A.; Eriksson, D.; Ernst, J.; Ernst, M.; Ernwein, J.; Errede, D.; Errede, S.; Ertel, E.; Escalier, M.; Escobar, C.; Espinal Curull, X.; Esposito, B.; Etienne, F.; Etienvre, A. I.; Etzion, E.; Evangelakou, D.; Evans, H.; Fabbri, L.; Fabre, C.; Fakhrutdinov, R. M.; Falciano, S.; Fang, Y.; Fanti, M.; Farbin, A.; Farilla, A.; Farley, J.; Farooque, T.; Farrell, S.; Farrington, S. M.; Farthouat, P.; Fassnacht, P.; Fassouliotis, D.; Fatholahzadeh, B.; Favareto, A.; Fayard, L.; Fazio, S.; Febbraro, R.; Federic, P.; Fedin, O. L.; Fedorko, W.; Fehling-Kaschek, M.; Feligioni, L.; Fellmann, D.; Feng, C.; Feng, E. J.; Fenyuk, A. B.; Ferencei, J.; Ferland, J.; Fernando, W.; Ferrag, S.; Ferrando, J.; Ferrara, V.; Ferrari, A.; Ferrari, P.; Ferrari, R.; Ferreira de Lima, D. E.; Ferrer, A.; Ferrer, M. L.; Ferrere, D.; Ferretti, C.; Ferretto Parodi, A.; Fiascaris, M.; Fiedler, F.; Filipčič, A.; Filippas, A.; Filthaut, F.; Fincke-Keeler, M.; Fiolhais, M. C. N.; Fiorini, L.; Firan, A.; Fischer, G.; Fischer, P.; Fisher, M. J.; Flechl, M.; Fleck, I.; Fleckner, J.; Fleischmann, P.; Fleischmann, S.; Flick, T.; Floderus, A.; Flores Castillo, L. R.; Flowerdew, M. J.; Fokitis, M.; Fonseca Martin, T.; Fopma, J.; Forbush, D. A.; Formica, A.; Forti, A.; Fortin, D.; Foster, J. M.; Fournier, D.; Foussat, A.; Fowler, A. J.; Fowler, K.; Fox, H.; Francavilla, P.; Franchino, S.; Francis, D.; Frank, T.; Franklin, M.; Franz, S.; Fraternali, M.; Fratina, S.; French, S. T.; Friedrich, C.; Friedrich, F.; Froeschl, R.; Froidevaux, D.; Frost, J. A.; Fukunaga, C.; Fullana Torregrosa, E.; Fulsom, B. G.; Fuster, J.; Gabaldon, C.; Gabizon, O.; Gadfort, T.; Gadomski, S.; Gagliardi, G.; Gagnon, P.; Galea, C.; Gallas, E. J.; Gallo, V.; Gallop, B. J.; Gallus, P.; Gan, K. K.; Gao, Y. S.; Gapienko, V. A.; Gaponenko, A.; Garberson, F.; Garcia-Sciveres, M.; García, C.; García Navarro, J. E.; Gardner, R. W.; Garelli, N.; Garitaonandia, H.; Garonne, V.; Garvey, J.; Gatti, C.; Gaudio, G.; Gaumer, O.; Gaur, B.; Gauthier, L.; Gauzzi, P.; Gavrilenko, I. L.; Gay, C.; Gaycken, G.; Gayde, J.-C.; Gazis, E. N.; Ge, P.; Gecse, Z.; Gee, C. N. P.; Geerts, D. A. A.; Geich-Gimbel, Ch.; Gellerstedt, K.; Gemme, C.; Gemmell, A.; Genest, M. H.; Gentile, S.; George, M.; George, S.; Gerlach, P.; Gershon, A.; Geweniger, C.; Ghazlane, H.; Ghodbane, N.; Giacobbe, B.; Giagu, S.; Giakoumopoulou, V.; Giangiobbe, V.; Gianotti, F.; Gibbard, B.; Gibson, A.; Gibson, S. M.; Gilbert, L. M.; Gilewsky, V.; Gillberg, D.; Gillman, A. R.; Gingrich, D. M.; Ginzburg, J.; Giokaris, N.; Giordani, M. P.; Giordano, R.; Giorgi, F. M.; Giovannini, P.; Giraud, P. F.; Giugni, D.; Giunta, M.; Giusti, P.; Gjelsten, B. K.; Gladilin, L. K.; Glasman, C.; Glatzer, J.; Glazov, A.; Glitza, K. W.; Glonti, G. L.; Goddard, J. R.; Godfrey, J.; Godlewski, J.; Goebel, M.; Göpfert, T.; Goeringer, C.; Gössling, C.; Goldfarb, S.; Golling, T.; Golovnia, S. N.; Gomes, A.; Gomez Fajardo, L. S.; Gonçalo, R.; Goncalves Pinto Firmino da Costa, J.; Gonella, L.; Gonidec, A.; Gonzalez, S.; González de La Hoz, S.; Gonzalez Parra, G.; Gonzalez Silva, M. L.; Gonzalez-Sevilla, S.; Goodson, J. J.; Goossens, L.; Gorbounov, P. A.; Gordon, H. A.; Gorelov, I.; Gorfine, G.; Gorini, B.; Gorini, E.; Gorišek, A.; Gornicki, E.; Gorokhov, S. A.; Goryachev, V. N.; Gosdzik, B.; Goshaw, A. T.; Gosselink, M.; Gostkin, M. I.; Gough Eschrich, I.; Gouighri, M.; Goujdami, D.; Goulette, M. P.; Goussiou, A. G.; Göttfert, T.; Goy, C.; Gozpinar, S.; Grabowska-Bold, I.; Grafström, P.; Grahn, K.-J.; Grancagnolo, F.; Grancagnolo, S.; Grassi, V.; Gratchev, V.; Grau, N.; Gray, H. M.; Gray, J. A.; Graziani, E.; Grebenyuk, O. G.; Greenshaw, T.; Greenwood, Z. D.; Gregersen, K.; Gregor, I. M.; Grenier, P.; Griffiths, J.; Grigalashvili, N.; Grillo, A. A.; Grinstein, S.; Grishkevich, Y. V.; Grivaz, J.-F.; Groh, M.; Gross, E.; Grosse-Knetter, J.; Groth-Jensen, J.; Grybel, K.; Guarino, V. J.; Guest, D.; Guicheney, C.; Guida, A.; Guindon, S.; Guler, H.; Gunther, J.; Guo, B.; Guo, J.; Gupta, A.; Gusakov, Y.; Gushchin, V. N.; Gutierrez, A.; Gutierrez, P.; Guttman, N.; Gutzwiller, O.; Guyot, C.; Gwenlan, C.; Gwilliam, C. B.; Haas, A.; Haas, S.; Haber, C.; Hadavand, H. K.; Hadley, D. R.; Haefner, P.; Hahn, F.; Haider, S.; Hajduk, Z.; Hakobyan, H.; Hall, D.; Haller, J.; Hamacher, K.; Hamal, P.; Hamer, M.; Hamilton, A.; Hamilton, S.; Han, H.; Han, L.; Hanagaki, K.; Hanawa, K.; Hance, M.; Handel, C.; Hanke, P.; Hansen, J. R.; Hansen, J. B.; Hansen, J. D.; Hansen, P. H.; Hansson, P.; Hara, K.; Hare, G. A.; Harenberg, T.; Harkusha, S.; Harper, D.; Harrington, R. D.; Harris, O. M.; Harrison, K.; Hartert, J.; Hartjes, F.; Haruyama, T.; Harvey, A.; Hasegawa, S.; Hasegawa, Y.; Hassani, S.; Hatch, M.; Hauff, D.; Haug, S.; Hauschild, M.; Hauser, R.; Havranek, M.; Hawes, B. M.; Hawkes, C. M.; Hawkings, R. J.; Hawkins, A. D.; Hawkins, D.; Hayakawa, T.; Hayashi, T.; Hayden, D.; Hayward, H. S.; Haywood, S. J.; Hazen, E.; He, M.; Head, S. J.; Hedberg, V.; Heelan, L.; Heim, S.; Heinemann, B.; Heisterkamp, S.; Helary, L.; Heller, C.; Heller, M.; Hellman, S.; Hellmich, D.; Helsens, C.; Henderson, R. C. W.; Henke, M.; Henrichs, A.; Henriques Correia, A. M.; Henrot-Versille, S.; Henry-Couannier, F.; Hensel, C.; Henß, T.; Hernandez, C. M.; Hernández Jiménez, Y.; Herrberg, R.; Hershenhorn, A. D.; Herten, G.; Hertenberger, R.; Hervas, L.; Hesketh, G. G.; Hessey, N. P.; Higón-Rodriguez, E.; Hill, D.; Hill, J. C.; Hill, N.; Hiller, K. H.; Hillert, S.; Hillier, S. J.; Hinchliffe, I.; Hines, E.; Hirose, M.; Hirsch, F.; Hirschbuehl, D.; Hobbs, J.; Hod, N.; Hodgkinson, M. C.; Hodgson, P.; Hoecker, A.; Hoeferkamp, M. R.; Hoffman, J.; Hoffmann, D.; Hohlfeld, M.; Holder, M.; Holmgren, S. O.; Holy, T.; Holzbauer, J. L.; Homma, Y.; Hong, T. M.; Hooft van Huysduynen, L.; Horazdovsky, T.; Horn, C.; Horner, S.; Hostachy, J.-Y.; Hou, S.; Houlden, M. A.; Hoummada, A.; Howard, J.; Howarth, J.; Howell, D. F.; Hristova, I.; Hrivnac, J.; Hruska, I.; Hryn'ova, T.; Hsu, P. J.; Hsu, S.-C.; Huang, G. S.; Hubacek, Z.; Hubaut, F.; Huegging, F.; Huettmann, A.; Huffman, T. B.; Hughes, E. W.; Hughes, G.; Hughes-Jones, R. E.; Huhtinen, M.; Hurst, P.; Hurwitz, M.; Husemann, U.; Huseynov, N.; Huston, J.; Huth, J.; Iacobucci, G.; Iakovidis, G.; Ibbotson, M.; Ibragimov, I.; Ichimiya, R.; Iconomidou-Fayard, L.; Idarraga, J.; Iengo, P.; Igonkina, O.; Ikegami, Y.; Ikeno, M.; Ilchenko, Y.; Iliadis, D.; Ilic, N.; Imbault, D.; Imori, M.; Ince, T.; Inigo-Golfin, J.; Ioannou, P.; Iodice, M.; Iordanidou, K.; Ippolito, V.; Irles Quiles, A.; Isaksson, C.; Ishikawa, A.; Ishino, M.; Ishmukhametov, R.; Issever, C.; Istin, S.; Ivashin, A. V.; Iwanski, W.; Iwasaki, H.; Izen, J. M.; Izzo, V.; Jackson, B.; Jackson, J. N.; Jackson, P.; Jaekel, M. R.; Jain, V.; Jakobs, K.; Jakobsen, S.; Jakoubek, T.; Jakubek, J.; Jana, D. K.; Jankowski, E.; Jansen, E.; Jansen, H.; Jantsch, A.; Janus, M.; Jarlskog, G.; Jeanty, L.; Jelen, K.; Jen-La Plante, I.; Jenni, P.; Jeremie, A.; Jež, P.; Jézéquel, S.; Jha, M. K.; Ji, H.; Ji, W.; Jia, J.; Jiang, Y.; Jimenez Belenguer, M.; Jin, G.; Jin, S.; Jinnouchi, O.; Joergensen, M. D.; Joffe, D.; Johansen, L. G.; Johansen, M.; Johansson, K. E.; Johansson, P.; Johnert, S.; Johns, K. A.; Jon-And, K.; Jones, G.; Jones, R. W. L.; Jones, T. W.; Jones, T. J.; Jonsson, O.; Joram, C.; Jorge, P. M.; Joseph, J.; Joshi, K. D.; Jovicevic, J.; Jovin, T.; Ju, X.; Jung, C. A.; Jungst, R. M.; Juranek, V.; Jussel, P.; Juste Rozas, A.; Kabachenko, V. V.; Kabana, S.; Kaci, M.; Kaczmarska, A.; Kadlecik, P.; Kado, M.; Kagan, H.; Kagan, M.; Kaiser, S.; Kajomovitz, E.; Kalinin, S.; Kalinovskaya, L. V.; Kama, S.; Kanaya, N.; Kaneda, M.; Kaneti, S.; Kanno, T.; Kantserov, V. A.; Kanzaki, J.; Kaplan, B.; Kapliy, A.; Kaplon, J.; Kar, D.; Karagounis, M.; Karagoz, M.; Karnevskiy, M.; Karr, K.; Kartvelishvili, V.; Karyukhin, A. N.; Kashif, L.; Kasieczka, G.; Kass, R. D.; Kastanas, A.; Kataoka, M.; Kataoka, Y.; Katsoufis, E.; Katzy, J.; Kaushik, V.; Kawagoe, K.; Kawamoto, T.; Kawamura, G.; Kayl, M. S.; Kazanin, V. A.; Kazarinov, M. Y.; Keates, J. R.; Keeler, R.; Kehoe, R.; Keil, M.; Kekelidze, G. D.; Keller, J. S.; Kennedy, J.; Kenney, C. J.; Kenyon, M.; Kepka, O.; Kerschen, N.; Kerševan, B. P.; Kersten, S.; Kessoku, K.; Keung, J.; Khalil-Zada, F.; Khandanyan, H.; Khanov, A.; Kharchenko, D.; Khodinov, A.; Kholodenko, A. G.; Khomich, A.; Khoo, T. J.; Khoriauli, G.; Khoroshilov, A.; Khovanskiy, N.; Khovanskiy, V.; Khramov, E.; Khubua, J.; Kim, H.; Kim, M. S.; Kim, P. C.; Kim, S. H.; Kimura, N.; Kind, O.; King, B. T.; King, M.; King, R. S. B.; Kirk, J.; Kirsch, L. E.; Kiryunin, A. E.; Kishimoto, T.; Kisielewska, D.; Kittelmann, T.; Kiver, A. M.; Kladiva, E.; Klaiber-Lodewigs, J.; Klein, M.; Klein, U.; Kleinknecht, K.; Klemetti, M.; Klier, A.; Klimek, P.; Klimentov, A.; Klingenberg, R.; Klinger, J. A.; Klinkby, E. B.; Klioutchnikova, T.; Klok, P. F.; Klous, S.; Kluge, E.-E.; Kluge, T.; Kluit, P.; Kluth, S.; Knecht, N. S.; Kneringer, E.; Knobloch, J.; Knoops, E. B. F. G.; Knue, A.; Ko, B. R.; Kobayashi, T.; Kobel, M.; Kocian, M.; Kodys, P.; Köneke, K.; König, A. C.; Koenig, S.; Köpke, L.; Koetsveld, F.; Koevesarki, P.; Koffas, T.; Koffeman, E.; Kogan, L. A.; Kohlmann, S.; Kohn, F.; Kohout, Z.; Kohriki, T.; Koi, T.; Kokott, T.; Kolachev, G. M.; Kolanoski, H.; Kolesnikov, V.; Koletsou, I.; Koll, J.; Kollar, D.; Kollefrath, M.; Kolya, S. D.; Komar, A. A.; Komori, Y.; Kondo, T.; Kono, T.; Kononov, A. I.; Konoplich, R.; Konstantinidis, N.; Kootz, A.; Koperny, S.; Korcyl, K.; Kordas, K.; Koreshev, V.; Korn, A.; Korol, A.; Korolkov, I.; Korolkova, E. V.; Korotkov, V. A.; Kortner, O.; Kortner, S.; Kostyukhin, V. V.; Kotamäki, M. J.; Kotov, S.; Kotov, V. M.; Kotwal, A.; Kourkoumelis, C.; Kouskoura, V.; Koutsman, A.; Kowalewski, R.; Kowalski, T. Z.; Kozanecki, W.; Kozhin, A. S.; Kral, V.; Kramarenko, V. A.; Kramberger, G.; Krasny, M. W.; Krasznahorkay, A.; Kraus, J.; Kraus, J. K.; Kreisel, A.; Krejci, F.; Kretzschmar, J.; Krieger, N.; Krieger, P.; Kroeninger, K.; Kroha, H.; Kroll, J.; Kroseberg, J.; Krstic, J.; Kruchonak, U.; Krüger, H.; Kruker, T.; Krumnack, N.; Krumshteyn, Z. V.; Kruth, A.; Kubota, T.; Kuday, S.; Kuehn, S.; Kugel, A.; Kuhl, T.; Kuhn, D.; Kukhtin, V.; Kulchitsky, Y.; Kuleshov, S.; Kummer, C.; Kuna, M.; Kundu, N.; Kunkle, J.; Kupco, A.; Kurashige, H.; Kurata, M.; Kurochkin, Y. A.; Kus, V.; Kuwertz, E. S.; Kuze, M.; Kvita, J.; Kwee, R.; La Rosa, A.; La Rotonda, L.; Labarga, L.; Labbe, J.; Lablak, S.; Lacasta, C.; Lacava, F.; Lacker, H.; Lacour, D.; Lacuesta, V. R.; Ladygin, E.; Lafaye, R.; Laforge, B.; Lagouri, T.; Lai, S.; Laisne, E.; Lamanna, M.; Lambourne, L.; Lampen, C. L.; Lampl, W.; Lancon, E.; Landgraf, U.; Landon, M. P. J.; Landsman, H.; Lane, J. L.; Lange, C.; Lankford, A. J.; Lanni, F.; Lantzsch, K.; Laplace, S.; Lapoire, C.; Laporte, J. F.; Lari, T.; Larionov, A. V.; Larner, A.; Lasseur, C.; Lassnig, M.; Laurelli, P.; Lavorini, V.; Lavrijsen, W.; Laycock, P.; Lazarev, A. B.; Le Dortz, O.; Le Guirriec, E.; Le Maner, C.; Le Menedeu, E.; Lebel, C.; Lecompte, T.; Ledroit-Guillon, F.; Lee, H.; Lee, J. S. H.; Lee, S. C.; Lee, L.; Lefebvre, M.; Legendre, M.; Leger, A.; Legeyt, B. C.; Legger, F.; Leggett, C.; Lehmacher, M.; Lehmann Miotto, G.; Lei, X.; Leite, M. A. L.; Leitner, R.; Lellouch, D.; Leltchouk, M.; Lemmer, B.; Lendermann, V.; Leney, K. J. C.; Lenz, T.; Lenzen, G.; Lenzi, B.; Leonhardt, K.; Leontsinis, S.; Lepold, F.; Leroy, C.; Lessard, J.-R.; Lesser, J.; Lester, C. G.; Lester, C. M.; Leung Fook Cheong, A.; Levêque, J.; Levin, D.; Levinson, L. J.; Levitski, M. S.; Lewis, A.; Lewis, G. H.; Leyko, A. M.; Leyton, M.; Li, B.; Li, H.; Li, S.; Li, X.; Liang, Z.; Liao, H.; Liberti, B.; Lichard, P.; Lichtnecker, M.; Lie, K.; Liebig, W.; Lifshitz, R.; Limbach, C.; Limosani, A.; Limper, M.; Lin, S. C.; Linde, F.; Linnemann, J. T.; Lipeles, E.; Lipinsky, L.; Lipniacka, A.; Liss, T. M.; Lissauer, D.; Lister, A.; Litke, A. M.; Liu, C.; Liu, D.; Liu, H.; Liu, J. B.; Liu, M.; Liu, Y.; Livan, M.; Livermore, S. S. A.; Lleres, A.; Llorente Merino, J.; Lloyd, S. L.; Lobodzinska, E.; Loch, P.; Lockman, W. S.; Loddenkoetter, T.; Loebinger, F. K.; Loginov, A.; Loh, C. W.; Lohse, T.; Lohwasser, K.; Lokajicek, M.; Loken, J.; Lombardo, V. P.; Long, R. E.; Lopes, L.; Lopez Mateos, D.; Lorenz, J.; Lorenzo Martinez, N.; Losada, M.; Loscutoff, P.; Lo Sterzo, F.; Losty, M. J.; Lou, X.; Lounis, A.; Loureiro, K. F.; Love, J.; Love, P. A.; Lowe, A. J.; Lu, F.; Lubatti, H. J.; Luci, C.; Lucotte, A.; Ludwig, A.; Ludwig, D.; Ludwig, I.; Ludwig, J.; Luehring, F.; Luijckx, G.; Lukas, W.; Lumb, D.; Luminari, L.; Lund, E.; Lund-Jensen, B.; Lundberg, B.; Lundberg, J.; Lundquist, J.; Lungwitz, M.; Lutz, G.; Lynn, D.; Lys, J.; Lytken, E.; Ma, H.; Ma, L. L.; Macana Goia, J. A.; Maccarrone, G.; Macchiolo, A.; Maček, B.; Machado Miguens, J.; Mackeprang, R.; Madaras, R. J.; Mader, W. F.; Maenner, R.; Maeno, T.; Mättig, P.; Mättig, S.; Magnoni, L.; Magradze, E.; Mahalalel, Y.; Mahboubi, K.; Mahmoud, S.; Mahout, G.; Maiani, C.; Maidantchik, C.; Maio, A.; Majewski, S.; Makida, Y.; Makovec, N.; Mal, P.; Malaescu, B.; Malecki, Pa.; Malecki, P.; Maleev, V. P.; Malek, F.; Mallik, U.; Malon, D.; Malone, C.; Maltezos, S.; Malyshev, V.; Malyukov, S.; Mameghani, R.; Mamuzic, J.; Manabe, A.; Mandelli, L.; Mandić, I.; Mandrysch, R.; Maneira, J.; Mangeard, P. S.; Manhaes de Andrade Filho, L.; Manjavidze, I. D.; Mann, A.; Manning, P. M.; Manousakis-Katsikakis, A.; Mansoulie, B.; Manz, A.; Mapelli, A.; Mapelli, L.; March, L.; Marchand, J. F.; Marchese, F.; Marchiori, G.; Marcisovsky, M.; Marin, A.; Marino, C. P.; Marroquim, F.; Marshall, R.; Marshall, Z.; Martens, F. K.; Marti-Garcia, S.; Martin, A. J.; Martin, B.; Martin, B.; Martin, F. F.; Martin, J. P.; Martin, Ph.; Martin, T. A.; Martin, V. J.; Martin Dit Latour, B.; Martin-Haugh, S.; Martinez, M.; Martinez Outschoorn, V.; Martyniuk, A. C.; Marx, M.; Marzano, F.; Marzin, A.; Masetti, L.; Mashimo, T.; Mashinistov, R.; Masik, J.; Maslennikov, A. L.; Massa, I.; Massaro, G.; Massol, N.; Mastrandrea, P.; Mastroberardino, A.; Masubuchi, T.; Mathes, M.; Matricon, P.; Matsumoto, H.; Matsunaga, H.; Matsushita, T.; Mattravers, C.; Maugain, J. M.; Maurer, J.; Maxfield, S. J.; Maximov, D. A.; May, E. N.; Mayne, A.; Mazini, R.; Mazur, M.; Mazzaferro, L.; Mazzanti, M.; Mc Kee, S. P.; McCarn, A.; McCarthy, R. L.; McCarthy, T. G.; McCubbin, N. A.; McFarlane, K. W.; McFayden, J. A.; McGlone, H.; McHedlidze, G.; McLaren, R. A.; McLaughlan, T.; McMahon, S. J.; McPherson, R. A.; Meade, A.; Mechnich, J.; Mechtel, M.; Medinnis, M.; Meera-Lebbai, R.; Meguro, T.; Mehdiyev, R.; Mehlhase, S.; Mehta, A.; Meier, K.; Meirose, B.; Melachrinos, C.; Mellado Garcia, B. R.; Meloni, F.; Mendoza Navas, L.; Meng, Z.; Mengarelli, A.; Menke, S.; Menot, C.; Meoni, E.; Mercurio, K. M.; Mermod, P.; Merola, L.; Meroni, C.; Merritt, F. S.; Merritt, H.; Messina, A.; Metcalfe, J.; Mete, A. S.; Meyer, C.; Meyer, C.; Meyer, J.-P.; Meyer, J.; Meyer, J.; Meyer, T. C.; Meyer, W. T.; Miao, J.; Michal, S.; Micu, L.; Middleton, R. P.; Migas, S.; Mijović, L.; Mikenberg, G.; Mikestikova, M.; Mikuž, M.; Miller, D. W.; Miller, R. J.; Mills, W. J.; Mills, C.; Milov, A.; Milstead, D. A.; Milstein, D.; Minaenko, A. A.; Miñano Moya, M.; Minashvili, I. A.; Mincer, A. I.; Mindur, B.; Mineev, M.; Ming, Y.; Mir, L. M.; Mirabelli, G.; Miralles Verge, L.; Misiejuk, A.; Mitrevski, J.; Mitrofanov, G. Y.; Mitsou, V. A.; Mitsui, S.; Miyagawa, P. S.; Miyazaki, K.; Mjörnmark, J. U.; Moa, T.; Mockett, P.; Moed, S.; Moeller, V.; Moisseev, A. M.; Mönig, K.; Möser, N.; Mohapatra, S.; Mohr, W.; Mohrdieck-Möck, S.; Moles-Valls, R.; Molina-Perez, J.; Monk, J.; Monnier, E.; Montesano, S.; Monticelli, F.; Monzani, S.; Moore, R. W.; Moorhead, G. F.; Mora Herrera, C.; Moraes, A.; Morange, N.; Morel, J.; Morello, G.; Moreno, D.; Moreno Llácer, M.; Morettini, P.; Morgenstern, M.; Morii, M.; Morin, J.; Morley, A. K.; Mornacchi, G.; Morozov, S. V.; Morris, J. D.; Morvaj, L.; Moser, H. G.; Mosidze, M.; Moss, J.; Mount, R.; Mountricha, E.; Mouraviev, S. V.; Moyse, E. J. W.; Mudrinic, M.; Mueller, F.; Mueller, J.; Mueller, K.; Müller, T. A.; Mueller, T.; Muenstermann, D.; Muir, A.; Munwes, Y.; Murray, W. J.; Mussche, I.; Musto, E.; Myagkov, A. G.; Myska, M.; Nadal, J.; Nagai, K.; Nagano, K.; Nagarkar, A.; Nagasaka, Y.; Nagel, M.; Nairz, A. M.; Nakahama, Y.; Nakamura, K.; Nakamura, T.; Nakano, I.; Nanava, G.; Napier, A.; Narayan, R.; Nash, M.; Nation, N. R.; Nattermann, T.; Naumann, T.; Navarro, G.; Neal, H. A.; Nebot, E.; Nechaeva, P. Yu.; Neep, T. J.; Negri, A.; Negri, G.; Nektarijevic, S.; Nelson, A.; Nelson, S.; Nelson, T. K.; Nemecek, S.; Nemethy, P.; Nepomuceno, A. A.; Nessi, M.; Neubauer, M. S.; Neusiedl, A.; Neves, R. M.; Nevski, P.; Newman, P. R.; Nguyen Thi Hong, V.; Nickerson, R. B.; Nicolaidou, R.; Nicolas, L.; Nicquevert, B.; Niedercorn, F.; Nielsen, J.; Niinikoski, T.; Nikiforou, N.; Nikiforov, A.; Nikolaenko, V.; Nikolaev, K.; Nikolic-Audit, I.; Nikolics, K.; Nikolopoulos, K.; Nilsen, H.; Nilsson, P.; Ninomiya, Y.; Nisati, A.; Nishiyama, T.; Nisius, R.; Nodulman, L.; Nomachi, M.; Nomidis, I.; Nordberg, M.; Norton, P. R.; Novakova, J.; Nozaki, M.; Nozka, L.; Nugent, I. M.; Nuncio-Quiroz, A.-E.; Nunes Hanninger, G.; Nunnemann, T.; Nurse, E.; Nyman, T.; O'Brien, B. J.; O'Neale, S. W.; O'Neil, D. C.; O'Shea, V.; Oakes, L. B.; Oakham, F. G.; Oberlack, H.; Ocariz, J.; Ochi, A.; Oda, S.; Odaka, S.; Odier, J.; Ogren, H.; Oh, A.; Oh, S. H.; Ohm, C. C.; Ohshima, T.; Ohshita, H.; Ohsugi, T.; Okada, S.; Okawa, H.; Okumura, Y.; Okuyama, T.; Olariu, A.; Olcese, M.; Olchevski, A. G.; Olivares Pino, S. A.; Oliveira, M.; Oliveira Damazio, D.; Oliver Garcia, E.; Olivito, D.; Olszewski, A.; Olszowska, J.; Omachi, C.; Onofre, A.; Onyisi, P. U. E.; Oram, C. J.; Oreglia, M. J.; Oren, Y.; Orestano, D.; Orlando, N.; Orlov, I.; Oropeza Barrera, C.; Orr, R. S.; Osculati, B.; Ospanov, R.; Osuna, C.; Otero Y Garzon, G.; Ottersbach, J. P.; Ouchrif, M.; Ouellette, E. A.; Ould-Saada, F.; Ouraou, A.; Ouyang, Q.; Ovcharova, A.; Owen, M.; Owen, S.; Ozcan, V. E.; Ozturk, N.; Pacheco Pages, A.; Padilla Aranda, C.; Pagan Griso, S.; Paganis, E.; Paige, F.; Pais, P.; Pajchel, K.; Palacino, G.; Paleari, C. P.; Palestini, S.; Pallin, D.; Palma, A.; Palmer, J. D.; Pan, Y. B.; Panagiotopoulou, E.; Panes, B.; Pani, P.; Panikashvili, N.; Panitkin, S.; Pantea, D.; Panuskova, M.; Paolone, V.; Papadelis, A.; Papadopoulou, Th. D.; Paramonov, A.; Paredes Hernandez, D.; Park, W.; Parker, M. A.; Parodi, F.; Parsons, J. A.; Parzefall, U.; Pashapour, S.; Pasqualucci, E.; Passaggio, S.; Passeri, A.; Pastore, F.; Pastore, Fr.; Pásztor, G.; Pataraia, S.; Patel, N.; Pater, J. R.; Patricelli, S.; Pauly, T.; Pecsy, M.; Pedraza Morales, M. I.; Peleganchuk, S. V.; Pelikan, D.; Peng, H.; Pengo, R.; Penning, B.; Penson, A.; Penwell, J.; Perantoni, M.; Perez, K.; Perez Cavalcanti, T.; Perez Codina, E.; Pérez García-Estañ, M. T.; Perez Reale, V.; Perini, L.; Pernegger, H.; Perrino, R.; Perrodo, P.; Persembe, S.; Perus, A.; Peshekhonov, V. D.; Peters, K.; Petersen, B. A.; Petersen, J.; Petersen, T. C.; Petit, E.; Petridis, A.; Petridou, C.; Petrolo, E.; Petrucci, F.; Petschull, D.; Petteni, M.; Pezoa, R.; Phan, A.; Phillips, P. W.; Piacquadio, G.; Picazio, A.; Piccaro, E.; Piccinini, M.; Piec, S. M.; Piegaia, R.; Pignotti, D. T.; Pilcher, J. E.; Pilkington, A. D.; Pina, J.; Pinamonti, M.; Pinder, A.; Pinfold, J. L.; Ping, J.; Pinto, B.; Pirotte, O.; Pizio, C.; Placakyte, R.; Plamondon, M.; Pleier, M.-A.; Pleskach, A. V.; Plotnikova, E.; Poblaguev, A.; Poddar, S.; Podlyski, F.; Poggioli, L.; Poghosyan, T.; Pohl, M.; Polci, F.; Polesello, G.; Policicchio, A.; Polini, A.; Poll, J.; Polychronakos, V.; Pomarede, D. M.; Pomeroy, D.; Pommès, K.; Pontecorvo, L.; Pope, B. G.; Popeneciu, G. A.; Popovic, D. S.; Poppleton, A.; Portell Bueso, X.; Posch, C.; Pospelov, G. E.; Pospisil, S.; Potrap, I. N.; Potter, C. J.; Potter, C. T.; Poulard, G.; Poveda, J.; Pozdnyakov, V.; Prabhu, R.; Pralavorio, P.; Pranko, A.; Prasad, S.; Pravahan, R.; Prell, S.; Pretzl, K.; Pribyl, L.; Price, D.; Price, J.; Price, L. E.; Price, M. J.; Prieur, D.; Primavera, M.; Prokofiev, K.; Prokoshin, F.; Protopopescu, S.; Proudfoot, J.; Prudent, X.; Przybycien, M.; Przysiezniak, H.; Psoroulas, S.; Ptacek, E.; Pueschel, E.; Purdham, J.; Purohit, M.; Puzo, P.; Pylypchenko, Y.; Qian, J.; Qian, Z.; Qin, Z.; Quadt, A.; Quarrie, D. R.; Quayle, W. B.; Quinonez, F.; Raas, M.; Radescu, V.; Radics, B.; Radloff, P.; Rador, T.; Ragusa, F.; Rahal, G.; Rahimi, A. M.; Rahm, D.; Rajagopalan, S.; Rammensee, M.; Rammes, M.; Randle-Conde, A. S.; Randrianarivony, K.; Ratoff, P. N.; Rauscher, F.; Rave, T. C.; Raymond, M.; Read, A. L.; Rebuzzi, D. M.; Redelbach, A.; Redlinger, G.; Reece, R.; Reeves, K.; Reichold, A.; Reinherz-Aronis, E.; Reinsch, A.; Reisinger, I.; Reljic, D.; Rembser, C.; Ren, Z. L.; Renaud, A.; Renkel, P.; Rescigno, M.; Resconi, S.; Resende, B.; Reznicek, P.; Rezvani, R.; Richards, A.; Richter, R.; Richter-Was, E.; Ridel, M.; Rijpstra, M.; Rijssenbeek, M.; Rimoldi, A.; Rinaldi, L.; Rios, R. R.; Riu, I.; Rivoltella, G.; Rizatdinova, F.; Rizvi, E.; Robertson, S. H.; Robichaud-Veronneau, A.; Robinson, D.; Robinson, J. E. M.; Robinson, M.; Robson, A.; Rocha de Lima, J. G.; Roda, C.; Roda Dos Santos, D.; Rodriguez, D.; Rodriguez Garcia, Y.; Roe, A.; Roe, S.; Røhne, O.; Rojo, V.; Rolli, S.; Romaniouk, A.; Romano, M.; Romanov, V. M.; Romeo, G.; Romero Adam, E.; Roos, L.; Ros, E.; Rosati, S.; Rosbach, K.; Rose, A.; Rose, M.; Rosenbaum, G. A.; Rosenberg, E. I.; Rosendahl, P. L.; Rosenthal, O.; Rosselet, L.; Rossetti, V.; Rossi, E.; Rossi, L. P.; Rotaru, M.; Roth, I.; Rothberg, J.; Rousseau, D.; Royon, C. R.; Rozanov, A.; Rozen, Y.; Ruan, X.; Rubbo, F.; Rubinskiy, I.; Ruckert, B.; Ruckstuhl, N.; Rud, V. I.; Rudolph, C.; Rudolph, G.; Rühr, F.; Ruggieri, F.; Ruiz-Martinez, A.; Rumiantsev, V.; Rumyantsev, L.; Runge, K.; Rurikova, Z.; Rusakovich, N. A.; Rust, D. R.; Rutherfoord, J. P.; Ruwiedel, C.; Ruzicka, P.; Ryabov, Y. F.; Ryadovikov, V.; Ryan, P.; Rybar, M.; Rybkin, G.; Ryder, N. C.; Rzaeva, S.; Saavedra, A. F.; Sadeh, I.; Sadrozinski, H. F.-W.; Sadykov, R.; Safai Tehrani, F.; Sakamoto, H.; Salamanna, G.; Salamon, A.; Saleem, M.; Salek, D.; Salihagic, D.; Salnikov, A.; Salt, J.; Salvachua Ferrando, B. M.; Salvatore, D.; Salvatore, F.; Salvucci, A.; Salzburger, A.; Sampsonidis, D.; Samset, B. H.; Sanchez, A.; Sanchez Martinez, V.; Sandaker, H.; Sander, H. G.; Sanders, M. P.; Sandhoff, M.; Sandoval, T.; Sandoval, C.; Sandstroem, R.; Sandvoss, S.; Sankey, D. P. C.; Sansoni, A.; Santamarina Rios, C.; Santoni, C.; Santonico, R.; Santos, H.; Saraiva, J. G.; Sarangi, T.; Sarkisyan-Grinbaum, E.; Sarri, F.; Sartisohn, G.; Sasaki, O.; Sasao, N.; Satsounkevitch, I.; Sauvage, G.; Sauvan, E.; Sauvan, J. B.; Savard, P.; Savinov, V.; Savu, D. O.; Sawyer, L.; Saxon, D. H.; Saxon, J.; Says, L. P.; Sbarra, C.; Sbrizzi, A.; Scallon, O.; Scannicchio, D. A.; Scarcella, M.; Schaarschmidt, J.; Schacht, P.; Schaefer, D.; Schäfer, U.; Schaepe, S.; Schaetzel, S.; Schaffer, A. C.; Schaile, D.; Schamberger, R. D.; Schamov, A. G.; Scharf, V.; Schegelsky, V. A.; Scheirich, D.; Schernau, M.; Scherzer, M. I.; Schiavi, C.; Schieck, J.; Schioppa, M.; Schlenker, S.; Schlereth, J. L.; Schmidt, E.; Schmieden, K.; Schmitt, C.; Schmitt, S.; Schmitz, M.; Schneider, B.; Schöning, A.; Schott, M.; Schouten, D.; Schovancova, J.; Schram, M.; Schroeder, C.; Schroer, N.; Schuh, S.; Schuler, G.; Schultens, M. J.; Schultes, J.; Schultz-Coulon, H.-C.; Schulz, H.; Schumacher, J. W.; Schumacher, M.; Schumm, B. A.; Schune, Ph.; Schwanenberger, C.; Schwartzman, A.; Schwemling, Ph.; Schwienhorst, R.; Schwierz, R.; Schwindling, J.; Schwindt, T.; Schwoerer, M.; Sciolla, G.; Scott, W. G.; Searcy, J.; Sedov, G.; Sedykh, E.; Segura, E.; Seidel, S. C.; Seiden, A.; Seifert, F.; Seixas, J. M.; Sekhniaidze, G.; Sekula, S. J.; Selbach, K. E.; Seliverstov, D. M.; Sellden, B.; Sellers, G.; Seman, M.; Semprini-Cesari, N.; Serfon, C.; Serin, L.; Serkin, L.; Seuster, R.; Severini, H.; Sevior, M. E.; Sfyrla, A.; Shabalina, E.; Shamim, M.; Shan, L. Y.; Shank, J. T.; Shao, Q. T.; Shapiro, M.; Shatalov, P. B.; Shaver, L.; Shaw, K.; Sherman, D.; Sherwood, P.; Shibata, A.; Shichi, H.; Shimizu, S.; Shimojima, M.; Shin, T.; Shiyakova, M.; Shmeleva, A.; Shochet, M. J.; Short, D.; Shrestha, S.; Shulga, E.; Shupe, M. A.; Sicho, P.; Sidoti, A.; Siegert, F.; Sijacki, Dj.; Silbert, O.; Silva, J.; Silver, Y.; Silverstein, D.; Silverstein, S. B.; Simak, V.; Simard, O.; Simic, Lj.; Simion, S.; Simmons, B.; Simoniello, R.; Simonyan, M.; Sinervo, P.; Sinev, N. B.; Sipica, V.; Siragusa, G.; Sircar, A.; Sisakyan, A. N.; Sivoklokov, S. Yu.; Sjölin, J.; Sjursen, T. B.; Skinnari, L. A.; Skottowe, H. P.; Skovpen, K.; Skubic, P.; Skvorodnev, N.; Slater, M.; Slavicek, T.; Sliwa, K.; Sloper, J.; Smakhtin, V.; Smart, B. H.; Smirnov, S. Yu.; Smirnov, Y.; Smirnova, L. N.; Smirnova, O.; Smith, B. C.; Smith, D.; Smith, K. M.; Smizanska, M.; Smolek, K.; Snesarev, A. A.; Snow, S. W.; Snow, J.; Snuverink, J.; Snyder, S.; Soares, M.; Sobie, R.; Sodomka, J.; Soffer, A.; Solans, C. A.; Solar, M.; Solc, J.; Soldatov, E.; Soldevila, U.; Solfaroli Camillocci, E.; Solodkov, A. A.; Solovyanov, O. V.; Sondericker, J.; Soni, N.; Sopko, V.; Sopko, B.; Sosebee, M.; Soualah, R.; Soukharev, A.; Spagnolo, S.; Spanò, F.; Spighi, R.; Spigo, G.; Spila, F.; Spiwoks, R.; Spousta, M.; Spreitzer, T.; Spurlock, B.; St. Denis, R. D.; Stahl, T.; Stahlman, J.; Stamen, R.; Stanecka, E.; Stanek, R. W.; Stanescu, C.; Stanescu-Bellu, M.; Stapnes, S.; Starchenko, E. A.; Stark, J.; Staroba, P.; Starovoitov, P.; Staude, A.; Stavina, P.; Stavropoulos, G.; Steele, G.; Steinbach, P.; Steinberg, P.; Stekl, I.; Stelzer, B.; Stelzer, H. J.; Stelzer-Chilton, O.; Stenzel, H.; Stern, S.; Stevenson, K.; Stewart, G. A.; Stillings, J. A.; Stockton, M. C.; Stoerig, K.; Stoicea, G.; Stonjek, S.; Strachota, P.; Stradling, A. R.; Straessner, A.; Strandberg, J.; Strandberg, S.; Strandlie, A.; Strang, M.; Strauss, E.; Strauss, M.; Strizenec, P.; Ströhmer, R.; Strom, D. M.; Strong, J. A.; Stroynowski, R.; Strube, J.; Stugu, B.; Stumer, I.; Stupak, J.; Sturm, P.; Styles, N. A.; Soh, D. A.; Su, D.; Subramania, H. S.; Succurro, A.; Sugaya, Y.; Sugimoto, T.; Suhr, C.; Suita, K.; Suk, M.; Sulin, V. V.; Sultansoy, S.; Sumida, T.; Sun, X.; Sundermann, J. E.; Suruliz, K.; Sushkov, S.; Susinno, G.; Sutton, M. R.; Suzuki, Y.; Suzuki, Y.; Svatos, M.; Sviridov, Yu. M.; Swedish, S.; Sykora, I.; Sykora, T.; Szeless, B.; Sánchez, J.; Ta, D.; Tackmann, K.; Taffard, A.; Tafirout, R.; Taiblum, N.; Takahashi, Y.; Takai, H.; Takashima, R.; Takeda, H.; Takeshita, T.; Takubo, Y.; Talby, M.; Talyshev, A.; Tamsett, M. C.; Tanaka, J.; Tanaka, R.; Tanaka, S.; Tanaka, S.; Tanaka, Y.; Tanasijczuk, A. J.; Tani, K.; Tannoury, N.; Tappern, G. P.; Tapprogge, S.; Tardif, D.; Tarem, S.; Tarrade, F.; Tartarelli, G. F.; Tas, P.; Tasevsky, M.; Tassi, E.; Tatarkhanov, M.; Tayalati, Y.; Taylor, C.; Taylor, F. E.; Taylor, G. N.; Taylor, W.; Teinturier, M.; Teixeira Dias Castanheira, M.; Teixeira-Dias, P.; Temming, K. K.; Ten Kate, H.; Teng, P. K.; Terada, S.; Terashi, K.; Terron, J.; Testa, M.; Teuscher, R. J.; Thadome, J.; Therhaag, J.; Theveneaux-Pelzer, T.; Thioye, M.; Thoma, S.; Thomas, J. P.; Thompson, E. N.; Thompson, P. D.; Thompson, P. D.; Thompson, A. S.; Thomsen, L. A.; Thomson, E.; Thomson, M.; Thun, R. P.; Tian, F.; Tibbetts, M. J.; Tic, T.; Tikhomirov, V. O.; Tikhonov, Y. A.; Timoshenko, S.; Tipton, P.; Tique Aires Viegas, F. J.; Tisserant, S.; Toczek, B.; Todorov, T.; Todorova-Nova, S.; Toggerson, B.; Tojo, J.; Tokár, S.; Tokunaga, K.; Tokushuku, K.; Tollefson, K.; Tomoto, M.; Tompkins, L.; Toms, K.; Tong, G.; Tonoyan, A.; Topfel, C.; Topilin, N. D.; Torchiani, I.; Torrence, E.; Torres, H.; Torró Pastor, E.; Toth, J.; Touchard, F.; Tovey, D. R.; Trefzger, T.; Tremblet, L.; Tricoli, A.; Trigger, I. M.; Trincaz-Duvoid, S.; Trinh, T. N.; Tripiana, M. F.; Trischuk, W.; Trivedi, A.; Trocmé, B.; Troncon, C.; Trottier-McDonald, M.; Trzebinski, M.; Trzupek, A.; Tsarouchas, C.; Tseng, J. C.-L.; Tsiakiris, M.; Tsiareshka, P. V.; Tsionou, D.; Tsipolitis, G.; Tsiskaridze, V.; Tskhadadze, E. G.; Tsukerman, I. I.; Tsulaia, V.; Tsung, J.-W.; Tsuno, S.; Tsybychev, D.; Tua, A.; Tudorache, A.; Tudorache, V.; Tuggle, J. M.; Turala, M.; Turecek, D.; Turk Cakir, I.; Turlay, E.; Turra, R.; Tuts, P. M.; Tykhonov, A.; Tylmad, M.; Tyndel, M.; Tzanakos, G.; Uchida, K.; Ueda, I.; Ueno, R.; Ugland, M.; Uhlenbrock, M.; Uhrmacher, M.; Ukegawa, F.; Unal, G.; Underwood, D. G.; Undrus, A.; Unel, G.; Unno, Y.; Urbaniec, D.; Usai, G.; Uslenghi, M.; Vacavant, L.; Vacek, V.; Vachon, B.; Vahsen, S.; Valenta, J.; Valente, P.; Valentinetti, S.; Valkar, S.; Valladolid Gallego, E.; Vallecorsa, S.; Valls Ferrer, J. A.; van der Graaf, H.; van der Kraaij, E.; van der Leeuw, R.; van der Poel, E.; van der Ster, D.; van Eldik, N.; van Gemmeren, P.; van Kesteren, Z.; van Vulpen, I.; Vanadia, M.; Vandelli, W.; Vandoni, G.; Vaniachine, A.; Vankov, P.; Vannucci, F.; Varela Rodriguez, F.; Vari, R.; Varnes, E. W.; Varol, T.; Varouchas, D.; Vartapetian, A.; Varvell, K. E.; Vassilakopoulos, V. I.; Vazeille, F.; Vazquez Schroeder, T.; Vegni, G.; Veillet, J. J.; Vellidis, C.; Veloso, F.; Veness, R.; Veneziano, S.; Ventura, A.; Ventura, D.; Venturi, M.; Venturi, N.; Vercesi, V.; Verducci, M.; Verkerke, W.; Vermeulen, J. C.; Vest, A.; Vetterli, M. C.; Vichou, I.; Vickey, T.; Vickey Boeriu, O. E.; Viehhauser, G. H. A.; Viel, S.; Villa, M.; Villaplana Perez, M.; Vilucchi, E.; Vincter, M. G.; Vinek, E.; Vinogradov, V. B.; Virchaux, M.; Virzi, J.; Vitells, O.; Viti, M.; Vivarelli, I.; Vives Vaque, F.; Vlachos, S.; Vladoiu, D.; Vlasak, M.; Vlasov, N.; Vogel, A.; Vokac, P.; Volpi, G.; Volpi, M.; Volpini, G.; von der Schmitt, H.; von Loeben, J.; von Radziewski, H.; von Toerne, E.; Vorobel, V.; Vorobiev, A. P.; Vorwerk, V.; Vos, M.; Voss, R.; Voss, T. T.; Vossebeld, J. H.; Vranjes, N.; Vranjes Milosavljevic, M.; Vrba, V.; Vreeswijk, M.; Vu Anh, T.; Vuillermet, R.; Vukotic, I.; Wagner, W.; Wagner, P.; Wahlen, H.; Wakabayashi, J.; Walbersloh, J.; Walch, S.; Walder, J.; Walker, R.; Walkowiak, W.; Wall, R.; Waller, P.; Wang, C.; Wang, H.; Wang, H.; Wang, J.; Wang, J.; Wang, J. C.; Wang, R.; Wang, S. M.; Wang, T.; Warburton, A.; Ward, C. P.; Warsinsky, M.; Washbrook, A.; Wasicki, C.; Wastie, R.; Watkins, P. M.; Watson, A. T.; Watson, I. J.; Watson, M. F.; Watts, G.; Watts, S.; Waugh, A. T.; Waugh, B. M.; Weber, M.; Weber, M. S.; Weber, P.; Weidberg, A. R.; Weigell, P.; Weingarten, J.; Weiser, C.; Wellenstein, H.; Wells, P. S.; Wen, M.; Wenaus, T.; Wendland, D.; Wendler, S.; Weng, Z.; Wengler, T.; Wenig, S.; Wermes, N.; Werner, M.; Werner, P.; Werth, M.; Wessels, M.; Wetter, J.; Weydert, C.; Whalen, K.; Wheeler-Ellis, S. J.; Whitaker, S. P.; White, A.; White, M. J.; White, S.; Whitehead, S. R.; Whiteson, D.; Whittington, D.; Wicek, F.; Wicke, D.; Wickens, F. J.; Wiedenmann, W.; Wielers, M.; Wienemann, P.; Wiglesworth, C.; Wiik-Fuchs, L. A. M.; Wijeratne, P. A.; Wildauer, A.; Wildt, M. A.; Wilhelm, I.; Wilkens, H. G.; Will, J. Z.; Williams, E.; Williams, H. H.; Willis, W.; Willocq, S.; Wilson, J. A.; Wilson, M. G.; Wilson, A.; Wingerter-Seez, I.; Winkelmann, S.; Winklmeier, F.; Wittgen, M.; Wolter, M. W.; Wolters, H.; Wong, W. C.; Wooden, G.; Wosiek, B. K.; Wotschack, J.; Woudstra, M. J.; Wozniak, K. W.; Wraight, K.; Wright, C.; Wright, M.; Wrona, B.; Wu, S. L.; Wu, X.; Wu, Y.; Wulf, E.; Wunstorf, R.; Wynne, B. M.; Xella, S.; Xiao, M.; Xie, S.; Xie, Y.; Xu, C.; Xu, D.; Xu, G.; Yabsley, B.; Yacoob, S.; Yamada, M.; Yamaguchi, H.; Yamamoto, A.; Yamamoto, K.; Yamamoto, S.; Yamamura, T.; Yamanaka, T.; Yamaoka, J.; Yamazaki, T.; Yamazaki, Y.; Yan, Z.; Yang, H.; Yang, U. K.; Yang, Y.; Yang, Y.; Yang, Z.; Yanush, S.; Yao, Y.; Yasu, Y.; Ybeles Smit, G. V.; Ye, J.; Ye, S.; Yilmaz, M.; Yoosoofmiya, R.; Yorita, K.; Yoshida, R.; Young, C.; Young, C. J.; Youssef, S.; Yu, D.; Yu, J.; Yu, J.; Yuan, L.; Yurkewicz, A.; Zabinski, B.; Zaets, V. G.; Zaidan, R.; Zaitsev, A. M.; Zajacova, Z.; Zanello, L.; Zarzhitsky, P.; Zaytsev, A.; Zeitnitz, C.; Zeller, M.; Zeman, M.; Zemla, A.; Zendler, C.; Zenin, O.; Ženiš, T.; Zinonos, Z.; Zenz, S.; Zerwas, D.; Zevi Della Porta, G.; Zhan, Z.; Zhang, D.; Zhang, H.; Zhang, J.; Zhang, X.; Zhang, Z.; Zhao, L.; Zhao, T.; Zhao, Z.; Zhemchugov, A.; Zheng, S.; Zhong, J.; Zhou, B.; Zhou, N.; Zhou, Y.; Zhu, C. G.; Zhu, H.; Zhu, J.; Zhu, Y.; Zhuang, X.; Zhuravlov, V.; Zieminska, D.; Zimmermann, R.; Zimmermann, S.; Zimmermann, S.; Ziolkowski, M.; Zitoun, R.; Živković, L.; Zmouchko, V. V.; Zobernig, G.; Zoccoli, A.; Zolnierowski, Y.; Zsenei, A.; Zur Nedden, M.; Zutshi, V.; Zwalinski, L.; Atlas Collaboration
2012-05-01
This Letter presents a search for singly produced vector-like quarks, Q, coupling to light quarks, q. The search is sensitive to both charged current (CC) and neutral current (NC) processes, pp → Qq → Wqq‧ and pp → Qq → Zqq‧ with a leptonic decay of the vector gauge boson. In 1.04 fb-1 of data taken in 2011 by the ATLAS experiment at a center-of-mass energy √{ s} = 7 TeV, no evidence of such heavy vector-like quarks is observed above the expected Standard Model background. Limits on the heavy vector-like quark production cross section times branching ratio as a function of mass mQ are obtained. For a coupling κqQ = v /mQ, where v is the Higgs vacuum expectation value, 95% C.L. lower limits on the mass of a vector-like quark are set at 900 GeV and 760 GeV from CC and NC processes, respectively.
Probing top quark neutral couplings in the Standard Model Effective Field Theory at NLO in QCD
NASA Astrophysics Data System (ADS)
Bylund, Olga Bessidskaia; Maltoni, Fabio; Tsinikos, Ioannis; Vryonidou, Eleni; Zhang, Cen
2016-05-01
Top quark pair production in association with a Z-boson or a photon at the LHC directly probes neutral top-quark couplings. We present predictions for these two processes in the Standard Model (SM) Effective Field Theory (EFT) at next-to-leading order (NLO) in QCD. We include the full set of CP-even dimension-six operators that enter the top-quark interactions with the SM gauge bosons. For comparison, we also present predictions in the SMEFT for top loop-induced HZ production at the LHC and for toverline{t} production at the ILC at NLO in QCD. Results for total cross sections and differential distributions are obtained and uncertainties coming from missing higher orders in the strong coupling and in the EFT expansions are discussed. NLO results matched to the parton shower are available, allowing for event generation to be directly employed in an experimental analyses. Our framework provides a solid basis for the interpretation of current and future measurements in the SMEFT, with improved accuracy and precision.
Properties of quark matter in a new quasiparticle model with QCD running coupling
NASA Astrophysics Data System (ADS)
Lu, ZhenYan; Peng, GuangXiong; Xu, JianFeng; Zhang, ShiPeng
2016-06-01
The running of the QCD coupling in the effective mass causes thermodynamic inconsistency problem in the conventional quasiparticle model. We provide a novel treatment which removes the inconsistency by an effective bag constant. The chemical potential dependence of the renormalization subtraction point is constrained by the Cauchy condition in the chemical potential space. The stability and microscopic properties of strange quark matter are then studied within the completely self-consistent quasiparticle model, and the obtained equation of state of quark matter is applied to the investigation of strange stars. It is found that our improved model can describe well compact stars with mass about two times the solar mass, which indicates that such massive compact stars could be strange stars.
Physical Origin of Density Dependent Force of the Skyrme Type within the Quark Meson Coupling Model
Pierre Guichon; Hrayr Matevosyan; N. Sandulescu; Anthony Thomas
2006-03-17
A density dependent, effective nucleon-nucleon force of the Skyrme type is derived from the quark-meson coupling model--a self-consistent, relativistic quark level description of nuclear matter. This new formulation requires no assumption that the mean scalar field is small and hence constitutes a significant advance over earlier work. The similarity of the effective interaction to the widely used SkM* force encourages us to apply it to a wide range of nuclear problems, beginning with the binding energies and charge distributions of doubly magic nuclei. Finding impressive results in this conventional arena, we apply the same effective interaction, within the Hartree-Fock-Bogoliubov approach, to the properties of nuclei far from stability. The resulting two neutron drip lines and shell quenching are quite satisfactory. Finally, we apply the relativistic formulation to the properties of dense nuclear matter in anticipation of future application to the properties of neutron stars.
Energy loss, equilibration, and thermodynamics of a baryon rich strongly coupled quark-gluon plasma
NASA Astrophysics Data System (ADS)
Rougemont, Romulo; Ficnar, Andrej; Finazzo, Stefano I.; Noronha, Jorge
2016-04-01
Lattice data for the QCD equation of state and the baryon susceptibility near the crossover phase transition (at zero baryon density) are used to determine the input parameters of a 5-dimensional Einstein-Maxwell-Dilaton holographic model that provides a consistent holographic framework to study both equilibrium and out-of-equilibrium properties of a hot and baryon rich strongly coupled quark-gluon plasma (QGP). We compare our holographic equation of state computed at nonzero baryon chemical potential, μ B , with recent lattice calculations and find quantitative agreement for the pressure and the speed of sound for μ B ≤ 400 MeV. This holographic model is used to obtain holographic predictions for the temperature and μ B dependence of the drag force and the Langevin diffusion coefficients associated with heavy quark jet propagation as well as the jet quenching parameter q and the shooting string energy loss of light quarks in the baryon dense plasma. We find that the energy loss of heavy and light quarks generally displays a nontrivial, fast-varying behavior as a function of the temperature near the crossover. Moreover, energy loss is also found to generally increase due to nonzero baryon density effects even though this strongly coupled liquid cannot be described in terms of well defined quasiparticle excitations. Furthermore, to get a glimpse of how thermalization occurs in a hot and baryon dense QGP, we study how the lowest quasinormal mode of an external massless scalar disturbance in the bulk is affected by a nonzero baryon charge. We find that the equilibration time associated with the lowest quasinormal mode decreases in a dense medium.
Measurements of the top quark mass and decay width with the D0 detector
Ilchenko, Yuriy
2011-11-01
The top quark discovery in 1995 at Fermilab is one of the major proofs of the standard model (SM). Due to its unique place in SM, the top quark is an important particle for testing the theory and probing for new physics. This article presents most recent measurements of top quark properties from the D0 detector. In particular, the measurement of the top quark mass, the top antitop mass difference and the top quark decay width. The discovery of the top quark in 1995 confirmed the existence of a third generation of quarks predicted in the standard model (SM). Being the heaviest elementary particle known, the top quark appears to become an important particle in our understanding of the standard model and physics beyond it. Because of its large mass the top quark has a very short lifetime, much shorter than the hadronization time. The predicted lifetime is only 3.3 {center_dot} 10{sup -25}s. Top quark is the only quark whose properties can be studied in isolation. A Lorentz-invariant local Quantum Field Theory, the standard model is expected to conserve CP. Due to its unique properties, the top quark provides a perfect test of CPT invariance in the standard model. An ability to look at the quark before being hadronized allows to measure directly mass of the top quark and its antiquark. An observation of a mass difference between particle and antiparticle would indicate violation of CPT invariance. Top quark through its radiative loop correction to the W mass constrains the mass of the Higgs boson. A precise measurement of the top quark mass provides useful information to the search of Higgs boson by constraining its region of possible masses. Another interesting aspect is that the top quark's Yukawa coupling to the Higgs boson is very close to unity (0.996 {+-} 0.006). That implies it may play a special role in the electroweak symmetry breaking mechanism.
Yukawa unification predictions with effective "mirage" mediation.
Anandakrishnan, Archana; Raby, Stuart
2013-11-22
In this Letter we analyze the consequences, for the LHC, of gauge and third family Yukawa coupling unification with a particular set of boundary conditions defined at the grand unified theory (GUT) scale, which we characterize as effective "mirage" mediation. We perform a global χ2 analysis including the observables M(W), M(Z), G(F), α(em)(-1), α(s)(M(Z)), M(t), m(b)(m(b)), M(τ), BR(B→X(s)γ), BR(B(s)→μ(+)μ(-)), and M(h). The fit is performed in the minimal supersymmetric standard model in terms of 10 GUT scale parameters, while tanβ and μ are fixed at the weak scale. We find good fits to the low energy data and a supersymmetry spectrum which is dramatically different than previously studied in the context of Yukawa unification. PMID:24313477
Yukawa Unification Predictions with Effective ``Mirage'' Mediation
NASA Astrophysics Data System (ADS)
Anandakrishnan, Archana; Raby, Stuart
2013-11-01
In this Letter we analyze the consequences, for the LHC, of gauge and third family Yukawa coupling unification with a particular set of boundary conditions defined at the grand unified theory (GUT) scale, which we characterize as effective “mirage” mediation. We perform a global χ2 analysis including the observables MW, MZ, GF, αem-1, αs(MZ), Mt, mb(mb), Mτ, BR(B→Xsγ), BR(Bs→μ+μ-), and Mh. The fit is performed in the minimal supersymmetric standard model in terms of 10 GUT scale parameters, while tanβ and μ are fixed at the weak scale. We find good fits to the low energy data and a supersymmetry spectrum which is dramatically different than previously studied in the context of Yukawa unification.
Cold Uniform Matter and Neutron Stars in the Quark-Meson-Coupling Model
J.R. Stone; P.A.M. Guichon; H.H. Matevosyan; A.W. Thomas
2007-08-01
A new density dependent effective baryon-baryon interaction has been recently derived from the quark-meson-coupling (QMC) model, offering impressive results in application to finite nuclei and dense baryon matter. This self-consistent, relativistic quark-level approach is used to construct the Equation of State (EoS) and to calculate key properties of high density matter and cold, slowly rotating neutron stars. The results include predictions for the maximum mass of neutron star models, together with the corresponding radius and central density, as well the properties of neutron stars with mass of order 1.4 M{sub {circle_dot}}. The cooling mechanism allowed by the QMC EoS is explored and the parameters relevant to slow rotation, namely the moment of inertia and the period of rotation investigated. The results of the calculation, which are found to be in good agreement with available observational data, are compared with the predictions of more traditional EoS, based on the A18+{delta}v+UIX* and modified Reid soft core potentials, the Skyrme SkM* interaction and two relativistic mean field (RMF) models for a hybrid stars including quark matter. The QMC EoS provides cold neutron star models with maximum mass 1.9-2.1 M{sub {circle_dot}}, with central density less than 6 times nuclear saturation density (n{sub 0} = 0.16 fm{sup -3}) and offers a consistent description of the stellar mass up to this density limit. In contrast with other models, QMC predicts no hyperon contribution at densities lower than 3n{sub 0}, for matter in {beta}-equilibrium. At higher densities, {Xi}{sup -,0} and {Lambda} hyperons are present. The absence of lighter {Sigma}{sup {+-},0} hyperons is understood as a consequence of antisymmetrization, together with the implementation of the color hyperfine interaction in the response of the quark bag to the nuclear scalar field.
Yukawa alignment in the two-Higgs-doublet model
Pich, Antonio; Tuzon, Paula
2009-11-01
In multi-Higgs-doublet models the alignment in flavor space of the relevant Yukawa matrices guarantees the absence of tree-level flavor-changing couplings of the neutral scalar fields. We analyze the consequences of this condition within the two-Higgs-doublet model and show that it leads to a generic Yukawa structure which contains as particular cases all known specific implementations of the model based on Z{sub 2} symmetries. All possible freedom in the Yukawa sector gets parametrized in terms of three complex couplings {sigma}{sub f}. In spite of having flavor conservation in the neutral scalar couplings, the phases of these three parameters represent potential new sources of CP violation.
Five easy pieces: The dynamics of quarks in strongly coupled plasmas
NASA Astrophysics Data System (ADS)
Mia, Mohammed; Dasgupta, Keshav; Gale, Charles; Jeon, Sangyong
2010-11-01
We revisit the analysis of the drag a massive quark experiences and the wake it creates at a temperature T while moving through a plasma using a gravity dual that captures the renormalisation group runnings in the dual gauge theory. Our gravity dual has a black hole and seven branes embedded via Ouyang embedding, but the geometry is a deformation of the usual conifold metric. In particular the gravity dual has squashed two spheres, and a small resolution at the IR. Using this background we show that the drag of a massive quark receives corrections that are proportional to powers of log T when compared with the drag computed using AdS/QCD correspondence. The massive quarks map to fundamental strings in the dual gravity theory, and we use this to analyse their behavior at strong 't Hooft coupling. We also study the shear viscosity in the theory with running couplings, analyse the viscosity to entropy ratio and compare the result with the bound derived from AdS backgrounds. In the presence of higher order curvature square corrections from the back-reactions of the embedded D7 branes, we argue the possibility of the entropy to viscosity bound being violated. Finally, we show that our set-up could in-principle allow us to study a family of gauge theories at the boundary by cutting off the dual geometry respectively at various points in the radial direction. All these gauge theories can have well-defined UV completions, and more interestingly, we demonstrate that any thermodynamical quantities derived from these theories would be completely independent of the cut-off scale and only depend on the temperature at which we define these theories. Such a result would justify the holographic renormalisabilities of these theories which we, in turn, also demonstrate. We give physical interpretations of these results and compare them with more realistic scenarios.
Equilibration Rates in a Strongly Coupled Nonconformal Quark-Gluon Plasma.
Buchel, Alex; Heller, Michal P; Myers, Robert C
2015-06-26
We initiate the study of equilibration rates of strongly coupled quark-gluon plasmas in the absence of conformal symmetry. We primarily consider a supersymmetric mass deformation within N=2^{*} gauge theory and use holography to compute quasinormal modes of a variety of scalar operators, as well as the energy-momentum tensor. In each case, the lowest quasinormal frequency, which provides an approximate upper bound on the thermalization time, is proportional to temperature, up to a prefactor with only a mild temperature dependence. We find similar behavior in other holographic plasmas, where the model contains an additional scale beyond the temperature. Hence, our study suggests that the thermalization time is generically set by the temperature, irrespective of any other scales, in strongly coupled gauge theories. PMID:26197117
Abazov, V M; Abbott, B; Abolins, M; Acharya, B S; Adams, M; Adams, T; Aguilo, E; Ahn, S H; Ahsan, M; Alexeev, G D; Alkhazov, G; Alton, A; Alverson, G; Alves, G A; Anastasoaie, M; Ancu, L S; Andeen, T; Anderson, S; Andrieu, B; Anzelc, M S; Arnoud, Y; Arov, M; Askew, A; Asman, B; Assis Jesus, A C S; Atramentov, O; Autermann, C; Avila, C; Ay, C; Badaud, F; Baden, A; Bagby, L; Baldin, B; Bandurin, D V; Banerjee, P; Banerjee, S; Barberis, E; Barfuss, A-F; Bargassa, P; Baringer, P; Barnes, C; Barreto, J; Bartlett, J F; Bassler, U; Bauer, D; Beale, S; Bean, A; Begalli, M; Begel, M; Belanger-Champagne, C; Bellantoni, L; Bellavance, A; Benitez, J A; Beri, S B; Bernardi, G; Bernhard, R; Berntzon, L; Bertram, I; Besançon, M; Beuselinck, R; Bezzubov, V A; Bhat, P C; Bhatnagar, V; Binder, M; Biscarat, C; Blackler, I; Blazey, G; Blekman, F; Blessing, S; Bloch, D; Bloom, K; Boehnlein, A; Boline, D; Bolton, T A; Boos, E E; Borissov, G; Bos, K; Bose, T; Brandt, A; Brock, R; Brooijmans, G; Bross, A; Brown, D; Buchanan, N J; Buchholz, D; Buehler, M; Buescher, V; Bunichev, V; Burdin, S; Burke, S; Burnett, T H; Busato, E; Buszello, C P; Butler, J M; Calfayan, P; Calvet, S; Cammin, J; Caron, S; Carvalho, W; Casey, B C K; Cason, N M; Castilla-Valdez, H; Chakrabarti, S; Chakraborty, D; Chan, K; Chan, K M; Chandra, A; Charles, F; Cheu, E; Chevallier, F; Cho, D K; Choi, S; Choudhary, B; Christofek, L; Christoudias, T; Claes, D; Clément, B; Clément, C; Coadou, Y; Cooke, M; Cooper, W E; Corcoran, M; Couderc, F; Cousinou, M-C; Cox, B; Crépé-Renaudin, S; Cutts, D; Cwiok, M; da Motta, H; Das, A; Davies, B; Davies, G; De, K; de Jong, P; de Jong, S J; De La Cruz-Burelo, E; De Oliveira Martins, C; Degenhardt, J D; Déliot, F; Demarteau, M; Demina, R; Denisov, D; Denisov, S P; Desai, S; Diehl, H T; Diesburg, M; Doidge, M; Dominguez, A; Dong, H; Dudko, L V; Duflot, L; Dugad, S R; Duggan, D; Duperrin, A; Dyer, J; Dyshkant, A; Eads, M; Edmunds, D; Ellison, J; Elvira, V D; Enari, Y; Eno, S; Ermolov, P; Evans, H; Evdokimov, A; Evdokimov, V N; Ferapontov, A V; Ferbel, T; Fiedler, F; Filthaut, F; Fisher, W; Fisk, H E; Ford, M; Fortner, M; Fox, H; Fu, S; Fuess, S; Gadfort, T; Galea, C F; Gallas, E; Galyaev, E; Garcia, C; Garcia-Bellido, A; Gavrilov, V; Gay, P; Geist, W; Gelé, D; Gerber, C E; Gershtein, Y; Gillberg, D; Ginther, G; Gollub, N; Gómez, B; Goussiou, A; Grannis, P D; Greenlee, H; Greenwood, Z D; Gregores, E M; Grenier, G; Gris, Ph; Grivaz, J-F; Grohsjean, A; Grünendahl, S; Grünewald, M W; Guo, F; Guo, J; Gutierrez, G; Gutierrez, P; Haas, A; Hadley, N J; Haefner, P; Hagopian, S; Haley, J; Hall, I; Hall, R E; Han, L; Hanagaki, K; Hansson, P; Harder, K; Harel, A; Harrington, R; Hauptman, J M; Hauser, R; Hays, J; Hebbeker, T; Hedin, D; Hegeman, J G; Heinmiller, J M; Heinson, A P; Heintz, U; Hensel, C; Herner, K; Hesketh, G; Hildreth, M D; Hirosky, R; Hobbs, J D; Hoeneisen, B; Hoeth, H; Hohlfeld, M; Hong, S J; Hooper, R; Houben, P; Hu, Y; Hubacek, Z; Hynek, V; Iashvili, I; Illingworth, R; Ito, A S; Jabeen, S; Jaffré, M; Jain, S; Jakobs, K; Jarvis, C; Jenkins, A; Jesik, R; Johns, K; Johnson, C; Johnson, M; Jonckheere, A; Jonsson, P; Juste, A; Käfer, D; Kahn, S; Kajfasz, E; Kalinin, A M; Kalk, J M; Kalk, J R; Kappler, S; Karmanov, D; Kasper, J; Kasper, P; Katsanos, I; Kau, D; Kaur, R; Kehoe, R; Kermiche, S; Khalatyan, N; Khanov, A; Kharchilava, A; Kharzheev, Y M; Khatidze, D; Kim, H; Kim, T J; Kirby, M H; Klima, B; Kohli, J M; Konrath, J-P; Kopal, M; Korablev, V M; Kotcher, J; Kothari, B; Koubarovsky, A; Kozelov, A V; Krop, D; Kryemadhi, A; Kuhl, T; Kumar, A; Kunori, S; Kupco, A; Kurca, T; Kvita, J; Lam, D; Lammers, S; Landsberg, G; Lazoflores, J; Lebrun, P; Lee, W M; Leflat, A; Lehner, F; Lesne, V; Leveque, J; Lewis, P; Li, J; Li, L; Li, Q Z; Lietti, S M; Lima, J G R; Lincoln, D; Linnemann, J; Lipaev, V V; Lipton, R; Liu, Z; Lobo, L; Lobodenko, A; Lokajicek, M; Lounis, A; Love, P; Lubatti, H J; Lynker, M; Lyon, A L; Maciel, A K A; Madaras, R J; Mättig, P; Magass, C; Magerkurth, A; Makovec, N; Mal, P K; Malbouisson, H B; Malik, S; Malyshev, V L; Mao, H S; Maravin, Y; Martin, B; McCarthy, R; Melnitchouk, A; Mendes, A; Mendoza, L; Mercadante, P G; Merkin, M; Merritt, K W; Meyer, A; Meyer, J; Michaut, M; Miettinen, H; Millet, T; Mitrevski, J; Molina, J; Mommsen, R K; Mondal, N K; Monk, J; Moore, R W; Moulik, T; Muanza, G S; Mulders, M; Mulhearn, M; Mundal, O; Mundim, L; Nagy, E; Naimuddin, M; Narain, M; Naumann, N A; Neal, H A; Negret, J P; Neustroev, P; Nilsen, H; Noeding, C; Nomerotski, A; Novaes, S F; Nunnemann, T; O'Dell, V; O'Neil, D C; Obrant, G; Ochando, C; Oguri, V; Oliveira, N; Onoprienko, D; Oshima, N; Osta, J; Otec, R; Otero Y Garzón, G J; Owen, M; Padley, P; Pangilinan, M; Parashar, N; Park, S-J; Park, S K; Parsons, J; Partridge, R; Parua, N; Patwa, A; Pawloski, G; Perea, P M; Perfilov, M; Peters, K; Peters, Y; Pétroff, P; Petteni, M; Piegaia, R; Piper, J; Pleier, M-A; Podesta-Lerma, P L M; Podstavkov, V M; Pogorelov, Y; Pol, M-E; Pompos, A; Pope, B G; Popov, A V; Potter, C; Prado da Silva, W L; Prosper, H B; Protopopescu, S; Qian, J; Quadt, A; Quinn, B; Rangel, M S; Rani, K J; Ranjan, K; Ratoff, P N; Renkel, P; Reucroft, S; Rijssenbeek, M; Ripp-Baudot, I; Rizatdinova, F; Robinson, S; Rodrigues, R F; Royon, C; Rubinov, P; Ruchti, R; Sajot, G; Sánchez-Hernández, A; Sanders, M P; Santoro, A; Savage, G; Sawyer, L; Scanlon, T; Schaile, D; Schamberger, R D; Scheglov, Y; Schellman, H; Schieferdecker, P; Schmitt, C; Schwanenberger, C; Schwartzman, A; Schwienhorst, R; Sekaric, J; Sengupta, S; Severini, H; Shabalina, E; Shamim, M; Shary, V; Shchukin, A A; Shivpuri, R K; Shpakov, D; Siccardi, V; Sidwell, R A; Simak, V; Sirotenko, V; Skubic, P; Slattery, P; Smirnov, D; Smith, R P; Snow, G R; Snow, J; Snyder, S; Söldner-Rembold, S; Sonnenschein, L; Sopczak, A; Sosebee, M; Soustruznik, K; Souza, M; Spurlock, B; Stark, J; Steele, J; Stolin, V; Stone, A; Stoyanova, D A; Strandberg, J; Strandberg, S; Strang, M A; Strauss, M; Ströhmer, R; Strom, D; Strovink, M; Stutte, L; Sumowidagdo, S; Svoisky, P; Sznajder, A; Talby, M; Tamburello, P; Taylor, W; Telford, P; Temple, J; Tiller, B; Tissandier, F; Titov, M; Tokmenin, V V; Tomoto, M; Toole, T; Torchiani, I; Trefzger, T; Trincaz-Duvoid, S; Tsybychev, D; Tuchming, B; Tully, C; Tuts, P M; Unalan, R; Uvarov, L; Uvarov, S; Uzunyan, S; Vachon, B; van den Berg, P J; van Eijk, B; Van Kooten, R; van Leeuwen, W M; Varelas, N; Varnes, E W; Vartapetian, A; Vasilyev, I A; Vaupel, M; Verdier, P; Vertogradov, L S; Verzocchi, M; Villeneuve-Seguier, F; Vint, P; Vlimant, J-R; Von Toerne, E; Voutilainen, M; Vreeswijk, M; Wahl, H D; Wang, L; Wang, M H L S; Warchol, J; Watts, G; Wayne, M; Weber, G; Weber, M; Weerts, H; Wenger, A; Wermes, N; Wetstein, M; White, A; Wicke, D; Wilson, G W; Wimpenny, S J; Wobisch, M; Wood, D R; Wyatt, T R; Xie, Y; Yacoob, S; Yamada, R; Yan, M; Yasuda, T; Yatsunenko, Y A; Yip, K; Yoo, H D; Youn, S W; Yu, C; Yu, J; Yurkewicz, A; Zatserklyaniy, A; Zeitnitz, C; Zhang, D; Zhao, T; Zhou, B; Zhu, J; Zielinski, M; Zieminska, D; Zieminski, A; Zutshi, V; Zverev, E G
2007-11-01
We search for the production of single top quarks via flavor-changing-neutral-current couplings of a gluon to the top quark and a charm (c) or up (u) quark. We analyze 230 pb{-1} of lepton+jets data from pp[over] collisions at a center of mass energy of 1.96 TeV collected by the D0 detector at the Fermilab Tevatron Collider. We observe no significant deviation from standard model predictions, and hence set upper limits on the anomalous coupling parameters kappa{g}{c}/Lambda and kappa{g}{u}/Lambda, where kappa{g} define the strength of tcg and tug couplings, and Lambda defines the scale of new physics. The limits at 95% C.L. are kappa{g}{c}/Lambda<0.15 TeV-1 and kappa{g}{u}/Lambda<0.037 TeV-1. PMID:18233063
Phase diagram of chiral quark matter: From weakly to strongly coupled Fulde-Ferrell phase
Sedrakian, Armen; Rischke, Dirk H.
2009-10-01
We calculate the phase diagram of two-flavor quark matter within the Nambu-Jona-Lasinio (NJL) model in the temperature-flavor asymmetry plane in the case where there are three competing phases: the homogeneous Bardeen-Cooper-Schrieffer (BCS) phase, the unpaired phase, and a phase with broken spatial symmetry, which is here taken to be the counterpart of the Fulde-Ferrell-Larkin-Ovchinnikov (FFLO) phase in condensed matter physics. The system belongs to the universality class of paramagnetic-ferromagnetic-helical systems, and therefore contains a tricritical Lifshitz point in its phase diagram, where the momentum scale characterizing the breaking of translational invariance has a critical exponent of 1/2 to leading order. Upon varying the coupling constant of the theory we find that in weak coupling, the FFLO phase is favored at arbitrary flavor asymmetries for sufficiently low temperatures; at intermediate coupling its occupancy domain is shifted towards larger asymmetries. Strong coupling features a new regime of an inhomogeneous FF state, which we identify with a current-carrying Bose-Einstein condensate of tightly bound up and down quarks. The temperature and asymmetry dependence of the gap function is studied. It is shown that the anomalous temperature dependence of the gap in the homogeneous, flavor-asymmetric phase is transformed into a normal dependence (self-similar to the BCS phase) at arbitrary coupling, once the FF phase is allowed for. We analyze the occupation numbers and the Cooper-pair wave function and show that when the condensate momentum is orthogonal to the particle momentum the minority component contains a blocking region (breach) around the Fermi sphere in the weak-coupling limit, which engulfs more low-momentum modes as the coupling is increased, and eventually leads to a topological change in strong coupling, where the minority Fermi sphere contains either two occupied strips or an empty sphere. For nonorthogonal momenta, the blocking
SUSY Threshold Effects on Quark and Lepton Masses at the GUT Scale
Antusch, Stefan
2008-11-23
We discuss the impact of supersymmetric (SUSY) threshold corrections on the values of the running quark and charged lepton masses at the GUT scale within the large tan{beta} regime of the MSSM. In addition to the typically dominant SUSY QCD contributions for the quarks, we also include the electroweak contributions for quarks and leptons which can have significant effects. We provide the GUT scale ranges of quark and charged lepton Yukawa couplings as well as of the ratios m{sub {mu}}/m{sub s}, m{sub e}/m{sub d}, y{sub {tau}}/y{sub b} and y{sub t}/y{sub b} for three example ranges of SUSY parameters and discuss how the enlarged ranges due to threshold effects might open up new possibilities for constructing GUT models of fermion masses and mixings. This is a brief summary of the work of Ref. [1].
Quark and lepton masses at the GUT scale including supersymmetric threshold corrections
Antusch, S.; Spinrath, M.
2008-10-01
We investigate the effect of supersymmetric (SUSY) threshold corrections on the values of the running quark and charged lepton masses at the grand unified theory (GUT) scale within the large tan{beta} regime of the minimal supersymmetric standard model. In addition to the typically dominant SUSY QCD contributions for the quarks, we also include the electroweak contributions for quarks and leptons and show that they can have significant effects. We provide the GUT scale ranges of quark and charged lepton Yukawa couplings as well as of the ratios m{sub {mu}}/m{sub s}, m{sub e}/m{sub d}, y{sub {tau}}/y{sub b} and y{sub t}/y{sub b} for three example ranges of SUSY parameters. We discuss how the enlarged ranges due to threshold effects might open up new possibilities for constructing GUT models of fermion masses and mixings.
Effects of the symmetry energy on the kaon condensates in the quark-meson coupling model
NASA Astrophysics Data System (ADS)
Panda, Prafulla K.; Menezes, Débora P.; Providência, Constança
2014-04-01
In this work we investigate protoneutron star properties within a modified version of the quark-meson coupling (QMC) model that incorporates an ω-ρ interaction plus kaon condensed matter at finite temperature. Fixed entropy and trapped neutrinos are taken into account. Our results are compared with the ones obtained with the GM1 parametrization of the nonlinear Walecka model for similar values of the symmetry energy slope. Contrary to GM1, within the QMC model the formation of low mass black holes during cooling are not probable. It is shown that the evolution of the protoneutron star may include the melting of the kaon condensate driven by the neutrino diffusion, followed by the formation of a second condensate after cooling. The signature of this complex process could be a neutrino signal followed by a gamma ray burst. We have seen that both models can, in general, describe very massive stars.
K. Tsushima, P. A. M. Guichon, R. Shyam, A. W. Thomas
2010-12-01
We study the binding of hypernuclei based on the latest version of quark-meson coupling model, and estimate the phtoproduction cross sections for the {sup 12}C({gamma},K{sup +}){sub {Lambda}}{sup 12}B reaction using the bound {Lambda} spinors obtained in the model.
On the shear viscosity of 3D Yukawa liquids
Donko, Z.; Hartmann, P.
2008-09-07
We report calculations of the shear viscosity of three-dimensional strongly-coupled Yukawa liquids, based on two different non-equilibrium molecular dynamics methods. The present simulations intend to improve the accuracy of shear viscosity data, compared to those obtained in earlier studies.
NASA Astrophysics Data System (ADS)
Chang, We-Fu; Ng, John N.; Wu, Jackson M. S.
2008-11-01
We study quark mass matrices in the Randall-Sundrum (RS) model with bulk symmetry SU(2)L×SU(2)R×U(1)B-L. The Yukawa couplings are assumed to be within an order of magnitude of each other, and perturbative. We find that quark mass matrices of the symmetrical form proposed by Koide et al. [Y. Koide, H. Nishiura, K. Matsuda, T. Kikuchi, and T. Fukuyama, Phys. Rev. D 66, 093006 (2002)PRVDAQ0556-282110.1103/PhysRevD.66.093006] can be accommodated in the RS framework with the assumption of hierarchyless Yukawa couplings, but not the Hermitian Fritzsch-type mass matrices. General asymmetrical mass matrices are also found which fit well simultaneously with the quark masses and the Cabibbo-Kobayashi-Maskawa matrix. Both left-handed (LH) and right-handed (RH) quark rotation matrices are obtained that allow analysis of flavor changing decay of both LH and RH top quarks. At a warped down scale of 1.65 TeV, the total branching ratio of t→Z+jets can be as high as ˜5×10-6 for symmetrical mass matrices and ˜2×10-5 for asymmetrical ones. This level of signal is within reach of the LHC.
Badaud, Frederique
2008-11-23
With the first evidence for single top quark production in the D0 detector at the Fermilab Tevatron pp-bar collider, the single top quark cross section is measured, limits on the masses of heavy W' boson resonances are set and anomalous Wtb couplings are studied.
NASA Astrophysics Data System (ADS)
Heller, Michal P.; Janik, Romuald A.; Spaliński, Michał; Witaszczyk, Przemysław
2014-12-01
Relativistic hydrodynamics simulations of quark-gluon plasma play a pivotal role in our understanding of heavy ion collisions at RHIC and LHC. They are based on a phenomenological description due to Müller, Israel, Stewart (MIS) and others, which incorporates viscous effects and ensures a well-posed initial value problem. Focusing on the case of conformal plasma we propose a generalization which includes, in addition, the dynamics of the least damped far-from-equilibrium degree of freedom found in strongly coupled plasmas through the AdS/CFT correspondence. We formulate new evolution equations for general flows and then test them in the case of N =4 super Yang-Mills plasma by comparing their solutions alongside solutions of MIS theory with numerical computations of isotropization and boost-invariant flow based on holography. In these tests the new equations reproduce the results of MIS theory when initialized close to the hydrodynamic stage of evolution, but give a more accurate description of the dynamics when initial conditions are set in the preequilibrium regime.
Jet-medium interactions at NLO in a weakly-coupled quark-gluon plasma
NASA Astrophysics Data System (ADS)
Ghiglieri, Jacopo; Moore, Guy D.; Teaney, Derek
2016-03-01
We present an extension to next-to-leading order in the strong coupling constant g of the AMY effective kinetic approach to the energy loss of high momentum particles in the quark-gluon plasma. At leading order, the transport of jet-like particles is determined by elastic scattering with the thermal constituents, and by inelastic collinear splittings induced by the medium. We reorganize this description into collinear splittings, high-momentum-transfer scatterings, drag and diffusion, and particle conversions (momentum-preserving identity-changing processes). We show that this reorganized description remains valid to NLO in g, and compute the appropriate modifications of the drag, diffusion, particle conversion, and inelastic splitting coefficients. In addition, a new kinematic regime opens at NLO for wider-angle collinear bremsstrahlung. These semi-collinear emissions smoothly interpolate between the leading order high-momentum-transfer scatterings and collinear splittings. To organize the calculation, we introduce a set of Wilson line operators on the light-cone which determine the diffusion and identity changing coefficients, and we show how to evaluate these operators at NLO.
Suppression of Baryon Diffusion and Transport in a Baryon Rich Strongly Coupled Quark-Gluon Plasma
NASA Astrophysics Data System (ADS)
Rougemont, Romulo; Noronha, Jorge; Noronha-Hostler, Jacquelyn
2015-11-01
Five dimensional black hole solutions that describe the QCD crossover transition seen in (2 +1 ) -flavor lattice QCD calculations at zero and nonzero baryon densities are used to obtain predictions for the baryon susceptibility, baryon conductivity, baryon diffusion constant, and thermal conductivity of the strongly coupled quark-gluon plasma in the range of temperatures 130 MeV ≤T ≤300 MeV and baryon chemical potentials 0 ≤μB≤400 MeV . Diffusive transport is predicted to be suppressed in this region of the QCD phase diagram, which is consistent with the existence of a critical end point at larger baryon densities. We also calculate the fourth-order baryon susceptibility at zero baryon chemical potential and find quantitative agreement with recent lattice results. The baryon transport coefficients computed in this Letter can be readily implemented in state-of-the-art hydrodynamic codes used to investigate the dense QGP currently produced at RHIC's low energy beam scan.
Heller, Michal P; Janik, Romuald A; Spaliński, Michał; Witaszczyk, Przemysław
2014-12-31
Relativistic hydrodynamics simulations of quark-gluon plasma play a pivotal role in our understanding of heavy ion collisions at RHIC and LHC. They are based on a phenomenological description due to Müller, Israel, Stewart (MIS) and others, which incorporates viscous effects and ensures a well-posed initial value problem. Focusing on the case of conformal plasma we propose a generalization which includes, in addition, the dynamics of the least damped far-from-equilibrium degree of freedom found in strongly coupled plasmas through the AdS/CFT correspondence. We formulate new evolution equations for general flows and then test them in the case of N=4 super Yang-Mills plasma by comparing their solutions alongside solutions of MIS theory with numerical computations of isotropization and boost-invariant flow based on holography. In these tests the new equations reproduce the results of MIS theory when initialized close to the hydrodynamic stage of evolution, but give a more accurate description of the dynamics when initial conditions are set in the preequilibrium regime. PMID:25615302
Suppression of Baryon Diffusion and Transport in a Baryon Rich Strongly Coupled Quark-Gluon Plasma.
Rougemont, Romulo; Noronha, Jorge; Noronha-Hostler, Jacquelyn
2015-11-13
Five dimensional black hole solutions that describe the QCD crossover transition seen in (2+1)-flavor lattice QCD calculations at zero and nonzero baryon densities are used to obtain predictions for the baryon susceptibility, baryon conductivity, baryon diffusion constant, and thermal conductivity of the strongly coupled quark-gluon plasma in the range of temperatures 130 MeV≤T≤300 MeV and baryon chemical potentials 0≤μ(B)≤400 MeV. Diffusive transport is predicted to be suppressed in this region of the QCD phase diagram, which is consistent with the existence of a critical end point at larger baryon densities. We also calculate the fourth-order baryon susceptibility at zero baryon chemical potential and find quantitative agreement with recent lattice results. The baryon transport coefficients computed in this Letter can be readily implemented in state-of-the-art hydrodynamic codes used to investigate the dense QGP currently produced at RHIC's low energy beam scan. PMID:26613433
Khan, A. Ali; Goeckeler, M.; Schaefer, A.; Haegler, Ph.; Hemmert, T. R.; Wollenweber, T.; Horsley, R.; Zanotti, J. M.; Pleiter, D.; Rakow, P. E. L.; Schierholz, G.
2006-11-01
We present data for the axial coupling constant g{sub A} of the nucleon obtained in lattice QCD with two degenerate flavors of dynamical nonperturbatively improved Wilson quarks. The renormalization is also performed nonperturbatively. For the analysis we give a chiral extrapolation formula for g{sub A} based on the small scale expansion scheme of chiral effective field theory for two degenerate quark flavors. Applying this formalism in a finite volume, we derive a formula that allows us to extrapolate our data simultaneously to the infinite volume and to the chiral limit. Using the additional lattice data in finite volume, we are able to determine the axial coupling of the nucleon in the chiral limit without imposing the known value at the physical point.
Madelung energy of Yukawa lattices.
Pereira, P C N; Apolinario, S W S
2012-10-01
We propose a method to obtain an approximate closed form expression for the Madelung energy (ME) of Yukawa lattices. Such a method is applied for lattices of different topologies and dimensions. The obtained Madelung energies have a satisfactory accuracy for all ranges of the screening parameter κ of the Yukawa potential, and it becomes exact in the asymptotic limits κ→0 and κ→+∞. For instance, for the triangular lattice, the maximum relative error of the ME given by the method is about 0.0047. Also, satisfactory results are obtained for the one-component plasma limit. The Madelung constants of the two-dimensional hexagonal BN and square NaCl and the three-dimensional cubic NaCl crystals are estimated with a relative error of 0.004, 0.006, and 0.03, respectively. Finally, different ways to improve the method are presented and discussed. PMID:23214705
Higgs production in heavy-quark annihilation through next-to-next-to-leading order QCD
NASA Astrophysics Data System (ADS)
Harlander, Robert V.
2016-05-01
The total inclusive cross section for charged and neutral Higgs production in heavy-quark annihilation is presented through NNLO QCD. It is shown that, aside from an overall factor, the partonic cross section is independent of the initial-state quark flavors, and that any interference terms involving two different Yukawa couplings vanish. A simple criterion for defining the central renormalization and factorization scale is proposed. Its application to the bbar{b}φ process yields results which are compatible with the values usually adopted for this process. Remarkably, we find little variation in these values for the other initial-state quark flavors. Finally, we disentangle the impact of the different parton luminosities from genuine hard NNLO effects and find that, for the central scales, a naive rescaling by the parton luminosities approximates the full result remarkably well.
Combination of searches for anomalous top quark couplings with 5.4 fb(-1) of p(p)over-bar collisions
Abazov V. M.; Abbott, B.; Acharya, B. S.; Adams, M.; Adams, T.; Alexeev, G. D.; Alkhazov, G.; Alton, A.; Alverson, G.; Aoki, M.; Askew, A.; Atkins, S.; Augsten, K.; Avila, C.; Badaud, F.; Bagby, L.; Baldin, B.; Bandurin, D. V.; Banerjee, S.; Barberis, E.; Baringer, P.; Barreto, J.; Bartlett, J. F.; Bassler, U.; Bazterra, V.; Bean, A.; Begalli, M.; Bellantoni, L.; Beri, S. B.; Bernardi, G.; Bernhard, R.; Bertram, I.; Besancon, M.; Beuselinck, R.; Bezzubov, V. A.; Bhat, P. C.; Bhatia, S.; Bhatnagar, V.; Blazey, G.; Blessing, S.; Bloom, K.; Boehnlein, A.; Boline, D.; Boos, E. E.; Borissov, G.; Bose, T.; Brandt, A.; Brandt, O.; Brock, R.; Brooijmans, G.; Bross, A.; Brown, D.; Brown, J.; Bu, X. B.; Buehler, M.; Buescher, V.; Bunichev, V.; Burdin, S.; Buszello, C. P.; Camacho-Perez, E.; Casey, B. C. K.; Castilla-Valdez, H.; Caughron, S.; Chakrabarti, S.; Chakraborty, D.; Chan, K. M.; Chandra, A.; Chapon, E.; Chen, G.; Chevalier-Thery, S.; Cho, D. K.; Cho, S. W.; Choi, S.; Choudhary, B.; Cihangir, S.; Claes, D.; Clutter, J.; Cooke, M.; Cooper, W. E.; Corcoran, M.; Couderc, F.; Cousinou, M. -C.; Croc, A.; Cutts, D.; Das, A.; Davies, G.; de Jong, S. J.; De La Cruz-Burelo, E.; Deliot, F.; Demina, R.; Denisov, D.; Denisov, S. P.; Desai, S.; Deterre, C.; DeVaughan, K.; Diehl, H. T.; Diesburg, M.; Ding, P. F.; Dominguez, A.; Dubey, A.; Dudko, L. V.; Duggan, D.; Duperrin, A.; Dutt, S.; Dyshkant, A.; Eads, M.; Edmunds, D.; Ellison, J.; Elvira, V. D.; Enari, Y.; Evans, H.; Evdokimov, A.; Evdokimov, V. N.; Facini, G.; Feng, L.; Ferbel, T.; Fiedler, F.; Filthaut, F.; Fisher, W.; Fisk, H. E.; Fortner, M.; Fox, H.; Fuess, S.; Garcia-Bellido, A.; Garcia-Gonzalez, J. A.; Garcia-Guerra, G. A.; Gavrilov, V.; Gay, P.; Geng, W.; Gerbaudo, D.; Gerber, C. E.; Gershtein, Y.; Ginther, G.; Golovanov, G.; Goussiou, A.; Grannis, P. D.; Greder, S.; Greenlee, H.; Grenier, G.; Gris, Ph; Grivaz, J-F; Grohsjean, A.; Gruenendahl, S.; Gruenewald, M. W.; Guillemin, T.; Gutierrez, G.; Gutierrez, P.; Haas, A.; Hagopian, S.; Haley, J.; Han, L.; Harder, K.; Harel, A.; Hauptman, J. M.; Hays, J.; Head, T.; Hebbeker, T.; Hedin, D.; Hegab, H.; Heinson, A. P.; Heintz, U.; Hensel, C.; Heredia-De La Cruz, I.; Herner, K.; Hesketh, G.; Hildreth, M. D.; Hirosky, R.; Hoang, T.; Hobbs, J. D.; Hoeneisen, B.; Hohlfeld, M.; Howley, I.; Hubacek, Z.; Hynek, V.; Lashvili, I.; Ilchenko, Y.; Illingworth, R.; Ito, A. S.; Jabeen, S.; Jaffe, M.; Jayasinghe, A.; Jesik, R.; Johns, K.; Johnson, E.; Johnson, M.; Jonckheere, A.; Jonsson, P.; Joshi, J.; Jung, A. W.; Juste, A.; Kaadze, K.; Kajfasz, E.; Karmanov, D.; Kasper, P. A.; Katsanos, I.; Kehoe, R.; Kermiche, S.; Khalatyan, N.; Khanov, A.; Kharchilava, A.; Kharzheev, Y. N.; Kiselevich, I.; Kohli, J. M.; Kozelov, A. V.; Kraus, J.; Kulikov, S.; Kumar, A.; Kupco, A.; Kurca, T.; Kuzmin, V. A.; Lammers, S.; Landsberg, G.; Lebrun, P.; Lee, H. S.; Lee, S. W.; Lee, W. M.; Lellouch, J.; Li, H.; Li, L.; Li, Q. Z.; Lim, J. K.; Lincoln, D.; Linnemann, J.; Lipaev, V. V.; Lipton, R.; Liu, H.; Liu, Y.; Lobodenko, A.; Lokajicek, M.; de Sa, R. Lopes; Lubatti, H. J.; Luna-Garcia, R.; Lyon, A. L.; Maciel, A. K. A.; Madar, R.; Magana-Villalba, R.; Malik, S.; Malyshev, V. L.; Maravin, Y.; Martinez-Ortega, J.; McCarthy, R.; McGivern, C. L.; Meijer, M. M.; Melnitchouk, A.; Menezes, D.; Mercadante, P. G.; Merkin, M.; Meyer, A.; Meyer, J.; et al.
2012-07-09
We present measurements of the tWb coupling form factors using information from electroweak single top quark production and from the helicity of W bosons from top quark decays in t{bar t} events. We set upper limits on anomalous tWb coupling form factors using data collected with the D0 detector at the Tevatron p{bar p} collider corresponding to an integrated luminosity of 5.4 fb{sup -1}.
Triple point of Yukawa systems
NASA Astrophysics Data System (ADS)
Hamaguchi, S.; Farouki, R. T.; Dubin, D. H. E.
1997-10-01
The molecular dynamics simulations of Yukawa (i.e., screened-Coulomb) systems that were applied to the regime of weak screening in an earlier study [S. Hamaguchi, R. T. Farouki, and D. H. E. Dubin, J. Chem. Phys. 105, 7641 (1996)] are extended to the strong screening regime. Transition temperatures at the fluid-solid phase boundary and the solid-solid phase boundary are obtained as functions of the screening parameter κ=a/λD (i.e., the ratio of the Wigner-Seitz radius a to the Debye length λD). The resulting phase diagram also covers the triple point-the intersection of the fluid-solid and solid-solid phase boundaries-at κ=4.28 and Γ=5.6×103, where Γ is the ratio of the Coulomb potential energy to the kinetic energy per particle (i.e., Γ=Q2/4πɛ0akT, where Q is the charge of each Yukawa particle and T is the system temperature). Yukawa systems serve as models for plasmas and colloidal suspensions of charged particulates.
Dynamical chiral symmetry breaking in Yukawa and Wess-Zumino models
Bashir, A.; Diaz Cruz, J. L.
1999-10-25
We study dynamical mass generation for fermions in the Yukawa and the supersymmetric Wess-Zumino (WZ) models. It is found that above a critical coupling fermion mass can be generated dynamically in the Yukawa model, whereas in the WZ model the fermion does not acquire mass. We also show that the supersymmetry (SUSY) preserving solution is permitted and hence the scalars may not acquire mass either.
Three-dimensional stereoscopy of Yukawa (Coulomb) balls in dusty plasmas
Kaeding, Sebastian; Melzer, Andre
2006-09-15
A stereoscopic approach with standard video cameras for positioning and tracking of micrometer sized polymer particles in a radio-frequency gas discharge is presented. The stereoscopy is applied to simultaneously determine the positions of all particles in a three-dimensional strongly coupled spherical dusty plasma (Yukawa ball). The accuracy of the stereoscopic method is discussed. The shell structure and the occupation number of various Yukawa balls are determined and compared to recent simulations and models.
Practical expressions for the internal energy and pressure of Yukawa fluids.
Khrapak, Sergey A; Thomas, Hubertus M
2015-02-01
Simple practical expressions that allow estimation of thermodynamic properties of Yukawa fluids in a wide range of coupling, up to the fluid-solid phase transition, are presented. These expressions demonstrate excellent agreement with the available results from numerical simulations. The approach provides simple and accurate tools to estimate thermodynamic properties of Yukawa fluids and related systems in a broad range of parameters. PMID:25768619
Does dark matter consist of baryons of new stable family quarks?
Bregar, G.; Mankoc Borstnik, N. S.
2009-10-15
We investigate the possibility that the dark matter consists of clusters of the heavy family quarks and leptons with zero Yukawa couplings to the lower families. Such a family is predicted by the approach unifying spin and charges as the fifth family. We make a rough estimation of properties of baryons of these new family members, of their behavior during the evolution of the Universe and when scattering on the ordinary matter, and study possible limitations on the family properties due to the cosmological and direct experimental evidences.
Search for mirror quarks at the LHC
NASA Astrophysics Data System (ADS)
Chakdar, Shreyashi; Ghosh, K.; Hoang, V.; Hung, P. Q.; Nandi, S.
2016-02-01
Observation of nonzero neutrino masses at a scale ˜1 0-1- 1 0-2 eV is a major problem in the otherwise highly successful Standard Model. The most elegant mechanism to explain such tiny neutrino masses is the seesaw mechanism with right-handed neutrinos. However, the required seesaw scale is so high, ˜1014 GeV , it will not have any collider implications. Recently, an explicit model has been constructed to realize the seesaw mechanism with the right-handed neutrinos at the electroweak scale. The model has a mirror symmetry, having both the left and right lepton and quark doublets and singlets for the same S U (2 )W gauge symmetry. Additional Higgs multiplets have been introduced to realize this scenario. It turns out that these extra Higgs fields also help to satisfy the precision electroweak tests, and other observables. Because the scale of the symmetry breaking is electroweak, both the mirror quark and the mirror leptons have masses in the electroweak scale in the range ˜150 - 800 GeV . The mirror quarks/leptons decay to ordinary quarks/leptons plus very light neutral scalars. In this work, we calculate the final-state signals arising from the pair productions of these mirror quarks and their subsequent decays. We find that these signals are well observable over the Standard Model background for the 13 TeV LHC. Depending on the associated Yukawa couplings, these decays can also give rise to displaced vertices with long decay lengths, very different from the usual displaced vertices associated with b decays.
NASA Astrophysics Data System (ADS)
Jo, Young Kwon; Choi, Su Yong; Roh, Youn Jung; Kim, Tae Jeong
2015-09-01
A large number of top quarks will be produced at the Large Hadron Collider (LHC) during the Run II period. This will allow us to measure the rare processes from the top sector in great details. We present a study of top-quark pair production in association with a bottom-quark pair (tbar tbbar b) from fast simulations for the Compact Muon Solenoid (CMS) experiment. The differential distributions of tbar tbbar b are compared with the top-quark pair production with two additional jets (tbar tjj) and with the production in association with the Higgs (tbar tH), where the Higgs decays to a bottom-quark pair. The significances of the tbar tbbar b process in the dileptonic and the semileptonic decay modes are calculated with the data corresponding to an integrated luminosity of 10 fb-1, which is foreseen to be collected in the early Run II period. This study will provide an important input in searching for new physics beyond the standard model, as well as in searching for the tbar tH process where the Yukawa coupling with the top quark can be directly measured.
Higgs mass and unified gauge coupling in the NMSSM with vector matter
NASA Astrophysics Data System (ADS)
Barbieri, Riccardo; Buttazzo, Dario; Hall, Lawrence J.; Marzocca, David
2016-07-01
We consider the NMSSM extended to include one vector-like family of quarks and leptons. If (some of) these vector-like matter particles, as the Higgs doublets, have Yukawa couplings to the singlet S that exceed unity at about the same scale Λ ≲ 103 TeV, this gives the order 40% enhancement of the tree level Higgs boson mass required in the MSSM to reach 125 GeV. It is conceivable that the Yukawa couplings to the singlet S, although naively blowing up close to Λ, will not spoil gauge coupling unification. In such a case the unified coupling α X could be interestingly led to a value not far from unity, thus providing a possible explanation for the number of generations. The characteristic signal is an enhanced resonant production of neutral spin zero particles at LHC, that could even explain the putative diphoton resonance hinted by the recent LHC data at 750 GeV.
Effective Hamiltonian for bound states in Yukawa theory
Weber, Axel
2013-07-15
A generalization of the Gell-Mann–Low theorem is applied to lowest nontrivial order to determine an effective Hamiltonian for two-fermion states in relativistic Yukawa theory. The consistency of the corresponding effective Schrödinger equation is thoroughly investigated in various aspects, among others the nonrelativistic and one-body limits, and the small-distance or large-momentum regime of the bound state solutions is discussed in detail. -- Highlights: •A generalization of the Gell-Mann–Low theorem is applied to Yukawa theory. •The effective Hamiltonian for two-fermion states is derived to lowest order. •The nonrelativistic and one-body limits are consistent. •The large-momentum behavior of the bound-state solutions is analyzed. •A critical value for the coupling constant is determined.
Is Hideki Yukawa's explanation of the strong force correct?
NASA Astrophysics Data System (ADS)
Vasiliev, Victor; Moon, Russell
2006-10-01
Reexamining Hideki Yukawa's explanation of the strong force using the principles of the Quark Theory and the Vortex Theory, it was discovered that it is possible for a virtual particle to be passed back and forth between the proton and the neutron. This discovery creates a new and revolutionary explanation of the strong force of nature. The creation of the strong force appears to be the combination of four processes at work in the nucleus: virtual particles, intrinsic magnetism, ``nuclear gravity'', and gluons. 1. V.V. Vasiliev, R.G. Moon, The bases of the vortex theory, Book of abstracts The 53 International Meeting on Nuclear Spectroscopy and Nuclear structure St. Petersburg, Russia, 2003, p.251. 2. H. Yukawa, Tabibito, (World Scientific, Singapore, 1982), p. 190-202. 3. K. Gridnev, V.V. Vasiliev, R.G. Moon, The Photon Acceleration Effect, Book of abstracts, OMEGA 5 -- Symposium on Origin of Matter and Evolution of Galaxies, Nov 8-11, University of Tokyo, Tokyo Japan. 4. R.G. Moon, V.V. Vasiliev. Explanation of the Conservation of Lepton Number, Book of abstracts LV. National Conference on Nuclear Physics, Frontiers in the Physics of Nucleus, June 28-July 1, 2005, Saint-Petersburg, Russia, 2005, p. 347.5. .
Is Hideki Yukawa's explanation of the strong force correct?
NASA Astrophysics Data System (ADS)
Vasiliev, Victor; Moon, Russell
2006-11-01
Reexamining Hideki Yukawa's explanation of the strong force using the principles of the Quark Theory and the Vortex Theory, it was discovered that it is possible for a virtual particle to be passed back and forth between the proton and the neutron. This discovery creates a new and revolutionary explanation of the strong force of nature. The creation of the strong force appears to be the combination of four processes at work in the nucleus: virtual particles, intrinsic magnetism, ``nuclear gravity'', and gluons. 1. V.V. Vasiliev, R.G. Moon, The bases of the vortex theory, Book of abstracts The 53 International Meeting on Nuclear Spectroscopy and Nuclear structure St. Petersburg, Russia, 2003, p.251. 2. H. Yukawa, Tabibito, (World Scientific, Singapore, 1982), p. 190-202. 3. K. Gridnev, V.V. Vasiliev, R.G. Moon, The Photon Acceleration Effect, Book of abstracts, OMEGA 5 -- Symposium on Origin of Matter and Evolution of Galaxies, Nov 8-11, University of Tokyo, Tokyo Japan. 4. R.G. Moon, V.V. Vasiliev. Explanation of the Conservation of Lepton Number, Book of abstracts LV. National Conference on Nuclear Physics, Frontiers in the Physics of Nucleus, June 28-July 1, 2005, Saint-Petersburg, Russia, 2005, p. 347.5. .
Universality in the Equilibration of Quenched Yukawa One Component Plasmas
NASA Astrophysics Data System (ADS)
Langin, Thomas; McQuillen, Patrick; Strickler, Trevor; Maksimovic, Nikola; Pohl, Thomas; Killian, Thomas
2015-11-01
We study the equilibration of a Yukawa One Component Plasma (OCP) after a rapid change in the screening parameter from κ0 = ∞ to κf (n ,Te) , which is realized by photoionizing a laser cooled (T ~ 10 mK), uncorrelated gas of 88Sr atoms with density n between 1014 m-3 and 3 ×1016 m-3 using a two photon process in which the energy of one of the photons is adjustable. The excess photon energy above the ionization threshold sets the electron temperature, Te, and thus gives us control of κf. The resultant plasma is a classical plasma with strongly coupled ions, and is therefore described by the Yukawa OCP model with the electrons treated as a screening background. After photoionization, the ions develop spatial correlations to minimize their interaction energy, thus heating the ions. Since the dynamics of a Yukawa OCP depend solely on κ, we expect the heating process to be uniquely determined by κf. We verify this behavior by measuring the ion heating curve and comparing it to molecular dynamics simulations. We also report on how this behavior can be used to accurately measure n given a measured equilibration curve at a known Te. This work was supported by the United States National Science Foundation and the Department of Energy (PHY-0714603), the Air Force Office of Scientific Research (FA9550- 12-1-0267), and the Department of Defense (DoD) through the NDSEG Program.
Higgs singlet boson as a diphoton resonance in a vectorlike quark model
NASA Astrophysics Data System (ADS)
Benbrik, R.; Chen, Chuan-Hung; Nomura, Takaaki
2016-03-01
ATLAS and CMS recently showed the first results from run 2 of the Large Hadron Collider (LHC) at √{s }=13 TeV . A resonant bump at a mass of around 750 GeV in the diphoton invariant mass spectrum was indicated and the corresponding diphoton production cross section is around 3-10 fb. Motivated by the LHC diphoton excess, we propose that the possible resonance candidate is a Higgs singlet. To produce the Higgs singlet via the gluon-gluon fusion process, we embed the Higgs singlet in the framework of the vector-like triplet quark (VLTQ) model. As a result, the Higgs singlet decaying to the diphoton final state is via VLTQ loops. Using the enhanced number of new quarks and new Yukawa couplings of the VLTQs and Higgs singlet, we successfully explain the diphoton production cross section. We find that the width of the Higgs singlet is below 1 GeV, its production cross section can be of the order of 1 pb at √{s }=13 TeV , and the branching ratio for it decaying to a diphoton is around 0.017 and is insensitive to the masses of VLTQs and new Yukawa couplings. We find a strong correlation between the Higgs Yukawa couplings to s -b and c -t ; the resulted branching ratio for t →c h can be 1.1 ×10-4 when the constraint from Bs oscillation is applied. With the constrained parameter values, the signal strength for the standard model Higgs decaying to a diphoton is μγ γ<1.18 , which is consistent with the current measurements at ATLAS and CMS.
The Legacies of Yukawa and His Disciples
NASA Astrophysics Data System (ADS)
Nambu, Yoichiro
2008-06-01
I review and discuss the historical roles Hideki Yukawa and his disciples, Shoichi Sakata in particular, played in developing what we now call particle physics, including their personal and cultural aspects.
Top-quark pole mass in the tadpole-free MS ¯ scheme
NASA Astrophysics Data System (ADS)
Martin, Stephen P.
2016-05-01
The complex pole mass of the top quark is presented at full two-loop order in the Standard Model, augmenting the known four-loop QCD contributions. The input parameters are the MS ¯ Yukawa and gauge couplings, the Higgs self-coupling, and the Higgs vacuum expectation value (VEV). Here, the VEV is defined as the minimum of the full effective potential in Landau gauge, so that tadpoles vanish. This is an alternative to earlier results that instead minimize the tree-level potential, resulting in a VEV that is gauge-fixing independent but accompanied by negative powers of the Higgs self-coupling in perturbative expansions. The effects of nonzero Goldstone boson mass are eliminated by resummation. I also study the renormalization scale dependence of the calculated pole mass.
Glass-transition properties of Yukawa potentials: from charged point particles to hard spheres.
Yazdi, Anoosheh; Ivlev, Alexei; Khrapak, Sergey; Thomas, Hubertus; Morfill, Gregor E; Löwen, Hartmut; Wysocki, Adam; Sperl, Matthias
2014-06-01
The glass transition is investigated in three dimensions for single and double Yukawa potentials for the full range of control parameters. For vanishing screening parameter, the limit of the one-component plasma is obtained; for large screening parameters and high coupling strengths, the glass-transition properties cross over to the hard-sphere system. Between the two limits, the entire transition diagram can be described by analytical functions. Unlike other potentials, the glass-transition and melting lines for Yukawa potentials are found to follow shifted but otherwise identical curves in control-parameter space. PMID:25019902
B{yields}X{sub s}{gamma} constraints on the top quark anomalous t{yields}c{gamma} coupling
Yuan Xingbo; Hao Yang; Yang Yadng
2011-01-01
Observation of the top quark flavor changing neutral process t{yields}c+{gamma} at the LHC would be the signal of physics beyond the standard model. If anomalous t{yields}c{gamma} coupling exists, it will affect the precisely measured B(B{yields}X{sub s}{gamma}). In this paper, we study the effects of a dimension 5 anomalous tc{gamma} operator in B{yields}X{sub s}{gamma} decay to derive constraints on its possible strength. It is found that, for real anomalous t{yields}c{gamma} coupling {kappa}{sub tcR}{sup {gamma}}, the constraints correspond to the upper bounds B(t{yields}c+{gamma})<6.54x10{sup -5} (for {kappa}{sub tcR}{sup {gamma}}>0) and B(t{yields}c+{gamma})<8.52x10{sup -5} (for {kappa}{sub tcR}{sup {gamma}}<0), respectively, which are about the same order as the 5{sigma} discovery potential of ATLAS (9.4x10{sup -5}) and slightly lower than that of CMS (4.1x10{sup -4}) with 10 fb{sup -1} integrated luminosity operating at {radical}(s)=14 TeV.
Measuring the Higgs-bottom coupling in weak boson fusion
NASA Astrophysics Data System (ADS)
Englert, Christoph; Mattelaer, Olivier; Spannowsky, Michael
2016-05-01
We study Higgs production through weak boson fusion with subsequent decay to bottom quarks. By combining jet substructure techniques and matrix element methods in different limits we motivate this channel as a probe of the bottom-Yukawa interactions in the boosted regime. In particular we ameliorate the "no-go" results of cut-and-count analyses in this channel. After applying a data-driven reconstruction approach we find that the Higgs-bottom coupling can be limited to 0.82
The effects of hyper-spherical approximation of Yukawa potential to diffusion properties
NASA Astrophysics Data System (ADS)
Kim, In Gee; Murillo, Michael S.
2015-11-01
The effects of Yukawa potential to the diffusion properties of binary ionic mixtures are investigated in terms of both the classical molecular dynamics and the kinetic theory. The Yukawa interatomic potential is treated by means of the hyper-spherical approximation, which replaces the Ewald summation by a multiple of the hyperbolic trigonometric functions and the lattice summation of screening. The influence of the hyper-spherical approximation of the Yukawa potential is able to be understood through the calculations of transport coefficients with the relationship to Coulomb logarithm. Numerical studies over a various range of the Debye-Hückel screening parameter and of the plasma coupling parameter to binary ionic mixtures will be provided. We consider primarily the interdiffusion coefficients and then discuss about the mixing properties of self-diffusion coefficients.
NASA Astrophysics Data System (ADS)
Rindani, Saurabh D.; Sharma, Pankaj; Thomas, Anthony W.
2015-10-01
We study the sensitivity of the Large Hadron Collider (LHC) to top quark chromomagnetic (CMDM) and chromoelectric (CEDM) dipole moments and W tb effective couplings in single-top production in association with a W - boson, followed by semileptonic decay of the top. The W t single-top production mode helps to isolate the anomalous ttg and W tb couplings, in contrast to top-pair production and other single-top production modes, where other new-physics effects can also contribute. We calculate the top polarization and the effects of these anomalous couplings on it at two centre-of-mass (cm) energies, 8 TeV and 14 TeV. As a measure of top polarization, we look at decay-lepton angular distributions in the laboratory frame, without requiring reconstruction of the rest frame of the top, and study the effect of the anomalous couplings on these distributions. We construct certain asymmetries to study the sensitivity of these distributions to top-quark couplings. We determine individual limits on the dominant couplings, viz., the real part of the CMDM Re ρ 2, the imaginary part of the CEDM Im ρ 3, and the real part of the tensor W tb coupling Ref2R, which may be obtained by utilizing these asymmetries at the LHC. We also obtain simultaneous limits on pairs of these couplings taking two couplings to be non-zero at a time.
Yukawa unification in heterotic string theory
NASA Astrophysics Data System (ADS)
Buchbinder, Evgeny I.; Constantin, Andrei; Gray, James; Lukas, Andre
2016-08-01
We analyze Yukawa unification in the context of E8×E8 heterotic Calabi-Yau models which rely on breaking to a grand unified theory (GUT) via a nonflat gauge bundle and subsequent Wilson line breaking to the standard model. Our focus is on underlying GUT theories with gauge group S U (5 ) or S O (10 ). We provide a detailed analysis of the fact that, in contrast to traditional field theory GUTs, the underlying GUT symmetry of these models does not enforce Yukawa unification. Using this formalism, we present various scenarios where Yukawa unification can occur as a consequence of additional symmetries. These additional symmetries arise naturally in some heterotic constructions, and we present an explicit heterotic line bundle model which realizes one of these scenarios.
Statistical understanding of quark and lepton masses in Gaussian landscapes
Hall, Lawrence J.; Salem, Michael P.; Watari, Taizan
2007-11-01
The fundamental theory of nature may allow a large landscape of vacua. Even if the theory contains a unified gauge symmetry, the 22 flavor parameters of the standard model, including neutrino masses, may be largely determined by the statistics of this landscape, and not by any symmetry. Then the measured values of the flavor parameters do not lead to any fundamental symmetries, but are statistical accidents; their precise values do not provide any insights into the fundamental theory, rather the overall pattern of flavor reflects the underlying landscape. We investigate whether random selection from the statistics of a simple landscape can explain the broad patterns of quark, charged lepton, and neutrino masses and mixings. We propose Gaussian landscapes as simplified models of landscapes where Yukawa couplings result from overlap integrals of zero-mode wave functions in higher-dimensional supersymmetric gauge theories. In terms of just five free parameters, such landscapes can account for all gross features of flavor, including the hierarchy of quark and charged-lepton masses; small quark mixing angles in the basis with quarks arranged according to mass, with 13 mixing less than 12 and 23 mixing; very light Majorana neutrino masses, with the solar to atmospheric neutrino mass ratio consistent with data; distributions for leptonic mixings sin2{theta}{sub 12} and sin2{theta}{sub 23} that are peaked at large values, while the distribution for sin2{theta}{sub 13} is peaked at low values; and order unity CP-violating phases in both the quark and lepton sectors. While the statistical distributions for flavor parameters are broad, the distributions are robust to changes in the geometry of the extra dimensions. Constraining the distributions by loose cuts about observed values leads to narrower distributions for neutrino measurements of {theta}{sub 13}, CP violation, and neutrinoless double beta decay.
Advances in Dusty Plasmas 5.Strongly Coupled Dusty Plasmas
NASA Astrophysics Data System (ADS)
Hamaguchi, Satoshi
We review thermodynamical and dynamical properties of strongly coupled dusty plasmas, focusing on the recent development of molecular dynamics (MD) simulations. In the present paper, dusty plasmas are modeled by the Yukawa system, which is a collection of particles interacting through Yukawa (i.e., screened Coulomb) potentials. The phase diagram, wave dispersion relations and some transport coefficients of Yukawa systems are discussed.
Top quark physics: Future measurements
Frey, R.; Vejcik, S.; Berger, E.L.
1997-04-04
The authors discuss the study of the top quark at future experiments and machines. Top`s large mass makes it a unique probe of physics at the natural electroweak scale. They emphasize measurements of the top quark`s mass, width, and couplings, as well as searches for rare or nonstandard decays, and discuss the complementary roles played by hadron and lepton colliders.
Split sfermion families, Yukawa unification and muon g - 2
NASA Astrophysics Data System (ADS)
Ajaib, M. Adeel; Gogoladze, Ilia; Shafi, Qaisar; Ün, Cem Salih
2014-05-01
We consider two distinct classes of Yukawa unified supersymmetric SO(10) models with non-universal and universal soft supersymmetry breaking (SSB) gaugino masses at M GUT. In both cases, we assume that the third family SSB sfermion masses at M GUT are different from the corresponding sfermion masses of the first two families (which are equal). For the SO(10) model with essentially arbitrary (non-universal) gaugino masses at M GUT, it is shown that t- b- τ Yukawa coupling unification is compatible, among other things, with the 125 GeV Higgs boson mass, the WMAP relic dark matter density, and with the resolution of the apparent muon g - 2 anomaly. The colored sparticles in this case all turn out to be quite heavy, of order 5 TeV or more, but the sleptons (smuon and stau) can be very light, of order 200 GeV or so. For the SO(10) model with universal gaugino masses and NUHM2 boundary conditions, the muon g - 2 anomaly cannot be resolved. However, the gluino in this class of models is not too heavy, ≲ 3 TeV, and therefore may be found at the LHC.
Invariants in the Yukawa system's thermodynamic phase diagram
Veldhorst, Arno A. Schrøder, Thomas B.; Dyre, Jeppe C.
2015-07-15
This paper shows that several known properties of the Yukawa system can be derived from the isomorph theory, which applies to any system that has strong correlations between its virial and potential-energy equilibrium fluctuations. Such “Roskilde-simple” systems have a simplified thermodynamic phase diagram deriving from the fact that they have curves (isomorphs) along which structure and dynamics in reduced units are invariant to a good approximation. We show that the Yukawa system has strong virial potential-energy correlations and identify its isomorphs by two different methods. One method, the so-called direct isomorph check, identifies isomorphs numerically from jumps of relatively small density changes (here 10%). The second method identifies isomorphs analytically from the pair potential. The curves obtained by the two methods are close to each other; these curves are confirmed to be isomorphs by demonstrating the invariance of the radial distribution function, the static structure factor, the mean-square displacement as a function of time, and the incoherent intermediate scattering function. Since the melting line is predicted to be an isomorph, the theory provides a derivation of a known approximate analytical expression for this line in the temperature-density phase diagram. The paper's results give the first demonstration that the isomorph theory can be applied to systems like dense colloidal suspensions and strongly coupled dusty plasmas.
Invariants in the Yukawa system's thermodynamic phase diagram
NASA Astrophysics Data System (ADS)
Veldhorst, Arno A.; Schrøder, Thomas B.; Dyre, Jeppe C.
2015-07-01
This paper shows that several known properties of the Yukawa system can be derived from the isomorph theory, which applies to any system that has strong correlations between its virial and potential-energy equilibrium fluctuations. Such "Roskilde-simple" systems have a simplified thermodynamic phase diagram deriving from the fact that they have curves (isomorphs) along which structure and dynamics in reduced units are invariant to a good approximation. We show that the Yukawa system has strong virial potential-energy correlations and identify its isomorphs by two different methods. One method, the so-called direct isomorph check, identifies isomorphs numerically from jumps of relatively small density changes (here 10%). The second method identifies isomorphs analytically from the pair potential. The curves obtained by the two methods are close to each other; these curves are confirmed to be isomorphs by demonstrating the invariance of the radial distribution function, the static structure factor, the mean-square displacement as a function of time, and the incoherent intermediate scattering function. Since the melting line is predicted to be an isomorph, the theory provides a derivation of a known approximate analytical expression for this line in the temperature-density phase diagram. The paper's results give the first demonstration that the isomorph theory can be applied to systems like dense colloidal suspensions and strongly coupled dusty plasmas.
Röntsch, Raoul; Schulze, Markus
2015-09-21
We study top quark pair production in association with a Z boson at the Large Hadron Collider (LHC) and investigate the prospects of measuring the couplings of top quarks to the Z boson. To date these couplings have not been constrained in direct measurements. Such a determination will be possible for the first time at the LHC. Our calculation improves previous coupling studies through the inclusion of next-to-leading order (NLO) QCD corrections in production and decays of all unstable particles. We treat top quarks in the narrow-width approximation and retain all NLO spin correlations. To determine the sensitivity of amore » coupling measurement we perform a binned log-likelihood ratio test based on normalization and shape information of the angle between the leptons from the Z boson decay. The obtained limits account for statistical uncertainties as well as leading theoretical systematics from residual scale dependence and parton distribution functions. We use current CMS data to place the first direct constraints on the ttbZ couplings. We also consider the upcoming high-energy LHC run and find that with 300 inverse fb of data at an energy of 13 TeV the vector and axial ttbZ couplings can be constrained at the 95% confidence level to C_V=0.24^{+0.39}_{-0.85} and C_A=-0.60^{+0.14}_{-0.18}, where the central values are the Standard Model predictions. This is a reduction of uncertainties by 25% and 42%, respectively, compared to an analysis based on leading-order predictions. We also translate these results into limits on dimension-six operators contributing to the ttbZ interactions beyond the Standard Model.« less
Röntsch, Raoul; Schulze, Markus
2015-09-21
We study top quark pair production in association with a Z boson at the Large Hadron Collider (LHC) and investigate the prospects of measuring the couplings of top quarks to the Z boson. To date these couplings have not been constrained in direct measurements. Such a determination will be possible for the first time at the LHC. Our calculation improves previous coupling studies through the inclusion of next-to-leading order (NLO) QCD corrections in production and decays of all unstable particles. We treat top quarks in the narrow-width approximation and retain all NLO spin correlations. To determine the sensitivity of a coupling measurement we perform a binned log-likelihood ratio test based on normalization and shape information of the angle between the leptons from the Z boson decay. The obtained limits account for statistical uncertainties as well as leading theoretical systematics from residual scale dependence and parton distribution functions. We use current CMS data to place the first direct constraints on the ttbZ couplings. We also consider the upcoming high-energy LHC run and find that with 300 inverse fb of data at an energy of 13 TeV the vector and axial ttbZ couplings can be constrained at the 95% confidence level to C_V=0.24^{+0.39}_{-0.85} and C_A=-0.60^{+0.14}_{-0.18}, where the central values are the Standard Model predictions. This is a reduction of uncertainties by 25% and 42%, respectively, compared to an analysis based on leading-order predictions. We also translate these results into limits on dimension-six operators contributing to the ttbZ interactions beyond the Standard Model.
On the estimation of sound speed in two-dimensional Yukawa fluids
Semenov, I. L. Thomas, H. M.; Khrapak, S. A.
2015-11-15
The longitudinal sound speed in two-dimensional Yukawa fluids is estimated using the conventional hydrodynamic expression supplemented by appropriate thermodynamic functions proposed recently by Khrapak et al. [Phys. Plasmas 22, 083706 (2015)]. In contrast to the existing approaches, such as quasi-localized charge approximation (QLCA) and molecular dynamics simulations, our model provides a relatively simple estimate for the sound speed over a wide range of parameters of interest. At strong coupling, our results are shown to be in good agreement with the results obtained using the QLCA approach and those derived from the phonon spectrum for the triangular lattice. On the other hand, our model is also expected to remain accurate at moderate values of the coupling strength. In addition, the obtained results are used to discuss the influence of the strong coupling effects on the adiabatic index of two-dimensional Yukawa fluids.
Molecular shear heating and vortex dynamics in thermostatted two dimensional Yukawa liquids
NASA Astrophysics Data System (ADS)
Gupta, Akanksha; Ganesh, Rajaraman; Joy, Ashwin
2016-07-01
It is well known that two-dimensional macroscale shear flows are susceptible to instabilities leading to macroscale vortical structures. The linear and nonlinear fate of such a macroscale flow in a strongly coupled medium is a fundamental problem. A popular example of a strongly coupled medium is a dusty plasma, often modelled as a Yukawa liquid. Recently, laboratory experiments and molecular dynamics (MD) studies of shear flows in strongly coupled Yukawa liquids indicated the occurrence of strong molecular shear heating, which is found to reduce the coupling strength exponentially leading to the destruction of macroscale vorticity. To understand the vortex dynamics of strongly coupled molecular fluids undergoing macroscale shear flows and molecular shear heating, MD simulation has been performed, which allows the macroscopic vortex dynamics to evolve, while at the same time "removes" the microscopically generated heat without using the velocity degrees of freedom. We demonstrate that by using a configurational thermostat in a novel way, the microscale heat generated by shear flow can be thermostatted out efficiently without compromising the large scale vortex dynamics. In the present work, using MD simulations, a comparative study of shear flow evolution in Yukawa liquids in the presence and absence of molecular or microscopic heating is presented for a prototype shear flow, namely, Kolmogorov flow.
Production of heavy Higgs bosons and decay into top quarks at the LHC
NASA Astrophysics Data System (ADS)
Bernreuther, W.; Galler, P.; Mellein, C.; Si, Z.-G.; Uwer, P.
2016-02-01
We investigate the production of heavy, neutral Higgs boson resonances and their decays to top-quark top-antiquark (t t ¯) pairs at the Large Hadron Collider (LHC) at next-to-leading order (NLO) in the strong coupling of quantum chromodynamics (QCD). The NLO corrections to heavy Higgs boson production and the Higgs-QCD interference are calculated in the large mt limit with an effective K-factor rescaling. The nonresonant t t ¯ background is taken into account at NLO QCD including weak-interaction corrections. In order to consistently determine the total decay widths of the heavy Higgs bosons, we consider for definiteness the type-II two-Higgs-doublet extension of the standard model and choose three parameter scenarios that entail two heavy neutral Higgs bosons with masses above the t t ¯ threshold and unsuppressed Yukawa couplings to top quarks. For these three scenarios we compute, for the LHC operating at 13 TeV, the t t ¯ cross section and the distributions of the t t ¯ invariant mass, of the transverse top-quark momentum and rapidity, and of the cosine of the Collins-Soper angle with and without the two heavy Higgs resonances. For selected Mt t ¯ bins we estimate the significances for detecting a heavy Higgs signal in the t t ¯ dileptonic and lepton plus jets decay channels.
On the light quark mass effects in Higgs boson production in gluon fusion
NASA Astrophysics Data System (ADS)
Melnikov, Kirill; Penin, Alexander
2016-05-01
Production of Higgs bosons at the LHC is affected by the contribution of light quarks, that mediate the gg → Hg transition. Although their impact is suppressed by small Yukawa couplings, it is enhanced by large logarithms of the ratio of the Higgs boson mass or its transverse momentum to light quark masses. We study the origin of this enhancement, focusing on the abelian corrections to gg → Hg amplitudes of the form {({C}_F{α}_s{mathcal{L}}^2)}^n , where mathcal{L}in \\{ ln (s/{m}_b^2),kern0.5em ln ({p}_{perp}^2/{m}_b^2)\\} . We show how these non-Sudakov double logarithmic terms can be resummed to all orders in the strong coupling constant. Interestingly, we find that the transverse momentum dependence of these corrections is very weak due to a peculiar cancellation between different logarithmic terms. Although the abelian part of QCD corrections is not expected to be dominant, it can be used to estimate missing higher-order corrections to light quark contributions to Higgs boson production at the LHC.
NASA Astrophysics Data System (ADS)
Chetyrkin, K. G.; Zoller, M. F.
2016-06-01
We present analytical results for the leading top-Yukawa and QCD contribution to the β-function for the Higgs self-coupling λ of the Standard Model at four-loop level, namely the part ∝ y t 4 g s 6 independently confirming a result given in [1]. We also give the contribution ∝ y t 2 g s 6 of the anomalous dimension of the Higgs field as well as the terms ∝ y t g s 8 to the top-Yukawa β-function which can also be derived from the anomalous dimension of the top quark mass. We compare the results with the RG functions of the correlators of two and four scalar currents in pure QCD and find a new relation between the anomalous dimension γ 0 of the QCD vacuum energy and the anomalous dimension γ m SS appearing in the RG equation of the correlator of two scalar currents. Together with the recently computed top-Yukawa and QCD contributions to β gs [2, 3] the β-functions presented here constitute the leading four-loop contributions to the evolution of the Higgs self-coupling. A numerical estimate of these terms at the scale of the top-quark mass is presented as well as an analysis of the impact on the evolution of λ up to the Planck scale and the vacuum stability problem.
Fermionic dark matter with pseudo-scalar Yukawa interaction
NASA Astrophysics Data System (ADS)
Ghorbani, Karim
2015-01-01
We consider a renormalizable extension of the standard model whose fermionic dark matter (DM) candidate interacts with a real singlet pseudo-scalar via a pseudo-scalar Yukawa term while we assume that the full Lagrangian is CP-conserved in the classical level. When the pseudo-scalar boson develops a non-zero vacuum expectation value, spontaneous CP-violation occurs and this provides a CP-violated interaction of the dark sector with the SM particles through mixing between the Higgs-like boson and the SM-like Higgs boson. This scenario suggests a minimal number of free parameters. Focusing mainly on the indirect detection observables, we calculate the dark matter annihilation cross section and then compute the DM relic density in the range up to mDM = 300 GeV.We then find viable regions in the parameter space constrained by the observed DM relic abundance as well as invisible Higgs decay width in the light of 125 GeV Higgs discovery at the LHC. We find that within the constrained region of the parameter space, there exists a model with dark matter mass mDM ~ 38 GeV annihilating predominantly into b quarks, which can explain the Fermi-LAT galactic gamma-ray excess.
Fermionic dark matter with pseudo-scalar Yukawa interaction
Ghorbani, Karim
2015-01-01
We consider a renormalizable extension of the standard model whose fermionic dark matter (DM) candidate interacts with a real singlet pseudo-scalar via a pseudo-scalar Yukawa term while we assume that the full Lagrangian is CP-conserved in the classical level. When the pseudo-scalar boson develops a non-zero vacuum expectation value, spontaneous CP-violation occurs and this provides a CP-violated interaction of the dark sector with the SM particles through mixing between the Higgs-like boson and the SM-like Higgs boson. This scenario suggests a minimal number of free parameters. Focusing mainly on the indirect detection observables, we calculate the dark matter annihilation cross section and then compute the DM relic density in the range up to m{sub DM} = 300 GeV.We then find viable regions in the parameter space constrained by the observed DM relic abundance as well as invisible Higgs decay width in the light of 125 GeV Higgs discovery at the LHC. We find that within the constrained region of the parameter space, there exists a model with dark matter mass m{sub DM} ∼ 38 GeV annihilating predominantly into b quarks, which can explain the Fermi-LAT galactic gamma-ray excess.
Liu, Huanzhao
2015-05-16
The top quark is a very special fundamental particle in the Standard Model (SM) mainly due to its heavy mass. The top quark has extremely short lifetime and decays before hadronization. This reduces the complexity for the measurement of its mass. The top quark couples very strongly to the Higgs boson since the fermion-Higgs Yukawa coupling linearly depends on the fermion’s mass. Therefore, the top quark is also heavily involved in Higgs production and related study. A precise measurement of the top quark mass is very important, as it allows for self-consistency check of the SM, and also gives a insight about the stability of our universe in the SM context. This dissertation presents my work on the measurement of the top quark mass in dilepton final states of t$\\bar{t}$ events in p$\\bar{p}$ collisions at √s = 1.96 TeV, using the full DØ Run II data corresponding to an integrated luminosity of 9.7 fb^{-1} at the Fermilab Tevatron. I extracted the top quark mass by reconstructing event kinematics, and integrating over expected neutrino rapidity distributions to obtain solutions over a scanned range of top quark mass hypotheses. The analysis features a comprehensive optimization that I made to minimize the expected statistical uncertainty. I also improve the calibration of jets in dilepton events by using the calibration determined in t$\\bar{t}$ → lepton+jets events, which reduces the otherwise limiting systematic uncertainty from the jet energy scale. The measured mass is 173.11 ± 1.34(stat)^{+0.83}_{ -0.72}(sys) GeV .
Signatures from scalar dark matter with a vector-like quark mediator
NASA Astrophysics Data System (ADS)
Giacchino, Federica; Ibarra, Alejandro; Lopez Honorez, Laura; Tytgat, Michel H. G.; Wild, Sebastian
2016-02-01
We present a comprehensive study of a model where the dark matter is composed of a singlet real scalar that couples to the Standard Model predominantly via a Yukawa interaction with a light quark and a colored vector-like fermion. A distinctive feature of this scenario is that thermal freeze-out in the early universe may be driven by annihilation both into gluon pairs at one-loop (gg) and by virtual internal Bremsstrahlung of a gluon (qbar q g). Such a dark matter candidate may also be tested through direct and indirect detection and at the LHC; viable candidates have either a mass nearly degenerate with that of the fermionic mediator or a mass above about 2 TeV.
Collective modes in strongly correlated yukawa liquids: waves in dusty plasmas.
Kalman, G; Rosenberg, M; DeWitt, H E
2000-06-26
We determine the collective mode structure of a strongly correlated Yukawa fluid, with the purpose of analyzing wave propagation in a strongly coupled dusty plasma. We identify a longitudinal plasmon and a transverse shear mode. The dispersion is characterized by a low- k acoustic behavior, a frequency maximum well below the plasma frequency, and a high- k merging of the two modes around the Einstein frequency of localized oscillations. The damping effect of collisions between neutrals and dust grains is estimated. PMID:10991116
Kurkela, Aleksi; Romatschke, Paul; Vuorinen, Aleksi
2010-05-15
We perform an O({alpha}{sub s}{sup 2}) perturbative calculation of the equation of state of cold but dense QCD matter with two massless and one massive quark flavor, finding that perturbation theory converges reasonably well for quark chemical potentials above 1 GeV. Using a running coupling constant and strange quark mass, and allowing for further nonperturbative effects, our results point to a narrow range where absolutely stable strange quark matter may exist. Absent stable strange quark matter, our findings suggest that quark matter in (slowly rotating) compact star cores becomes confined to hadrons only slightly above the density of atomic nuclei. Finally, we show that equations of state including quark matter lead to hybrid star masses up to M{approx}2M{sub {center_dot},} in agreement with current observations. For strange stars, we find maximal masses of M{approx}2.75M{sub {center_dot}}and conclude that confirmed observations of compact stars with M>2M{sub {center_dot}}would strongly favor the existence of stable strange quark matter.
CP violating anomalous top-quark coupling in p$\\bar{p}$ collision at $\\sqrt{s}=1.96$ TeV
Lee, Sehwook
2011-01-01
We conduct the first study of the T-odd correlations in tt events produced in p$\\bar{p}$ collision at the Fermilab Tevatron collider that can be used to search for CP violation. We select events which have lepton+jets final states to identify t$\\bar{t}$ events and measure counting asymmetries of several physics observables. Based on the result, we search the top quark anomalous couplings at the production vertex at the Tevatron. In addition, Geant4 development, photon identification, the discrimination of a single photon and a photon doublet from π^{0} decay are discussed in this thesis.
Periodically sheared 2D Yukawa systems
Kovács, Anikó Zsuzsa; Hartmann, Peter; Donkó, Zoltán
2015-10-15
We present non-equilibrium molecular dynamics simulation studies on the dynamic (complex) shear viscosity of a 2D Yukawa system. We have identified a non-monotonic frequency dependence of the viscosity at high frequencies and shear rates, an energy absorption maximum (local resonance) at the Einstein frequency of the system at medium shear rates, an enhanced collective wave activity, when the excitation is near the plateau frequency of the longitudinal wave dispersion, and the emergence of significant configurational anisotropy at small frequencies and high shear rates.
Pressure of two-dimensional Yukawa liquids
NASA Astrophysics Data System (ADS)
Feng, Yan; Goree, J.; Liu, Bin; Wang, Lei; Tian, Wen-de
2016-06-01
A simple analytic expression for the pressure of a two-dimensional Yukawa liquid is found by fitting results from a molecular dynamics simulation. The results verify that the pressure can be written as the sum of a potential term which is a simple multiple of the Coulomb potential energy at a distance of the Wigner–Seitz radius, and a kinetic term which is a multiple of the one for an ideal gas. Dimensionless coefficients for each of these terms are found empirically, by fitting. The resulting analytic expression, with its empirically determined coefficients, is plotted as isochores, or curves of constant area. These results should be applicable to monolayer dusty plasmas.
NASA Astrophysics Data System (ADS)
Mamo, Kiminad A.
2016-08-01
Using AdS /CFT correspondence, we find that a massless quark moving at the speed of light v =1 , in arbitrary direction, through a strongly coupled N =4 super Yang-Mills (SYM) vacuum at T =0 , in the presence of strong magnetic field B , loses its energy at a rate linearly dependent on B , i.e., d/E d t =-√{λ/} 6 π B . We also show that a heavy quark of mass M ≠0 moving at near the speed of light v2=v*2=1 -4/π2T2 B ≃1 , in arbitrary direction, through a strongly coupled N =4 SYM plasma at finite temperature T ≠0 , in the presence of strong magnetic field B ≫T2, loses its energy at a rate linearly dependent on B , i.e., d/E d t =-√{λ/}6 π B v*2≃-√{λ/}6 π B . Moreover, we argue that, in the strong magnetic field B ≫T2 (IR) regime, N =4 SYM and adjoint QCD theories (when the adjoint QCD theory has four flavors of Weyl fermions and is at its conformal IR fixed point λ =λ*) have the same microscopic degrees of freedom (i.e., gluons and lowest Landau levels of Weyl fermions) even though they have quite different microscopic degrees of freedom in the UV when we consider higher Landau levels. Therefore, in the strong magnetic field B ≫T2 (IR) regime, the thermodynamic and hydrodynamic properties of N =4 SYM and adjoint QCD plasmas, as well as the rates of energy loss of a quark moving through the plasmas, should be the same.
Phase diagram and dynamics of Yukawa systems
NASA Astrophysics Data System (ADS)
Robbins, Mark. O.; Kremer, Kurt; Grest, Gary S.
1988-03-01
The phase diagram and dynamical properties of systems of particles interacting through a repulsive screened Coulomb (Yukawa) potential have been calculated using molecular and lattice dynamics techniques. The phase diagram contains both a melting transition and a transition from fcc to bcc crystalline phases. These phase transitions have been studied as a function of potential shape (screening length) and compared to phenomenological criteria for transition temperatures such as those of Lindemann and of Hansen and Verlet. The transition from fcc to bcc with increasing temperature is shown to result from a higher entropy in the bcc phase because of its softer shear modes. Even when the stable solid phase below the melting temperature is fcc, bcc-like local order is found in the liquid phase. This may substantially slow crystallization. The calculated phase diagram and shear modulus are in good agreement with experiments on colloidal suspensions of polystyrene spheres. The single particle dynamics of Yukawa systems show several unusual features. There is a pronounced subdiffusive regime in liquids near and below the melting temperature. This regime reflects the existence of two time scales: a typical phonon period, and the time for a particle to feel a new environment. The second time scale becomes longer as the temperature is lowered or the range of interaction (screening length) increases.
Thermodynamics of Yukawa fluids near the one-component-plasma limit
Khrapak, Sergey A.; Semenov, Igor L.; Thomas, Hubertus M.; Couëdel, Lénaïc
2015-08-15
Thermodynamics of weakly screened (near the one-component-plasma limit) Yukawa fluids in two and three dimensions is analyzed in detail. It is shown that the thermal component of the excess internal energy of these fluids, when expressed in terms of the properly normalized coupling strength, exhibits the scaling pertinent to the corresponding one-component-plasma limit (the scalings differ considerably between the two- and three-dimensional situations). This provides us with a simple and accurate practical tool to estimate thermodynamic properties of weakly screened Yukawa fluids. Particular attention is paid to the two-dimensional fluids, for which several important thermodynamic quantities are calculated to illustrate the application of the approach.
Peters, Yvonne
2011-12-01
Since its discovery in 1995 by the CDF and D0 collaborations at the Fermilab Tevatron collider, the top quark has undergone intensive studies. Besides the Tevatron experiments, with the start of the LHC in 2010 a top quark factory started its operation. It is now possible to measure top quark properties simultaneously at four different experiments, namely ATLAS and CMS at LHC and CDF and D0 at Tevatron. Having collected thousands of top quarks each, several top quark properties have been measured precisely, while others are being measured for the first time. In this article, recent measurements of top quark properties from ATLAS, CDF, CMS and D0 are presented, using up to 5.4 fb{sup -1} of integrated luminosity at the Tevatron and 1.1 fb{sup -1} at the LHC. In particular, measurements of the top quark mass, mass difference, foward backward charge asymmetry, t{bar t} spin correlations, the ratio of branching fractions, W helicity, anomalous couplings, color flow and the search for flavor changing neutral currents are discussed.
Anisovich, A. V.; Anisovich, V. V.; Dakhno, L. G.; Matveev, M. A.; Nikonov, V. A.; Sarantsev, A. V.
2010-03-15
In the framework of the relativistic and gauge-invariant spectral integral technique, we calculate radiative decays {rho}(770) {sup {yields} {gamma}{pi}}(140) and {omega}(780) {sup {yields} {gamma}{pi}}(140) supposing all mesons ({pi}, {rho}, and {omega}) to be quark-antiquark states. The qq-bar wave functions found for mesons and photon lead to a reasonably good description of data ( {Gamma} (exp){rho} {+-} to {gamma} {pi} 68 {+-} 30 keV, {Gamma} (exp) {rho} 0 to {gamma} {pi} 0 = 77 {+-} 28 keV, {Gamma} (exp) {omega} to {gamma} {pi} 0 = 776 {+-} 45 keV) which makes it possible to estimate the coupling for the bremsstrahlung emission of pion by quarks g{sub {pi} {identical_to}} g{sub {pi}}(u {sup {yields}}d{pi}). We have found two values for the pion bremsstrahlung coupling: vertical bar g{sub {pi}}vertical bar = 16.7 {+-} 0.3{sub -2.3}{sup +0.1} (Solution I) and vertical bar g{sub {pi}}vertical bar = 3.0 {+-} 0.3{sub -2.1}{sup +0.1} (Solution II). Within SU(6) symmetry for nucleons, Solution I gives us for {pi}NN coupling the value 16.4 {<=} g{sub {pi}NN}{sup 2}(4{pi}) {<=} 23.2, which is in qualitative agreement with the {pi}N scattering data, g{sub {pi}NN}{sup 2}/(4{pi}) {r_brace}{approx} 14. For excited states, we have estimated the partial widths in Solution I as follows: {Gamma}({rho}{sub 2S}{sup {+-} {yields} {gamma}{pi}}) {r_brace}{approx} 10-130 keV, {Gamma}({rho}{sub 2S}{sup 0} {sup {yields} {gamma}{pi}}) {r_brace}{approx} 10-130 keV, {Gamma}({omega}{sub 2S} {sup {yields} {gamma}{pi}}) {r_brace}{approx} 60-1080 keV. The large uncertainties emphasize the necessity to carry out measurements of the meson radiative processes in the region of large masses.
Quark and Gluon Relaxation in Quark-Gluon Plasmas
NASA Technical Reports Server (NTRS)
Heiselberg, H.; Pethick, C. J.
1993-01-01
The quasiparticle decay rates for quarks and gluons in quark-gluon plasmas are calculated by solving the kinetic equation. Introducing an infrared cutoff to allow for nonperturbative effects, we evaluate the quasiparticle lifetime at momenta greater than the inverse Debye screening length to leading order in the coupling constant.
Top quark physics: Future Measurements
Frey, Raymond; Gerdes, David; Jaros, John; Vejcik, Steve; Berger, Edmond L.; Chivukula, R. Sekhar; Cuypers, Frank; Drell, Persis S.; Fero, Michael; Hadley, Nicholas; Han, Tao; Heinson, Ann P.; Knuteson, Bruce; Larios, Francisco; Miettinen, Hannu; Orr, Lynne H.; Peskin, Michael E.; Rizzo, Thomas; Sarid, Uri; Schmidt, Carl; Stelzer, Tim; Sullivan, Zack
1996-12-31
We discuss the study of the top quark at future experiments and machines. Top's large mass makes it a unique probe of physics at the natural electroweak scale. We emphasize measurements of the top quark's mass, width, and couplings, as well as searches for rare or nonstandard decays, and discuss the complementary roles played by hadron and lepton colliders.
Non-perturbative Calculation of the Scalar Yukawa Theory in Four-Body Truncation
NASA Astrophysics Data System (ADS)
Li, Yang; Karmanov, V. A.; Maris, P.; Vary, J. P.
2015-09-01
The quenched scalar Yukawa theory is solved in the light-front Tamm-Dancoff approach including up to four constituents (one scalar nucleon, three scalar pions). The Fock sector dependent renormalization is implemented. By studying the Fock sector norms, we find that the lowest two Fock sectors dominate the state even in the large-coupling region. The one-body sector shows convergence with respect to the Fock sector truncation. However, the four-body norm exceeds the three-body norm at the coupling.
He, Guangliang.
1992-05-15
The Cloudy Quark Bag Model is extended from S-wave to P- and D-wave. The parameters of the model are determined by K{sup {minus}}p scattering cross section data, K{sup {minus}}p {yields}{Sigma}{pi}{pi}{pi} production data, K{sup {minus}}p threshold branching ratio data, and K{sup {minus}}p {yields}{Lambda}{pi}{pi}{pi} production data. The resonance structure of the {Lambda}(1405), {Sigma}(1385), and {Lambda}(1520) are studied in the model. The shift and width of kaonic hydrogen are calculated using the model.
Haxhimali, Tomorr; Rudd, Robert E; Cabot, William H; Graziani, Frank R
2015-11-01
We present molecular dynamics (MD) calculations of shear viscosity for asymmetric mixed plasma for thermodynamic conditions relevant to astrophysical and inertial confinement fusion plasmas. Specifically, we consider mixtures of deuterium and argon at temperatures of 100-500 eV and a number density of 10^{25} ions/cc. The motion of 30,000-120,000 ions is simulated in which the ions interact via the Yukawa (screened Coulomb) potential. The electric field of the electrons is included in this effective interaction; the electrons are not simulated explicitly. Shear viscosity is calculated using the Green-Kubo approach with an integral of the shear stress autocorrelation function, a quantity calculated in the equilibrium MD simulations. We systematically study different mixtures through a series of simulations with increasing fraction of the minority high-Z element (Ar) in the D-Ar plasma mixture. In the more weakly coupled plasmas, at 500 eV and low Ar fractions, results from MD compare very well with Chapman-Enskog kinetic results. In the more strongly coupled plasmas, the kinetic theory does not agree well with the MD results. We develop a simple model that interpolates between classical kinetic theories at weak coupling and the Murillo Yukawa viscosity model at higher coupling. This hybrid kinetics-MD viscosity model agrees well with the MD results over the conditions simulated, ranging from moderately weakly coupled to moderately strongly coupled asymmetric plasma mixtures. PMID:26651805
NASA Astrophysics Data System (ADS)
Haxhimali, Tomorr; Rudd, Robert E.; Cabot, William H.; Graziani, Frank R.
2015-11-01
We present molecular dynamics (MD) calculations of shear viscosity for asymmetric mixed plasma for thermodynamic conditions relevant to astrophysical and inertial confinement fusion plasmas. Specifically, we consider mixtures of deuterium and argon at temperatures of 100-500 eV and a number density of 1025 ions/cc. The motion of 30 000-120 000 ions is simulated in which the ions interact via the Yukawa (screened Coulomb) potential. The electric field of the electrons is included in this effective interaction; the electrons are not simulated explicitly. Shear viscosity is calculated using the Green-Kubo approach with an integral of the shear stress autocorrelation function, a quantity calculated in the equilibrium MD simulations. We systematically study different mixtures through a series of simulations with increasing fraction of the minority high-Z element (Ar) in the D-Ar plasma mixture. In the more weakly coupled plasmas, at 500 eV and low Ar fractions, results from MD compare very well with Chapman-Enskog kinetic results. In the more strongly coupled plasmas, the kinetic theory does not agree well with the MD results. We develop a simple model that interpolates between classical kinetic theories at weak coupling and the Murillo Yukawa viscosity model at higher coupling. This hybrid kinetics-MD viscosity model agrees well with the MD results over the conditions simulated, ranging from moderately weakly coupled to moderately strongly coupled asymmetric plasma mixtures.
NASA Astrophysics Data System (ADS)
Alves, Alexandre; Camargo, Daniel A.; Dias, Alex G.
2016-07-01
Motivated by a solution to the strong C P problem, we propose a model where a new heavy neutral C P -even Higgs boson couples to vectorlike quarks enhancing its production cross section whose dominant decays are into weak bosons. The masses of the vectorlike quarks are generated through interactions with a singlet scalar field charged under a broken global U (1 ) symmetry, providing a solution to the strong C P problem by means of the Peccei-Quinn mechanism. The diboson excess observed by the ATLAS Collaboration is discussed as the new heavy Higgs boson is a candidate to explain a possible signal in this channel. We also show that the 14 TeV LHC is capable of discovering this heavy Higgs with masses up to 1 TeV in the H →Z Z →ℓ+ℓ,SUP- ℓ'+ℓ'- search channel using boosted decision trees to better discriminate between signals and backgrounds and to tame systematic uncertainties in the background rates.
Higgs boson production with heavy quarks at hadron colliders
NASA Astrophysics Data System (ADS)
Jackson, Christopher B.
2005-11-01
One of the remaining puzzles in particle physics is the origin of electroweak symmetry breaking. In the Standard Model (SM), a single doublet of complex scalar fields is responsible for breaking the SU(2) L x U(1)Y gauge symmetry thus giving mass to the electroweak gauge bosons via the Higgs mechanism and to the fermions via Yukawa couplings. The remnant of the process is a vet to he discovered scalar particle, the Higgs boson (h). However, current and future experiments at hadron colliders hold great promise. Of particular interest at hadron colliders is the production of a Higgs boson in association with a pair of heavy quarks, pp¯(pp) → QQ¯h, where Q can be either a top or a bottom quark. Indeed, the production of a Higgs boson with a pair of top quarks provides a very distinctive signal in hadronic collisions where background processes are formidable, and it will be instrumental in the discovery of a Higgs boson below about 130 GeV at the LHC. On the other hand, the production of a Higgs boson with bottom quarks can be strongly enhanced in models of new physics beyond the SM, e.g. supersymmetric models. If this is the case, bb¯h production will play a crucial role at the Tevatron where it could provide the first signal of new physics. Given the prominent role that Higgs production with heavy quarks can play at hadron colliders, it becomes imperative to have precise theoretical predictions for total and differential cross sections. In this dissertation, we outline and present detailed results for the next-to-leading order (NLO) calculation of the Quantum Chromodynamic (QCD) corrections to QQ¯h production at both the Tevatron and the LHC. This calculation involves several difficult issues due to the three massive particles in the final state, a situation which is at the frontier of radiative correction calculations in quantum field theory. We detail the novel techniques developed to deal with these challenges. The calculation of pp¯(pp) → bb¯h at NLO in
Models of Yukawa interaction in the two Higgs doublet model, and their collider phenomenology
Aoki, Mayumi; Kanemura, Shinya; Yagyu, Kei; Tsumura, Koji
2009-07-01
Possible models of Yukawa interaction are discussed in the two Higgs doublet model (THDM) under the discrete symmetry imposed to avoid the flavor changing neutral current at the leading order. It is known that there are four types of such models corresponding to the possible different assignment of charges for the discrete symmetry on quarks and leptons. We first examine the decay properties of Higgs bosons in each type model, and summarize constraints on the models from current experimental data. We then shed light on the differences among these models in collider phenomenology. In particular, we mainly discuss the so-called type-II THDM and type-X THDM. The type-II THDM corresponds to the model with the same Yukawa interaction as the minimal supersymmetric standard model. On the other hand, in the type-X THDM, additional Higgs bosons can predominantly decay into leptons. This scenario may be interesting because of the motivation for a light charged Higgs boson scenario such as in the TeV-scale model of neutrinos, dark matter, and baryogenesis. We study how we can distinguish the type-X THDM from the minimal supersymmetric standard model at the Large Hadron Collider and the International Linear Collider.
NASA Astrophysics Data System (ADS)
Haxhimali, Tomorr; Rudd, Robert; Jackson, Julie; Surh, Michael; Cabot, William; Caspersen, Kyle; Greenough, Jeffrey; Graziani, Frank; Miller, Paul
2012-10-01
We employ classical molecular dynamics (MD) to investigate species diffusivity in binary Yukawa mixtures. The Yukawa potential is used to describe the screened Coulomb interaction between the ions, providing the basis for models of dense stellar materials, inertial confined plasmas, and colloidal particles in electrolytes. We use Green-Kubo techniques to calculate self-diffusivities and the Maxwell-Stefan diffusivities, and evaluate the validity of the Darken relation over a range of thermodynamic conditions of the mixture. The inter-diffusivity (or mutual diffusivity) can then be related to the Maxwell-Stefan diffusivities through the thermodynamic factor. The latter requires knowledge of the equation of state of the mixture. To test these Green-Kubo approaches and to estimate the activity contribution we have also employed large-scale non-equilibrium MD. In these simulations we can extract the inter-diffusivity value by calculating the rate of broadening of the interface in a diffusion couple. We also explore thermodynamic conditions for possible non-Fickian diffusivity. The main motivation in this work is to build a model that describes the transport coefficients in binary Yukawa mixtures over a broad range of thermodynamic conditions up to 1keV.
Numerical experiment of thermal conductivity in two-dimensional Yukawa liquids
Shahzad, Aamir; He, Mao-Gang
2015-12-15
A newly improved homogenous nonequilibrium molecular dynamics simulation (HNEMDS) method, proposed by the Evans, has been used to compute the thermal conductivity of two-dimensional (2D) strongly coupled complex (dusty) plasma liquids (SCCDPLs), for the first time. The effects of equilibrium external field strength along with different system sizes and plasma states (Γ, κ) on the thermal conductivity of SCCDPLs have been calculated using an enhanced HNEMDS method. A simple analytical temperature representation of Yukawa 2D thermal conductivity with appropriate normalized frequencies (plasma and Einstein) has also been calculated. The new HNEMDS algorithm shows that the present method provides more accurate results with fast convergence and small size effects over a wide range of plasma states. The presented thermal conductivity obtained from HNEMDS method is found to be in very good agreement with that obtained through the previously known numerical simulations and experimental results for 2D Yukawa liquids (SCCDPLs) and with the three-dimensional nonequilibrium molecular dynamics simulation (MDS) and equilibrium MDS calculations. It is shown that the HNEMDS algorithm is a powerful tool, making the calculations very efficient and can be used to predict the thermal conductivity in 2D Yukawa liquid systems.
Non-perturbative Renormalization in Truncated Yukawa Model
NASA Astrophysics Data System (ADS)
Karmanov, V. A.
2016-06-01
An approach to non-perturbative calculations in the light-front quantum field theory and its new developments are briefly reviewed. We start with the decomposition of the state vector in Fock components. After truncation of this decomposition (main approximation in this approach), the eigenvalue equation for the light-front Hamiltonian generates, in Minkowski space, a finite system of integral equations for the Fock components. Solving this system numerically and performing the non-perturbative renormalization, we find the state vector of fermion in the quenched scalar Yukawa model, up to the four-body truncation (one fermion + three bosons), for rather large values of the coupling constant. With the state vector, found in this way, the fermion electromagnetic form factors are calculated. Comparing results obtained in the four-body truncation with those found in the previous, three-body truncation, we discover very good convergence relative to truncation, that indicates that we are close to the exact non-perturbative solution in this field-theoretical model. The approach can be extended to more realistic field theories and, after further development, it could constitute an alternative to the lattice calculations.
Structural arrest transitions in fluids described by two Yukawa potentials
NASA Astrophysics Data System (ADS)
Wu, Jianlan; Liu, Yun; Chen, Wei-Ren; Cao, Jianshu; Chen, Sow-Hsin
2004-11-01
We study a model colloidal system where particles interact via short-range attractive and long-range repulsive Yukawa potentials. Using the structure factor calculated from the mean-spherical approximation as the input, the kinetic phase diagrams as functions of the attraction depth and the volume fraction are obtained by calculating the Debye-Waller factors in the framework of the mode-coupling theory for three different heights of the repulsive barrier. The glass-glass reentrance phenomenon in the attractive colloidal case is also observed in the presence of the long-range repulsive barrier, which results in the lower and upper glass regimes. Competition between the short-range attraction and the long-range repulsion gives rise to new regimes associated with clusters such as “static cluster glass” and “dynamic cluster glass,” which appear in the lower glass regime. Along the liquid-glass transition line between the liquid regime and the lower glass regime, crossover points separating different glass states are identified.
Quark and lepton masses and mixing in the landscape
Donoghue, John F.; Dutta, Koushik; Ross, Andreas
2006-06-01
Even if quark and lepton masses are not uniquely predicted by the fundamental theory, as may be the case in the string theory landscape, nevertheless their pattern may reveal features of the underlying theory. We use statistical techniques to show that the observed masses appear to be representative of a scale-invariant distribution, {rho}(m){approx}1/m. If we extend this distribution to include all the Yukawa couplings, we show that the resulting Cabibbo-Kobayashi-Maskawa matrix elements typically show a hierarchical pattern similar to observations. The Jarlskog invariant measuring the amount of CP violation is also well reproduced in magnitude. We also apply this framework to neutrinos using the seesaw mechanism. The neutrino results are ambiguous, with the observed pattern being statistically allowed even though the framework does not provide a natural explanation for the observed two large mixing angles. Our framework highly favors a normal hierarchy of neutrino masses. We also are able to make statistical predictions in the neutrino sector when we specialize to situations consistent with the known mass differences and two large mixing angles. Within our framework, we show that with 95% confidence the presently unmeasured Maki-Nakagawa-Sakata mixing angle sin{theta}{sub 13} is larger than 0.04 and typically of order 0.1. The leptonic Jarlskog invariant is found to be typically of order 10{sup -2} and the magnitude of the effective Majorana mass m{sub ee} is typically of order 0.001 eV.
Hierarchy plus anarchy in quark masses and mixings
NASA Astrophysics Data System (ADS)
Aguilar-Saavedra, J. A.
2003-04-01
We introduce a parametrization of the effect of unknown corrections from new physics on quark and lepton mass matrices. This parametrization is used in order to study how the hierarchies of quark masses and mixing angles are modified by random perturbations of the Yukawa matrices. We discuss several examples of flavor relations predicted by different textures, analyzing how these relations are influenced by the random perturbations. We also comment on the unlikely possibility that unknown corrections contribute significantly to the hierarchy of masses and mixings.
Numerical studies of the melting transition in 2D Yukawa systems
Hartmann, P.; Donko, Z.; Kalman, G. J.
2008-09-07
We present the latest results of our systematic studies of the solid--liquid phase transition in 2D classical many-particle systems interacting with the Yukawa potential. Our previous work is extended by applying the molecular dynamic simulations to systems with up to 1.6 million particles in the computational box (for {kappa} = 2 case). Equilibrium simulations are performed for different coupling parameters in the vicinity of the expected melting transition ({gamma}{sub m}{sup {kappa}}{sup ={sup 2}}{approx_equal}415) and a wide range of observables are averaged over uncorrelated samples of the micro-canonical ensemble generated by the simulations.
Collective Modes in Strongly Correlated Yukawa Liquids: Waves in Dusty Plasmas
Kalman, G.; Rosenberg, M.; DeWitt, H. E.
2000-06-26
We determine the collective mode structure of a strongly correlated Yukawa fluid, with the purpose of analyzing wave propagation in a strongly coupled dusty plasma. We identify a longitudinal plasmon and a transverse shear mode. The dispersion is characterized by a low-k acoustic behavior, a frequency maximum well below the plasma frequency, and a high-k merging of the two modes around the Einstein frequency of localized oscillations. The damping effect of collisions between neutrals and dust grains is estimated. (c) 2000 The American Physical Society.
The Non-Perturbative Scalar Yukawa Theory on the Light Front
NASA Astrophysics Data System (ADS)
Li, Yang; Karmanov, Vladimir; Maris, Pieter; Vary, James
2015-04-01
We present a non-perturbative calculation of the scalar Yukawa model in light-front dynamics with a Fock sector dependent renormalization. The Fock space is truncated to four particles and then the ab initio Hamiltonian approach is applied. We compute the electromagnetic form factor and compare it with the results obtained from the lower Fock sector truncations. We find that the one- and two-body contributions dominate the Fock space even in the non-perturbative region. However, the four-body contribution exceeds the three-body one as the coupling constant increases. Nevertheless, the form factor shows a good converge as the number of constituent bosons increases.
Yukawa couplings in superstring compactification. [in quantum gravity theory
NASA Technical Reports Server (NTRS)
Strominger, A.
1985-01-01
A topological formula is given for the entire tree-level contribution to the low-energy effective action of a Calabi-Yau superstring compactification. The constraints on proton lifetime in the Calabi-Yau compactification are discussed in detail.
NASA Astrophysics Data System (ADS)
Haxhimali, Tomorr; Rudd, Robert; Cabot, William; Graziani, Frank
2015-11-01
We present molecular dynamics (MD) calculations of shear viscosity for asymmetric mixed plasma for thermodynamic conditions relevant to astrophysical and Inertial Confinement Fusion plasmas. Specifically, we consider mixtures of deuterium and argon at temperatures of 100-500 eV and a number density of 1025 ions/cc. The motion of 30000-120000 ions is simulated in which the ions interact via the Yukawa (screened Coulomb) potential. The electric field of the electrons is included in this effective interaction. Shear viscosity is calculated using the Green-Kubo approach with an integral of the shear stress autocorrelation function, a quantity calculated in the equilibrium MD simulations. We study different mixtures with increasing fraction of the minority high-Z element (Ar) in the D-Ar plasma mixture. In the more weakly coupled plasmas, at 500 eV and low Ar fractions, results from MD compare very well with Chapman-Enskog kinetic results. We introduce a model that interpolates between a screened-plasma kinetic theory at weak coupling and the Murillo Yukawa viscosity model at higher coupling. This hybrid kinetics-MD viscosity model agrees well with the MD results over the conditions simulated. This work was performed under the auspices of the US Dept. of Energy by Lawrence Livermore National Security, LLC under Contract DE-AC52-07NA27344.
Confining quark condensate model of the nucleon.
Frank, Michael; Tandy, Peter
1992-07-01
We obtain a mean-field solution for the nucleon as a quark-meson soliton obtained from the action of the global color-symmetry model of QCD. All dynamics is generated from an effective interaction of quark currents. At the quark-meson level there are two novel features: (1) absolute confinement is produced from the space-time structure of the dynamical self-energy in the vacuum quark propagator; and (2) the related scalar meson field is an extended q-barq composite that couples nonlocally to quarks. The influence of these features upon the nucleon mass contributions and other nucleon properties is presented.
Conformal gauge-Yukawa theories away from four dimensions
NASA Astrophysics Data System (ADS)
Codello, Alessandro; Langæble, Kasper; Litim, Daniel F.; Sannino, Francesco
2016-07-01
We present the phase diagram and associated fixed points for a wide class of Gauge-Yukawa theories in d = 4 + ɛ dimensions. The theories we investigate involve non-abelian gauge fields, fermions and scalars in the Veneziano-Witten limit. The analysis is performed in steps, we start with QCD d and then we add Yukawa interactions and scalars which we study at next-to- and next-to-next-to-leading order. Interacting infrared fixed points naturally emerge in dimensions lower than four while ultraviolet ones appear above four. We also analyse the stability of the scalar potential for the discovered fixed points. We argue for a very rich phase diagram in three dimensions while in dimensions higher than four certain Gauge-Yukawa theories are ultraviolet complete because of the emergence of an asymptotically safe fixed point.
Zero-temperature phase diagram of Yukawa bosons
NASA Astrophysics Data System (ADS)
Osychenko, O. N.; Astrakharchik, G. E.; Mazzanti, F.; Boronat, J.
2012-06-01
We study the zero-temperature phase diagram of bosons interacting via screened Coulomb (Yukawa) potential by means of the diffusion Monte Carlo method. The Yukawa potential is used as a model interaction in the neutron matter, dusty plasmas, and charged colloids. As shown by Petrov [Phys. Rev. Lett.PRLTAO0031-900710.1103/PhysRevLett.99.130407 99, 130407 (2007)], interactions between weakly bound molecules of heavy and light fermionic atoms are described by an effective Yukawa potential with a strength related to the heavy-light mass ratio M/m, which might lead to crystallization in a two-dimensional geometry if the mass ratio of heavy-light fermions exceeds a certain critical value. In the present work we do a thorough study of the quantum three-dimensional Yukawa system. For strong interactions (equivalently, large mass ratios) the system experiences several phase transitions as the density is increased, passing from gas to solid and to gas phase again. Weakly interacting Yukawa particles do not crystallize at any density. We find the minimal interaction strength at which the crystallization happens. In terms of the two-component fermionic system, this strength corresponds to a heavy-light mass ratio of M/m˜180, so that it is impossible to realize the gas-crystal transition in a conventional bulk system. For the Yukawa model of fermionic mixtures we also analyze the possibility of building molecular systems with very large effective mass ratios by confining the heavy component to a sufficiently deep optical lattice. We show how the effective mass of the heavy component can be made arbitrarily large by increasing the lattice depth, thus leading to a tunable effective mass ratio that can be used to realize a molecular superlattice.
Beam-Plasma Interaction and Instabilities in a 2D Yukawa Plasma
NASA Astrophysics Data System (ADS)
Kyrkos, S.; Kalman, G.; Rosenberg, M.
2008-11-01
In a complex plasma, penetrating charged particle beams may lead to beam-plasma instabilities. When either the plasma, the beam, or both, are strongly interacting [1], the features of the instability are different from those in a weakly coupled plasma. We consider the case when a 2D dusty plasma forms a lattice, and the beam is moving in the lattice plane. Both the grains and the beam particles interact through a Yukawa potential; the beam particles are weakly coupled to each other and to the lattice. The system develops both a longitudinal and a transverse instability. Based on the phonon spectrum of a 2D hexagonal Yukawa lattice [2], we determine and compare the transverse and longitudinal growth rates. As a function of the wavenumber, the growth rates exhibit remarkable gaps, where no instability is excited. The gap locations are governed by the ratio of the lattice and the beam plasma frequencies. The behavior of the growth rates also depends on the direction of the beam and on the relationship between the beam speed and the longitudinal and transverse sound speeds. [1] GJ Kalman, M Rosenberg, JPA 36, 5963 (2003). [2] T Sullivan, GJ Kalman, S Kyrkos, P Bakshi, M Rosenberg, Z Donko, JPA 39, 4607 (2006).
OBSERVATIONAL EVIDENCE FOR DARK MATTER INTERACTING THROUGH A YUKAWA POTENTIAL
Chan, M. H.
2013-05-20
Recent observations in galaxies and clusters indicate that dark matter density profiles exhibit core-like structures which contradict the numerical simulation results of collisionless cold dark matter (CDM). On the other hand, it has been shown that CDM particles interacting through a Yukawa potential could naturally explain the cores in dwarf galaxies. In this Letter, I use the Yukawa potential interacting dark matter model to derive two simple scaling relations on the galactic and cluster scales, respectively, which give excellent agreements with observations. Also, in our model, the masses of the force carrier and dark matter particle can be constrained by the observational data.
Longitudinal viscosity of two-dimensional Yukawa liquids
NASA Astrophysics Data System (ADS)
Feng, Yan; Goree, J.; Liu, Bin
2013-01-01
The longitudinal viscosity ηl is obtained for a two-dimensional (2D) liquid using a Green-Kubo method with a molecular dynamics simulation. The interparticle potential used has the Debye-Hückel or Yukawa form, which models a 2D dusty plasma. The longitudinal ηl and shear ηs viscosities are found to have values that match very closely, with only negligible differences for the entire range of temperatures that is considered. For a 2D Yukawa liquid, the bulk viscosity ηb is determined to be either negligibly small or not a meaningful transport coefficient.
Ground state of a confined Yukawa plasma including correlation effects
NASA Astrophysics Data System (ADS)
Henning, C.; Ludwig, P.; Filinov, A.; Piel, A.; Bonitz, M.
2007-09-01
The ground state of an externally confined one-component Yukawa plasma is derived analytically using the local density approximation (LDA). In particular, the radial density profile is computed. The results are compared with the recently obtained mean-field (MF) density profile [Henning , Phys. Rev. E 74, 056403 (2006)]. While the MF results are more accurate for weak screening, the LDA with correlations included yields the proper description for large screening. By comparison with first-principles simulations for three-dimensional spherical Yukawa crystals, we demonstrate that the two approximations complement each other. Together they accurately describe the density profile in the full range of screening parameters.
Yukawa and the Birth of Meson Theory: Fiftieth Anniversary for Nuclear Forces.
ERIC Educational Resources Information Center
Spradley, Joseph L.
1985-01-01
In 1935 physicist Hideki Yukawa proposed the meson theory of nuclear forces. Background, influences, and chronology of Yukawa's work are presented and discussed. Yukawa was supported in his meson idea by Japan's strong emphasis on intuitive and creative approaches which are also evident in subsequent developments in that country. (DH)
Accurate momentum transfer cross section for the attractive Yukawa potential
Khrapak, S. A.
2014-04-15
Accurate expression for the momentum transfer cross section for the attractive Yukawa potential is proposed. This simple analytic expression agrees with the numerical results better than to within ±2% in the regime relevant for ion-particle collisions in complex (dusty) plasmas.
Equilibrium properties and phase diagram of two-dimensional Yukawa systems
NASA Astrophysics Data System (ADS)
Hartmann, P.; Kalman, G. J.; Donkó, Z.; Kutasi, K.
2005-08-01
Properties of two-dimensional strongly coupled Yukawa systems are explored through molecular dynamics simulations. An effective coupling coefficient Γ* for the liquid phase is introduced on the basis of the constancy of the first peak amplitude of the pair-correlation functions. Thermodynamic quantities are calculated from the pair-correlation function. The solid-liquid transition of the system is investigated through the analysis of the bond-angular order parameter. The static structure function satisfies consistency relation, attesting to the reliability of the computational method. The response is shown to be governed by the correlational part of the inverse compressibility. An analysis of the velocity autocorrelation demonstrates that this latter also exhibits a universal behavior.
Equilibrium properties and phase diagram of two-dimensional Yukawa systems
Hartmann, P.; Donko, Z.; Kutasi, K.; Kalman, G.J.
2005-08-01
Properties of two-dimensional strongly coupled Yukawa systems are explored through molecular dynamics simulations. An effective coupling coefficient {gamma}{sup *} for the liquid phase is introduced on the basis of the constancy of the first peak amplitude of the pair-correlation functions. Thermodynamic quantities are calculated from the pair-correlation function. The solid-liquid transition of the system is investigated through the analysis of the bond-angular order parameter. The static structure function satisfies consistency relation, attesting to the reliability of the computational method. The response is shown to be governed by the correlational part of the inverse compressibility. An analysis of the velocity autocorrelation demonstrates that this latter also exhibits a universal behavior.
Ab initio approach to the non-perturbative scalar Yukawa model
NASA Astrophysics Data System (ADS)
Li, Yang; Karmanov, V. A.; Maris, P.; Vary, J. P.
2015-09-01
We report on the first non-perturbative calculation of the scalar Yukawa model in the single-nucleon sector up to four-body Fock sector truncation (one "scalar nucleon" and three "scalar pions"). The light-front Hamiltonian approach with a systematic non-perturbative renormalization is applied. We study the n-body norms and the electromagnetic form factor. We find that the one- and two-body contributions dominate up to coupling α ≈ 1.7. As we approach the coupling α ≈ 2.2, we discover that the four-body contribution rises rapidly and overtakes the two- and three-body contributions. By comparing with lower sector truncations, we show that the form factor converges with respect to the Fock sector expansion.
Yukawa Meson, Sakata Model and Baryon-Lepton Symmetry Revisited
NASA Astrophysics Data System (ADS)
Marshak, R. E.
It is difficult for me to grasp that this symposium is celebrating the jubilee of meson theory since I was a junior at Columbia College in 1935. I recall hearing a colloquium by Paul Dirac that year telling an enraptured audience about the infinite sea of negative energy states but I do not recall any special note being taken of the birth of an equally revolutionary concept, the Yukawa meson. Perhaps the reason was the publication of Hideki Yukawa's paper in an inaccessible Japanese journal, perhaps Dirac's electron theory was dealing with the well-known electromagnetic force whereas Yukawa' meson theory was put forth to understand the nature of two new forces - the nuclear and the weak. Whatever the reason, the situation changed drastically when I migrated to Cornell (to do my thesis under Hans Bethe during the years 1937sim39) and found a deep interest in meson theory. Thus, my own scientific career has almost spanned the period since the birth of meson theory but, what is more to the point, it has been strongly influenced by the work of Yukawa and his collaborators. It therefore gives me great pleasure to be able to talk at this MESON 50 symposium. As one of the oldest speakers, I shall respond in a loose way to Professor Maki's invitation to cover ``topics concerning the historical developments of hadron physics''. I shall select several major themes from the Japanese work that have had special interest for me. My remarks will fall under the four headings: (A) Yukawa Meson; (B) Sakata Model; (C) Baryon-Lepton Symmetry; and (D) Extensions of Baryon-Lepton Symmetry.
Finite and Gauge-Yukawa unified theories: Theory and predictions
Kobayashi, T.; Kubo, J.; Mondragon, M.; Zoupanos, G.
1999-10-25
All-loop Finite Unified Theories (FUTs) are very interesting N=1 GUTs in which a complete reduction of couplings has been achieved. FUTs realize an old field theoretical dream and have remarkable predictive power. Reduction of dimensionless couplings in N=1 GUTs is achieved by searching for renormalization group invariant (RGI) relations among them holding beyond the unification scale. Finiteness results from the fact that there exists RGI relations among dimensionless couplings that guarantee the vanishing of the {beta}- functions in certain N=1 supersymmetric GUTS even to all orders. Recent developments in the soft supersymmetry breaking (SSB) sector of N=1 GUTs and FUTs lead to exact RGI relations also in this sector of the theories. Of particular interest is a RGI sum rule for the soft scalar masses holding to all orders. The characteristic features of SU(5) models that have been constructed based on the above tools are: a) the old agreement of the top quark prediction with the measured value remains unchanged, b) the lightest Higgs boson is predicted to be around 120 GeV, c) the s-spectrum starts above several hundreds of GeV.
Dynamical breakdown of Abelian gauge chiral symmetry by strong Yukawa interactions
Benes, Petr; Brauner, Tomas; Hosek, Jiri
2007-03-01
We consider a model with anomaly-free Abelian gauge axial-vector symmetry, which is intended to mimic the standard electroweak gauge chiral SU(2){sub L}xU(1){sub Y} theory. Within this model we demonstrate: (1) Strong Yukawa interactions between massless fermion fields and a massive scalar field carrying the axial charge generate dynamically the fermion and boson proper self-energies, which are ultraviolet-finite and chirally noninvariant. (2) Solutions of the underlying Schwinger-Dyson equations found numerically exhibit a huge amplification of the fermion mass ratios as a response to mild changes of the ratios of the Yukawa couplings. (3) The 'would-be' Nambu-Goldstone boson is a composite of both the fermion and scalar fields, and it gives rise to the mass of the axial-vector gauge boson. (4) Spontaneous breakdown of the gauge symmetry further manifests by mass splitting of the complex scalar and by new symmetry-breaking vertices, generated at one loop. In particular, we work out in detail the cubic vertex of the Abelian gauge boson.
Properties of gravitationally equilibrated Yukawa systems—A molecular dynamics study
Charan, Harish; Ganesh, Rajaraman Joy, Ashwin
2014-04-15
Using 2D Molecular Dynamics simulation, the equilibrium and dynamical properties of a gravitationally equilibrated Yukawa liquid are investigated. We observe that due to asymmetry introduced in one direction by gravity, several interesting features arise. For example, for a given value of coupling parameter Γ, screening parameter κ, and according to a chosen value of gravitational force g (say in y-direction), the system is seen to exhibit super-, sub- or normal diffusion. Interestingly, x-averaged density profiles, unlike a barotropic fluid, acquires sharp, free surface with scale free linear y-dependence. As can be expected for a system with macroscopic gradients, self-diffusion calculated from Green-Kubo’s formalism does not agree with that obtained from Einstein-Smoluchowski diffusion. A 2D angular-radial pair correlation function g(r, θ) clearly indicates asymmetric features induced by gravity. We observe that due to compression in y-direction, though in liquid state for all values of gravity considered, the transverse mode is found to predominant as compared to the longitudinal mode, leading to a novel Anisotropic Solid-like Yukawa liquid.
Single Top Quarks at the Tevatron
Heinson, Ann P.; /UC, Riverside
2008-09-01
After many years searching for electroweak production of top quarks, the Tevatron collider experiments have now moved from obtaining first evidence for single top quark production to an impressive array of measurements that test the standard model in several directions. This paper describes measurements of the single top quark cross sections, limits set on the CKM matrix element |Vtb|, searches for production of single top quarks produced via flavor-changing neutral currents and from heavy W-prime and H+ boson resonances, and studies of anomalous Wtb couplings. It concludes with projections for future expected significance as the analyzed datasets grow.
Measurements of top quark properties at the Tevatron collider
Margaroli, Fabrizio
2011-05-01
The discovery of the top quark in 1995 opened a whole new sector of investigation of the Standard Model; today top quark physics remains a key priority of the Tevatron program. Some of the measurements of top quark properties, for example its mass, will be a long-standing legacy. The recent evidence of an anomalously large charge asymmetry in top quark events suggests that new physics could couple preferably with top quarks. I will summarize this long chapter of particle physics history and discuss the road the top quark is highlighting for the LHC program.
Quark matter symmetry energy and quark stars
Chu, Peng-Cheng; Chen, Lie-Wen
2014-01-10
We extend the confined-density-dependent-mass (CDDM) model to include isospin dependence of the equivalent quark mass. Within the confined-isospin-density-dependent-mass (CIDDM) model, we study the quark matter symmetry energy, the stability of strange quark matter, and the properties of quark stars. We find that including isospin dependence of the equivalent quark mass can significantly influence the quark matter symmetry energy as well as the properties of strange quark matter and quark stars. While the recently discovered large mass pulsars PSR J1614–2230 and PSR J0348+0432 with masses around 2 M {sub ☉} cannot be quark stars within the CDDM model, they can be well described by quark stars in the CIDDM model. In particular, our results indicate that the two-flavor u-d quark matter symmetry energy should be at least about twice that of a free quark gas or normal quark matter within the conventional Nambu-Jona-Lasinio model in order to describe PSR J1614–2230 and PSR J0348+0432 as quark stars.
Effective multipoles and Yukawa electrostatics in dressed molecule theory
NASA Astrophysics Data System (ADS)
Ramirez, Rosa; Kjellander, Roland
2006-10-01
In this paper we derive the multipolar expansion of the screened Coulomb potential in electrolyte solutions with molecular solvent. The solute and solvent molecules can have arbitrary sizes, shapes, and internal charge distributions. We use the exact statistical mechanical definition of renormalized charge distributions coming from "dressed molecule theory" to determine the effective multipoles of a molecule immersed in an electrolyte. The effects of many-body correlations are fully included in our formally exact theory. We restrict ourselves to sufficiently dilute solutions so the screened Coulomb potential decays for large distances like a Yukawa function, exp(-κr )/r, where r is the distance and 1/κ is the decay length (it is normally different from the Debye length). The resulting "Yukawa electrostatics" differ in many respects from ordinary, unscreened electrostatics. The "Yukawa charge" of a molecule (the lowest order moment in the multipolar expansion) is in general not equal to its Coulombic charge and it is not the integral of the renormalized charge distribution of the molecule. Moreover, as shown in this paper, the multipolar expansion of the Yukawa potential does not correspond, contrary to the case of the Coulomb potential, to its asymptotic expansion for large r. As a consequence, the charge term in the multipolar expansion is not the leading term in the asymptotic expansion. Instead, for large r values, multipoles of all orders contribute to the leading asymptotic term. Thus, the electrostatic potential from, for example, an electroneutral solvent molecule in an electrolyte solution has generally the same range as that from an ion. The proper asymptotic expansion for electrostatic interactions in electrolytes is derived. It is briefly shown how the multipole expansion formalism can also be applied in the Poisson-Boltzmann approximation for primitive model electrolytes.
Effective multipoles and Yukawa electrostatics in dressed molecule theory.
Ramirez, Rosa; Kjellander, Roland
2006-10-14
In this paper we derive the multipolar expansion of the screened Coulomb potential in electrolyte solutions with molecular solvent. The solute and solvent molecules can have arbitrary sizes, shapes, and internal charge distributions. We use the exact statistical mechanical definition of renormalized charge distributions coming from "dressed molecule theory" to determine the effective multipoles of a molecule immersed in an electrolyte. The effects of many-body correlations are fully included in our formally exact theory. We restrict ourselves to sufficiently dilute solutions so the screened Coulomb potential decays for large distances like a Yukawa function, exp(-kappa r)/r, where r is the distance and 1/kappa is the decay length (it is normally different from the Debye length). The resulting "Yukawa electrostatics" differ in many respects from ordinary, unscreened electrostatics. The "Yukawa charge" of a molecule (the lowest order moment in the multipolar expansion) is in general not equal to its Coulombic charge and it is not the integral of the renormalized charge distribution of the molecule. Moreover, as shown in this paper, the multipolar expansion of the Yukawa potential does not correspond, contrary to the case of the Coulomb potential, to its asymptotic expansion for large r. As a consequence, the charge term in the multipolar expansion is not the leading term in the asymptotic expansion. Instead, for large r values, multipoles of all orders contribute to the leading asymptotic term. Thus, the electrostatic potential from, for example, an electroneutral solvent molecule in an electrolyte solution has generally the same range as that from an ion. The proper asymptotic expansion for electrostatic interactions in electrolytes is derived. It is briefly shown how the multipole expansion formalism can also be applied in the Poisson-Boltzmann approximation for primitive model electrolytes. PMID:17042582
Higgs Boson Mass in Yukawa Unified SUSY SO(10)
NASA Astrophysics Data System (ADS)
Shafi, Qaisar
2012-09-01
We employ third family Yukawa unification, predicted by simple supersymmetric SO(10) models, to estimate the lightest MSSM Higgs boson mass. For μ > 0 (or μ < 0) and mt = 173.1 GeV, the Higgs mass is estimated to lie close to 123-124 GeV. The theoretical uncertainty in this estimate is ±3 GeV. We highlight some LHC testable benchmark points which also display the presence of neutralino-stau coannihilation channel.
Quark interchange model of baryon interactions
Maslow, J.N.
1983-01-01
The strong interactions at low energy are traditionally described by meson field theories treating hadrons as point-like particles. Here a mesonic quark interchange model (QIM) is presented which takes into account the finite size of the baryons and the internal quark structure of hadrons. The model incorporates the basic quark-gluon coupling of quantum chromodynamics (QCD) and the MIT bag model for color confinement. Because the quark-gluon coupling constant is large and it is assumed that confinement excludes overlap of hadronic quark bags except at high momenta, a non-perturbative method of nuclear interactions is presented. The QIM allows for exchange of quark quantum numbers at the bag boundary between colliding hadrons mediated at short distances by a gluon exchange between two quarks within the hadronic interior. This generates, via a Fierz transformation, an effective space-like t channel exchange of color singlet (q anti-q) states that can be identified with the low lying meson multiplets. Thus, a one boson exchange (OBE) model is obtained that allows for comparison with traditional phenomenological models of nuclear scattering. Inclusion of strange quarks enables calculation of YN scattering. The NN and YN coupling constants and the nucleon form factors show good agreement with experimental values as do the deuteron low energy data and the NN low energy phase shifts. Thus, the QIM provides a simple model of strong interactions that is chirally invariant, includes confinement and allows for an OBE form of hadronic interaction at low energies and momentum transfers.
Quark Interchange Model of Baryon Interactions.
NASA Astrophysics Data System (ADS)
Maslow, Joel Neal
The strong interactions at low energy are traditionally described by meson field theories treating hadrons as point -like particles. Here a mesonic quark interchange model (QIM) is presented which takes into account the finite size of the baryons and the internal quark structure of hadrons. The model incorporates the basic quark-gluon coupling of quantum chromodynamics (QCD) and the MIT bag model for color confinement. Because the quark-gluon coupling constant is large and we assume that confinement excludes overlap of hadronic quark bags except at high momenta, a non-perturbative method of nuclear interactions is presented. The QIM allows for exchange of quark quantum numbers at the bag boundary between colliding hadrons mediated at short distances by a gluon exchange between two quarks within the hadronic interior. This generates, via a Fierz transformation, an effective space-like t channel exchange of color singlet (qq) states that can be identified with the low lying meson multiplets. Thus, a one boson exchange (OBE) model is obtained that allows for comparison with traditional phenomenological models of nuclear scattering. Inclusion of strange quarks enables calculation of Yn scattering. The NN and YN coupling constants and the nucleon form factors show good agreement with experimental values as do the deuteron low energy data and the NN low energy phase shifts. Thus, the QIM provides a simple model of strong interactions that is chirally invariant, includes confinement and allows for an OBE form of hadronic interaction at low energies and momentum transfers.
Hideki Yukawa ---January 23, 1907 - September 8, 1981---
NASA Astrophysics Data System (ADS)
Tanikawa, Y.
1981-10-01
Hideki Yukawa took the first step in his research in 1929 as an associate at Kyoto Imperial University (nowadays called Kyoto University). Most Japanese physicists of those days were isolated far from Western centers of physical science, where the `Sturm und Drang' of astonighing developments in the twentieth century physics had been roaring. There were only a handful of physicists in Japan who had already set to work in quantum physics, but never any one working on the quantum field theory and theoretical nuclear physics. Yukawa had to initiate his study of these frontiers of physical science by himself, without any teacher or senior scholar in this field. In 1935, Yukawa published his first paper with the title ``On the Interaction of Elementary Particles. I'', in which he developed the revolutionary idea of the meson theory. Although even the term `elementary particle' was not so popular in those days, the meson theory was proposed as a unified theory of interactions of elementary particles. His theory opened up a new fundamental view of Nature. This event might be regarded as a miracle in the history of Japanese physics. Through all of his works and thoughts, we are impressed by the simplicity of approach, the unfailing intuition and the creativity of a great master, which are deep-rooted in his culture. A sketch of his life, mainly based on his autobiographical material and partly based on the present writer's personal recollection, is presented to show his thought and activity.
The mean spherical approximation for a dipolar Yukawa fluid
NASA Astrophysics Data System (ADS)
Henderson, Douglas; Boda, Dezső; Szalai, István; Chan, Kwong-Yu
1999-04-01
The dipolar hard sphere fluid (DHSF) is a useful model of a polar fluid. However, the DHSF lacks a vapor-liquid transition due to the formation of chain-like structures. Such chains are not characteristic of real polar fluids. A more realistic model of a polar fluid is obtained by adding a Lennard-Jones potential to the intermolecular potential. Very similar results are obtained by adding a Yukawa potential, instead of the Lennard-Jones potential. We call this fluid the dipolar Yukawa fluid (DYF). We show that an analytical solution of the mean spherical approximation (MSA) can be obtained for the DYF. Thus, the DYF has many of the attractive features of the DHSF. We find that, within the MSA, the Yukawa potential modifies only the spherically averaged distribution function. Thus, although the thermodynamic properties of the DYF differ from those of the DHSF, the MSA dielectric constant of the DYF is the same as that of the DHSF. This result, and some other predictions, are tested by simulations and are found to be good approximations.
NASA Astrophysics Data System (ADS)
Aad, G.; Abbott, B.; Abdallah, J.; Abdinov, O.; Aben, R.; Abolins, M.; AbouZeid, O. S.; Abramowicz, H.; Abreu, H.; Abreu, R.; Abulaiti, Y.; Acharya, B. S.; Adamczyk, L.; Adams, D. L.; Adelman, J.; Adomeit, S.; Adye, T.; Affolder, A. A.; Agatonovic-Jovin, T.; Agricola, J.; Aguilar-Saavedra, J. A.; Ahlen, S. P.; Ahmadov, F.; Aielli, G.; Akerstedt, H.; Åkesson, T. P. A.; Akimov, A. V.; Alberghi, G. L.; Albert, J.; Albrand, S.; Alconada Verzini, M. J.; Aleksa, M.; Aleksandrov, I. N.; Alexa, C.; Alexander, G.; Alexopoulos, T.; Alhroob, M.; Alimonti, G.; Alio, L.; Alison, J.; Alkire, S. P.; Allbrooke, B. M. M.; Allport, P. P.; Aloisio, A.; Alonso, A.; Alonso, F.; Alpigiani, C.; Altheimer, A.; Alvarez Gonzalez, B.; Álvarez Piqueras, D.; Alviggi, M. G.; Amadio, B. T.; Amaral Amako, K.; Coutinho, Y.; Amelung, C.; Amidei, D.; Amor Dos Santos, S. P.; Amorim, A.; Amoroso, S.; Amram, N.; Amundsen, G.; Anastopoulos, C.; Ancu, L. S.; Andari, N.; Andeen, T.; Anders, C. F.; Anders, G.; Anders, J. K.; Anderson, K. J.; Andreazza, A.; Andrei, V.; Angelidakis, S.; Angelozzi, I.; Anger, P.; Angerami, A.; Anghinolfi, F.; Anisenkov, A. V.; Anjos, N.; Annovi, A.; Antonelli, M.; Antonov, A.; Antos, J.; Anulli, F.; Aoki, M.; Aperio Bella, L.; Arabidze, G.; Arai, Y.; Araque, J. P.; Arce, A. T. H.; Arduh, F. A.; Arguin, J.-F.; Argyropoulos, S.; Arik, M.; Armbruster, A. J.; Arnaez, O.; Arnold, H.; Arratia, M.; Arslan, O.; Artamonov, A.; Artoni, G.; Asai, S.; Asbah, N.; Ashkenazi, A.; Åsman, B.; Asquith, L.; Assamagan, K.; Astalos, R.; Atkinson, M.; Atlay, N. B.; Augsten, K.; Aurousseau, M.; Avolio, G.; Axen, B.; Ayoub, M. K.; Azuelos, G.; Baak, M. A.; Baas, A. E.; Baca, M. J.; Bacci, C.; Bachacou, H.; Bachas, K.; Backes, M.; Backhaus, M.; Bagiacchi, P.; Bagnaia, P.; Bai, Y.; Bain, T.; Baines, J. T.; Baker, O. K.; Baldin, E. M.; Balek, P.; Balestri, T.; Balli, F.; Balunas, W. K.; Banas, E.; Banerjee, Sw.; Bannoura, A. A. E.; Barak, L.; Barberio, E. L.; Barberis, D.; Barbero, M.; Barillari, T.; Barisonzi, M.; Barklow, T.; Barlow, N.; Barnes, S. L.; Barnett, B. M.; Barnett, R. M.; Barnovska, Z.; Baroncelli, A.; Barone, G.; Barr, A. J.; Barreiro, F.; Barreiro Guimarães da Costa, J.; Bartoldus, R.; Barton, A. E.; Bartos, P.; Basalaev, A.; Bassalat, A.; Basye, A.; Bates, R. L.; Batista, S. J.; Batley, J. R.; Battaglia, M.; Bauce, M.; Bauer, F.; Bawa, H. S.; Beacham, J. B.; Beattie, M. D.; Beau, T.; Beauchemin, P. H.; Beccherle, R.; Bechtle, P.; Beck, H. P.; Becker, K.; Becker, M.; Beckingham, M.; Becot, C.; Beddall, A. J.; Beddall, A.; Bednyakov, V. A.; Bee, C. P.; Beemster, L. J.; Beermann, T. A.; Begel, M.; Behr, J. K.; Belanger-Champagne, C.; Bell, W. H.; Bella, G.; Bellagamba, L.; Bellerive, A.; Bellomo, M.; Belotskiy, K.; Beltramello, O.; Benary, O.; Benchekroun, D.; Bender, M.; Bendtz, K.; Benekos, N.; Benhammou, Y.; Benhar Noccioli, E.; Benitez Garcia, J. A.; Benjamin, D. P.; Bensinger, J. R.; Bentvelsen, S.; Beresford, L.; Beretta, M.; Berge, D.; Bergeaas Kuutmann, E.; Berger, N.; Berghaus, F.; Beringer, J.; Bernard, C.; Bernard, N. R.; Bernius, C.; Bernlochner, F. U.; Berry, T.; Berta, P.; Bertella, C.; Bertoli, G.; Bertolucci, F.; Bertsche, C.; Bertsche, D.; Besana, M. I.; Besjes, G. J.; Bessidskaia Bylund, O.; Bessner, M.; Besson, N.; Betancourt, C.; Bethke, S.; Bevan, A. J.; Bhimji, W.; Bianchi, R. M.; Bianchini, L.; Bianco, M.; Biebel, O.; Biedermann, D.; Biesuz, N. V.; Biglietti, M.; Bilbao De Mendizabal, J.; Bilokon, H.; Bindi, M.; Binet, S.; Bingul, A.; Bini, C.; Biondi, S.; Bjergaard, D. M.; Black, C. W.; Black, J. E.; Black, K. M.; Blackburn, D.; Blair, R. E.; Blanchard, J.-B.; Blanco, J. E.; Blazek, T.; Bloch, I.; Blocker, C.; Blum, W.; Blumenschein, U.; Blunier, S.; Bobbink, G. J.; Bobrovnikov, V. S.; Bocchetta, S. S.; Bocci, A.; Bock, C.; Boehler, M.; Bogaerts, J. A.; Bogavac, D.; Bogdanchikov, A. G.; Bohm, C.; Boisvert, V.; Bold, T.; Boldea, V.; Boldyrev, A. S.; Bomben, M.; Bona, M.; Boonekamp, M.; Borisov, A.; Borissov, G.; Borroni, S.; Bortfeldt, J.; Bortolotto, V.; Bos, K.; Boscherini, D.; Bosman, M.; Boudreau, J.; Bouffard, J.; Bouhova-Thacker, E. V.; Boumediene, D.; Bourdarios, C.; Bousson, N.; Boutle, S. K.; Boveia, A.; Boyd, J.; Boyko, I. R.; Bozic, I.; Bracinik, J.; Brandt, A.; Brandt, G.; Brandt, O.; Bratzler, U.; Brau, B.; Brau, J. E.; Braun, H. M.; Breaden Madden, W. D.; Brendlinger, K.; Brennan, A. J.; Brenner, L.; Brenner, R.; Bressler, S.; Bristow, T. M.; Britton, D.; Britzger, D.; Brochu, F. M.; Brock, I.; Brock, R.; Bronner, J.; Brooijmans, G.; Brooks, T.; Brooks, W. K.; Brosamer, J.; Brost, E.; Bruckman de Renstrom, P. A.; Bruncko, D.; Bruneliere, R.; Bruni, A.; Bruni, G.; Bruschi, M.; Bruscino, N.; Bryngemark, L.; Buanes, T.; Buat, Q.; Buchholz, P.; Buckley, A. G.
2016-04-01
The electroweak production and subsequent decay of single top quarks is determined by the properties of the Wtb vertex. This vertex can be described by the complex parameters of an effective Lagrangian. An analysis of angular distributions of the decay products of single top quarks produced in the t -channel constrains these parameters simultaneously. The analysis described in this paper uses 4.6 fb-1 of proton-proton collision data at √{s}=7 TeV collected with the ATLAS detector at the LHC. Two parameters are measured simultaneously in this analysis. The fraction f 1 of decays containing transversely polarised W bosons is measured to be 0 .37 ± 0 .07 (stat.⊕syst.). The phase δ - between amplitudes for transversely and longitudinally polarised W bosons recoiling against left-handed b-quarks is measured to be -0 .014 π ± 0 .036 π (stat.⊕syst.). The correlation in the measurement of these parameters is 0 .15. These values result in two-dimensional limits at the 95% confidence level on the ratio of the complex coupling parameters g R and V L, yielding Re[ g R /V L] ∈ [-0 .36 , 0 .10] and Im[ g R /V L] ∈ [-0 .17 , 0 .23] with a correlation of 0 .11. The results are in good agreement with the predictions of the Standard Model. [Figure not available: see fulltext.
Chatrchyan, Serguei
2014-08-21
The inclusive cross section for top-quark pair production measured by the CMS experiment in proton-proton collisions at a center-of-mass energy of 7 TeV is compared to the QCD prediction at next-to-next-to-leading order with various parton distribution functions to determine the top-quark pole mass,more » $$m_t^{pole}$$, or the strong coupling constant, $$\\alpha_S$$. With the parton distribution function set NNPDF2.3, a pole mass of 176.7$$^{+3.0}_{-2.8}$$ GeV is obtained when constraining $$\\alpha_S$$ at the scale of the Z boson mass, $m_Z$, to the current world average. Alternatively, by constraining $$m_t^{pole}$$ to the latest average from direct mass measurements, a value of $$\\alpha_S(m_Z)$$ = 0.1151$$^{+0.0028}_{-0.0027}$$ is extracted. This is the first determination of $$\\alpha_S$$ using events from top-quark production.« less
Chatrchyan, Serguei
2014-08-21
The inclusive cross section for top-quark pair production measured by the CMS experiment in proton-proton collisions at a center-of-mass energy of 7 TeV is compared to the QCD prediction at next-to-next-to-leading order with various parton distribution functions to determine the top-quark pole mass, $m_t^{pole}$, or the strong coupling constant, $\\alpha_S$. With the parton distribution function set NNPDF2.3, a pole mass of 176.7$^{+3.0}_{-2.8}$ GeV is obtained when constraining $\\alpha_S$ at the scale of the Z boson mass, $m_Z$, to the current world average. Alternatively, by constraining $m_t^{pole}$ to the latest average from direct mass measurements, a value of $\\alpha_S(m_Z)$ = 0.1151$^{+0.0028}_{-0.0027}$ is extracted. This is the first determination of $\\alpha_S$ using events from top-quark production.
Aad, G.; Abbott, B.; Abdallah, J.; Abdinov, O.; Aben, R.; Abolins, M.; AbouZeid, O. S.; Abramowicz, H.; Abreu, H.; Abreu, R.; et al
2016-04-05
The electroweak production and subsequent decay of single top quarks is determined by the properties of the Wtb vertex. This vertex can be described by the complex parameters of an effective Lagrangian. An analysis of angular distributions of the decay products of single top quarks produced in the t -channel constrains these parameters simultaneously. The analysis described in this paper uses 4.6 fb-1 of proton-proton collision data at √s=7 TeV collected with the ATLAS detector at the LHC. Two parameters are measured simultaneously in this analysis. The fraction f 1 of decays containing transversely polarised W bosons is measured tomore » be 0.37 ± 0.07 (stat.⊕syst.). The phase δ - between amplitudes for transversely and longitudinally polarised W bosons recoiling against left-handed b-quarks is measured to be -0.014π ± 0.036π (stat.⊕syst.). The correlation in the measurement of these parameters is 0.15. These values result in two-dimensional limits at the 95% confidence level on the ratio of the complex coupling parameters g R and V L, yielding Re[g R /V L] ϵ [-0.36, 0.10] and Im[g R /V L] ϵ [-0.17, 0.23] with a correlation of 0.11. We find the results are in good agreement with the predictions of the Standard Model.« less
NASA Astrophysics Data System (ADS)
Kurkela, Aleksi; Vuorinen, Aleksi
2016-07-01
We generalize the state-of-the-art perturbative equation of state of cold quark matter to nonzero temperatures, needed in the description of neutron star mergers and core collapse processes. The new result is accurate to O (g5) in the gauge coupling, and is based on a novel framework for dealing with the infrared sensitive soft field modes of the theory. The zero Matsubara mode sector is treated via a dimensionally reduced effective theory, while the soft nonzero modes are resummed using the hard thermal loop approximation. This combination of known effective descriptions offers unprecedented access to small but nonzero temperatures, both in and out of beta equilibrium.
Kurkela, Aleksi; Vuorinen, Aleksi
2016-07-22
We generalize the state-of-the-art perturbative equation of state of cold quark matter to nonzero temperatures, needed in the description of neutron star mergers and core collapse processes. The new result is accurate to O(g^{5}) in the gauge coupling, and is based on a novel framework for dealing with the infrared sensitive soft field modes of the theory. The zero Matsubara mode sector is treated via a dimensionally reduced effective theory, while the soft nonzero modes are resummed using the hard thermal loop approximation. This combination of known effective descriptions offers unprecedented access to small but nonzero temperatures, both in and out of beta equilibrium. PMID:27494468
Quaternion family symmetry of quarks and leptons
Frigerio, Michele; Ma, Ernest; Kaneko, Satoru; Tanimoto, Morimitsu
2005-01-01
To a first approximation, the quark mixing matrix has {theta}{sub 13}{sup q}={theta}{sub 23}{sup q}=0, whereas the lepton mixing matrix has {theta}{sub 23}{sup l}={pi}/4. We show how this structure may be understood if the family symmetry is Q{sub 8}, the quaternion group of eight elements. We find three viable scenarios for the Majorana neutrino mass matrix, each depending on four parameters and predicting a specific mass spectrum. The phenomenology of the two Higgs doublets which generate the Yukawa sector is analyzed and testable predictions are derived. We discuss also the closely related model based on D{sub 4}, the symmetry group of the square.
Ground states of finite spherical Yukawa crystals
NASA Astrophysics Data System (ADS)
Baumgartner, H.; Asmus, D.; Golubnychiy, V.; Ludwig, P.; Kählert, H.; Bonitz, M.
2008-09-01
Small three-dimensional strongly coupled clusters of charged particles in a spherical confinement potential arrange themselves in nested concentric shells. If the particles are immersed into a background plasma the interaction is screened. The cluster shell configuration is known to be sensitive to the screening strength. With increased screening, an increased population of the inner shell(s) is observed. Here, we present a detailed analysis of the ground state shell configurations and configuration changes in a wide range of screening parameters for clusters with particle numbers N in the range of 11 to 60. We report three types of anomalous behaviors which are observed upon increase of screening, at fixed N or for an increase of N at fixed screening. The results are obtained by means of extensive first principle molecular dynamics simulations.
Enhanced thj signal at the LHC with h → γγ decay and CP-violating top-Higgs coupling
NASA Astrophysics Data System (ADS)
Yue, Jason
2015-05-01
We study the observability of non-standard top Yukawa couplings in the pp → t (→ ℓνℓ b) h (→ γγ) j channel at 14 TeV high-luminosity LHC (HL-LHC). The small diphoton branching ratio is enhanced when the CP-violating phase, ξ, of the top-Higgs interaction is non-zero. When the modulus of the top-Higgs interaction assumes the SM value, yt = ytSM, we find that the signal significance reaches 2.7σ (7.7 σ) when ξ = 0.25 π (0.5 π). Furthermore, the different couplings modify the polarisation of the top quark, and can subsequently be distinguished via asymmetries in spin correlations with the final state leptons. The diphoton decay mode is found to be significantly more promising than the previously considered pp → t (→ ℓνℓ b) h (→ bbbar) j channel.
New GUT predictions for quark and lepton mass ratios confronted with phenomenology
Antusch, S.; Spinrath, M.
2009-05-01
Group theoretical factors from grand unified theory (GUT) symmetry breaking can lead to predictions for the ratios of quark and lepton masses (or Yukawa couplings) at the unification scale. Because of supersymmetric (SUSY) threshold corrections the viability of such predictions can depend strongly on the SUSY parameters. For three common minimal SUSY breaking scenarios with anomaly, gauge, and gravity mediation we investigate which GUT scale ratios m{sub e}/m{sub d}, m{sub {mu}}/m{sub s}, y{sub {tau}}/y{sub b}, and y{sub t}/y{sub b} are allowed when phenomenological constraints from electroweak precision observables, B physics, (g-2){sub {mu}}, mass limits on sparticles from direct searches as well as, optionally, dark matter constraints are taken into account. We derive possible new predictions for the GUT scale mass ratios and compare them with the phenomenologically allowed ranges. We find that new GUT scale predictions such as m{sub {mu}}/m{sub s}=9/2 or 6 and y{sub {tau}}/y{sub b}=3/2 or 2 are often favored compared to the ubiquitous relations m{sub {mu}}/m{sub s}=3 or y{sub {tau}}/y{sub b}=1. They are viable for characteristic SUSY scenarios, testable at the CERN LHC and future colliders.
Fluid approach to evaluate sound velocity in Yukawa systems and complex plasmas.
Khrapak, Sergey A; Thomas, Hubertus M
2015-03-01
The conventional fluid description of multicomponent plasma, supplemented by an appropriate equation of state for the macroparticle component, is used to evaluate the longitudinal sound velocity of Yukawa fluids. The obtained results are in very good agreement with those obtained earlier employing the quasilocalized charge approximation and molecular dynamics simulations in a rather broad parameter regime. Thus, a simple yet accurate tool to estimate the sound velocity across coupling regimes is proposed, which can be particularly helpful in estimating the dust-acoustic velocity in strongly coupled dusty (complex) plasmas. It is shown that, within the present approach, the sound velocity is completely determined by particle-particle correlations and the neutralizing medium (plasma), apart from providing screening of the Coulomb interaction, has no other effect on the sound propagation. The ratio of the actual sound velocity to its "ideal gas" (weak coupling) scale only weakly depends on the coupling strength in the fluid regime but exhibits a pronounced decrease with the increase of the screening strength. The limitations of the present approach in applications to real complex plasmas are briefly discussed. PMID:25871227
NASA Astrophysics Data System (ADS)
Khachatryan, V.; Sirunyan, A. M.; Tumasyan, A.; Adam, W.; Asilar, E.; Bergauer, T.; Brandstetter, J.; Brondolin, E.; Dragicevic, M.; Erö, J.; Flechl, M.; Friedl, M.; Frühwirth, R.; Ghete, V. M.; Hartl, C.; Hörmann, N.; Hrubec, J.; Jeitler, M.; Knünz, V.; König, A.; Krammer, M.; Krätschmer, I.; Liko, D.; Matsushita, T.; Mikulec, I.; Rabady, D.; Rahbaran, B.; Rohringer, H.; Schieck, J.; Schöfbeck, R.; Strauss, J.; Treberer-Treberspurg, W.; Waltenberger, W.; Wulz, C.-E.; Mossolov, V.; Shumeiko, N.; Suarez Gonzalez, J.; Alderweireldt, S.; Cornelis, T.; de Wolf, E. A.; Janssen, X.; Knutsson, A.; Lauwers, J.; Luyckx, S.; van de Klundert, M.; van Haevermaet, H.; van Mechelen, P.; van Remortel, N.; van Spilbeeck, A.; Abu Zeid, S.; Blekman, F.; D'Hondt, J.; Daci, N.; de Bruyn, I.; Deroover, K.; Heracleous, N.; Keaveney, J.; Lowette, S.; Moreels, L.; Olbrechts, A.; Python, Q.; Strom, D.; Tavernier, S.; van Doninck, W.; van Mulders, P.; van Onsem, G. P.; van Parijs, I.; Barria, P.; Brun, H.; Caillol, C.; Clerbaux, B.; de Lentdecker, G.; Fasanella, G.; Favart, L.; Grebenyuk, A.; Karapostoli, G.; Lenzi, T.; Léonard, A.; Maerschalk, T.; Marinov, A.; Perniè, L.; Randle-Conde, A.; Reis, T.; Seva, T.; Vander Velde, C.; Vanlaer, P.; Yonamine, R.; Zenoni, F.; Zhang, F.; Beernaert, K.; Benucci, L.; Cimmino, A.; Crucy, S.; Dobur, D.; Fagot, A.; Garcia, G.; Gul, M.; McCartin, J.; Ocampo Rios, A. A.; Poyraz, D.; Ryckbosch, D.; Salva, S.; Sigamani, M.; Strobbe, N.; Tytgat, M.; van Driessche, W.; Yazgan, E.; Zaganidis, N.; Basegmez, S.; Beluffi, C.; Bondu, O.; Brochet, S.; Bruno, G.; Caudron, A.; Ceard, L.; da Silveira, G. G.; Delaere, C.; Favart, D.; Forthomme, L.; Giammanco, A.; Hollar, J.; Jafari, A.; Jez, P.; Komm, M.; Lemaitre, V.; Mertens, A.; Musich, M.; Nuttens, C.; Perrini, L.; Pin, A.; Piotrzkowski, K.; Popov, A.; Quertenmont, L.; Selvaggi, M.; Vidal Marono, M.; Beliy, N.; Hammad, G. H.; Aldá Júnior, W. L.; Alves, F. L.; Alves, G. A.; Brito, L.; Correa Martins Junior, M.; Hamer, M.; Hensel, C.; Mora Herrera, C.; Moraes, A.; Pol, M. E.; Rebello Teles, P.; Belchior Batista Das Chagas, E.; Carvalho, W.; Chinellato, J.; Custódio, A.; da Costa, E. M.; de Jesus Damiao, D.; de Oliveira Martins, C.; Fonseca de Souza, S.; Huertas Guativa, L. M.; Malbouisson, H.; Matos Figueiredo, D.; Mundim, L.; Nogima, H.; Prado da Silva, W. L.; Santoro, A.; Sznajder, A.; Tonelli Manganote, E. J.; Vilela Pereira, A.; Ahuja, S.; Bernardes, C. A.; de Souza Santos, A.; Dogra, S.; Fernandez Perez Tomei, T. R.; Gregores, E. M.; Mercadante, P. G.; Moon, C. S.; Novaes, S. F.; Padula, Sandra S.; Romero Abad, D.; Ruiz Vargas, J. C.; Aleksandrov, A.; Hadjiiska, R.; Iaydjiev, P.; Rodozov, M.; Stoykova, S.; Sultanov, G.; Vutova, M.; Dimitrov, A.; Glushkov, I.; Litov, L.; Pavlov, B.; Petkov, P.; Ahmad, M.; Bian, J. G.; Chen, G. M.; Chen, H. S.; Chen, M.; Cheng, T.; Du, R.; Jiang, C. H.; Plestina, R.; Romeo, F.; Shaheen, S. M.; Tao, J.; Wang, C.; Wang, Z.; Zhang, H.; Asawatangtrakuldee, C.; Ban, Y.; Li, Q.; Liu, S.; Mao, Y.; Qian, S. J.; Wang, D.; Xu, Z.; Avila, C.; Cabrera, A.; Chaparro Sierra, L. F.; Florez, C.; Gomez, J. P.; Gomez Moreno, B.; Sanabria, J. C.; Godinovic, N.; Lelas, D.; Puljak, I.; Ribeiro Cipriano, P. M.; Antunovic, Z.; Kovac, M.; Brigljevic, V.; Kadija, K.; Luetic, J.; Micanovic, S.; Sudic, L.; Attikis, A.; Mavromanolakis, G.; Mousa, J.; Nicolaou, C.; Ptochos, F.; Razis, P. A.; Rykaczewski, H.; Bodlak, M.; Finger, M.; Finger, M.; Assran, Y.; El Sawy, M.; Elgammal, S.; Ellithi Kamel, A.; Mahmoud, M. A.; Calpas, B.; Kadastik, M.; Murumaa, M.; Raidal, M.; Tiko, A.; Veelken, C.; Eerola, P.; Pekkanen, J.; Voutilainen, M.; Härkönen, J.; Karimäki, V.; Kinnunen, R.; Lampén, T.; Lassila-Perini, K.; Lehti, S.; Lindén, T.; Luukka, P.; Mäenpää, T.; Peltola, T.; Tuominen, E.; Tuominiemi, J.; Tuovinen, E.; Wendland, L.; Talvitie, J.; Tuuva, T.; Besancon, M.; Couderc, F.; Dejardin, M.; Denegri, D.; Fabbro, B.; Faure, J. L.; Favaro, C.; Ferri, F.; Ganjour, S.; Givernaud, A.; Gras, P.; Hamel de Monchenault, G.; Jarry, P.; Locci, E.; Machet, M.; Malcles, J.; Rander, J.; Rosowsky, A.; Titov, M.; Zghiche, A.; Antropov, I.; Baffioni, S.; Beaudette, F.; Busson, P.; Cadamuro, L.; Chapon, E.; Charlot, C.; Dahms, T.; Davignon, O.; Filipovic, N.; Florent, A.; Granier de Cassagnac, R.; Lisniak, S.; Mastrolorenzo, L.; Miné, P.; Naranjo, I. N.; Nguyen, M.; Ochando, C.; Ortona, G.; Paganini, P.; Pigard, P.; Regnard, S.; Salerno, R.; Sauvan, J. B.; Sirois, Y.; Strebler, T.; Yilmaz, Y.; Zabi, A.; Agram, J.-L.; Andrea, J.; Aubin, A.; Bloch, D.; Brom, J.-M.; Buttignol, M.; Chabert, E. C.; Chanon, N.; Collard, C.; Conte, E.; Coubez, X.; Fontaine, J.-C.; Gelé, D.; Goerlach, U.; Goetzmann, C.; Le Bihan, A.-C.; Merlin, J. A.
2016-06-01
This paper presents the search for the production of a Higgs boson in association with a single top quark (tHq), using data collected in proton-proton collisions at a center-of-mass energy of 8 TeV corresponding to an integrated luminosity of 19.7 fb-1. The search exploits a variety of Higgs boson decay modes resulting in final states with photons, bottom quarks, and multiple charged leptons, including tau leptons, and employs a variety of multivariate techniques to maximize sensitivity to the signal. The analysis is optimized for the opposite sign of the Yukawa coupling to that in the standard model, corresponding to a large enhancement of the signal cross section. In the absence of an excess of candidate signal events over the background predictions, 95% confidence level observed (expected) upper limits on anomalous tHq production are set, ranging between 600 (450) fb and 1000 (700) fb depending on the assumed diphoton branching fraction of the Higgs boson. This is the first time that results on anomalous tHq production have been reported. [Figure not available: see fulltext.
Khachatryan, Vardan
2015-09-29
Our paper presents the search for the production of a Higgs boson in association with a single top quark, using data collected in proton-proton collisions at a centerof-mass energy of 8 TeV corresponding to an integrated luminosity of 19.7 fb^{-1}. The search exploits a variety of Higgs boson decay modes resulting in final states with photons, bottom quarks, and multiple charged leptons, including tau leptons, and employs a variety of multivariate techniques to maximize sensitivity to the signal. Furthermore, our analysis is optimized for the opposite sign of the Yukawa coupling to that in the standard model and corresponding to a large enhancement of the signal cross section. In the absence of an excess of candidate signal events over the background predictions, 95% confidence level observed (expected) upper limits on anomalous tHq production are set, ranging between 600 (450) fb and 1000 (700) fb depending on the assumed diphoton branching fraction of the Higgs boson. This is the first time that results on anomalous tHq production have been reported.
Steiner, Andrew W.
2007-02-27
If strange quark matter is absolutely stable, some neutron stars may be strange quark stars. Strange quark stars are usually assumed to have a simple liquid surface. We show that if the surface tension of droplets of quark matter in the vacuum is sufficiently small, droplets of quark matter on the surface of a strange quark star may form a solid crust on top of the strange quark star. This solid crust can significantly modify the predictions for the photon emission for the surface in an observable way.
Diffusion coefficient of three-dimensional Yukawa liquids
NASA Astrophysics Data System (ADS)
Dzhumagulova, K. N.; Ramazanov, T. S.; Masheeva, R. U.
2013-11-01
The purpose of this work is an investigation of the diffusion coefficient of the dust component in complex plasma. The computer simulation of the Yukawa liquids was made on the basis of the Langevin equation, which takes into account the influence of buffer plasma on the dust particles dynamics. The Green-Kubo relation was used to calculate the diffusion coefficient. Calculations of the diffusion coefficient for a wide range of the system parameters were performed. Using obtained numerical data, we constructed the interpolation formula for the diffusion coefficient. We also show that the interpolation formula correctly describes experimental data obtained under microgravity conditions.
Memorial Archival Libraries of Yukawa, Tomonaga, and Sakata
NASA Astrophysics Data System (ADS)
Takaiwa, Yoshinobu; Bando, Masako; Gotoh, Haruyoshi; Hayakawa, Hisao; Hirata, Kohji; Ito, Kazuyuki; Ito, Kenji; Kanaya, Kazuyuki; Konagaya, Daisuke; Konuma, Michiji; Kugo, Taichiro; Namba, Chusei; Nishitani, Tadashi; Tanabashi, Masaharu; Tanaka, Kio; Tanaka, Sho; Ukegawa, Fumihiko; Yoshikawa, Tadashi
Brief history of the memorial archival libraries of Hideki Yukawa, Sin-itiro Tomonaga, and Shoichi Sakata, the great pioneers of nuclear and particle physics in Japan, is described. A recent project of maintaining the archival libraries is going on and the catalog databases of their documents are now almost ready for public access using Internet. In the project it is tried to make use of recent knowledge and technologies of archival science and the databases, and thus the documents themselves, willbe made accessible easier than before and may attract the interest of much broader range of audiences. Some interesting documents are picked up for demonstration.
Diffusion coefficient of three-dimensional Yukawa liquids
Dzhumagulova, K. N.; Ramazanov, T. S.; Masheeva, R. U.
2013-11-15
The purpose of this work is an investigation of the diffusion coefficient of the dust component in complex plasma. The computer simulation of the Yukawa liquids was made on the basis of the Langevin equation, which takes into account the influence of buffer plasma on the dust particles dynamics. The Green–Kubo relation was used to calculate the diffusion coefficient. Calculations of the diffusion coefficient for a wide range of the system parameters were performed. Using obtained numerical data, we constructed the interpolation formula for the diffusion coefficient. We also show that the interpolation formula correctly describes experimental data obtained under microgravity conditions.
Beam-Plasma Instabilities in a 2D Yukawa Lattice
Kyrkos, S.; Kalman, G. J.; Rosenberg, M.
2009-06-05
We consider a 2D Yukawa lattice of grains, with a beam of other charged grains moving in the lattice plane. In contrast to Vlasov plasmas, where the electrostatic instability excited by the beam is only longitudinal, here both longitudinal and transverse instabilities of the lattice phonons can develop. We determine and compare the transverse and longitudinal growth rates. The growth rate spectrum in wave number space exhibits remarkable gaps where no instability can develop. Depending on the system parameters, the transverse instability can be selectively excited.
QCD spectrum with three quark flavors
Bernard, Claude; Burch, Tom; Orginos, Kostas; Toussaint, Doug; DeGrand, Thomas A.; DeTar, Carleton; Datta, Saumen; Gottlieb, Steven; Heller, Urs M.; Sugar, Robert
2001-09-01
We present results from a lattice hadron spectrum calculation using three flavors of dynamical quarks -- two light and one strange -- and quenched simulations for comparison. These simulations were done using a one-loop Symanzik improved gauge action and an improved Kogut-Susskind quark action. The lattice spacings, and hence also the physical volumes, were tuned to be the same in all the runs to better expose differences due to flavor number. Lattice spacings were tuned using the static quark potential, so as a by-product we obtain updated results for the effect of sea quarks on the static quark potential. We find indications that the full QCD meson spectrum is in better agreement with experiment than the quenched spectrum. For the 0{sup ++} (a{sub 0}) meson we see a coupling to two pseudoscalar mesons, or a meson decay on the lattice.
Quark and Lepton Masses from Gaussian Landscapes
Hall, Lawrence J.; Salem, Michael P.; Watari, Taizan
2008-04-11
The flavor structure of the standard model (SM) might arise from random selection on a landscape. We propose a class of simple models, 'Gaussian landscapes', where Yukawa couplings derive from overlap integrals of Gaussian wave functions on extra-dimensions. Statistics of vacua are generated by scanning the peak positions of these zero-modes, giving probability distributions for all flavor observables. Gaussian landscapes can account for all observed flavor patterns with few free parameters. Although they give broad probability distributions, the predictions are correlated and accounting for measured parameters sharpens the distributions of future neutrino measurements.
Quark-Gluon Plasma Model and Origin of Magic Numbers
Ghahramany, N.; Ghanaatian, M.; Hooshmand, M.
2008-04-21
Using Boltzman distribution in a quark-gluon plasma sample it is possible to obtain all existing magic numbers and their extensions without applying the spin and spin-orbit couplings. In this model it is assumed that in a quark-gluon thermodynamic plasma, quarks have no interactions and they are trying to form nucleons. Considering a lattice for a central quark and the surrounding quarks, using a statistical approach to find the maximum number of microstates, the origin of magic numbers is explained and a new magic number is obtained.
Early quark production and approach to chemical equilibrium
NASA Astrophysics Data System (ADS)
Gelfand, D.; Hebenstreit, F.; Berges, J.
2016-04-01
We perform real-time lattice simulations of out-of-equilibrium quark production in non-Abelian gauge theory in 3 +1 dimensions. Our simulations include the backreaction of quarks onto the dynamical gluon sector, which is particularly relevant for strongly correlated quarks. We observe fast isotropization and universal behavior of quarks and gluons at weak coupling and establish a quantitative connection to previous pure glue results. In order to understand the strongly correlated regime, we perform simulations for a large number of flavors and compare them to those obtained with two light quark flavors. By doing this we are able to provide estimates of the chemical equilibration time.
Meson properties in a nonlocal SU(3) chiral quark model at finite temperature
Contrera, G. A.; Gomez Dumm, D.; Scoccola, N. N.
2010-11-12
Finite temperature meson properties are studied in the context of a nonlocal SU(3) quark model which includes flavor mixing and the coupling of quarks to the Polyakov loop (PL). We analyze the behavior of scalar and pseudoscalar meson masses and mixing angles, as well as quark-meson couplings and pseudoscalar meson decay constants.
NASA Astrophysics Data System (ADS)
Huang, He
In this thesis, I present the results of studies of the structural properties and phase transition of a charge neutral FCC Lattice Gas with Yukawa Interaction and discuss a novel fast calculation algorithm---Accelerated Cartesian Expansion (ACE) method. In the first part of my thesis, I discuss the results of Monte Carlo simulations carried out to understand the finite temperature (phase transition) properties and the ground state structure of a Yukawa Lattice Gas (YLG) model. In this model the ions interact via the potential q iqjexp(-kappar> ij)/rij where qi,j are the charges of the ions located at the lattice sites i and j with position vectors R i and Rj; rij = Ri-Rj, kappa is a measure of the range of the interaction and is called the screening parameter. This model approximates an interesting quaternary system of great current thermoelectric interest called LAST-m, AgSbPbmTem+2. I have also developed rapid calculation methods for the potential energy calculation in a lattice gas system with periodic boundary condition bases on the Ewald summation method and coded the algorithm to compute the energies in MC simulation. Some of the interesting results of the MC simulations are: (i) how the nature and strength of the phase transition depend on the range of interaction (Yukawa screening parameter kappa) (ii) what is the degeneracy of the ground state for different values of the concentration of charges, and (iii) what is the nature of two-stage disordering transition seen for certain values of x. In addition, based on the analysis of the surface energy of different nano-clusters formed near the transition temperature, the solidification process and the rate of production of these nano-clusters have been studied. In the second part of my thesis, we have developed two methods for rapidly computing potentials of the form R-nu. Both these methods are founded on addition theorems based on Taylor expansions. Taylor's series has a couple of inherent advantages: (i) it
LHC phenomenology of SO(10) models with Yukawa unification. II.
NASA Astrophysics Data System (ADS)
Anandakrishnan, Archana; Bryant, B. Charles; Raby, Stuart
2014-07-01
In this paper we study Yukawa-unified SO(10) supersymmetric (SUSY) grand unified theories (GUTs) with two types of SO(10) boundary conditions: (i) universal gaugino masses and (ii) nonuniversal gaugino masses with effective "mirage" mediation. With these boundary conditions, we perform a global χ2 analysis to obtain the parameters consistent with 11 low energy observables, including the top, bottom, and tau masses. Both boundary conditions have universal scalar masses and "just so" splitting for the up- and down-type Higgs masses. In these models, the third family scalars are lighter than the first two families and the gauginos are lighter than all the scalars. We therefore focus on the gluino phenomenology in these models. In particular, we estimate the lowest allowed gluino mass in our models coming from the most recent LHC data and compare this to limits obtained using simplified models. We find that the lower bound on Mg ˜ in Yukawa-unified SO(10) SUSY GUTs is generically ˜1.2 TEV at the 1σ level unless there is considerable degeneracy between the gluino and the lightest supersymmetric particle, in which case the bounds are much weaker. Hence many of our benchmark points are not ruled out by the present LHC data and are still viable models which can be tested at LHC 14.
Phase diagram and critical properties of Yukawa bilayers
NASA Astrophysics Data System (ADS)
Travěnec, Igor; Šamaj, Ladislav
2015-08-01
We study the ground-state Wigner bilayers of pointlike particles with Yukawa pairwise interactions, confined to the surface of two parallel hard walls at dimensionless distance η . The model involves as limiting cases the unscreened Coulomb potential and hard spheres. The phase diagram of Yukawa particles, studied numerically by Messina and Löwen [Phys. Rev. Lett. 91, 146101 (2003), 10.1103/PhysRevLett.91.146101], exhibits five different staggered phases as η varies from 0 to intermediate values. We present a lattice summation method using the generalized Misra functions which permits us to calculate the energy per particle of the phases with a precision much higher than usual in computer simulations. This allows us to address some tiny details of the phase diagram. Going from the hexagonal phase I to phase II is shown to occur at η =0 . All second-order phase transitions are proved to be of mean-field type. We also derive the asymptotic shape of critical lines close to the Coulomb and hard-spheres limits. In and close to the hard-spheres limit, the dependence of the internal parameters of the present phases on η is determined exactly.
Mach Cones in Three-Dimensional Yukawa Crystals
NASA Astrophysics Data System (ADS)
Qian, Xin; Bhattacharjee, Amitava
2006-10-01
Mach cones have been observed in two-dimensional dusty plasma experiments (D. Samsonov et al., Phys. Rev. Lett., 83, 3649, 1999) and molecular dynamics (MD) simulations assuming that the dust particles interact via a Yukawa potential (Z. W. Ma and A. Bhattacharjee, Phys. Plasmas, 9, 3349, 2002). We present new simulation results of Mach cones in three-dimensional Yukawa crystals excited by external laser forcing. As is well known, these crystals can be of the bcc and fcc type, and experiments have produced crystals with both types coexisting. Under a variety of conditions, our simulations show stable three-dimensional Mach cones with a tent structure. While the two-dimensional projection of these cones resemble the multiple cone structure of two-dimensional cones, they need larger dust charge and higher-amplitude forcing for their excitation. We present results on the effect of melting on these Mach cones, and their structures in the near-field and far-field regions.
Hawke, B.C.
1963-02-26
This patent relates to a releasable coupling connecting a control rod to a control rod drive. This remotely operable coupling mechanism can connect two elements which are laterally and angviarly misaligned, and provides a means for sensing the locked condition of the elements. The coupling utilizes a spherical bayonet joint which is locked against rotation by a ball detent lock. (AEC)
The Top Quark, QCD, And New Physics.
DOE R&D Accomplishments Database
Dawson, S.
2002-06-01
The role of the top quark in completing the Standard Model quark sector is reviewed, along with a discussion of production, decay, and theoretical restrictions on the top quark properties. Particular attention is paid to the top quark as a laboratory for perturbative QCD. As examples of the relevance of QCD corrections in the top quark sector, the calculation of e{sup+}e{sup -}+ t{bar t} at next-to-leading-order QCD using the phase space slicing algorithm and the implications of a precision measurement of the top quark mass are discussed in detail. The associated production of a t{bar t} pair and a Higgs boson in either e{sup+}e{sup -} or hadronic collisions is presented at next-to-leading-order QCD and its importance for a measurement of the top quark Yulrawa coupling emphasized. Implications of the heavy top quark mass for model builders are briefly examined, with the minimal supersymmetric Standard Model and topcolor discussed as specific examples.
THE TOP QUARK, QCD, AND NEW PHYSICS.
DAWSON,S.
2002-06-01
The role of the top quark in completing the Standard Model quark sector is reviewed, along with a discussion of production, decay, and theoretical restrictions on the top quark properties. Particular attention is paid to the top quark as a laboratory for perturbative QCD. As examples of the relevance of QCD corrections in the top quark sector, the calculation of e{sup +}e{sup -} + t{bar t} at next-to-leading-order QCD using the phase space slicing algorithm and the implications of a precision measurement of the top quark mass are discussed in detail. The associated production of a t{bar t} pair and a Higgs boson in either e{sup +}e{sup -} or hadronic collisions is presented at next-to-leading-order QCD and its importance for a measurement of the top quark Yulrawa coupling emphasized. Implications of the heavy top quark mass for model builders are briefly examined, with the minimal supersymmetric Standard Model and topcolor discussed as specific examples.
Review of Top Quark Physics Results
Kehoe, R.; Narain, M.; Kumar, A.
2007-12-01
As the heaviest known fundamental particle, the top quark has taken a central role in the study of fundamental interactions. Production of top quarks in pairs provides an important probe of strong interactions. The top quark mass is a key fundamental parameter which places a valuable constraint on the Higgs boson mass and electroweak symmetry breaking. Observations of the relative rates and kinematics of top quark final states constrain potential new physics. In many cases, the tests available with study of the top quark are both critical and unique. Large increases in data samples from the Fermilab Tevatron have been coupled with major improvements in experimental techniques to produce many new precision measurements of the top quark. The first direct evidence for electroweak production of top quarks has been obtained, with a resulting direct determination of V{sub tb}. Several of the properties of the top quark have been measured. Progress has also been made in obtaining improved limits on potential anomalous production and decay mechanisms. This review presents an overview of recent theoretical and experimental developments in this field. We also provide a brief discussion of the implications for further efforts.
Quark confinement in a constituent quark model
Langfeld, K.; Rho, M.
1995-07-01
On the level of an effective quark theory, we define confinement by the absence of quark anti-quark thresholds in correlation function. We then propose a confining Nambu-Jona-Lasinio-type model. The confinement is implemented in analogy to Anderson localization in condensed matter systems. We study the model`s phase structure as well as its behavior under extreme conditions, i.e. high temperature and/or high density.
Charmonium with three flavors of synamical quarks
Massimo Di Pierro et al.
2003-12-23
We present a calculation of the charmonium spectrum with three flavors of dynamical staggered quarks from gauge configurations that were generated by the MILC collaboration. We use the Fermilab action for the valence charm quarks. Our calculation of the spin-averaged 1P-1S and 2S-1S splittings yields a determination of the strong coupling, with {alpha}{sub {ovr MS}}(M{sub Z}) = 0.119(4).
New Mechanism for Quark Energy Loss
Casalderrey-Solana, Jorge; Fernandez, Daniel; Mateos, David
2010-04-30
We show that a heavy quark moving sufficiently fast through a quark-gluon plasma may lose energy by Cherenkov-radiating mesons. We demonstrate that this takes place in all strongly coupled, large-N{sub c} plasmas with a gravity dual. The energy loss is exactly calculable in these models despite being an O(1/N{sub c}) effect. We discuss implications for heavy-ion collision experiments.
Hadron spectrum with staggered dynamical quarks
Bitar, K.M.; Kennedy, A.D.; Liu, Weiqiang . Supercomputer Computations Research Inst.); DeGrand, T.A. . Dept. of Physics); Gottlieb, S. ); Kogut, J.B.; Renken, R.L. . Dept. of Physics); Ogilvie, M.C. . Dept. of Physic
1989-01-01
We describe a recent calculation of the hadron spectrum with two flavors of staggered dynamical quarks with a gauge coupling 6/g{sup 2} = 5.60 and quark masses of 0.025 and 0.01. The gauge fields were generated using the hybrid algorithm on a 12{sup 4} lattice that was doubled or quadrupoled to calculate hadron propagators. 5 refs., 5 figs.
Flavor-phenomenology of two-Higgs-doublet models with generic Yukawa structure
NASA Astrophysics Data System (ADS)
Crivellin, Andreas; Greub, Christoph; Kokulu, Ahmet
2013-05-01
In this article, we perform an extensive study of flavor observables in a two-Higgs-doublet model with generic Yukawa structure (of type III). This model is interesting not only because it is the decoupling limit of the minimal supersymmetric standard model but also because of its rich flavor phenomenology which also allows for sizable effects not only in flavor-changing neutral-current (FCNC) processes but also in tauonic B decays. We examine the possible effects in flavor physics and constrain the model both from tree-level processes and from loop observables. The free parameters of the model are the heavy Higgs mass, tanβ (the ratio of vacuum expectation values) and the “nonholomorphic” Yukawa couplings ɛijf(f=u,d,ℓ). In our analysis we constrain the elements ɛijf in various ways: In a first step we give order of magnitude constraints on ɛijf from ’t Hooft’s naturalness criterion, finding that all ɛijf must be rather small unless the third generation is involved. In a second step, we constrain the Yukawa structure of the type-III two-Higgs-doublet model from tree-level FCNC processes (Bs,d→μ+μ-, KL→μ+μ-, D¯0→μ+μ-, ΔF=2 processes, τ-→μ-μ+μ-, τ-→e-μ+μ- and μ-→e-e+e-) and observe that all flavor off-diagonal elements of these couplings, except ɛ32,31u and ɛ23,13u, must be very small in order to satisfy the current experimental bounds. In a third step, we consider Higgs mediated loop contributions to FCNC processes [b→s(d)γ, Bs,d mixing, K-K¯ mixing and μ→eγ] finding that also ɛ13u and ɛ23u must be very small, while the bounds on ɛ31u and ɛ32u are especially weak. Furthermore, considering the constraints from electric dipole moments we obtain constrains on some parameters ɛiju,ℓ. Taking into account the constraints from FCNC processes we study the size of possible effects in the tauonic B decays (B→τν, B→Dτν and B→D*τν) as well as in D(s)→τν, D(s)→μν, K(π)→eν, K(π)→μν and
Abazov V. M.; Abazov V. M.; Abbott B.; Acharya B. S.; Adams M.; Adams T.; Alexeev G. D.; Alkhazov G.; Alton A.; Alverson G.; Alves G. A.; Aoki M.; Askew A.; Asman B.; Atkins S.; Atramentov O.; Augsten K.; Avila C.; BackusMayes J.; Badaud F.; Bagby L.; Baldin B.; Bandurin D. V.; Banerjee S.; Barberis E.; Baringer P.; Barreto J.; Bartlett J. F.; Bassler U.; Bazterra V.; Bean A.; Begalli M.; Belanger-Champagne C.; Bellantoni L.; Beni S. B.; Bernardi G.; Bernhard R.; Bertram I.; Besancon M.; Beuselinck R.; Bezzubov V. A.; Bhat P. C.; Bhatnagar V.; Blazey G.; Blessing S.; Bloom K.; Boehnlein A.; Boline D.; Boos E. E.; Borissov G.; Bose T.; Brandt A.; Brandt O.; Brock R.; Brooijmans G.; Bross A.; Brown D.; Brown J.; Bu X. B.; Buehler M.; Buescher V.; Bunichev V.; Burdin S.; Burnett T. H.; Buszello C. P.; Calpas B.; Camacho-Perez E.; Carrasco-Lizarraga M. A.; Casey B. C. K.; Castilla-Valdez H.; Chakrabarti S.; Chakraborty D.; Chan K. M.; Chandra A.; Chapon E.; Chen G.; Chevalier-Thery S.; Cho D. K.; Cho S. W.; Choi S.; Choudhary B.; Cihangir S.; Claes D.; Clutter J.; Cooke M.; Cooper W. E.; Corcoran M.; Couderc F.; Cousinou M. -C.; Croc A.; Cutts D.; Das A.; Davies G.; De K.; de Jong S. J.; De La Cruz-Burelo E.; Deliot F.; Demina R.; Denisov D.; Denisov S. P.; Desai S.; Deterre C.; DeVaughan K.; Diehl H. T.; Diesburg M.; Ding P. F.; Dominguez A.; Dorland T.; Dubey A.; Dudko L. V.; Duggan D.; Duperrin A.; Dutt S.; Dyshkant A.; Eads M.; Edmunds D.; Ellison J.; Elvira V. D.; Enari Y.; Evans H.; Evdokimov A.; Evdokimov V. N.; Facini G.; Ferbel T.; Fiedler F.; Filthaut F.; Fisher W.; Fisk H. E.; Fortner M.; Fox H.; Fuess S.; Garcia-Bellido A.; Garcia-Guerra G. A.; Gavrilov V.; Gay P.; Geng W.; Gerbaudo D.; Gerber C. E.; Gershtein Y.; Ginther G.; Golovanov G.; Goussiou A.; Grannis P. D.; Greder S.; Greenlee H.; Greenwood Z. D.; Gregores E. M.; Grenier G.; Gris Ph.; Grivaz J. -F.; Grohsjean A.; Gruenendahl S.; Gruenewald M. W.; Guillemin T.; Gutierrez G.; Gutierrez P.; Haas A.; Hagopian S.; Haley J.; Han L.; Harder K.; Harel A.; Hauptman J. M.; Hays J.; Head T.; Hebbeker T.; Hedin D.; Hegab H.; Heinson A. P.; Heintz U.; Hensel C.; Heredia-De La Cruz I.; Herner K.; Hesketh G.; Hildreth M. D.; Hirosky R.; Hoang T.; Hobbs J. D.; Hoeneisen B.; Hohlfeld M.; Hubacek Z.; Hynek V.; Iashvili I.; Ilchenko Y.; Illingworth R.; Ito A. S.; Jabeen S.; Jaffre M.; Jamin D.; Jayasinghe A.; Jesik R.; Johns K.; Johnson M.; Jonckheere A.; Jonsson P.; Joshi J.; Jung A. W.; Juste A.; Kaadze K.; Kajfasz E.; Karmanov D.; Kasper P. A.; Katsanos I.; Kehoe R.; Kermiche S.; Khalatyan N.; Khanov A.; Kharchilava A.; Kharzheev Y. N.; Kohli J. M.; Kozelov A. V.; Kraus J.; Kulikov S.; Kumar A.; Kupco A.; Kurca T.; Kuzmin V. A.; Kvita J.; Lammers S.; Landsberg G.; Lebrun P.; Lee H. S.; Lee S. W.; Lee W. M.; Lellouch J.; Li L.; Li Q. Z.; Lietti S. M.; Lim J. K.; Lincoln D.; Linnemann J.; Lipaev V. V.; Lipton R.; Liu Y.; Lobodenko A.; Lokajicek M.; de Sa R. Lopes; Lubatti H. J.; Luna-Garcia R.; Lyon A. L.; Maciel A. K. A.; Mackin D.; Madar R.; Magana-Villalba R.; Malik S.; Malyshev V. L.; Maravin Y.; Martinez-Ortega J.; McCarthy R.; McGivern C. L.; Meijer M. M.; Melnitchouk A.; Menezes D.; Mercadante P. G.; Merkin M.; Meyer A.; Meyer J.; et al.
2012-02-14
We present new direct constraints on a general Wtb interaction using data corresponding to an integrated luminosity of 5.4 fb{sup -1} collected by the D0 detector at the Tevatron p{bar p} collider. The standard model provides a purely left-handed vector coupling at the Wtb vertex, while the most general, lowest dimension Lagrangian allows right-handed vector and left- or right-handed tensor couplings as well. We obtain precise limits on these anomalous couplings by comparing the data to the expectations from different assumptions on the Wtb coupling.
Nonlinear compressional waves in a two-dimensional Yukawa lattice.
Avinash, K; Zhu, P; Nosenko, V; Goree, J
2003-10-01
A modified Korteweg-de Vries (KdV) equation is obtained for studying the propagation of nonlinear compressional waves and pulses in a chain of particles including the effect of damping. Suitably altering the linear phase velocity makes this equation useful also for the problem of phonon propagation in a two-dimensional (2D) lattice. Assuming a Yukawa potential, we use this method to model compressional wave propagation in a 2D plasma crystal, as in a recent experiment. By integrating the modified KdV equation the pulse is allowed to evolve, and good agreement with the experiment is found. It is shown that the speed of a compressional pulse increases with its amplitude, while the speed of a rarefactive pulse decreases. It is further discussed how the drag due to the background gas has a crucial role in weakening nonlinear effects and preventing the emergence of a soliton. PMID:14683049
SO(10) Yukawa unification: SUSY on the edge
NASA Astrophysics Data System (ADS)
Raby, Stuart
2016-06-01
In this talk we discuss SO(10) Yukawa unification and its ramifications for phenomenology. The initial constraints come from fitting the top, bottom and tau masses, requiring large tan β ~ 50 and particular values for soft SUSY breaking parameters. We perform a global χ2 analysis, fitting the recently observed `Higgs' with mass of order 125 GeV in addition to fermion masses and mixing angles and several flavor violating observables. We discuss two distinct GUT scale boundary conditions for soft SUSY breaking masses. In both cases we have a universal cubic scalar parameter, A0, non-universal Higgs masses and universal squark and slepton masses, m16. In the first case we consider universal gaugino masses, while in the latter case we have non-universal gaugino masses. We discuss the spectrum of SUSY particle masses, consequences for the LHC and the issue of fine-tuning.
Thermal conductivity measurements in a 2D Yukawa system
NASA Astrophysics Data System (ADS)
Nosenko, V.; Ivlev, A.; Zhdanov, S.; Morfill, G.; Goree, J.; Piel, A.
2007-03-01
Thermal conductivity was measured for a 2D Yukawa system. First, we formed a monolayer suspension of microspheres in a plasma, i.e., a dusty plasma, which is like a colloidal suspension, but with an extremely low volume fraction and a partially-ionized rarefied gas instead of solvent. In the absence of manipulation, the suspension forms a 2D triangular lattice. To melt this lattice and form a liquid, we used a laser-heating method. Two focused laser beams were moved rapidly around in the monolayer. The kinetic temperature of the particles increased with the laser power applied, and above a threshold a melting transition occurred. We used digital video microscopy for direct imaging and particle tracking. The spatial profiles of the particle kinetic temperature were calculated. Using the heat transport equation with an additional term to account for the energy dissipation due to the gas drag, we analyzed the temperature distribution to derive the thermal conductivity.
Santopinto, E.; Bijker, R.
2008-10-13
We present a new generation of unquenched quark models for baryons in which the effects of quark-antiquark pairs are taken into account in an explicit form via a microscopic, QCD-inspired, pair creation mechanism. As an application, we study the effect of quark-antiquark pairs on the spin of the proton.
Statics and dynamics of Yukawa cluster crystals on ordered substrates
NASA Astrophysics Data System (ADS)
Reichhardt, C.; Olson Reichhardt, C. J.
2012-05-01
We examine the statics and dynamics of particles with repulsive Yukawa interactions in the presence of a two-dimensional triangular substrate for fillings of up to 12 particles per potential minimum. We term the ordered states Yukawa cluster crystals and show that they are distinct from the colloidal molecular crystal states found at low fillings. As a function of substrate and interaction strength at fixed particle density we find a series of novel crystalline states that we characterize using the structure factor. For fillings greater than four, shell and ring structures form at each potential minimum and can exhibit sample-wide orientational order. A disordered state can appear between ordered states as the substrate strength varies. Under an external drive, the onsets of different orderings produce clear changes in the critical depinning force, including a peak effect phenomenon that has generally only previously been observed in systems with random substrates. We also find a rich variety of dynamic ordering transitions that can be observed via changes in the structure factor and features in the velocity-force curves. The dynamical states encompass a variety of moving structures including one-dimensional stripes, smectic ordering, polycrystalline states, triangular lattices, and symmetry locking states. Despite the complexity of the system, we identify several generic features of the dynamical phase transitions which we map out in a series of phase diagrams. Our results have implications for the structure and depinning of colloids on periodic substrates, vortices in superconductors and Bose-Einstein condensates, Wigner crystals, and dusty plasmas.
QUARK MATTER IN MASSIVE COMPACT STARS
Weissenborn, Simon; Pagliara, Giuseppe; Schaffner-Bielich, Juergen; Sagert, Irina; Hempel, Matthias
2011-10-10
The recent observation of the pulsar PSR J1614-2230 with a mass of 1.97 {+-} 0.04 M{sub sun} gives a strong constraint on the quark and nuclear matter equations of state (EoS). We explore the parameter ranges for a parameterized EoS for quark stars. We find that strange stars, made of absolutely stable strange quark matter, comply with the new constraint only if effects from the strong coupling constant and color-superconductivity are taken into account. Hybrid stars, compact stars with a quark matter core and a hadronic outer layer, can be as massive as 2 M{sub sun}, but only for a significantly limited range of parameters. We demonstrate that the appearance of quark matter in massive stars crucially depends on the stiffness of the nuclear matter EoS. We show that the masses of hybrid stars stay below the ones of hadronic and pure quark stars, due to the softening of the EoS at the quark-hadron phase transition.
Quark Orbital Angular Momentum
NASA Astrophysics Data System (ADS)
Burkardt, Matthias
2016-06-01
Generalized parton distributions provide information on the distribution of quarks in impact parameter space. For transversely polarized nucleons, these impact parameter distributions are transversely distorted and this deviation from axial symmetry leads on average to a net transverse force from the spectators on the active quark in a DIS experiment. This force when acting along the whole trajectory of the active quark leads to transverse single-spin asymmetries. For a longitudinally polarized nucleon target, the transverse force implies a torque acting on the quark orbital angular momentum (OAM). The resulting change in OAM as the quark leaves the target equals the difference between the Jaffe-Manohar and Ji OAMs.
Frisch, E.; Johnson, C.G.
1962-05-15
A detachable coupling arrangement is described which provides for varying the length of the handle of a tool used in relatively narrow channels. The arrangement consists of mating the key and keyhole formations in the cooperating handle sections. (AEC)
Evidence for production of single top quarks
Abazov, V. M.; Alexeev, G. D.; Kalinin, A. M.; Kharzheev, Y. M.; Malyshev, V. L.; Tokmenin, V. V.; Vertogradov, L. S.; Yatsunenko, Y. A.; Abbott, B.; Gutierrez, P.; Hossain, S.; Jain, S.; Rominsky, M.; Severini, H.; Skubic, P.; Strauss, M.; Abolins, M.; Benitez, J. A.; Brock, R.; Dyer, J.
2008-07-01
We present first evidence for the production of single top quarks in the D0 detector at the Fermilab Tevatron pp collider. The standard model predicts that the electroweak interaction can produce a top quark together with an antibottom quark or light quark, without the antiparticle top-quark partner that is always produced from strong-coupling processes. Top quarks were first observed in pair production in 1995, and since then, single top-quark production has been searched for in ever larger data sets. In this analysis, we select events from a 0.9 fb{sup -1} data set that have an electron or muon and missing transverse energy from the decay of a W boson from the top-quark decay, and two, three, or four jets, with one or two of the jets identified as originating from a b hadron decay. The selected events are mostly backgrounds such as W+jets and tt events, which we separate from the expected signals using three multivariate analysis techniques: boosted decision trees, Bayesian neural networks, and matrix-element calculations. A binned likelihood fit of the signal cross section plus background to the data from the combination of the results from the three analysis methods gives a cross section for single top-quark production of {sigma}(pp{yields}tb+X,tqb+X)=4.7{+-}1.3 pb. The probability to measure a cross section at this value or higher in the absence of signal is 0.014%, corresponding to a 3.6 standard deviation significance. The measured cross section value is compatible at the 10% level with the standard model prediction for electroweak top-quark production. We use the cross section measurement to directly determine the Cabibbo-Kobayashi-Maskawa quark mixing matrix element that describes the Wtb coupling and find |V{sub tb}f{sub 1}{sup L}|=1.31{sub -0.21}{sup +0.25}, where f{sub 1}{sup L} is a generic vector coupling. This model-independent measurement translates into 0.68<|V{sub tb}|{<=}1 at the 95% C.L. in the standard model.
Evidence for production of single top quarks
Abazov, V.M.; Abbott, B.; Abolins, M.; Acharya, B.S.; Adams, M.; Adams, T.; Aguilo, E.; Ahn, S.H.; Ahsan, M.; Alexeev, G.D.; Alkhazov, G.; /St. Petersburg, INP /Michigan U.
2008-03-01
We present first evidence for the production of single top quarks in the D0 detector at the Fermilab Tevatron p{bar p} collider. The standard model predicts that the electroweak interaction can produce a top quark together with an antibottom quark or light quark, without the antiparticle top quark partner that is always produced from strong coupling processes. Top quarks were first observed in pair production in 1995, and since then, single top quark production has been searched for in ever larger datasets. In this analysis, we select events from a 0.9 fb{sup -1} dataset that have an electron or muon and missing transverse energy from the decay of a W boson from the top quark decay, and two, three, or four jets, with one or two of the jets identified as originating from a b hadron decay. The selected events are mostly backgrounds such as W+jets and t{bar t} events, which we separate from the expected signals using three multivariate analysis techniques: boosted decision trees, Bayesian neural networks, and matrix element calculations. A binned likelihood fit of the signal cross section plus background to the data from the combination of the results from the three analysis methods gives a cross section for single top quark production of {sigma}(p{bar p} {yields} tb + X, tqb + X) = 4.7 {+-} 1.3 pb. The probability to measure a cross section at this value or higher in the absence of signal is 0.014%, corresponding to a 3.6 standard deviation significance. The measured cross section value is compatible at the 10% level with the standard model prediction for electroweak top quark production. We use the cross section measurement to directly determine the Cabibbo-Kobayashi-Maskawa quark mixing matrix element that describes the Wtb coupling and find |V{sub tb}f{sub 1}{sup L}| = 1.31{sub -0.21}{sup +0.25}, where f{sub 1}{sup L} is a generic vector coupling. This model-independent measurement translates into 0.68 < |V{sub tb}| {le} 1 at the 95% C.L. in the standard model.
Khachatryan, V.; Sirunyan, A. M.; Tumasyan, A.; Adam, W.; Asilar, E.; Bergauer, T.; Brandstetter, J.; Brondolin, E.; Dragicevic, M.; Erö, J.; et al
2016-06-01
Our paper presents the search for the production of a Higgs boson in association with a single top quark, using data collected in proton-proton collisions at a centerof-mass energy of 8 TeV corresponding to an integrated luminosity of 19.7 fb-1. The search exploits a variety of Higgs boson decay modes resulting in final states with photons, bottom quarks, and multiple charged leptons, including tau leptons, and employs a variety of multivariate techniques to maximize sensitivity to the signal. Furthermore, our analysis is optimized for the opposite sign of the Yukawa coupling to that in the standard model and corresponding tomore » a large enhancement of the signal cross section. In the absence of an excess of candidate signal events over the background predictions, 95% confidence level observed (expected) upper limits on anomalous tHq production are set, ranging between 600 (450) fb and 1000 (700) fb depending on the assumed diphoton branching fraction of the Higgs boson. This is the first time that results on anomalous tHq production have been reported.« less
Heinson, A.P.; /UC, Riverside
2006-08-01
First observed in 1995, the top quark is one of a pair of third-generation quarks in the Standard Model of particle physics. It has charge +2/3e and a mass of 171.4 GeV, about 40 times heavier than its partner, the bottom quark. The CDF and D0 collaborations have identified several hundred events containing the decays of top-antitop pairs in the large dataset collected at the Tevatron proton-antiproton collider over the last four years. They have used these events to measure the top quark's mass to nearly 1% precision and to study other top quark properties. The mass of the top quark is a fundamental parameter of the Standard Model, and knowledge of its value with small uncertainty allows us to predict properties of the as-yet-unobserved Higgs boson. This paper presents the status of the measurements of the top quark mass.
Gao Jun; Li Chongsheng; Zhang Jiajun; Zhu Huaxing
2009-12-01
We present the calculations of the complete next-to-leading order (NLO) QCD effects on the single top productions induced by model-independent tqg flavor-changing neutral-current couplings at hadron colliders. Our results show that, for the tcg coupling, the NLO QCD corrections can enhance the total cross sections by about 60% and 30%, and for the tug coupling by about 50% and 20% at the Tevatron and LHC, respectively, which means that the NLO corrections can increase the experimental sensitivity to the flavor-changing neutral-current couplings by about 10%-30%. Moreover, the NLO corrections reduce the dependence of the total cross sections on the renormalization or factorization scale significantly, which lead to increased confidence on the theoretical predictions. Besides, we also evaluate the NLO corrections to several important kinematic distributions, and find that for most of them the NLO corrections are almost the same and do not change the shape of the distributions.
Equation of state and critical point behavior of hard-core double-Yukawa fluids.
Montes, J; Robles, M; López de Haro, M
2016-02-28
A theoretical study on the equation of state and the critical point behavior of hard-core double-Yukawa fluids is presented. Thermodynamic perturbation theory, restricted to first order in the inverse temperature and having the hard-sphere fluid as the reference system, is used to derive a relatively simple analytical equation of state of hard-core multi-Yukawa fluids. Using such an equation of state, the compressibility factor and phase behavior of six representative hard-core double-Yukawa fluids are examined and compared with available simulation results. The effect of varying the parameters of the hard-core double-Yukawa intermolecular potential on the location of the critical point is also analyzed using different perspectives. The relevance of this analysis for fluids whose molecules interact with realistic potentials is also pointed out. PMID:26931708
Debye mass and heavy quark potential in a PNJL quark plasma
Jankowski, J. Blaschke, D.
2012-07-15
We calculate the Debye mass for the screening of the heavy quark potential in a plasma of massless quarks coupled to the temporal gluon background governed by the Polyakov loop potential within the PNJL model in RPA approximation. We give a physical motivation for a recent phenomenological fit of lattice data by applying the calculated Debye mass with its suppression in the confined phase due to the Polyakov loop to a description of the temperature dependence of the singlet free energy for QCD with a heavy quark pair at infinite separation. We compare the result to lattice data.
Yukawas, G-flux, and spectral covers from resolved Calabi-Yau's
NASA Astrophysics Data System (ADS)
Marsano, Joseph; Schäfer-Nameki, Sakura
2011-11-01
We use the resolution procedure of Esole and Yau [1] to study Yukawa couplings, G-flux, and the emergence of spectral covers from elliptically fibered Calabi-Yau's with a surface of A 4 singularities. We provide a global description of the Esole-Yau resolution and use it to explicitly compute Chern classes of the resolved 4-fold, proving the conjecture of [2] for the Euler character in the process. We comment on the physical implications of the surprising singular fibers in codimension 2 and 3 in [1] and emphasize a group theoretic interpretation based on the A 4 weight lattice. We then construct explicit G-fluxes by brute force in one of the 6 birationally equivalent Esole-Yau resolutions, quantize them explicitly using our result for the second Chern class, and compute the spectrum and flux-induced 3-brane charges, finding agreement with results and conjectures of local models in all cases. Finally, we provide a precise description of the spectral divisor formalism in this setting and sharpen the procedure described in [3] in order to explicitly demonstrate how the Higgs bundle spectral cover of the local model emerges from the resolved Calabi-Yau geometry. Along the way, we demonstrate explicitly how the quantization rules for fluxes in the local and global models are related.
Quark matter and meson properties in a Nonlocal SU(3) chiral quark model at finite temperature
Gomez Dumm, D.; Contrera, G. A.
2012-06-15
We study the finite temperature behavior of light scalar and pseudoscalar meson properties in the context of a three-flavor nonlocal chiral quark model. The model includes mixing with active strangeness degrees of freedom, and takes care of the effect of gauge interactions by coupling the quarks with a background color field. We analyze the chiral restoration and deconfinement transitions, as well as the temperature dependence of meson masses, mixing angles, and decay constants.
Measurements and searches with top quarks
Peters, Reinhild Yvonne; /Wuppertal U.
2008-10-01
In 1995 the last missing member of the known families of quarks, the top quark, was discovered by the CDF and D0 experiments at the Tevatron, a proton-antiproton collider at Fermilab near Chicago. Until today, the Tevatron is the only place where top quarks can be produced. The determination of top quark production and properties is crucial to understand the Standard Model of particle physics and beyond. The most striking property of the top quark is its mass--of the order of the mass of a gold atom and close to the electroweak scale--making the top quark not only interesting in itself but also as a window to new physics. Due to the high mass, much higher than of any other known fermion, it is expected that the top quark plays an important role in electroweak symmetry breaking, which is the most prominent candidate to explain the mass of particles. In the Standard Model, electroweak symmetry breaking is induced by one Higgs field, producing one additional physical particle, the Higgs boson. Although various searches have been performed, for example at the Large Electron Positron Collider (LEP), no evidence for the Higgs boson could yet be found in any experiment. At the Tevatron, multiple searches for the last missing particle of the Standard Model are ongoing with ever higher statistics and improved analysis techniques. The exclusion or verification of the Higgs boson can only be achieved by combining many techniques and many final states and production mechanisms. As part of this thesis, the search for Higgs bosons produced in association with a top quark pair (t{bar t}H) has been performed. This channel is especially interesting for the understanding of the coupling between Higgs and the top quark. Even though the Standard Model Higgs boson is an attractive candidate, there is no reason to believe that the electroweak symmetry breaking is induced by only one Higgs field. In many models more than one Higgs boson are expected to exist, opening even more channels
Studies of top quark properties at the Tevatron
Shary, Viatcheslav
2012-05-01
An overview of the recent measurements of the top quark properties in proton antiproton collisions at {radical}s = 1.96 TeV is presented. These measurements are based on 5.4-8.7 fb{sup -1} of data collected with the D0 and CDF experiments at the Fermilab Tevatron collider. The top quark mass and width measurements, studies of the spin correlation in top quark pair production, W boson helicity measurement, searches for anomalous top quark couplings and Lorentz invariance violation are discussed.
Nucleon sigma term and quark condensate in nuclear matter
K. Tsushima; K. Saito; A. W. Thomas; A. Valcarce
2007-03-01
We study the bound nucleon sigma term and its effect on the quark condensate in nuclear matter. In the quark-meson coupling (QMC) model it is shown that the nuclear correction to the sigma term is small and negative. Thus, the correction decelerates the decrease of the quark condensate in nuclear matter. However, the quark condensate in nuclear matter is controlled primarily by the scalar-isoscalar sigma field of the model. It appreciably moderates the decrease relative to the leading term at densities around and larger than the normal nuclear matter density.
NASA Astrophysics Data System (ADS)
Harlander, Robert V.; Liebler, Stefan; Mantler, Hendrik
2013-06-01
This article describes the code SusHi (for "Supersymmetric Higgs") [108] which calculates the cross sections pp/pp ¯ →ϕ+X in gluon fusion and bottom-quark annihilation in the SM and the MSSM, where ϕ is any of the neutral Higgs bosons within these models. Apart from inclusive cross sections up to NNLO QCD, differential cross sections with respect to the Higgs transverse momentum pT and (pseudo-)rapidity y(η) can be calculated through NLO QCD. In the case of gluon fusion, SusHi contains NLO QCD contributions from the third family of quarks and squarks, NNLO corrections due to top-quarks, approximate NNLO corrections due to top-squarks, and electro-weak effects. It supports various renormalization schemes for the sbottom sector and the bottom Yukawa coupling, as well as resummation effects of higher order tanβ-enhanced sbottom contributions. SusHi provides a link to FeynHiggs for the calculation of the Higgs masses. Program SummaryProgram title: SusHi Catalogue identifier: AEOY_v1_0 Program summary URL:http://cpc.cs.qub.ac.uk/summaries/AEOY_v1_0.html Program obtainable from: CPC Program Library, Queen's University, Belfast, N. Ireland Licensing provisions: Standard CPC licence, http://cpc.cs.qub.ac.uk/licence/licence.html No. of lines in distributed program, including test data, etc.: 47725 No. of bytes in distributed program, including test data, etc.: 338380 Distribution format: tar.gz Programming language: Fortran 77. Computer: Personal computer. Operating system: Unix/Linux, Mac OS. RAM: A few 100 MB Classification: 11.1. External routines: LHAPDF (http://lhapdf.hepforge.org), FeynHiggs (http://www.feynhiggs.de) Nature of problem: Calculation of inclusive and exclusive Higgs production cross sections in gluon fusion and bottom-quark annihilation in the Standard Model and the MSSM through next-to-leading order QCD, includes next-to-next-to-leading order top-(s)quark contributions and electro-weak effects Solution method: Numerical Monte Carlo integration
Discovery of single top quark production
Gillberg, Dag
2009-04-01
The top quark is by far the heaviest known fundamental particle with a mass nearing that of a gold atom. Because of this strikingly high mass, the top quark has several unique properties and might play an important role in electroweak symmetry breaking - the mechanism that gives all elementary particles mass. Creating top quarks requires access to very high energy collisions, and at present only the Tevatron collider at Fermilab is capable of reaching these energies. Until now, top quarks have only been observed produced in pairs via the strong interaction. At hadron colliders, it should also be possible to produce single top quarks via the electroweak interaction. Studies of single top quark production provide opportunities to measure the top quark spin, how top quarks mix with other quarks, and to look for new physics beyond the standard model. Because of these interesting properties, scientists have been looking for single top quarks for more than 15 years. This thesis presents the first discovery of single top quark production. An analysis is performed using 2.3 fb^{-1} of data recorded by the D0 detector at the Fermilab Tevatron Collider at centre-of-mass energy √s = 1.96 TeV. Boosted decision trees are used to isolate the single top signal from background, and the single top cross section is measured to be σ(p$\\bar{p}$ → tb + X, tqb + X) = 3.74_{-0.74}^{+0.95} pb. Using the same analysis, a measurement of the amplitude of the CKM matrix element V_{tb}, governing how top and b quarks mix, is also performed. The measurement yields: |V{sub tb}|f_{1}^{L}| = 1.05 -_{0.12}^{+0.13}, where f_{1}^{L} is the left-handed Wtb coupling. The separation of signal from background is improved by combining the boosted decision trees with two other multivariate techniques. A new cross section measurement is performed, and the significance for the excess over the predicted background exceeds 5
Diffusivity in asymmetric Yukawa ionic mixtures in dense plasmas
NASA Astrophysics Data System (ADS)
Haxhimali, Tomorr; Rudd, Robert E.; Cabot, William H.; Graziani, Frank R.
2014-08-01
In this paper we present molecular dynamics (MD) calculations of the interdiffusion coefficient for asymmetric mixed plasma for thermodynamic conditions relevant to astrophysical and inertial confinement fusion plasmas. Specifically, we consider mixtures of deuterium and argon at temperatures of 100-500 eV and a number density ˜1025 ions/cm3. The motion of 30 000-120 000 ions is simulated in which the ions interact via the Yukawa (screened Coulomb) potential. The electric field of the electrons is included in this effective interaction; the electrons are not simulated explicitly. The species diffusivity is then calculated using the Green-Kubo approach using an integral of the interdiffusion current autocorrelation function, a quantity calculated in the equilibrium MD simulations. Our MD simulation results show that a widely used expression relating the interdiffusion coefficient with the concentration-weighted sum of self-diffusion coefficients overestimates the interdiffusion coefficient. We argue that this effect due to cross-correlation terms in velocities is characteristic of asymmetric mixed plasmas. Comparison of the MD results with predictions of kinetic theories also shows a discrepancy with MD giving effectively a larger Coulomb logarithm.
Diffusivity in asymmetric Yukawa ionic mixtures in dense plasmas.
Haxhimali, Tomorr; Rudd, Robert E; Cabot, William H; Graziani, Frank R
2014-08-01
In this paper we present molecular dynamics (MD) calculations of the interdiffusion coefficient for asymmetric mixed plasma for thermodynamic conditions relevant to astrophysical and inertial confinement fusion plasmas. Specifically, we consider mixtures of deuterium and argon at temperatures of 100-500 eV and a number density ∼10(25) ions/cm(3). The motion of 30,000-120,000 ions is simulated in which the ions interact via the Yukawa (screened Coulomb) potential. The electric field of the electrons is included in this effective interaction; the electrons are not simulated explicitly. The species diffusivity is then calculated using the Green-Kubo approach using an integral of the interdiffusion current autocorrelation function, a quantity calculated in the equilibrium MD simulations. Our MD simulation results show that a widely used expression relating the interdiffusion coefficient with the concentration-weighted sum of self-diffusion coefficients overestimates the interdiffusion coefficient. We argue that this effect due to cross-correlation terms in velocities is characteristic of asymmetric mixed plasmas. Comparison of the MD results with predictions of kinetic theories also shows a discrepancy with MD giving effectively a larger Coulomb logarithm. PMID:25215836
Density profile of strongly correlated spherical Yukawa plasmas
NASA Astrophysics Data System (ADS)
Bonitz, M.; Henning, C.; Ludwig, P.; Golubnychiy, V.; Baumgartner, H.; Piel, A.; Block, D.
2006-10-01
Recently the discovery of 3D-dust crystals [1] excited intensive experimental and theoretical activities [2-4]. Details of the shell structure of these crystals has been very well explained theoretically by a simple model involving an isotropic Yukawa-type pair repulsion and an external harmonic confinement potential [4]. On the other hand, it has remained an open question how the average radial density profile, looks like. We show that screening has a dramatic effect on the density profile, which we derive analytically for the ground state. Interestingly, the result applies not only to a continuous plasma distribution but also to simulation data for the Coulomb crystals exhibiting the above mentioned shell structure. Furthermore, excellent agreement between the continuum model and shell models is found [5]. [1] O. Arp, D. Block, A. Piel, and A. Melzer, Phys. Rev. Lett. 93, 165004 (2004). [2] H. Totsuji, C. Totsuji, T. Ogawa, and K. Tsuruta, Phys. Rev. E 71, 045401 (2005) [3] P. Ludwig, S. Kosse, and M. Bonitz, Phys. Rev. E 71, 046403 (2005) [4] M. Bonitz, D. Block, O. Arp, V. Golubnychiy, H. Baumgartner, P. Ludwig, A. Piel, and A. Filinov, Phys. Rev. Lett. 96, 075001 (2006) [5] C. Henning, M. Bonitz, A. Piel, P. Ludwig, H. Baumgartner, V. Golubnichiy, and D. Block, submitted to Phys. Rev. E
Non-unique monopole oscillations of harmonically confined Yukawa systems
NASA Astrophysics Data System (ADS)
Ducatman, Samuel; Henning, Christian; Kaehlert, Hanno; Bonitz, Michael
2008-11-01
Recently it was shown that the Breathing Mode (BM), the mode of uniform radial expansion and contraction, which is well known from harmonically confined Coulomb systems [1], does not exist in general for other systems [2]. As a consequence the monopole oscillation (MO), the radial collective excitation, is not unique, but there are several MO with different frequencies. Within this work we show simulation results of those monopole oscillations of 2-dimensional harmonically confined Yukawa systems, which are known from, e.g., dusty plasma crystals [3,4]. We present the corresponding spectrum of the particle motion, including analysis of the frequencies found, and compare with theoretical investigations.[1] D.H.E. Dubin and J.P. Schiffer, Phys. Rev. E 53, 5249 (1996)[2] C. Henning at al., accepted for publication in Phys. Rev. Lett. (2008)[3] A. Melzer et al., Phys. Rev. Lett. 87, 115002 (2001)[4] M. Bonitz et al., Phys. Rev. Lett. 96, 075001 (2006)
NASA Technical Reports Server (NTRS)
Testa, Massimo
1990-01-01
In the large quark mass limit, an argument which identifies the mass of the heavy-light pseudoscalar or scalar bound state with the renormalized mass of the heavy quark is given. The following equation is discussed: m(sub Q) = m(sub B), where m(sub Q) and m(sub B) are respectively the mass of the heavy quark and the mass of the pseudoscalar bound state.
Measurement of the W boson helicity in top-antitop quark events with the CDF II experiment
Chwalek, Thorsten; /Karlsruhe U., EKP
2006-10-01
bosons depends on the Yukawa coupling of the top quarks, the measurement of F{sub 0} is sensitive to the mechanism of electroweak symmetry breaking. Alternative models can lead to an altered F{sub 0} fraction. In this analysis the W helicity fractions are measured in a selected sample rich in t{bar B} events where one lepton, at least four jets, and missing transverse energy are required. All kinematic quantities describing the t{bar t} decay are determined. As a sensitive observable, we use the cosine of the decay angle {theta}*, which is defined as the angle between the momentum of the charged lepton in the W boson rest frame and the W boson momentum in the top quark rest frame. The data used in this analysis were taken with the Collider Detector at Fermilab (CDF II) in the years 2002-2006 and correspond to an integrated luminosity of about 955 pb{sup -1}. Previous CDF measurements of the W boson helicity fractions in top quark decays used either the square of the invariant mass of the charged lepton and the b quark jet, M{sub {ell}b}{sup 2}, or the lepton p{sub T} distribution as a discriminant. The D0 collaboration used a matrix-element method to extract a value of F{sub 0}; in a second analysis the reconstructed distribution of cos {theta}* was utilized to measure F{sub +}. CDF gives the latest value of F{sub 0} = 0.74{sub -0.34}{sup +0.22}, while D measured F{sub 0} = 0.56 {+-} 0.31. The CDF collaboration also gives the current upper limit of F{sub +} < 0.09.
Catara, F.; Sambataro, M. Italy Dipartimento di Fisica dell'Universita, 95129 Catania )
1992-08-01
By making use of a mapping procedure recently proposed, we construct the nucleon image of the one-body quark density operator in the framework of the nonrelativistic quark model of the nucleons. We evaluate the expectation value of this operator in the ground state of the doubly magic nuclei {sup 4}He, {sup 16}O, and {sup 40}Ca described within the nuclear shell model. We analyze the role of quark exchanges between nucleons. We also investigate the effect on the quark density of short-range correlations in the nuclear wave functions as well as of variations in the nucleon size.
Preskill, J.
1982-01-01
Calculability of quark and lepton masses and mixing angles is stressed as the primary motivation for constructing models in which quarks and leptons are composite particles. A general strategy for constructing such models is outlined, in which quarks and leptons are kept light compared to their inverse sizes by approximate chiral symmetries. The origin of multiple families is discussed, and an unrealistic model is exhibited which has several generations and a complicated pattern of masses and generation-mixing angles. The new physics responsible for binding quarks and leptons tends to induce various rare processes at rates which are potentially too large.
Hadronic physics with domain-wall valence and improved staggered sea quarks
D. B. Renner; W. Schroers; R. Edwards; G. T. Fleming; Ph. Hagler; J. W. Negele; K. Orginos; A. V. Pochinski; D. Richards
2004-06-01
With the advent of chiral fermion formulations, the simulation of light valence quarks has finally become realistic for numerical simulations of lattice QCD. The simulation of light dynamical quarks, however, remains one of the major challenges and is still an obstacle to realistic simulations. We attempt to meet this challenge using a hybrid combination of Asqtad sea quarks and domain-wall valence quarks. Initial results for the proton form factor and the nucleon axial coupling are presented.
Threshold corrections to the bottom quark mass revisited
NASA Astrophysics Data System (ADS)
Anandakrishnan, Archana; Bryant, B. Charles; Raby, Stuart
2015-05-01
Threshold corrections to the bottom quark mass are often estimated under the approximation that tan β enhanced contributions are the most dominant. In this work we revisit this common approximation made to the estimation of the supersymmetric thresh-old corrections to the bottom quark mass. We calculate the full one-loop supersymmetric corrections to the bottom quark mass and survey a large part of the phenomenological MSSM parameter space to study the validity of considering only the tan β enhanced corrections. Our analysis demonstrates that this approximation underestimates the size of the threshold corrections by ˜ 12.5% for most of the considered parameter space. We discuss the consequences for fitting the bottom quark mass and for the effective couplings to Higgses. We find that it is important to consider the additional contributions when fitting the bottom quark mass but the modifications to the effective Higgs couplings are typically (few)% for the majority of the parameter space considered.
ERIC Educational Resources Information Center
Dakin, James T.
1974-01-01
Reviews theoretical principles underlying the quark model. Indicates that the agreement with experimental results and the understanding of the quark-quark force are two hurdles for the model to survive in the future. (CC)
Heinson, A. P.
2006-11-17
First observed in 1995, the top quark is one of a pair of third-generation quarks in the Standard Model of particle physics. It has charge +2/3e and a mass of 171.4 GeV, about 40 times heavier than its partner, the bottom quark. The CDF and DO collaborations have identified several hundred events containing the decays of top-antitop pairs in the large dataset collected at the Tevatron proton-antiproton collider over the last four years. They have used these events to measure the top quark's mass to nearly 1% precision and to study other top quark properties. The mass of the top quark is a fundamental parameter of the Standard Model, and knowledge of its value with small uncertainty allows us to predict properties of the as-yet-unobserved Higgs boson. This paper presents the status of the measurements of the top quark mass. It is based on a talk I gave at the Conference on the Intersections of Particle and Nuclear Physics in Puerto Rico, May 2006, which also included discussion of measurements of other top quark properties.
Blankenbecler, R.
1981-01-01
A brief review is given of selected topics involved in the relativistic quark structure of nuclei such as the infinite momentum variables, scaling variables, counting rules, forward-backward variables, thermodynamic-like limit, QCD effects, higher quark bags, confinement, and many unanswered questions.
NASA Astrophysics Data System (ADS)
Watson, Andrew
2008-11-01
Preface; Acknowledgments; 1. Introduction; 2. Symmetry; 3. The quantum world; 4. Towards QCD; 5. The one number of QCD; 6. The gregarious gluon; 7. Quarks and hadrons; 8. Quarks under the microscope; 9. Much ado about nothing; 10. Checkerboard QCD; Appendix 1. A QCD chronology; Appendix 2. Greek alphabet and SI prefixes; Appendix 3. Glossary; Appendix 4. Further reading; Index.
Structure of multi-component/multi-Yukawa mixtures
NASA Astrophysics Data System (ADS)
Blum, L.; Arias, M.
2006-09-01
Recent small angle scattering experiments reveal new peaks in the structure function S(k) of colloidal systems (Liu et al 2005 J. Chem. Phys. 122 044507), in a region that was inaccessible with older instruments. It has been increasingly evident that a single (or double) Yukawa MSA-closure cannot account for these observations, and three or more terms are needed. On the other hand the MSA is not sufficiently accurate (Broccio et al 2005 Preprint); more accurate theories such as the HNC have been tried. But while the MSA is asymptotically exact at high densities (Rosenfield and Blum 1986 J. Chem. Phys. 85 1556), it does not satisfy the low density asymptotics. This has been corrected in the soft MSA (Blum et al 1972 J. Chem. Phys. 56 5197, Narten et al 1974 J. Chem. Phys. 60 3378) by adding exponential type terms. The results compared to experiment and simulation for liquid sodium by Rahman and Paskin (as shown in Blum et al 1972 J. Chem. Phys. 56 5197) are remarkably good. We use here a general closure of the Ornstein-Zernike equation, which is not necessarily the MSA closure (Blum and Hernando 2001 Condensed Matter Theories vol 16 ed Hernandez and Clark (New York: Nova) p 411). \\begin{equation} \\fl c_{ij}(r)=\\sum_{n=1}^{M}{\\cal{K}}_{ij}^{(n)}\\rme^{-z_{n}r}/r\\tqs {\\cal{K}}_{ij}^{(n)}=K^{(n)}\\delta_{i}^{(n)}\\delta_{j}^{(n)}\\tqs r\\geq \\sigma_{ij} \\label{eq1} \\end{equation} with the boundary condition for gij(r) = 0 for r<=σij. This general closure of the Ornstein-Zernike equation will go well beyond the MSA since it has been tested by Monte Carlo simulation for tetrahedral water (Blum et al 1999 Physica A 265 396), toroidal ion channels (Enriquez and Blum 2005 Mol. Phys. 103 3201) and polyelectrolytes (Blum and Bernard 2004 Proc. Int. School of Physics Enrico Fermi, Course CLV vol 155, ed Mallamace and Stanley (Amsterdam: IOS Press) p 335). For this closure we get for the Laplace transform of the pair correlation function an explicitly symmetric result
NASA Astrophysics Data System (ADS)
Pérez-García, M. Ángeles; Martins, C. J. A. P.
2012-12-01
We discuss the coupled variations of the gravitational, strong and electroweak coupling constants and the current knowledge of the nuclear equation of state based on heavy ion collision experiments and neutron star mass-radius relationship. In particular we focus in our description on phenomenological parameters, R, relating variations in the quantum chromodynamics scale ΛQCD and the fine structure constant α, and S, relating variations of v, the Higgs vacuum expectation value and the Yukawa couplings, h, in the quark sector. This parametrization is valid for any model where gauge coupling unification occurs at some (unspecified) high energy scale. From a physically motivated set of equations of state for dense matter we obtain the constrained parameter phase space (R,S) in high density nuclear environments. This procedure is complementary to (although currently less powerful than) those used in low-density conditions. For variations of Δα/α=0.005 we find that the obtained constrained parameter lies on a strip region in the (R,S) plane that partially overlaps some of the allowed values of parameters derived from primordial abundances. This may be of interest in the context of unification scenarios where a dense phase of the universe may have existed at early times.
LHC phenomenology of SO(10) models with Yukawa unification
NASA Astrophysics Data System (ADS)
Anandakrishnan, Archana; Bryant, B. Charles; Raby, Stuart; Wingerter, Akın
2013-10-01
In this paper we study an SO(10) SUSY GUT with Yukawa unification for the third generation. We perform a global χ2 analysis given to obtain the GUT boundary conditions consistent with 11 low-energy observables, including the top, bottom and tau masses. We assume a universal mass, m16, for squarks and sleptons and a universal gaugino mass, M1/2. We then analyze the phenomenological consequences for the LHC for 15 benchmark models with fixed m16=20TeV and with varying values of the gluino mass. The goal of the present work is to (i) evaluate the lower bound on the gluino mass in our model coming from the most recent published data of CMS and (ii) to compare this bound with similar bounds obtained by CMS using simplified models. The bottom line is that the bounds coming from the same-sign dilepton analysis are comparable for our model and the simplified model studied assuming B(g˜→tt¯χ˜10)=100%. However the bounds coming from the purely hadronic analyses for our model are 10%-20% lower than obtained for the simplified models. This is due to the fact that for our models the branching ratio for the decay g˜→gχ˜1,20 is significant. Thus there are significantly fewer b-jets. We find a lower bound on the gluino mass in our models with Mg˜≳1000GeV. Finally, there is a theoretical upper bound on the gluino mass which increases with the value of m16. For m16≤30TeV, the gluino mass satisfies Mg˜≤2.8TeV at 90% C.L. Thus, unless we further increase the amount of fine-tuning, we expect gluinos to be discovered at LHC 14.
Constraining the range of Yukawa gravity interaction from S2 star orbits
Borka, D.; Jovanović, V. Borka; Jovanović, P.; Zakharov, A.F. E-mail: pjovanovic@aob.rs E-mail: zakharov@itep.ru
2013-11-01
We consider possible signatures for Yukawa gravity within the Galactic Central Parsec, based on our analysis of the S2 star orbital precession around the massive compact dark object at the Galactic Centre, and on the comparisons between the simulated orbits in Yukawa gravity and two independent sets of observations. Our simulations resulted in strong constraints on the range of Yukawa interaction Λ and showed that its most probable value in the case of S2 star is around 5000 - 7000 AU. At the same time, we were not able to obtain reliable constrains on the universal constant δ of Yukawa gravity, because the current observations of S2 star indicated that it may be highly correlated with parameter Λ in the range (0 < δ < 1). For δ > 2 they are not correlated. However, the same universal constant which was successfully applied to clusters of galaxies and rotation curves of spiral galaxies (δ = 1/3) also gives a satisfactory agreement with the observed orbital precession of the S2 star, and in that case the most probable value for the scale parameter is Λ ≈ 3000±1500 AU. Also, the Yukawa gravity potential induces precession of S2 star orbit in the same direction as General Relativity for δ > 0 and for δ < −1, and in the opposite direction for −1 < δ < 0. The future observations with advanced facilities, such as GRAVITY or/and European Extremely Large Telescope, are needed in order to verify these claims.
Erbacher, Robin D.; /UC, Davis
2005-10-01
While the top quark was discovered in 1995 at the Fermilab Tevatron, a decade later they still have very little information about the top. As the heaviest particle yet discovered, the top quark is interesting in and of itself, but some speculate that it may play a special role in physics beyond the Standard Model. With Run 2 of the Tevatron well underway, they have the opportunity to study top quark properties with much better sensitivity, and to test whether top quarks behave as predicted by current theories. This article focuses on the basics of top quark physics at the Tevatron, highlighting only a sample of the many recent measurements, as new results are being released monthly, and constantly changing the landscape of our knowledge of top.
NASA Astrophysics Data System (ADS)
Abe, Kenji; Abe, Koya; Abe, T.; Adam, I.; Akimoto, H.; Akagi, T.; Allen, N. J.; Ash, W. W.; Aston, D.; Baird, K. G.; Baltay, C.; Band, H. R.; Barakat, M. B.; Bardon, O.; Barklow, T. L.; Bashindzhagyan, G. L.; Bauer, J. M.; Bellodi, G.; Ben-David, R.; Benvenuti, A. C.; Bilei, G. M.; Bisello, D.; Blaylock, G.; Bogart, J. R.; Bower, G. R.; Brau, J. E.; Breidenbach, M.; Bugg, W. M.; Burke, D.; Burnett, T. H.; Burrows, P. N.; Calcattera, A.; Calloway, D.; Camanzi, B.; Carpinelli, M.; Cassell, R.; Castaldi, R.; Castro, A.; Cavalli-Sforza, M.; Chou, A.; Church, E.; Cohn, H. O.; Coller, J. A.; Convery, M. R.; Cook, V.; Cotton, R.; Cowan, R. F.; Coyne, D. G.; Crawford, G.; Damerell, C. J.; Danielson, M. N.; Daoudi, M.; de Groot, N.; dell'orso, R.; Dervan, P. J.; de Sangro, R.; Dima, M.; D'oliveira, A.; Dong, D. N.; Doser, M.; Dubois, R.; Eisenstein, B. I.; Eschenburg, V.; Etzion, E.; Fahey, S.; Falciai, D.; Fan, C.; Fernandez, J. P.; Fero, M. J.; Flood, K.; Frey, R.; Gifford, J.; Gillman, T.; Gladding, G.; Gonzalez, S.; Goodman, E. R.; Hart, E. L.; Harton, J. L.; Hasan, A.; Hasuko, K.; Hedges, S. J.; Hertzbach, S. S.; Hildreth, M. D.; Huber, J.; Huffer, M. E.; Hughes, E. W.; Huynh, X.; Hwang, H.; Iwasaki, M.; Jackson, D. J.; Jacques, P.; Jaros, J. A.; Jiang, Z. Y.; Johnson, A. S.; Johnson, J. R.; Johnson, R. A.; Junk, T.; Kajikawa, R.; Kalelkar, M.; Kamyshkov, Y.; Kang, H. J.; Karliner, I.; Kawahara, H.; Kim, Y. D.; King, M. E.; King, R.; Kofler, R. R.; Krishna, N. M.; Kroeger, R. S.; Langston, M.; Lath, A.; Leith, D. W.; Lia, V.; Lin, C.; Liu, M. X.; Liu, X.; Loreti, M.; Lu, A.; Lynch, H. L.; Ma, J.; Mancinelli, G.; Manly, S.; Mantovani, G.; Markiewicz, T. W.; Maruyama, T.; Masuda, H.; Mazzucato, E.; McKemey, A. K.; Meadows, B. T.; Menegatti, G.; Messner, R.; Mockett, P. M.; Moffeit, K. C.; Moore, T. B.; Morii, M.; Muller, D.; Murzin, V.; Nagamine, T.; Narita, S.; Nauenberg, U.; Neal, H.; Nussbaum, M.; Oishi, N.; Onoprienko, D.; Osborne, L. S.; Panvini, R. S.; Park, C. H.; Pavel, T. J.; Peruzzi, I.; Piccolo, M.; Piemontese, L.; Pitts, K. T.; Plano, R. J.; Prepost, R.; Prescott, C. Y.; Punkar, G. D.; Quigley, J.; Ratcliff, B. N.; Reeves, T. W.; Reidy, J.; Reinertsen, P. L.; Rensing, P. E.; Rochester, L. S.; Rowson, P. C.; Russell, J. J.; Saxton, O. H.; Schalk, T.; Schindler, R. H.; Schumm, B. A.; Schwiening, J.; Sen, S.; Serbo, V. V.; Shaevitz, M. H.; Shank, J. T.; Shapiro, G.; Sherden, D. J.; Shmakov, K. D.; Simopoulos, C.; Sinev, N. B.; Smith, S. R.; Smy, M. B.; Snyder, J. A.; Staengle, H.; Stahl, A.; Stamer, P.; Steiner, H.; Steiner, R.; Strauss, M. G.; Su, D.; Suekane, F.; Sugiyama, A.; Suzuki, S.; Swartz, M.; Szumilo, A.; Takahashi, T.; Taylor, F. E.; Thom, J.; Torrence, E.; Toumbas, N. K.; Usher, T.; Vannini, C.; Va'vra, J.; Vella, E.; Venuti, J. P.; Verdier, R.; Verdini, P. G.; Wagner, D. L.; Wagner, S. R.; Waite, A. P.; Walston, S.; Wang, J.; Watts, S. J.; Weidemann, A. W.; Weiss, E. R.; Whitaker, J. S.; White, S. L.; Wickens, F. J.; Williams, B.; Williams, D. C.; Williams, S. H.; Willocq, S.; Wilson, R. J.; Wisniewski, W. J.; Wittlin, J. L.; Woods, M.; Word, G. B.; Wright, T. R.; Wyss, J.; Yamamoto, R. K.; Yamartino, J. M.; Yang, X.; Yashima, J.; Yellin, S. J.; Young, C. C.; Yuta, H.; Zapalac, G.; Zdarko, R. W.; Zhou, J.
1999-11-01
The structure of e+e--->bb¯g events was studied using Z0 decays recorded in the SLC Large Detector experiment at SLAC. Three-jet final states were selected and the charge-coupled device-based vertex detector was used to identify two of the jets as b or b¯. Distributions of the gluon energy and polar angle were measured over the full kinematic range for the first time, and compared with perturbative QCD predictions. The energy distribution is potentially sensitive to an anomalous b chromomagnetic moment κ. We measured κ to be consistent with zero and set the first limits on its value: -0.17<κ<0.11 at 95% C.L.
New lattice action for heavy quarks
Oktay, Mehmet B.; Kronfeld, Andreas S.
2008-03-01
We extend the Fermilab method for heavy quarks to include interactions of dimension six and seven in the action. There are, in general, many new interactions, but we carry out the calculations needed to match the lattice action to continuum QCD at the tree level, finding six non-zero couplings. Using the heavy-quark theory of cutoff effects, we estimate how large the remaining discretization errors are. We find that our tree-level matching, augmented with one-loop matching of the dimension-five interactions, can bring these errors below 1%, at currently available lattice spacings.
Quark matter in an SU(3) Nambu-Jona-Lasinio model with two types of vector interactions
NASA Astrophysics Data System (ADS)
Chu, Peng-Cheng; Wang, Bin; Ma, Hong-Yang; Dong, Yu-Min; Chang, Su-Ling; Zheng, Chun-Hong; Liu, Jun-Ting; Zhang, Xiao-Min
2016-05-01
We investigate the properties of asymmetric quark matter and strange quark matter in the framework of the SU(3) Nambu-Jona-Lasinio (NJL) model with two types of vector interactions: (1) the flavor-dependent repulsion among different flavors of quarks with the coupling constant GV , and (2) the universal repulsion and the vector-isovector interaction among different flavors of quarks with the coupling constants gV and GI V. Using these two types of vector interactions in the NJL model, we study the quark symmetry energy in asymmetric quark matter, the constituent quark mass, the quark fraction, the equation of state in strange quark matter, the maximum mass of a quark star, and the properties of the QCD phase diagram. We find that including the two types of vector interactions in the SU(3) NJL model can significantly influence the quark matter symmetry energy as well as the properties of strange quark matter and quark stars. In particular, our results indicate that we can describe PSR J 1614 -2230 and PSR J 0348 +0432 as quark stars by considering the universal repulsion and the vector-isovector interaction among quark matter in the SU(3) NJL model.
A corresponding-state approach to quark-cluster matter
NASA Astrophysics Data System (ADS)
Guo, Yan-Jun; Lai, Xiao-Yu; Xu, Ren-Xin
2014-05-01
The state of super-dense matter is essential for us to understand the nature of pulsars; however, non-perturbative quantum chromodynamics makes it very difficult to make direct calculations of the state of cold matter at realistic baryon number densities inside compact stars. Nevertheless, from an observational point of view, it is conjectured that pulsars could be made up of quark clusters since the strong coupling between quarks might render the quarks to be grouped in clusters. In this paper, we attempt to find an equation of state of condensed quark-cluster matter in a phenomenological way. Supposing that the quark-clusters could be analogized to inert gases, we apply here the corresponding-state approach to derive the equation of state of quark-cluster matter, as was similarly demonstrated for nuclear and neutron-star matter in the 1970s. According to the calculations that we have presented, the quark-cluster stars, which are composed of quark-cluster matter, could have a high maximum mass that is consistent with observations and, in turn, further observations of pulsar mass could also place a constraint on the properties of quark-cluster matter. We will also briefly discuss the melting heat during the solid-liquid phase conversion and its related astrophysical consequences.
Spinless particles in the field of unequal scalar—vector Yukawa potentials
NASA Astrophysics Data System (ADS)
Hamzavi, M.; M. Ikhdair, S.; E. Thylwe, K.
2013-04-01
We present analytical bound state solutions of the spin-zero Klein—Gordon (KG) particles in the field of unequal mixture of scalar and vector Yukawa potentials within the framework of the approximation scheme to the centrifugal potential term for any arbitrary l-state. The approximate energy eigenvalues and unnormalized wave functions are obtained in closed forms using a simple shortcut of the Nikiforov—Uvarov (NU) method. Further, we solve the KG—Yukawa problem for its exact numerical energy eigenvalues via the amplitude phase (AP) method to test the accuracy of the present solutions found by using the NU method. Our numerical tests using energy calculations demonstrate the existence of inter-dimensional degeneracy amongst the energy states of the KG—Yukawa problem. The dependence of the energy on the dimension D is numerically discussed for spatial dimensions D = 2-6.
NASA Astrophysics Data System (ADS)
Ghosh, Sabyasachi; Peixoto, Thiago C.; Roy, Victor; Serna, Fernando E.; Krein, Gastão
2016-04-01
We have calculated the temperature dependence of shear η and bulk ζ viscosities of quark matter due to quark-meson fluctuations. The quark thermal width originating from quantum fluctuations of quark-π and quark-σ loops at finite temperature is calculated with the formalism of real-time thermal field theory. Temperature-dependent constituent-quark and meson masses and quark-meson couplings are obtained in the Nambu-Jona-Lasinio model. We found a nontrivial influence of the temperature-dependent masses and couplings on the Landau-cut structure of the quark self-energy. Our results for the ratios η /s and ζ /s , where s is the entropy density (also determined in the Nambu-Jona-Lasinio model in the quasiparticle approximation), are in fair agreement with results of the literature obtained from different models and techniques. In particular, our result for η /s has a minimum very close to the quantum lower bound, η /s =1 /4 π .
Transport properties of quark and gluon plasmas
Heiselberg, H.
1993-12-01
The kinetic properties of relativistic quark-gluon and electron-photon plasmas are described in the weak coupling limit. The troublesome Rutherford divergence at small scattering angles is screened by Debye screening for the longitudinal or electric part of the interactions. The transverse or magnetic part of the interactions is effectively screened by Landau damping of the virtual photons and gluons transferred in the QED and QCD interactions respectively. Including screening a number of transport coefficients for QCD and QED plasmas can be calculated to leading order in the interaction strength, including rates of momentum and thermal relaxation, electrical conductivity, viscosities, flavor and spin diffusion of both high temperature and degenerate plasmas. Damping of quarks and gluons as well as color diffusion in quark-gluon plasmas is, however, shown not to be sufficiently screened and the rates depends on an infrared cut-off of order the ``magnetic mass,`` m{sub mag} {approximately} g{sup 2}T.
NASA Astrophysics Data System (ADS)
Alkofer, Reinhard; Fischer, Christian S.; Llanes-Estrada, Felipe J.; Schwenzer, Kai
2009-01-01
The infrared behavior of the quark-gluon vertex of quenched Landau gauge QCD is studied by analyzing its Dyson-Schwinger equation. Building on previously obtained results for Green functions in the Yang-Mills sector, we analytically derive the existence of power-law infrared singularities for this vertex. We establish that dynamical chiral symmetry breaking leads to the self-consistent generation of components of the quark-gluon vertex forbidden when chiral symmetry is forced to stay in the Wigner-Weyl mode. In the latter case the running strong coupling assumes an infrared fixed point. If chiral symmetry is broken, either dynamically or explicitly, the running coupling is infrared divergent. Based on a truncation for the quark-gluon vertex Dyson-Schwinger equation which respects the analytically determined infrared behavior, numerical results for the coupled system of the quark propagator and vertex Dyson-Schwinger equation are presented. The resulting quark mass function as well as the vertex function show only a very weak dependence on the current quark mass in the deep infrared. From this we infer by an analysis of the quark-quark scattering kernel a linearly rising quark potential with an almost mass independent string tension in the case of broken chiral symmetry. Enforcing chiral symmetry does lead to a Coulomb type potential. Therefore, we conclude that chiral symmetry breaking and confinement are closely related. Furthermore, we discuss aspects of confinement as the absence of long-range van der Waals forces and Casimir scaling. An examination of experimental data for quarkonia provides further evidence for the viability of the presented mechanism for quark confinement in the Landau gauge.
Phenomenological calculation of nuclear binding energy and density with Yukawa-potentials
NASA Astrophysics Data System (ADS)
Scheid, W.
2016-01-01
In this paper, we study a phenomenological collective model for the calculation of the nuclear density and ground state binding energy of nuclei. The proton density is assumed proportional to the nuclear density. The total binding energy of the nuclear matter consists of the binding energy of infinite nuclear matter, of two Yukawa-potentials, of the Coulomb-energy and of the symmetry-energy. The parameters of the Yukawa-potential are fitted with the Bethe-Weizsäcker (BW) mass formula. The resulting binding energies and nuclear densities agree quite satisfying with known nuclear values.
Phase diagram of neutral quark matter in nonlocal chiral quark models
NASA Astrophysics Data System (ADS)
Gómez Dumm, D.; Blaschke, D. B.; Grunfeld, A. G.; Scoccola, N. N.
2006-06-01
We consider the phase diagram of two-flavor quark matter under neutron star constraints for two nonlocal, covariant quark models within the mean-field approximation. In the first case (Model I) the nonlocality arises from the regularization procedure, motivated by the instanton liquid model, whereas in the second one (Model II) a separable approximation of the one-gluon exchange interaction is applied. We find that Model II predicts a larger quark mass gap and a chiral symmetry breaking (CSB) phase transition line which extends 15 20% further into the phase diagram spanned by temperature (T) and chemical potential (μ). The corresponding critical temperature at μ=0, Tc(0)≃140MeV, is in better accordance to recent lattice QCD results than the prediction of the standard local NJL model, which exceeds 200 MeV. For both Model I and Model II we have considered various coupling strengths in the scalar diquark channel, showing that different low-temperature quark matter phases can occur at intermediate densities: a normal quark matter (NQM) phase, a two-flavor superconducting (2SC) quark matter phase and a mixed 2SC-NQM phase. Although in most cases there is also a gapless 2SC phase, this occurs in general in a small region at nonzero temperatures, thus its effect should be negligible for compact star applications.
Toward a consistent evolution of the quark-gluon plasma and heavy quarks
NASA Astrophysics Data System (ADS)
Nahrgang, Marlene; Aichelin, Jörg; Gossiaux, Pol Bernard; Werner, Klaus
2016-04-01
Heavy-quark observables in ultrarelativistic heavy-ion collisions, like the nuclear modification factor and the elliptic flow, give insight into the mechanisms of high-momentum suppression and low-momentum thermalization of heavy quarks. Here, we present a global study of these two observables within a coupled approach of the heavy-quark propagation in a realistic fluid dynamical medium, MC@sHQ+EPOS2 , and compare with experimental data from the BNL Relativistic Heavy Ion Collider and the CERN Large Hadron Collider experiments. The heavy quarks scatter elastically and inelastically with the quasiparticles of the quark-gluon plasma (QGP), which are represented consistently with the underlying equation of state. We examine two scenarios: first, we interpret the lattice QCD equation of state as a sum of partonic and hadronic contributions and, second, as a gas of massive partonic quasiparticles. It is observed that, independent of their momentum, the energy loss of heavy quarks depends strongly on how the lattice QCD equation of state is translated into degrees of freedom of the QGP.
Hill, Christopher S.; /UC, Santa Barbara
2004-12-01
The top quark, with its extraordinarily large mass (nearly that of a gold atom), plays a significant role in the phenomenology of EWSB in the Standard Model. In particular, the top quark mass when combined with the W mass constrains the mass of the as yet unobserved Higgs boson. Thus, a precise determination of the mass of the top quark is a principal goal of the CDF and D0 experiments. With the data collected thus far in Runs 1 and 2 of the Tevatron, CDF and D0 have measured the top quark mass in both the lepton+jets and dilepton decay channels using a variety of complementary experimental techniques. The author presents an overview of the most recent of the measurements.
Abazov, V. M.
2011-07-26
We measure the mass dependence of the forward-backward charge asymmetry in 157,553 pp = Z/γ* = e^{+}e^{-} interactions, corresponding to 5.0 fb^{-1} of integrated luminosity collected by the D0 experiment at the Fermilab Tevatron Collider at √s = 1.96 TeV. The effective weak mixing angle (θ^{ℓ}_{eff}) from this process involving predominantly the first generation of quarks is extracted as sin^{2} θ^{ℓ}_{eff} = 0.2309 ± 0.0008 (stat.) ± 0.0006 (syst.). We also present the most precise direct measurement of the vector and axial-vector couplings of u and d quarks to the Z boson.
Abazov, V. M.
2011-07-26
We measure the mass dependence of the forward-backward charge asymmetry in 157,553 pp = Z/γ* = e+e- interactions, corresponding to 5.0 fb-1 of integrated luminosity collected by the D0 experiment at the Fermilab Tevatron Collider at √s = 1.96 TeV. The effective weak mixing angle (θℓeff) from this process involving predominantly the first generation of quarks is extracted as sin2 θℓeff = 0.2309 ± 0.0008 (stat.) ± 0.0006 (syst.). We also present the most precise direct measurement of the vector and axial-vector couplings of u and d quarks to the Z boson.
Flavor signatures of isosinglet vector-like down quark model
NASA Astrophysics Data System (ADS)
Alok, Ashutosh Kumar; Banerjee, Subhashish; Kumar, Dinesh; Uma Sankar, S.
2016-05-01
We consider a model where the standard model is extended by the addition of a vector-like isosinglet down-type quark b‧. We perform a χ2 fit to the flavor physics data and obtain the preferred central values along with errors of all the elements of the measurable 3 × 4 quark mixing matrix. The fit indicates that all the new-physics parameters are consistent with zero and the mixing of the b‧ quark with the other three is constrained to be small. The current flavor physics data rules out possibility of detectable new physics signals in most of the flavor physics observables. We also investigate possible deviations in the standard model Wtb couplings and bottom quark coupling to Higgs boson. We find that these deviations are less than a percent level which is too small to be observed at the LHC with current precision.
NASA Astrophysics Data System (ADS)
Tung, Kwong-Kwai Humphrey
1992-01-01
The rare decays bto sX are sensitive to strong interaction corrections. The effects can be estimated by a renormalization group technique which requires the evaluation of QCD mixing among effective operators. In the dimensional reduction and the naive dimensional regularization methods, there are discrepancies in evaluating the QCD mixing of the four-quark operators with the bto sgamma and bto s+gluon dipole operators. In this thesis, the problem is investigated by considering the contributions of the epsilon -scalar field and the epsilon -dimensional operators that distinguish between the two methods. The discrepancies are shown to come from the epsilon-dimensional four-quark operators in dimensional reduction and not from the epsilon -scalar field. In the decay bto sl^+l^ -, the intermediate of cc pairs in the charm-penguin diagram can form the resonance states J/psi and psi^'. In the published literature, there is a sign discrepancy in the Breit-Wigner amplitude for the resonance effects. Here, the sign difference is settled by considering the unitarity limit of the amplitude in the Argand diagram. The effects of the resonances are quite substantial on the invariant mass spectrum for this decay. However, they are shown to be negligible on the dilepton energy spectrum below 0.95 GeV. The energy spectrum is, thus, more useful than the invariant mass spectrum for measurements of the top -quark mass. The decays Bto K^*X are well modeled by the quark-level decays bto sX. In the quark model, the hadronization is done using a nonrelativistic wave function. In the decay B to K^*gamma, the large K ^* recoil creates an uncertainty in calculating the branching ratio using the quark model. The problem is explored by considering other meson processes where data exist. The data on the pi form factor and the omegapi^0 transition form factor suggest the necessity to retain relativistic spinor and meson normalizations in the quark -model; however, the data do not resolve the
Prediction of new Quarks, Generations and Quark Masses
NASA Astrophysics Data System (ADS)
Lach, Thedore
2002-04-01
The Standard model currently suggests no relationship between the quark and lepton masses. The CBM (model) of the nucleus has resulted in the prediction of two new quarks, an up quark mass of 237.31 MeV/c2 and a dn quark mass of 42.392 MeV/c2. These two new quarks help explain the numerical relationship between all the quark and lepton masses in a single function. The mass of each SNU-P (quark or lepton) is just the geometric mean of two related SNU-Ps, either in the same generation or in the same family. This numerology predicts the following masses for the electron family: 0.511000 (electron), 7.743828 (predicted), 117.3520, 1778.38, 26950.08 MeV. The resulting slope of these masses when plotted on semi log paper is "e" to 5 significant figures using the currently accepted mass for Tau. This theory suggests that all the "dn like" quarks have a mass of just 10X multiples of 4.24 MeV (the mass of the "d" quark). The first 3 "up like" quark masses are 38, 237 and 1500 MeV. This theory also predicts a new heavy generation with a lepton mass of 27 GeV, a "dn like" quark of 42.4 GeV, and an "up like" quark of 65 GeV. Significant evidence already exists for the existence of these quarks, and lepton.
Hidden GeV-scale interactions of quarks.
Dobrescu, Bogdan A; Frugiuele, Claudia
2014-08-01
We explore quark interactions mediated by new gauge bosons of masses in the 0.3-50 GeV range. A tight upper limit on the gauge coupling of light Z(') bosons is imposed by the anomaly cancellation conditions in conjunction with collider bounds on new charged fermions. Limits from quarkonium decays are model dependent, while electroweak constraints are mild. We derive the limits for a Z(') boson coupled to baryon number and then construct a Z(') model with relaxed constraints, allowing quark couplings as large as 0.2 for a mass of a few GeV. PMID:25148315
Hidden GeV-Scale Interactions of Quarks
Dobrescu, Bogdan A.; Frugiuele, Claudia
2014-08-05
We explore quark interactions mediated by new gauge bosons of masses in the 0.3 – 50 GeV range. A tight upper limit on the gauge coupling of light Z' bosons is imposed by the anomaly cancellation conditions in conjunction with collider bounds on new charged fermions. Limits from quarkonium decays are model dependent, while electroweak constraints are mild. We derive the limits for a Z' boson coupled to baryon number, and then construct a Z' model with relaxed constraints, allowing quark couplings as large as 0.2 for a mass of a few GeV.
ZANTOW, F.; KACZMAREK, O.
2005-08-02
We discuss quark antiquark energies and the screening mass in hot QCD using the non-perturbative lattice approach. For this purpose we analyze properties of quark antiquark energies and entropies at infinitely large separation of the quark antiquark pair at low and high temperatures. In the limit of high temperatures these energies and entropies can be related perturbatively to the temperature dependence of the Debye mass and the coupling. On the one hand our analysis thus suggests that the quark antiquark energies at (infinite) large distances are rather related to the Debye screening mass and the coupling than to the temperature dependence of heavy-light meson masses. On the other hand we find no or only little differences in all mass scales introduced by us when changing from quenched to 2-flavor QCD at temperatures which are only moderately above the phase transition.
NASA Astrophysics Data System (ADS)
Friedman, J. I.
2001-01-01
In the period following World War II, there was a rapid development of particle physics. With the construction of synchrotrons and the development of detector technology, many new particles were discovered and the systematics of their interactions investigated. The invention of the bubble chamber played an especially important role in uncovering the rich array of hadrons that were discovered in this period.In 1961 Murray Gell-Mann [1] and Yuval Ne'eman [2] independently introduced a classification scheme, based on SU(3) symmetry, which placed hadrons into families on the basis of spin and parity. Like the periodic table for the elements, this scheme was predictive as well as descriptive, and various hadrons, such as the - , were predicted within this framework and were later discovered.In 1964 Gell-Mann [3] and George Zweig [4] independently proposed quarks as the building blocks of hadrons as a way of generating the SU(3) classification scheme. When the quark model was first proposed, it postulated three types of quarks: up (u), down (d), and strange (s), with charges 2/3, - 1/3, and - 1/3 respectively. Each of these was hypothesized to be a spin1/2 particle. In this model the nucleon (and all other baryons) is made up of three quarks, and each meson consists of a quark and an antiquark. For example, as the proton and neutron both have ero strangeness, they are (u,u,d) and (d,d,u) systems respectively.
Search of anomalous $Wtb$ couplins in single top quark prodution at D0
Joshi, Jyoti; Beri, Suman; /Panjab U.
2011-12-01
The large mass of the top quark, close to the electroweak symmetry-breaking scale, makes it a good candidate for probing physics beyond the Standard Model, including possible anomalous couplings. D0 has made measurements of single top quark production using 5.4 fb{sup -1} of integrated luminosity. We examine the data to study the Lorentz structure of the Wtb coupling. We find that the data prefer the left-handed vector coupling and set upper limits on the anomalous couplings. In 2009, the electroweak single top quark production was observed by the D0 and CDF collaborations. Electroweak production of top quarks at the Tevatron proceeds mainly via the decay of a time-like virtual W boson accompanied by a bottom quark in the s-channel (tb = t{bar b} + {bar t}b), or via the exchange of a space-like virtual W boson between a light quark and a bottom quark in the t-channel (tqb = tq{bar b} + {bar t}qb, where q refers to the light quark). For a top quark mass of 172.5 GeV, The Standard Model (SM) prediction of single top production rate at next-to-leading order with soft-gluon contributions at next-to-next-to-leading order are 1.04 {+-} 0.04 pb (s-channel) and 2.26 {+-} 0.12 pb (t-channel). The large mass of the top quark implies that it has large couplings to the electroweak symmetry breaking sector of the SM and may have non-standard interactions with the weak gauge bosons. Single top quark production provides a unique probe to study the interactions of the top quark with the W boson.
Measurements of the top-quark mass and properties at CMS
NASA Astrophysics Data System (ADS)
Dünser, Marc; CMS Collaboration
2015-06-01
Measurements of the top-quark mass and other top-quark properties are presented, obtained from the CMS data collected in 2011 and 2012 at centre-of-mass energies of 7 and 8 TeV. The mass of the top quark is measured using several methods and decay channels. The measurements of the top-quark properties include the W helicity in top-quark decays, the search for anomalous couplings, and the ratio of top-quarks decaying to bW over qW in order to gain information on |Vtb| using both t\\bar t and single-top quark event samples. The results are compared with predictions from the standard model as well as new physics models. The cross section of t\\bar t events produced in association with a W, Z boson or a photon is also measured.
Benenson, G.; Chau, L.L.; Ludlam, T.; Paige, F.E.; Platner, E.D.; Protopopescu, S.D.; Rehak, P.
1983-01-01
In this exercise we examine the performance of a detector specifically configured to tag heavy quark (HQ) jets through direct observations of D-meson decays with a high resolution vertex detector. To optimize the performance of such a detector, we assume the small diamond beam crossing configuration as described in the 1978 ISABELLE proposal, giving a luminosity of 10/sup 32/ cm/sup -2/ sec/sup -1/. Because of the very large backgrounds from light quark (LQ) jets, most triggering schemes at this luminosity require high P/sub perpendicular to/ leptons and inevitably give missing neutrinos. If alternative triggering schemes could be found, then one can hope to find and calculate the mass of objects decaying to heavy quarks. A scheme using the high resolution detector will also be discussed in detail. The study was carried out with events generated by the ISAJET Monte Carlo and a computer simulation of the described detector system. (WHK)
Andreas S. Kronfeld
2003-11-05
This paper is a review of heavy quarks in lattice gauge theory, focusing on methodology. It includes a status report on some of the calculations that are relevant to heavy-quark spectroscopy and to flavor physics.
The Quark's Model and Confinement
ERIC Educational Resources Information Center
Novozhilov, Yuri V.
1977-01-01
Quarks are elementary particles considered to be components of the proton, the neutron, and others. This article presents the quark model as a mathematical concept. Also discussed are gluons and bag models. A bibliography is included. (MA)
NASA Astrophysics Data System (ADS)
Fedi, G.; CMS Collaboration
2016-07-01
The most recent results which concern the heavy quark hadrons done in the CMS experiment are reported. The searching area spans over the heavy quark spectroscopy, production cross sections, beauty meson decay properties, rare decays, and CP violation.
Larsen, R.C.; Leipuner, L.B.; Morse, W.M.; Adair, R.K.; Kasha, H.; Schmidt, M.P.
1983-03-13
An experiment to search for quarks at the CBA is described. The cross sections for the production of massive quark-antiquark pairs in nucleon-nucleon interactions is estimated, and the experimental design and procedures are described. (WHK)
Heavy quark production processes in QCD
Brodsky, S.J.; Gunion, J.F.
1984-12-01
We have identified two novel effects in QCD, each of which acts to enhance the production of heavy quark and supersymmetric particles beyond what is conventionally expected from gluon fusion. Both effects are present in QED, but are compounded in QCD because of the increased number of diagrams and the much larger coupling constant. The intrinsic charm quark distribution in the nucleon could account for the observed enhancements of the charm structure function at large x and features of the charm production data but this mechanism is relatively suppressed for heavier systems. Prebinding distortion of the fusion cross section is, however, likely to be significant for the production at low p/sub T/ of all particles containing heavy colored constituents. At this stage the QCD calculations are highly model dependent although they agree with the general properties which can be inferred from the operator product expansion in the heavy quark mass. Much more theoretical analysis of these effects is clearly needed. It is also clear that much more experimental work is necessary to extend and confirm the reported anomalous heavy quark signals. 22 references.
NASA Astrophysics Data System (ADS)
Konuma, Michiji; Bando, Masako; Gotoh, Haruyoshi; Hayakawa, Hisao; Hirata, Kohji; Ito, Kazuyuki; Ito, Kenji; Kanaya, Kazuyuki; Konagaya, Daisuke; Kugo, Taichiro; Namba, Chusei; Nishitani, Tadashi; Takaiwa, Yoshinobu; Tanabashi, Masaharu; Tanaka, Kio; Tanaka, Sho; Ukegawa, Fumihiko; Yoshikawa, Tadashi
Hideki Yukawa, Sin-itiro Tomonaga and Shoichi Sakata pioneered nuclear and particle physics and left enduring legacies. Their friendly collaboration and severe competition laid the foundation to bring up the active postwar generation of nuclear and particle physicists in Japan. In this presentation we illustrate milestones of nuclear and particle physics in Japan from 1930's to mid-1940's which have been clarified in Yukawa Hall Archival Library, Tomonaga Memorial Room and Sakata Memorial Archival Library.
Phase diagram of Yukawa systems near the one-component-plasma limit revisited
NASA Astrophysics Data System (ADS)
Hamaguchi, S.; Farouki, R. T.; Dubin, D. H. E.
1996-11-01
Transition inverse temperatures (or Γ values) at the fluid-solid phase boundary of Yukawa systems near the one-component-plasma (OCP) limit have been evaluated by molecular dynamics simulations. These values are systematically smaller than those obtained in an earlier study by Farouki and Hamaguchi [J. Chem. Phys. 101, 9885 (1994)]. The discrepancy is attributed to the fact that, in the earlier study, the harmonic entropy constants were approximated by that of the OCP, whereas the new results are based on more accurate harmonic entropy constants obtained from lattice-dynamics calculations. The new molecular dynamics simulations also confirm that the bcc-fcc phase transition curve is in good agreement with that of the quasiharmonic theory in the regime κ≤1.4, where κ is the ratio of the Wigner-Seitz radius to the Debye length. Examples of Yukawa systems include dusty plasmas and colloidal suspensions.
The Quest for Pionic and Kaonic Nuclear Bound Systems Following Yukawa and Tomonaga
NASA Astrophysics Data System (ADS)
Yamazaki, T.
After sketching some historical events related to Yukawa and Tomonagaconcerning the birth of mesons, the author describes recent developments in the spectroscopy of pion-nucleus bound states via ``pion-transfer" reactions. The role of pions as Nambu-Goldstone bosons in nuclear media is emphasized by recently obtained experimental evidence for the partial restoration of chiral symmetry breaking. New light is shed on bar{K} mesons, which play a unique role in forming dense nuclear systems. The basic unit, K^-pp, is predicted to possess a molecular structure with quasi-Λ(1405) as an ``atomic constituent". We find here super strong nuclear force produced by a migrating real bar{K} meson in the Heitler-London-Heisenberg scheme in place of the normal nuclear force mediated by Yukawa's virtual mesons.
Hadron resonances with a quark core embedded in the continuum
Shimizu, Kiyotaka; Takeuchi, Sachiko; Takizawa, Makoto
2011-05-06
We investigate the excited baryons and mesons which cannot be described in terms of a simple constituent quark model, such as {Lambda}(1405) and X(3872) as a resonance in a coupled channel hadron-hadron (baryon-meson or meson-meson) scattering with a 'bound state embedded in the continuum' (BSEC). For this purpose, we solve the Lippmann-Schwinger equation including a BSEC in the momentum space. This BSEC is introduced by hand, as a state not originated from a simple baryon-meson or meson-meson system. We assume it comes from the three-quark state or quark-anti quark state and show such a picture can describe the {Lambda}(1405) and X(3872) resonances.
Phase diagram of the hard-core Yukawa fluid within the integral equation method.
El Mendoub, E B; Wax, J-F; Jakse, N
2006-11-01
In this study, the integral equation method proposed recently by Sarkisov [J. Chem. Phys. 114, 9496 (2001).], which has proved accurate for continuous potentials, is extended successfully to the hard sphere potential plus an attractive Yukawa tail. By comparing the results of thermodynamic properties, including the liquid-vapor phase diagram, with available simulation data, it is found that this method remains reliable for this class of models of interaction often used in colloid science. PMID:17279956
Higgs boson mass and sparticle spectroscopy in Yukawa unified SUSY SO(10)
NASA Astrophysics Data System (ADS)
Shafi, Qaisar
2012-07-01
We employ third family Yukawa unification, predicted by simple supersymmetric SO(10) models, to estimate the lightest MSSM Higgs boson mass. For μ > 0 (or μ < 0) and mt = 173.1GeV, the Higgs mass is estimated to lie close to 123-124 GeV. The theoretical uncertainty in this estimate is ±3 GeV. We highlight some LHC testable benchmark points which also display the presence of neutralino-stau coannihilation channel.
Measurements of heavy quark and lepton lifetimes
Jaros, J.A.
1985-02-01
The PEP/PETRA energy range has proved to be well-suited for the study of the lifetimes of hadrons containing the b and c quarks and the tau lepton for several reasons. First, these states comprise a large fraction of the total interaction rate in e/sup +/e/sup -/ annihilation and can be cleanly identified. Second, the storage rings have operated at high luminosity and so produced these exotic states copiously. And finally, thanks to the interplay of the Fermi coupling strength, the quark and lepton masses, and the beam energy, the expected decay lengths are in the 1/2 mm range and so are comparatively easy to measure. This pleasant coincidence of cleanly identified and abundant signal with potentially large effects has made possible the first measurements of two fundamental weak couplings, tau ..-->.. nu/sub tau/W and b ..-->.. cW. These measurements have provided a sharp test of the standard model and allowed, for the first time, the full determination of the magnitudes of the quark mixing matrix. This paper reviews the lifetime studies made at PEP during the past year. It begins with a brief review of the three detectors, DELCO, MAC and MARK II, which have reported lifetime measurements. Next it discusses two new measurements of the tau lifetime, and briefly reviews a measurement of the D/sup 0/ lifetime. Finally, it turns to measurements of the B lifetime, which are discussed in some detail. 18 references, 14 figures, 1 table.
Density profile and breathing mode of strongly correlated spherical Yukawa plasmas
NASA Astrophysics Data System (ADS)
Henning, Christian; Fujioka, Kenji; Ludwig, Patrick; Bonitz, Michael
2007-11-01
The structure of ``Yukawa balls,'' i.e. spherical 3D dust crystals, which recently have been produced [1], is well explained by computer simulations of charged Yukawa interacting particles within an external parabolic confinement [2]. Dynamical properties (e.g. breathing mode) of these systems were investigated by experiment, simulations as well as theoretically by using the ansatz of a uniform ground state density [3]. Here we show analytically that screening has a dramatic effect on the density profile which decreases away from the center [4,5] and which is in excellent agreement with MD simulations of Yukawa balls. This result is used to improve former calculations of the breathing mode [6].References[1] O. Arp et al. Phys. Rev. Lett. 93, 165004 (2004)[2] M. Bonitz et al., Phys. Rev. Lett. 96, 075001 (2006)[3] T. E. Sheridan, Phys. Plasmas 13, 022106 (2006)[4] C. Henning et al., Phys. Rev. E 74, 056403 (2006)[5] C. Henning at al., Phys. Rev. E (2007)[6] C. Henning at al., submitted for publication
Theoretical approach to the ground state of spherically confined Yukawa plasmas
NASA Astrophysics Data System (ADS)
Henning, Christian; Bonitz, Michael; Piel, Alexander; Ludwig, Patrick; Baumgartner, Henning
2007-11-01
Recently spherical 3D dust crystals (aka Yukawa balls) were discovered [1], which allow direct observation of strong correlation phenomena and the structure of which is well explained by computer simulations of charged Yukawa interacting particles within an external parabolic confinement [2]. Here we present an analytical approach to the ground state of these systems using the minimization of the system's energy. Applying the non-local mean-field approximation we show that screening has a dramatic effect on the density profile, which can be derived explicitly [3]. In addition the local density approximation allows for the inclusion of correlations, which further improves the results in the regime of large screening [4]. Comparisons with MD simulations of Yukawa balls show excellent agreement.[1] O. Arp et al. Phys. Rev. Lett. 93, 165004 (2004)[2] M. Bonitz et al., Phys. Rev. Lett. 96, 075001 (2006)[3] C. Henning et al., Phys. Rev. E 74, 056403 (2006)[4] C. Henning at al., Phys. Rev. E (2007)
Nucleon quark distributions in a covariant quark-diquark model
Ian Cloet; W. Bentz; Anthony Thomas
2005-04-01
Spin-dependent and spin-independent quark light-cone momentum distributions and structure functions are calculated for the nucleon. We utilize a modified Nambu-Jona-Lasinio model in which confinement is simulated by eliminating unphysical thresholds for nucleon decay into quarks. The nucleon bound state is obtained by solving the Faddeev equation in the quark-diquark approximation, where both scalar and axial-vector diquarks channels are included. We find excellent agreement between our model results and empirical data.
Prediction of new Quarks, Generations & low Mass Quarks
NASA Astrophysics Data System (ADS)
Lach, Theodore
2003-04-01
The CBM (model) of the nucleus has resulted in the prediction of two new quarks, an "up" quark of mass 237.31 MeV/c2 and a "dn" quark of mass 42.392 MeV/c2. These two new predicted quarks helped to determine that the masses of the quarks and leptons are all related by a geometric progression relationship. The mass of each quark or lepton is just the "geometric mean" of two related elementary particles, either in the same generation or in the same family. This numerology predicts the following masses for the electron family: 0.511000 (electron), 7.74 (predicted), 117.3, 1778.4 (tau), 26950.1 MeV. The geometric ratio of this progression is 15.154 (e to the power e). The mass of the tau in this theory agrees very well with accepted values. This theory suggests that all the "dn like" quarks have a mass of just 10X multiples of 4.24 MeV (the mass of the "d" quark). The first 3 "up like" quark masses are 38, 237.31 and 1500 MeV. This theory also predicts a new heavy generation with a lepton mass of 27 GeV, a "dn like" quark of 42.4 GeV, and an "up like" quark of 65 GeV. Significant evidence already exists for the existence of these new quarks, and lepton. Ref. Masses of the Sub-Nuclear Particles, nucl-th/ 0008026, @ http://xxx.lanl.gov. Infinite Energy, Vol 5, issue 30.
NASA Astrophysics Data System (ADS)
Kane, Gordon L.; Perry, Malcolm J.
2015-03-01
We are used to thinking of quarks as fundamental particles in the same way we think of the electron, or gauge bosons, neutrinos, leptons. In strong theory, these objects are unified with gravitation and the physics of spacetime into what is hoped to be an ultimate theory, string/M theory. The string/M theory paradigm completely changes the way we think of the socalled elementary particles in quantum field theory.
NASA Astrophysics Data System (ADS)
Kane, Gordon L.; Perry, Malcolm J.
2015-01-01
We are used to thinking of quarks as fundamental particles in the same way we think of the electron, or gauge bosons, neutrinos, leptons. In strong theory, these objects are unified with gravitation and the physics of spacetime into what is hoped to be an ultimate theory, string/M theory. The string/M theory paradigm completely changes the way we think of the so-called elementary particles in quantum field theory.
NASA Astrophysics Data System (ADS)
Vainshtein, Arkady
2011-04-01
Anomalous quark triangles with one axial and two vector currents are studied in special kinematics when one of the vector currents carries a soft momentum. According to the Adler-Bardeen theorem the anomalous longitudinal part of the triangle is not renormalized in the chiral limit. We show that perturbative corrections the transversal part of the triangle is also absent. This nonrenormalization, in difference with the longitudinal part, holds on only perturbatively.
Transversity quark distributions in a covariant quark-diquark model
I.C. Cloet; W. Bentz; A.W. Thomas
2008-01-01
Transversity quark light-cone momentum distributions are calculated for the nucleon. We utilize a modified Nambu--Jona-Lasinio model in which confinement is simulated by eliminating unphysical thresholds for nucleon decay into quarks. The nucleon bound state is obtained by solving the relativistic Faddeev equation in the quark-diquark approximation, where both scalar and axial-vector diquark channels are included. Particular attention is paid to comparing our results with the recent experimental extraction of the transversity distributions by Anselmino et al. We also compare our transversity results with earlier spin-independent and helicity quark distributions calculated in the same approach.
String worldsheet for accelerating quark
NASA Astrophysics Data System (ADS)
Hubeny, Veronika E.; Semenoff, Gordon W.
2015-10-01
We consider the AdS bulk dual to an external massive quark in SYM following an arbitrary trajectory on Minkowski background. While a purely outgoing boundary condition on the gluonic field allows one to express the corresponding string worldsheet in a closed form, the setup has curious consequences. In particular, we argue that any quark whose trajectory on flat spacetime approaches that of a light ray in the remote past (as happens e.g. in the case of uniform acceleration) must necessarily be accompanied by an anti-quark. This is puzzling from the field theory standpoint, since one would expect that a sole quark following any timelike trajectory should be allowed. We explain the resolution in terms of boundary and initial conditions. We analyze the configuration in global AdS, which naturally suggests a modification to the boundary conditions allowing for a single accelerated quark without accompanying anti-quark. We contrast this resolution with earlier proposals.
Searches for new physics in the top quark samples at the CDF experiment
Scodellaro, Luca; /Cantabria Inst. of Phys.
2007-10-01
Twelve years after the discovery of the top quark at Fermilab's Tevatron, they are now finally beginning to shed light on this peculiarily massive quark. With 1-1.7 fb{sup -1} of integrated luminosity collected by the CDF detector, they are able to probe the knowledge of the top quark physics, and to search for signals of physics beyond the Standard Model. In this paper, they present results of measurements of top quark properties, as well as tests for the production mechanism of the top quark. They also describe CDF latest searches for beyond Standard Model couplings of the top quark. Finally, they present the most recent searches for direct production of new particles in the collected data samples.
Quark matter or new particles?
NASA Technical Reports Server (NTRS)
Michel, F. Curtis
1988-01-01
It has been argued that compression of nuclear matter to somewhat higher densities may lead to the formation of stable quark matter. A plausible alternative, which leads to radically new astrophysical scenarios, is that the stability of quark matter simply represents the stability of new particles compounded of quarks. A specific example is the SU(3)-symmetric version of the alpha particle, composed of spin-zero pairs of each of the baryon octet (an 'octet' particle).
NASA Astrophysics Data System (ADS)
Antinori, Federico; Bass, Steffen A.; Bellwied, Rene; Ullrich, Thomas; Velkovska, Julia; Wiedemann, Urs
2005-04-01
Why another conference devoted to ultra-relativistic heavy-ion physics? As we looked around the landscape of the existing international conferences and workshops, we realized that there was not a single one tailored to the people who are most directly involved with the actual research work: students, post-docs, and junior faculty/research scientists. Of course there are schools, but that was not what we had in mind. We wanted a meeting where young researchers could come together to discuss in depth the physics that they are working on without any hindrance. The major conferences have very limited time for discussions which is often shared amongst the most established. This leaves little room for young people to ask their questions and to get the detailed feedback which they deserve and which satisfies their curiosity. A discussion-driven workshop, centering on those without whom there will be no future—that seemed like what was needed. And thus the Hot Quarks workshop was born. The aim of Hot Quarks was to enhance the direct exchange of scientific information among the younger members of the community, from both experiment and theory. Participation was by invitation only in order to emphasize the contributions from junior researchers. This approach makes the workshop unique among the many forums in the field. For young scientists it represented an opportunity for exposure that they would not have had in one of the major conferences. The hope is that this meeting has helped to stimulate the next generation of scientists in our field and, at the same time, strengthened their sense of community. It all came together from 18 24 July 2004, when the 77 participants met at The Inn at Snakedance in the Taos Ski Valley, New Mexico, USA, for the first Hot Quarks workshop. Photograph Participants gather in the sunshine at the foot of the Taos Ski Valley chairlift. By all accounts, Hot Quarks 2004 was a great success. Every participant had the opportunity to present her or
Potamianos, Karolos
2011-12-01
We present the recent results of top-quark physics using up to 6 fb{sup -1} of p{bar p} collisions analyzed by the CDF collaboration. The large number of top quark events analyzed, of the order of several thousands, allows stringent checks of the standard model predictions. Also, the top quark is widely believed to be a window to new physics. We present the latest measurements of top quark intrinsic properties as well as direct searches for new physics in the top sector.
Valence quark spin distribution functions
Nathan Isgur
1998-09-01
The hyperfine interactions of the constituent quark model provide a natural explanation for many nucleon properties, including the {Delta} - N splitting, the charge radius of the neutron, and the observation that the proton's quark distribution function ratio d(x)/u(x) {r_arrow} 0 as x {r_arrow} 1. The hyperfine-perturbed quark model also makes predictions for the nucleon spin-dependent distribution functions. Precision measurements of the resulting asymmetries A{sub 1}{sup p}(x) and A{sub 1}{sup n}(x) in the valence region can test this model and thereby the hypothesis that the valence quark spin distributions are ''normal''.
Eric S. Swanson; Adam P. Szczepaniak
2002-06-07
The relationship of the quark model to the known chiral properties of QCD is a long-standing problem in the interpretation of low energy QCD. In particular, how can the pion be viewed as both a collective Goldstone boson quasiparticle and as a valence quark antiquark bound state? A comparison of the many-body solution of a simplified model of QCD to the constituent quark model demonstrates that the quark model is sufficiently flexible to describe meson hyperfine splitting provided proper renormalization conditions and correct degrees of freedom are employed consistently.
Comparing the drag force on heavy quarks in N=4 super-Yang-Mills theory and QCD
Gubser, Steven S.
2007-12-15
Computations of the drag force on a heavy quark moving through a thermal state of strongly coupled N=4 super-Yang-Mills theory have appeared recently. I compare the strength of this effect between N=4 gauge theory and QCD, using the static force between external quarks to normalize the 't Hooft coupling. Comparing N=4 and QCD at fixed energy density then leads to a relaxation time of roughly 2 fm/c for charm quarks moving through a quark-gluon plasma at T=250 MeV. This estimate should be regarded as preliminary because of the difficulties of comparing two such different theories.
The Discovery of the Top Quark
DOE R&D Accomplishments Database
Sinervo, P.K.
1995-12-01
The top quark and the Higgs boson are the heaviest elementary particles predicted by the standard model. The four lightest quark flavours, the up, down, strange and charm quarks, were well-established by the mid-1970's. The discovery in 1977 of the {Tau} resonances, a new family of massive hadrons, required the introduction of the fifth quark flavour. Experimental and theoretical studies have indicated that this quark also has a heavier partner, the top quark.
Lincoln, Don
2015-05-07
Matter is malleable and can change its properties with temperature. This is most familiar when comparing ice, liquid water and steam, which are all different forms of the same thing. However beyond the usual states of matter, physicists can explore other states, both much colder and hotter. In this video, Fermilab’s Dr. Don Lincoln explains the hottest known state of matter – a state that is so hot that protons and neutrons from the center of atoms can literally melt. This form of matter is called a quark gluon plasma and it is an important research topic being pursued at the LHC.
Uechi, Hiroshi; Uechi, Schun T.
2011-05-06
Density-dependent relations among the saturation properties of symmetric nuclear matter and hyperonic matter, and properties of hadron-(strange) quark stars are shown by applying the conserving nonlinear {sigma}-{omega}-{rho} hadronic mean-field theory. Nonlinear interactions are renormalized self-consistently as effective coupling constants, effective masses, and sources of equations of motion by maintaining thermodynamic consistency to the mean-field approximation. Effective masses and coupling constants at the saturation point of symmetric nuclear matter simultaneously determine the binding energy and saturation properties of hyperonic matter. The coupling constants expected from the hadronic mean-field model and SU(6) quark model for the vector coupling constants are compared by calculating masses of hadron-quark neutron stars. The nonlinear {sigma}-{omega}-{rho} mean-field approximation with vacuum fluctuation corrections and strange quark matter defined by the MIT-bag model were employed to examine properties of hadron-(strange) quark stars. We found that hadron-(strange) quark stars become more stable at high densities compared to pure hadronic and strange quark stars.
Heat transfer coefficients in two-dimensional Yukawa systems (numerical simulations)
NASA Astrophysics Data System (ADS)
Khrustalyov, Yu. V.; Vaulina, O. S.
2013-05-01
New data on heat transfer in two-dimensional Yukawa systems have been obtained. The results of a numerical study of the thermal conductivity for equilibrium systems with parameters close to the conditions of laboratory experiments in dusty plasma are presented. The Green-Kubo relations are used to calculate the heat transfer coefficients. The influence of dissipation (internal friction) on the heat transfer processes in nonideal systems is studied. New approximations are proposed for the thermal conductivity and diffusivity for nonideal dissipative systems. The results obtained are compared with the existing experimental and numerical data.
Numerical simulations of thermal conductivity in dissipative two-dimensional Yukawa systems.
Khrustalyov, Yu V; Vaulina, O S
2012-04-01
Numerical data on the heat transfer constants in two-dimensional Yukawa systems were obtained. Numerical study of the thermal conductivity and diffusivity was carried out for the equilibrium systems with parameters close to conditions of laboratory experiments with dusty plasma. For calculations of heat transfer constants the Green-Kubo formulas were used. The influence of dissipation (friction) on the heat transfer processes in nonideal systems was investigated. The approximation of the coefficient of thermal conductivity is proposed. Comparison of the obtained results to the existing experimental and numerical data is discussed. PMID:22680584
Contribution of plasminos to the shear viscosity of a hot and dense Yukawa-Fermi gas
NASA Astrophysics Data System (ADS)
Sadooghi, N.; Taghinavaz, F.
2016-01-01
Using the standard Green-Kubo formalism, we determine the shear viscosity η of a hot and dense Yukawa-Fermi gas. In particular, we study the effect of particle and plasmino excitations on thermal properties of the fermionic part of the shear viscosity, and explore the effects of thermal corrections to particle masses on bosonic and fermionic shear viscosities, ηb and ηf. It turns out that the effects of plasminos on ηf become negligible with increasing (decreasing) temperature (chemical potential).
Decay of a Yukawa fermion at finite temperature and applications to leptogenesis
Kiessig, Clemens P.; Pluemacher, Michael; Thoma, Markus H.
2010-08-01
We calculate the decay rate of a Yukawa fermion in a thermal bath using finite-temperature cutting rules and effective Green's functions according to the hard thermal loop resummation technique. We apply this result to the decay of a heavy Majorana neutrino in leptogenesis. Compared to the usual approach where thermal masses are inserted into the kinematics of final states, we find that deviations arise through two different leptonic dispersion relations. The decay rate differs from the usual approach by more than 1 order of magnitude in the temperature range which is interesting for the weak washout regime. We discuss how to arrive at consistent finite-temperature treatments of leptogenesis.
Cores in dwarf galaxies from dark matter with a Yukawa potential.
Loeb, Abraham; Weiner, Neal
2011-04-29
We show that cold dark matter particles interacting through a Yukawa potential could naturally explain the recently observed cores in dwarf galaxies without affecting the dynamics of objects with a much larger velocity dispersion, such as clusters of galaxies. The velocity dependence of the associated cross section as well as the possible exothermic nature of the interaction alleviates earlier concerns about strongly interacting dark matter. Dark matter evaporation in low-mass objects might explain the observed deficit of satellite galaxies in the Milky Way halo and have important implications for the first galaxies and reionization. PMID:21635025
S2 like Star Orbits near the Galactic Center in Rn and Yukawa Gravity
NASA Astrophysics Data System (ADS)
Borka, Dusko; Jovanović, Predrag; Jovanović Vesna Borka; Zakharov, Alexander F.
2015-01-01
In this chapter we investigate the possibility to provide theoretical explanation for the observed deviations of S2 star orbit around the Galactic Center using gravitational potentials derived from extended gravity models, but in absence of dark matter. Extended Theories of Gravity are alternative theories of gravitational interaction developed from the exact starting points investigated first by Einstein and Hilbert and aimed from one side to extend the positive results of General Relativity and, on the other hand, to cure its shortcomings. One of the aims of these theories is to explain galactic and extragalactic dynamics without introduction of dark matter. They are based on straightforward generalizations of the Einstein theory where the gravitational action (the Hilbert-Einstein action) is assumed to be linear in the Ricci curvature scalar R. The f(R) gravity is a type of modified gravity which generalizes Einstein's General Relativity, i.e. the simplest case is just the General Relativity. It is actually a family of models, each one defined by a different function of the Ricci scalar. Here, we consider Rn (power-law fourth-order theories of gravity) and Yukawa-like modified gravities in the weak field limit and discuss the constrains on these theories. For that purpose we simulate the orbit of S2 star around the Galactic Center in Rn and Yukawa-like gravity potentials and compare it with New Technology Telescope/Very Large Telescope (NTT/VLT) as well as by Keck telescope observations. Our simulations result in strong constraints on the range of gravity interaction and showed that both Rn and Yukawa gravity could satisfactorily explain the observed orbits of S2 star. However, we concluded that parameters of Rn and Yukawa gravity theories must be very close to those corresponding to the Newtonian limit of the theory. Besides, in contrast to Newtonian gravity, these two modified theories induce orbital precession, even in the case of point-like central mass. The
Vapor-liquid surface tension of strong short-range Yukawa fluid.
Odriozola, G; Bárcenas, M; Orea, P
2011-04-21
The thermodynamic properties of strong short-range attractive Yukawa fluids, κ = 10, 9, 8, and 7, are determined by combining the slab technique with the standard and the replica exchange Monte Carlo (REMC) methods. A good agreement was found among the coexistence curves of these systems calculated by REMC and those previously reported in the literature. However, REMC allows exploring the coexistence at lower temperatures, where dynamics turns glassy. To obtain the surface tension we employed, for both methods, a procedure that yields the pressure tensor components for discontinuous potentials. The surface tension results obtained by the standard MC and REMC techniques are in good agreement. PMID:21513403
Neutrino mass matrices from two zero 3 × 2 Yukawa textures and minimal d = 5 entries
NASA Astrophysics Data System (ADS)
Achelashvili, Avtandil; Tavartkiladze, Zurab
2016-05-01
Aiming to relate leptonic CP violating phase δ to the cosmological CP asymmetry, we study the extension of MSSM by two quasi-degenerate (strictly degenerate at tree level) right-handed neutrinos and consider all possible two texture zero 3 × 2 Yukawa matrices plus one ΔL = 2 dimension five (d = 5) operator contributing to the light neutrino mass matrix. We classify all experimentally viable mass matrices, leading to several predictions, and analytically derive predictive relations. We also relate the CP violating δ phase to the CP phase of the thermal leptogenesis.
NASA Astrophysics Data System (ADS)
Kyae, Bumseok
2009-07-01
We present a supersymmetric model with two dark matter (DM) components explaining the galactic positron excess observed by PAMELA/HEAT and ATIC/PPB-BETS: One is the conventional (bino-like) lightest supersymmetric particle (LSP) χ, and the other is a TeV scale meta-stable neutral singlet ND, which is a Dirac fermion (N,Nc). In this model, ND decays dominantly into χe+e- through an R parity preserving dimension 6 operator with the life time τN ~ 1026 sec. We introduce a pair of vector-like superheavy SU(2) lepton doublets (L,Lc) and lepton singlets (E,Ec). The dimension 6 operator leading to the ND decay is generated from the leptophilic Yukawa interactions by W ⊃ NecE+LhdEc+m3/2l1Lc with the dimensionless couplings of order unity, and the gauge interaction by Script L ⊃ (2)1/2g'tilde ec*ecχ+h.c. The superheavy masses of the vector-like leptons (ML,ME ~ 1016 GeV) are responsible for the longevity of ND. The low energy field spectrum in this model is just the MSSM fields and ND. Even for the case that the portion of ND is much smaller than that of χ in the total DM density [Script O(10-10) lesssim nND/nχ], the observed positron excess can be explained by adopting relatively lighter masses of the vector-like leptons (1013 GeV lesssim ML,E lesssim 1016 GeV). The smallness of the electron mass is also explained. This model is easily embedded in the flipped SU(5) grand unification, which is a leptophilic unified theory.
Search for W-prime Boson Resonances Decaying to a Top Quark and a Bottom Quark
Abazov, V.M.; Abbott, B.; Abolins, M.; Acharya, B.S.; Adams, M.; Adams, T.; Aguilo, E.; Ahn, S.H.; Ahsan, M.; Alexeev, G.D.; Alkhazov, Georgiy; /Dubna, JINR /St. Petersburg, INP /Northeastern U.
2008-03-01
We search for the production of a heavy W{prime} gauge boson that decays to third generation quarks in 0.9 fb{sup -1} of p{bar p} collisions at {radical}s = 1.96 TeV, collected with the D0 detector at the Fermilab Tevatron collider. We find no significant excess in the final-state invariant mass distribution and set upper limits on the production cross section times branching fraction. For a left-handed W{prime} boson with SM couplings, we set a lower mass limit of 731 GeV. For right-handed W{prime} bosons, we set lower mass limits of 739 GeV if the W{prime} boson decays to both leptons and quarks and 768 GeV if the W{prime} boson decays only to quarks. We also set limits on the coupling of the W{prime} boson to fermions as a function of its mass.
Thomson, Evelyn J.
2006-07-11
Experimental measurements of the properties of the top quark have improved and will continue to improve significantly, with the excellent operation of the CDF and D0 experiments and the Tevatron pp-bar collider at the Fermi National Accelerator Laboratory. All of the final state experimental signatures from top quark production and decay are being analysed to test if this most massive quark is sensitive to new physics beyond the standard model. So far, observations are consistent with the standard model. New techniques have dramatically improved the precision of the top quark mass measurement to 1.7% and set the stage for a sub-1% measurement by 2008. This improved knowledge of the top quark mass sharpens the standard model prediction for the mass of the undiscovered Higgs boson, with implications for Higgs studies at the future LHC and ILC.
Thomson, Evelyn J.; /Pennsylvania U.
2006-02-01
Experimental measurements of the properties of the top quark have improved and will continue to improve significantly, with the excellent operation of the CDF and D0 experiments and the Tevatron p{bar p} collider at the Fermi National Accelerator Laboratory. All of the final state experimental signatures from top quark production and decay are being analyzed to test if this most massive quark is sensitive to new physics beyond the standard model. So far, observations are consistent with the standard model. New techniques have dramatically improved the precision of the top quark mass measurement to 1.7% and set the stage for a sub-1% measurement by 2008. This improved knowledge of the top quark mass sharpens the standard model prediction for the mass of the undiscovered Higgs boson, with implications for Higgs studies at the future LHC and ILC.
Phenomenology of heavy quark production
Berger, E.L.
1989-01-01
A review is presented of heavy quark production in {bar p}p, {pi}{sup -}p, and pp interactions at fixed target and collider energies. Calculations of total cross sections and of single quark inclusive differential cross sections d{sup 2}{omega}/dk{sub T}dy are described including contributions through next-to-leading order in QCD perturbation theory. Comparisons with available data on charm and bottom quark production show good agreement for reasonable values of the charm and bottom quark masses and other parameters. Predictions and open issues in the interpretation of results are summarized. A brief discussion is presented of signatures, backgrounds, and expected event rates for top quark production. 24 refs., 6 figs.
Schramm, D.N. |; Fields, B.; Thomas, D.
1992-01-01
The possible implications of the quark-hadron transition for cosmology are explored. Possible surviving signatures are discussed. In particular, the possibility of generating a dark matter candidate such as strange nuggets or planetary mass black holes is noted. Much discussion is devoted to the possible role of the transition for cosmological nucleosynthesis. It is emphasized that even an optimized first order phase transition will not significantly alter the nucleosynthesis constraints on the cosmological baryon density nor on neutrino counting. However, it is noted that Be and B observations in old stars may eventually be able to be a signature of a cosmologically significant quark-hadron transition. It is pointed out that the critical point in this regard is whether the observed B/Be ratio can be produced by spallation processes or requires cosmological input. Spallation cannot produce a B/Be ratio below 7.6. A supporting signature would be Be and B ratios to oxygen that greatly exceed galactic values. At present, all data is still consistent with a spallagenic origin.
L. Cerrito
2004-07-16
Preliminary results on the measurement of the top quark mass at the Tevatron Collider are presented. In the dilepton decay channel, the CDF Collaboration measures m{sub t} = 175.0{sub -16.9}{sup +17.4}(stat.){+-}8.4(syst.) GeV/c{sup 2}, using a sample of {approx} 126 pb{sup -1} of proton-antiproton collision data at {radical}s = 1.96 TeV (Run II). In the lepton plus jets channel, the CDF Collaboration measures 177.5{sub -9.4}{sup +12.7}(stat.) {+-} 7.1(syst.) GeV/c{sup 2}, using a sample of {approx} 102 pb{sup -1} at {radical}s = 1.96 TeV. The D0 Collaboration has newly applied a likelihood technique to improve the analysis of {approx} 125 pb{sup -1} of proton-antiproton collisions at {radical}s = 1.8 TeV (Run I), with the result: m{sub t} = 180.1 {+-} 3.6(stat.) {+-}3.9(syst.) GeV/c{sup 2}. The latter is combined with all the measurements based on the data collected in Run I to yield the most recent and comprehensive experimental determination of the top quark mass: m{sub t} = 178.0 {+-} 2.7(stat.) {+-} 3.3(syst.) GeV/c{sup 2}.
Diphoton excess and running couplings
NASA Astrophysics Data System (ADS)
Bae, Kyu Jung; Endo, Motoi; Hamaguchi, Koichi; Moroi, Takeo
2016-06-01
The recently observed diphoton excess at the LHC may suggest the existence of a singlet (pseudo-)scalar particle with a mass of 750 GeV which couples to gluons and photons. Assuming that the couplings to gluons and photons originate from loops of fermions and/or scalars charged under the Standard Model gauge groups, we show that there is a model-independent upper bound on the cross section σ (pp → S → γγ) as a function of the cutoff scale Λ and masses of the fermions and scalars in the loop. Such a bound comes from the fact that the contribution of each particle to the diphoton event amplitude is proportional to its contribution to the one-loop β functions of the gauge couplings. We also investigate the perturbativity of running Yukawa couplings in models with fermion loops, and show the upper bounds on σ (pp → S → γγ) for explicit models.
STRANGE GOINGS ON IN QUARK MATTER.
SCHAFER,T.
2001-06-05
We review recent work on how the superfluid state of three flavor quark matter is affected by non-zero quark masses and chemical potentials. The study of hadronic matter at high baryon density has recently attracted a lot of interest. At zero baryon density chiral symmetry is broken by a quark-anti-quark condensate. At high density condensation in the quark-anti-quark channel is suppressed. Instead, attractive interactions in the color anti-symmetric quark-quark channel favor the formation of diquark condensates. As a consequence, cold dense quark matter is expected to be a color superconductor. The symmetry breaking pattern depends on the density, the number of quark flavors, and their masses. A particularly symmetric phase is the color-flavor-locked (CFL) phase of three flavor quark matter. This phase is believed to be the true ground state of ordinary matter at very large density.
NASA Astrophysics Data System (ADS)
Alam, Jan-e.; Chattopadhyay, Subhasis; Nayak, Tapan; Sinha, Bikash; Viyogi, Yogendra P.
2008-10-01
Quark Matter 2008—the 20th International Conference on Ultra-Relativistic Nucleus-Nucleus Collisions was held in Jaipur, the Pink City of India, from 4-10 February, 2008. Organizing Quark Matter 2008 in India itself indicates the international recognition of the Indian contribution to the field of heavy-ion physics, which was initiated and nurtured by Bikash Sinha, Chair of the conference. The conference was inaugurated by the Honourable Chief Minister of Rajasthan, Smt. Vasundhara Raje followed by the key note address by Professor Carlo Rubbia. The scientific programme started with the theoretical overview, `SPS to RHIC and onwards to LHC' by Larry McLerran followed by several theoretical and experimental overview talks on the ongoing experiments at SPS and RHIC. The future experiments at the LHC, FAIR and J-PARC, along with the theoretical predictions, were discussed in great depth. Lattice QCD predictions on the nature of the phase transition and critical point were vigorously debated during several plenary and parallel session presentations. The conference was enriched by the presence of an unprecedented number of participants; about 600 participants representing 31 countries across the globe. This issue contains papers based on plenary talks and oral presentations presented at the conference. Besides invited and contributed talks, there were also a large number of poster presentations. Members of the International Advisory Committee played a pivotal role in the selection of speakers, both for plenary and parallel session talks. The contributions of the Organizing Committee in all aspects, from helping to prepare the academic programme down to arranging local hospitality, were much appreciated. We thank the members of both the committees for making Quark Matter 2008 a very effective and interesting platform for scientific deliberations. Quark Matter 2008 was financially supported by: Air Liquide (New Delhi) Board of Research Nuclear Sciences (Mumbai) Bose
NN interaction from bag-model quark interchange
NASA Astrophysics Data System (ADS)
Bakker, B. L. G.; Bozoian, M.; Maslow, J. N.; Weber, H. J.
1982-03-01
A partial-wave helicity-state analysis of elastic nucleon-nuclon scattering is carried out in momentum space. Its basis is a one- and two-boson exchange amplitude from a bag-model quark interchange mechanism. The resulting phase shifts and bound-state parameters of the deuteron are compared with other meson theoretic potentials and data up to laboratory energies of ~350 MeV. NUCLEAR REACTIONS NN elastic scattering, Elab<=350 MeV. Coupling constants, form factors of renormalized OBE calculated from bag-model quark interchange. Phase shifts, deuteron parameters calculated from covariant partial-wave analysis.
NASA Astrophysics Data System (ADS)
Cao, Shanshan; Luo, Tan; Qin, Guang-You; Wang, Xin-Nian
2016-07-01
A linearized Boltzmann transport (LBT) model coupled with hydrodynamical background is established to describe the evolution of jet shower partons and medium excitations in high energy heavy-ion collisions. We extend the LBT model to include both elastic and inelastic processes for light and heavy partons in the quark-gluon plasma. A hybrid model of fragmentation and coalescence is developed for the hadronization of heavy quarks. Within this framework, we investigate how heavy flavor observables depend on various ingredients, such as different energy loss and hadronization mechanisms, the momentum and temperature dependences of the transport coefficients, and the radial flow of the expanding fireball. Our model calculations show good descriptions of the D meson suppression and elliptic flow observed at the Larege Hadron Collider and the Relativistic Heavy-Ion Collider. The prediction for the Pb-Pb collisions at √{sN N}=5.02 TeV is provided.
Stability of the celestial body orbits under the influence of Yukawa potential
NASA Astrophysics Data System (ADS)
Pricopi, D.
2016-08-01
The famous Yukawa-type potential was very often used for explaining a great variety of recent observed astronomical phenomena which range from the solar-system scale to cosmological distances. In this paper we tackle the two-body problem in the Yukawa post-Newtonian field from the particular standpoint of orbits stability. Starting from the equations of motion and first integrals written in standard polar coordinates, we apply McGehee-type transformations of the second kind. Then we depict the phase-space structure considering the foliations by the energy constant and the angular momentum constant. Various stability regions are found for each case. The problem presents interesting features, such as: cases when all trajectories (maybe except for a separatrix) are stable; cases when there exist totally different types of orbits, both stable and unstable, for the same values of the energy constant and the angular momentum constant; the existence of stable motion for nonnegative energy levels; positive Lebesgue measure for initial data leading to quasiperiodic and noncircular periodic orbits; the key role of the angular momentum.
SOSpin, a C++ library for Yukawa decomposition in SO(2 N) models
NASA Astrophysics Data System (ADS)
Cardoso, Nuno; Emmanuel-Costa, David; Gonçalves, Nuno; Simões, C.
2016-06-01
We present in this paper the SOSpin library, which calculates an analytic decomposition of the Yukawa interactions invariant under SO(2N) in terms of an SU(N) basis. We make use of the oscillator expansion formalism, where the SO(2N) spinor representations are expressed in terms of creation and annihilation operators of a Grassmann algebra acting on a vacuum state. These noncommutative operators and their products are simulated in SOSpin through the implementation of doubly-linked-list data structures. These data structures were determinant to achieve a higher performance in the simplification of large products of creation and annihilation operators. We illustrate the use of our library with complete examples of how to decompose Yukawa terms invariant under SO(2N) in terms of SU(N) degrees of freedom for N=2N=2 and 5. We further demonstrate, with an example for SO(4), that higher dimensional field-operator terms can also be processed with our library. Finally, we describe the functions available in SOSpin that are made to simplify the writing of spinors and their interactions specifically for SO(10) models.
Top quark properties and single top at CMS
NASA Astrophysics Data System (ADS)
Skovpenon, K.; CMS Collaboration
2016-07-01
Measurements of top-quark properties as well as single top-quark production are presented, obtained from the CMS data collected in 2011 and 2012 at centre-of-mass energies of 7 and 8TeV. The results include measurements of the top pair charge asymmetry, the W helicity in top decays, the t bar{{t}} spin correlation and the search for anomalous couplings. The cross sections for the electroweak production of single top quarks in the t-channel and in association with W-bosons are measured and the results are used to place constraints on the CKM matrix element Vtb. In the t-channel the ratio of top and antitop production cross sections is determined and compared with predictions from different parton density distribution functions. The results are compared with predictions from the standard model as well as new physics models.
Landau levels of cold dense quark matter in a strong magnetic field
NASA Astrophysics Data System (ADS)
Wen, Xin-Jian; Liang, Jun-Jun
2016-07-01
The occupied Landau levels of strange quark matter are investigated in the framework of the SU(3) NJL model with a conventional coupling and a magnetic-field dependent coupling respectively. At lower density, the Landau levels are mainly dominated by u and d quarks. Threshold values of the chemical potential for the s quark onset are shown in the μ -B plane. The magnetic-field-dependent running coupling can broaden the region of three-flavor matter by decreasing the dynamical masses of s quarks. Before the onset of s quarks, the Landau level number of light quarks is directly dependent on the magnetic field strength B by a simple inverse proportional relation ki ,max≈Bi0/B with Bd0=5 ×1 019 G , which is approximately 2 times Bu0 of u quarks at a common chemical potential. When the magnetic field increases up to Bd0, almost all three flavors are lying in the lowest Landau level.
Menzione, A.
1995-10-01
Most of the material presented in this report, comes from contributions to the parallel session PL20 of this conference. We summarise the experimental results of direct production of Top quarks, coming from the CDF and C0 Collaborations at Fermilab, and compare these results to what one expects within current theoretical understanding. Particular attention is given to new results such as all hadronic modes of t{bar t} decay. As far as the mass is concerned, a comparison is made with precision measurements of related quantities, coming from LEP and other experiments. An attempt is made to look at the medium-term future and understand which variables and with what accuracy one can measure them with increased integrated luminosity.
Melting hadrons, boiling quarks
NASA Astrophysics Data System (ADS)
Rafelski, Johann
2015-09-01
In the context of the Hagedorn temperature half-centenary I describe our understanding of the hot phases of hadronic matter both below and above the Hagedorn temperature. The first part of the review addresses many frequently posed questions about properties of hadronic matter in different phases, phase transition and the exploration of quark-gluon plasma (QGP). The historical context of the discovery of QGP is shown and the role of strangeness and strange antibaryon signature of QGP illustrated. In the second part I discuss the corresponding theoretical ideas and show how experimental results can be used to describe the properties of QGP at hadronization. The material of this review is complemented by two early and unpublished reports containing the prediction of the different forms of hadron matter, and of the formation of QGP in relativistic heavy ion collisions, including the discussion of strangeness, and in particular strange antibaryon signature of QGP.
Top quark and Higgs boson masses from wormhole physics
Harris, B.A.; Joshi, G.C. )
1994-11-01
We bring together quantum field theory on [ital S][sub 4] with the Coleman wormhole hypothesis, which imposes constraints on terms in the gravitational Lagrangian. In particular, we investigate the effect of matter fields on the trace anomaly, which is related to the (curvature)[sup 2] terms, by the use of the renormalization group equations. We consider a toy model of a nonconformally coupled Higgs boson to a single top'' quark. By numerically solving the renormalization group equations for the couplings of the model, we can find preferred values of the particle masses for various values of the bare nonconformal coupling. By making the [ital ad] [ital hoc] assumption that the tree-level, Higgs boson treace anomaly vanishes on shell, a unique prediction can be made within this model for the masses of both the Higgs boson and the top quark.
Bottom quark mass from {Upsilon} mesons
Hoang, A.H.
1999-01-01
The bottom quark pole mass M{sub b} is determined using a sum rule which relates the masses and the electronic decay widths of the {Upsilon} mesons to large {ital n} moments of the vacuum polarization function calculated from nonrelativistic quantum chromodynamics. The complete set of next-to-next-to-leading order [i.e., O({alpha}{sub s}{sup 2},{alpha}{sub s}v,v{sup 2}) where v is the bottom quark c.m. velocity] corrections is calculated and leads to a considerable reduction of theoretical uncertainties compared to a pure next-to-leading order analysis. However, the theoretical uncertainties remain much larger than the experimental ones. For a two parameter fit for M{sub b}, and the strong
Quantifying zigzag motion of quarks
Antonov, D.; Ribeiro, J. E. F. T.
2010-03-01
The quark condensate is calculated in terms of the effective string tension and the constituent quark mass. For 3 colors and 2 light flavors, the constituent mass is bounded from below by the value of 460 MeV. This value is only accessible when the string tension decreases linearly with the Schwinger proper time. For this reason, the Hausdorff dimension of a light-quark trajectory is equal to 4, indicating that these trajectories are similar to branched polymers, which can describe a weak first-order deconfinement phase transition in SU(3) Yang-Mills theory. Using this indication, we develop a gluon-chain model based on such trajectories.
Moed, Shulamit
2010-02-10
The large data samples of top quark candidate events collected at the Tevatron CDF II experiment allow for a variety of measurements to analyze the production of the top quark. This article discusses recent results of top quark production at CDF presented at the SUSY09 conference, including updates to the top pair production cross section, forward-backward asymmetry in tt-bar production, single top search, search for top resonances and a search for heavy top. The discussed measurements utilize up to 3.2 fb{sup -1} of integrated luminosity collected at CDF.
Moed, Shulamit; /Harvard U.
2010-01-01
The large data samples of top quark candidate events collected at the Tevatron CDF II experiment allow for a variety of measurements to analyze the production of the top quark. This article discusses recent results of top quark production at CDF presented at the SUSY09 conference, including updates to the top pair production cross section, forward-backward asymmetry in t{bar t} production, single top search, search for top resonances and a search for heavy top. The discussed measurements utilize up to 3.2 fb{sup -1} of integrated luminosity collected at CDF.
Top quark studies at hadron colliders
Sinervo, P.K.; CDF Collaboration
1996-08-01
The techniques used to study top quarks at hadron colliders are presented. The analyses that discovered the top quark are described, with emphasis on the techniques used to tag {ital b} quark jets in candidate events. The most recent measurements of top quark properties by the CDF and D{null} collaborations are reviewed, including the top quark cross section, mass, branching fractions and production properties. Future top quark studies at hadron colliders are discussed, and predictions for event yields and uncertainties in the measurements of top quark properties are presented.
Heavy quarks in the jet calculus
Jones, L.M.
1983-07-01
In this paper we explore a method for treating heavy quarks such as c and b quarks within the jet calculus. These quarks are differentiated from the more common u, d, and s quarks by the requirement that the gluons never branch into heavy-quark pairs during the jet development. We compute and discuss the charmed-quark ''propagators''; the x distribution of colorless clusters containing a charmed quark, a noncharmed antiquark, and gluons; and the mass distribution of the parent partons giving rise to these colorless clusters.
Top quark studies at hadron colliders
Sinervo, P.K.
1997-01-01
The techniques used to study top quarks at hadron colliders are presented. The analyses that discovered the top quark are described, with emphasis on the techniques used to tag b quark jets in candidate events. The most recent measurements of top quark properties by the CDF and DO Collaborations are reviewed, including the top quark cross section, mass, branching fractions, and production properties. Future top quark studies at hadron colliders are discussed, and predictions for event yields and uncertainties in the measurements of top quark properties are presented.
Wicke, Daniel; /Wuppertal U., Dept. Math.
2009-08-01
The aim of particle physics is the understanding of elementary particles and their interactions. The current theory of elementary particle physics, the Standard Model, contains twelve different types of fermions which (neglecting gravity) interact through the gauge bosons of three forces. In addition a scalar particle, the Higgs boson, is needed for theoretical consistency. These few building blocks explain all experimental results found in the context of particle physics, so far. Nevertheless, it is believed that the Standard Model is only an approximation to a more complete theory. First of all the fourth known force, gravity, has withstood all attempts to be included until now. Furthermore, the Standard Model describes several features of the elementary particles like the existence of three families of fermions or the quantisation of charges, but does not explain these properties from underlying principles. Finally, the lightness of the Higgs boson needed to explain the symmetry breaking is difficult to maintain in the presence of expected corrections from gravity at high scales. This is the so called hierarchy problem. In addition astrophysical results indicate that the universe consists only to a very small fraction of matter described by the Standard Model. Large fractions of dark energy and dark matter are needed to describe the observations. Both do not have any correspondence in the Standard Model. Also the very small asymmetry between matter and anti-matter that results in the observed universe built of matter (and not of anti-matter) cannot be explained until now. It is thus an important task of experimental particle physics to test the predictions of the Standard Model to the best possible accuracy and to search for deviations pointing to necessary extensions or modifications of our current theoretical understanding. The top quark was predicted to exist by the Standard Model as the partner of the bottom quark. It was first observed in 1995 by the
Off-forward quark-quark correlation function
Casanova, Sabrina
2006-09-01
The properties of the nonforward quark-quark correlation function are examined. We derive constraints on the correlation function from the transformation properties of the fundamental fields of QCD occurring in its definition. We further develop a method to construct an Ansatz for this correlator. We present the complete leading order set of generalized parton distributions in terms of the amplitudes of the Ansatz. Finally we conclude that the number of independent generalized parton helicity changing distributions is four.
NASA Astrophysics Data System (ADS)
Alemany, M. M. G.; Rey, C.; Gallego, L. J.
1996-11-01
We present a molecular dynamics study of the collective correlation functions of a hard-core system with an attractive Yukawa tail, for various thermodynamic states in the fluid and liquid regions of the phase diagram. The results are compared with available information for hard spheres. The small-q behavior of the intermediate scattering functions indicates the propagation of sound waves, i.e., phononlike collective excitations, in the hard-core Yukawa system. The upper limit of q for these collective modes is practically independent of the thermodynamic state. The computed transverse current correlation functions show that at liquid densities the hard-core Yukawa system is able to sustain shear wave propagation above a critical q; the upper limit of q for sound waves and the lower limit for shear waves nearly coincide. All of these features are qualitatively similar to those found for hard spheres. However, there are significant quantitative differences, which reflect the influence of the attractive Yukawa tail on the dynamical behavior of the system.
Back reaction effects on the dynamics of heavy probes in heavy quark cloud
NASA Astrophysics Data System (ADS)
Chakrabortty, Shankhadeep; Dey, Tanay K.
2016-05-01
We holographically study the effect of back reaction on the hydrodynamical properties of {N}=4 strongly coupled super Yang-Mills (SYM) thermal plasma. The back reaction we consider arises from the presence of static heavy quarks uniformly distributed over {N}=4 SYM plasma. In order to study the hydrodynamical properties, we use heavy quark as well as heavy quark-antiquark bound state as probes and compute the jet quenching parameter, screening length and binding energy. We also consider the rotational dynamics of heavy probe quark in the back-reacted plasma and analyse associated energy loss. We observe that the presence of back reaction enhances the energy-loss in the thermal plasma. Finally, we show that there is no effect of angular drag on the rotational motion of quark-antiquark bound state probing the back reacted thermal plasma.
Carrillo Moreno, Salvador; Vazquez Valencia, Elsa Fabiola
2006-09-25
This is a brief summary about the development of the charm quark physics in the area of experimental physics. The summary is centered in what is done by mexican physicists, particularly in the E791 and the FOCUS Experiment at FERMILAB. FOCUS (or E831) was designed to detect states of matter combining one or more charm quarks with light quarks (strange, up, down). The experiment created 10 times as many such particles as in previous experiments and investigated several topics on charm physics including high precision studies of charm semileptonic decays, studies of hadronic charm decays (branching ratios and Daltiz analyses), lifetime measurements of all charm particles, searches for mixing, CP/CPT violation, rare and forbidden decays, spectroscopy of excited charm mesons and baryons, charm production asymmetry measurements, light quark diffractive studies, QCD studies using charm pair events and searches for and upper limits on: charm pentaquarks, double charm baryons, DSJ(2632)
NASA Astrophysics Data System (ADS)
Kobayashi, Makoto
2014-11-01
After a short review of the activities of Shoichi Sakata and his group, how the six-quark model explains CP violation is described. Experimental verification of the model at the B-factories is also briefly discussed.
Sohrabi Mahboub, Mahdi; Farrokhpour, Hossein
2016-06-15
In this paper, we present the results of an extensive study on a novel approach to the molecular modeling of pure ionic liquids (ILs) that incorporates the perturbed thermodynamic linear Yukawa isotherm regularity (LYIR), which is derived based on an effective nearest neighboring pair attractive interaction of the Yukawa potential. The LYIR was used to model the densities of ILs up to high pressures (35 MPa) and in the temperature range 293.15 to 393.15 K. To use the LYIR for ILs, a simple molecular model was proposed to describe their molecular structure, in which they were considered as a liquid consisting of the ion pairs moving together in the fluid, and each ion pair was assumed to be a one-center spherical united atom. The ILs under consideration contained one of the IL cations [C2mim](+), [C4mim](+), [C7mim](+), [C8mim](+), [C3mpy](+), [C3mpip](+), [C3mpyr](+) or [C4mpyr](+), and one of the IL anions [BF4](-), [C(CN)3](-), [CF3SO4](-) or [NTf2](-). The reliability and physical significance of the parameters as well as the proposed molecular model were tested by calculating the densities of pure imidazolium-, pyridinium-, piperidinium- and pyrrolidimium-based ILs. The results showed that the LYIR can be used to predict and reproduce the density of ILs in good agreement with the experimental data. In addition, the LYIR enabled us to determine the physical quantities, such as an effective Yukawa screening length, λ eff, the product of the effective energy well depth and the effective coordination number, (ε eff/k)z eff, the contribution of the non-reference thermal pressure and also the influence of the anionic and cationic structure on the λ eff parameter. The standard deviation of the IL densities predicted in this work is lower than those calculated by the one other important equation of state reported in the literature. PMID:27157142
NASA Astrophysics Data System (ADS)
Sohrabi Mahboub, Mahdi; Farrokhpour, Hossein
2016-06-01
In this paper, we present the results of an extensive study on a novel approach to the molecular modeling of pure ionic liquids (ILs) that incorporates the perturbed thermodynamic linear Yukawa isotherm regularity (LYIR), which is derived based on an effective nearest neighboring pair attractive interaction of the Yukawa potential. The LYIR was used to model the densities of ILs up to high pressures (35 MPa) and in the temperature range 293.15 to 393.15 K. To use the LYIR for ILs, a simple molecular model was proposed to describe their molecular structure, in which they were considered as a liquid consisting of the ion pairs moving together in the fluid, and each ion pair was assumed to be a one-center spherical united atom. The ILs under consideration contained one of the IL cations [C2mim]+, [C4mim]+, [C7mim]+, [C8mim]+, [C3mpy]+, [C3mpip]+, [C3mpyr]+ or [C4mpyr]+, and one of the IL anions [BF4]‑, [C(CN)3]‑, [CF3SO4]‑ or [NTf2]‑. The reliability and physical significance of the parameters as well as the proposed molecular model were tested by calculating the densities of pure imidazolium-, pyridinium-, piperidinium- and pyrrolidimium-based ILs. The results showed that the LYIR can be used to predict and reproduce the density of ILs in good agreement with the experimental data. In addition, the LYIR enabled us to determine the physical quantities, such as an effective Yukawa screening length, λ eff, the product of the effective energy well depth and the effective coordination number, (ε eff/k)z eff, the contribution of the non-reference thermal pressure and also the influence of the anionic and cationic structure on the λ eff parameter. The standard deviation of the IL densities predicted in this work is lower than those calculated by the one other important equation of state reported in the literature.
Stability of Quark Star Models
NASA Astrophysics Data System (ADS)
M., Azam; S. A., Mardan; M. A., Rehman
2016-05-01
In this paper, we investigate the stability of quark stars with four different types of inner matter configurations; isotropic, charged isotropic, anisotropic and charged anisotropic by using the concept of cracking. For this purpose, we have applied local density perturbations technique to the hydrostatic equilibrium equation as well as on physical parameters involved in the model. We conclude that quark stars become potentially unstable when inner matter configuration is changed and electromagnetic field is applied.
Unexpected manifestation of quark condensation
Zinovjev, G. M.; Molodtsov, S. V.
2015-05-15
A comparative analysis of some quark ensembles governed by a four-fermion interaction is performed. Arguments in support of the statement that the presence of a gas-liquid phase transition is a feature peculiar to them are adduced. The instability of small quark droplets is discussed and is attributed to the formation of a chiral soliton. The stability of baryon matter is due to a mixed phase of the vacuum and baryon matter.
Heavy quark production and spectroscopy
Appel, J.A.
1993-11-01
This review covers many new experimental results on heavy flavor production and spectroscopy. It also shows some of the increasingly improved theoretical understanding of results in light of basic perturbative QCD and heavy quark symmetry. At the same time, there are some remaining discrepancies among experiments as well as significant missing information on some of the anticipated lowest lying heavy quark states. Most interesting, perhaps, are some clearly measured production effects awaiting full explanation.
Heavy quark diffusion with relativistic Langevin dynamics in the quark-gluon fluid
Akamatsu, Yukinao; Hatsuda, Tetsuo; Hirano, Tetsufumi
2009-05-15
The relativistic diffusion process of heavy quarks is formulated on the basis of the relativistic Langevin equation in Ito discretization scheme. The drag force inside the quark-gluon plasma (QGP) is parametrized according to the formula for the strongly coupled plasma obtained by the anti-de-Sitter space/conformal field theory (AdS/CFT) correspondence. The diffusion dynamics of charm and bottom quarks in QGP is described by combining the Langevin simulation under the background matter described by the relativistic hydrodynamics. Theoretical calculations of the nuclear modification factor R{sub AA} and the elliptic flow v{sub 2} for the single electrons from the charm and bottom decays are compared with the experimental data from the relativistic heavy-ion collisions. The R{sub AA} for electrons with large transverse momentum (p{sub T}>3 GeV) indicates that the drag force from the QGP is as strong as the AdS/CFT prediction.
The phase diagram in the SU(3) Nambu-Jona-Lasinio model with 't Hooft and eight-quark interactions
Moreira, J.; Hiller, B.; Blin, A. H.; Osipov, A. A.
2010-08-05
It is shown that the endpoint of the first order transition line which merges into a crossover regime in the phase diagram of the Nambu--Jona-Lasinio model, extended to include the six-quark 't Hooft and eight-quark interaction Lagrangians, is pushed towards vanishing chemical potential and higher temperatures with increasing strength of the OZI-violating eight-quark interactions. We clarify a connection between the location of the endpoint in the phase diagram and the mechanism of chiral symmetry breaking at the quark level. Constraints on the coupling strengths based on groundstate stability and physical considerations are explained.
HIGGS BOSON PRODUCTION IN ASSOCIATION WITH BOTTOM QUARKS.
DAWSON, S.; CAMPBELL, J.; DITTMAIER, S.; JACKSON, C.; KRAMER, M.; MALTONI, F.; ET AL.
2003-05-26
In the Standard Model, the coupling of the Higgs boson to b quarks is weak, leading to small cross sections for producing a Higgs boson in association with b quarks. However, Higgs bosons with enhanced couplings to b quarks, such as occur in supersymmetric models for large values of tan {beta}, will be copiously produced at both the Tevatron and the LHC in association with b quarks which will be an important discovery channel. We investigate the connections between the production channels, bg {yields} bh and gg {yields} b{bar b}h, at next-to-leading order (NLO) in perturbative QCD and present results for the case with two high-p{sub T} b jets and with one high-p{sub T} b jet at both the Tevatron and the LHC. Finally, the total cross sections without cuts are compared between gg {yields} b{bar b}h at NLO and b{bar b} {yields} h at NNLO.
Inverse magnetic catalysis from the properties of the QCD coupling in a magnetic field
NASA Astrophysics Data System (ADS)
Ayala, Alejandro; Dominguez, C. A.; Hernández, L. A.; Loewe, M.; Zamora, R.
2016-08-01
We compute the vacuum one-loop quark-gluon vertex correction at zero temperature in the presence of a magnetic field. From the vertex function we extract the effective quark-gluon coupling and show that it grows with increasing magnetic field strength. The effect is due to a subtle competition between the color charge associated to gluons and the color charge associated to quarks, the former being larger than the latter. In contrast, at high temperature the effective thermo-magnetic coupling results exclusively from the contribution of the color charge associated to quarks. This produces a decrease of the coupling with increasing field strength. We interpret the results in terms of a geometrical effect whereby the magnetic field induces, on average, a closer distance between the (electrically charged) quarks and antiquarks. At high temperature, since the effective coupling is proportional only to the color charge associated to quarks, such proximity with increasing field strength makes the effective coupling decrease due to asymptotic freedom. In turn, this leads to a decreasing quark condensate. In contrast, at zero temperature both the effective strong coupling and the quark condensate increase with increasing magnetic field. This is due to the color charge associated to gluons dominating over that associated to quarks, with both having the opposite sign. Thus, the gluons induce a kind of screening of the quark color charge, in spite of the quark-antiquark proximity. We discuss the implications for the inverse magnetic catalysis phenomenon.
Mixed Axion/Axino Dark Matter in mSUGRA and Yukawa-unified SUSY
Ann Summy, Heaya
2010-02-10
Axion/axino dark matter (DM) is explored in the minimal supergravity (mSUGRA) and Yukawa-unified supersymmetric grand-unified theory (SUSY GUT) models with surprising results. For this type of scenario, relic DM abundance has three components: i.) cold axions, ii.) warm axinos from neutralino decay, and iii.) cold or warm thermally produced axinos. Reheat temperatures T{sub R} exceeding 10{sup 6} GeV are required in order to solve the gravitino/Big Bang Nucleosynthesis (BBN) problem while also allowing for baryogensis via non-thermal leptogenesis. In order to attain high enough reheat temperatures, we also need high values of the Peccei-Quinn (PQ) breaking scale f{sub a} on the order 10{sup 11}-10{sup 12} GeV.
Two-Yukawa fluid at a hard wall: Field theory treatment
Kravtsiv, I.; Patsahan, T.; Holovko, M.; Caprio, D. di
2015-05-21
We apply a field-theoretical approach to study the structure and thermodynamics of a two-Yukawa fluid confined by a hard wall. We derive mean field equations allowing for numerical evaluation of the density profile which is compared to analytical estimations. Beyond the mean field approximation, analytical expressions for the free energy, the pressure, and the correlation function are derived. Subsequently, contributions to the density profile and the adsorption coefficient due to Gaussian fluctuations are found. Both the mean field and the fluctuation terms of the density profile are shown to satisfy the contact theorem. We further use the contact theorem to improve the Gaussian approximation for the density profile based on a better approximation for the bulk pressure. The results obtained are compared to computer simulation data.
Mixed Axion/Axino Dark Matter in mSUGRA and Yukawa-unified SUSY
NASA Astrophysics Data System (ADS)
Summy, Heaya Ann
2010-02-01
Axion/axino dark matter (DM) is explored in the minimal supergravity (mSUGRA) and Yukawa-unified supersymmetric grand-unified theory (SUSY GUT) models with surprising results. For this type of scenario, relic DM abundance has three components: i.) cold axions, ii.) warm axinos from neutralino decay, and iii.) cold or warm thermally produced axinos. Reheat temperatures TR exceeding 106 GeV are required in order to solve the gravitino/Big Bang Nucleosynthesis (BBN) problem while also allowing for baryogensis via non-thermal leptogenesis. In order to attain high enough reheat temperatures, we also need high values of the Peccei-Quinn (PQ) breaking scale fa on the order 1011-1012 GeV.
Viscosity of confined two-dimensional Yukawa liquids: A nonequilibrium method
Landmann, S.; Kählert, H.; Thomsen, H.; Bonitz, M.
2015-09-15
We present a nonequilibrium method that allows one to determine the viscosity of two-dimensional dust clusters in an isotropic confinement. By applying a tangential external force to the outer parts of the cluster (e.g., with lasers), a sheared velocity profile is created. The decay of the angular velocity towards the center of the confinement potential is determined by a balance between internal (viscosity) and external friction (neutral gas damping). The viscosity can then be calculated from a fit of the measured velocity profile to a solution of the Navier-Stokes equation. Langevin dynamics simulations are used to demonstrate the feasibility of the method. We find good agreement of the measured viscosity with previous results for macroscopic Yukawa plasmas.
Solving the eigenvalue problem of the nuclear Yukawa-folded mean-field Hamiltonian
NASA Astrophysics Data System (ADS)
Dobrowolski, A.; Pomorski, K.; Bartel, J.
2016-02-01
The nuclear Hamiltonian with a Yukawa-folded mean-field potential is diagonalized within the basis of a deformed harmonic-oscillator in Cartesian coordinates. The nuclear shape is characterized by the equivalent sharp surface described either by the well known Funny-Hills or the Trentalange-Koonin-Sierk parametrizations. They are both able to describe a very vast variety of nuclear deformations, including necked-in shapes, left-right asymmetry and non-axiality. The only imposed limitation on the nuclear shape is the z-signature symmetry, which corresponds to a symmetry of the shape with respect to a rotation by an angle π around the z-axis. On output, the computer code produces for a given nucleus with mass number A and charge number Z the energy eigenvalues and eigenfunctions of the mean-field Hamiltonian at chosen deformation.
A thermodynamic self-consistent theory of asymmetric hard-core Yukawa mixtures.
Pellicane, Giuseppe; Caccamo, Carlo
2016-10-19
We perform structural and thermodynamic calculations in the framework of the modified hypernetted chain (MHNC) integral equation closure to the Ornstein-Zernike equation for binary mixtures of size-different particles interacting with hard-core Yukawa pair potentials. We use the Percus-Yevick (PY) bridge functions of a binary mixture of hard-sphere (HSM) particles. The hard-sphere diameters of the PY bridge functions of the HSM system are adjusted so to achieve thermodynamic consistency between the virial and compressibility equations of state. We show the benefit of thermodynamic consistency by comparing the MHNC results with the available computer simulation data reported in the literature, and we demonstrate that the self-consistent thermodynamic theory provides a better reproduction of the simulation data over other microscopic theories. PMID:27545096
Enhanced auxeticity in Yukawa systems due to introduction of nanochannels in [001]-direction
NASA Astrophysics Data System (ADS)
Tretiakov, Konstantin V.; Pigłowski, Paweł M.; Hyżorek, Krzysztof; Wojciechowski, Krzysztof W.
2016-05-01
A new approach to search for materials with auxetic properties by modifying structures of solids at molecular level has been proposed. The analysis of elastic properties of the face-centered cubic Yukawa crystals with very narrow nanochannels in the [001] crystallographic direction using Monte Carlo simulations in the isothermal–isobaric ensemble has been done. An influence of the size of nanochannels on the value of Poisson’s ratio in main crystallographic directions has been studied. It has been shown that the insertion of nanochannels in the system causes a decrease of the Poisson’s ratio in the direction [110][1\\bar{1}0] from –0.15(2) to –0.29(3). That means an amplification of auxetity in the studied system twice as compared to the system without nanochannels.
A Dream of Yukawa — Non-Local Fields out of Non-Commutative Spacetime —
NASA Astrophysics Data System (ADS)
Naka, Shigefumi; Toyoda, Haruki; Takanashi, Takahiro; Umezawa, Eizo
The coordinates of κ-Minkowski spacetime form Lie algebraic elements, in which time and space coordinates do not commute in spite of that space coordinates commute each other. The non-commutativity is realized by a Planck-length-scale constant κ - 1( ne 0), which is a universal constant other than the light velocity under the κ-Poincare transformation. Such a non-commutative structure can be realized by SO(1,4) generators in dS4 spacetime. In this work, we try to construct a κ-Minkowski like spacetime with commutative 4-dimensional spacetime based on Adsn+1 spacetime. Another aim of this work is to study invariant wave equations in this spacetime from the viewpoint of non-local field theory by H. Yukawa, who expected to realize elementary particle theories without divergence according to this viewpoint.
Thermodynamic properties of short-range attractive Yukawa fluid: simulation and theory.
Orea, Pedro; Tapia-Medina, Carlos; Pini, Davide; Reiner, Albert
2010-03-21
Coexistence properties of the hard-core attractive Yukawa potential with inverse-range parameter kappa=9, 10, 12, and 15 are calculated by applying canonical Monte Carlo simulation. As previously shown for longer ranges, we show that also for the ranges considered here the coexistence curves scaled by the critical density and temperature obey the law of corresponding states, and that a linear relationship between the critical density and the reciprocal of the critical temperature holds. The simulation results are compared to the predictions of the self-consistent Ornstein-Zernike approximation, and a good agreement is found for both the critical points and the coexistence curves, although some slight discrepancies are present. PMID:20331282
Non-Relativistic Phase Shifts for Scattering on Generalized Radial Yukawa Potentials
NASA Astrophysics Data System (ADS)
O. J., Oluwadare; K. E., Thylwe; K. J., Oyewumi
2016-04-01
Non-relativistic phase shifts for a generalized Yukawa potential V(r) = ‑ V0(e‑αr/r) ‑ V1(e‑2αr/r2) are studied by the amplitude-phase method and by a frequently used analytic method based on a Pekeris-type approximation of power-law potential terms. Small variations of V1 seem to have marginal effects on the effective potential and on exact phase shifts. However, as pointed out in this study, a Pekeris-type approximation in scattering applications often implies serious distortions of both effective potentials and phase shifts. The Pekeris-type based analytic approximation in this study seems to give low-quality scattering results for this model potential at low energies.
Flavor Physics in the Quark Sector
Antonelli, Mario; Asner, David Mark; Bauer, Daniel Adams; Becher, Thomas G.; Beneke, M.; Bevan, Adrian John; Blanke, Monika; Bloise, C.; Bona, Marcella; Bondar, Alexander E.; Bozzi, Concezio; Brod, Joachim; Buras, Andrzej J.; Cabibbo, N.; Carbone, A.; Cavoto, Gianluca; Cirigliano, Vincenzo; Ciuchini, Marco; Coleman, Jonathon P.; Cronin-Hennessy, Daniel P.; Dalseno, J.P.; /KEK, Tsukuba /Glasgow U. /Queen Mary, U. of London /Freiburg U. /Charles U. /Pisa U. /Vienna, OAW /Imperial Coll., London /Bergen U. /INFN, Rome /Rome U. /Munich, Tech. U. /INFN, Rome /Rome U. /Southampton U. /INFN, Rome /Nara Women's U. /Florida U. /INFN, Turin /Turin U. /Edinburgh U. /Warwick U. /INFN, Rome /Rome U. /Massachusetts U., Amherst /KEK, Tsukuba /Bern U. /CERN /Munich, Tech. U. /Mainz U., Inst. Phys. /Wayne State U. /Munich, Max Planck Inst. /CERN /Frascati /Brookhaven /Mainz U., Inst. Kernphys. /Munich, Tech. U. /Siegen U. /Imperial Coll., London /Victoria U. /KEK, Tsukuba /Fermilab /Washington U., St. Louis /Frascati /Warwick U. /Indian Inst. Tech., Madras /Melbourne U. /Princeton U. /Beijing, Inst. High Energy Phys. /INFN, Rome /INFN, Rome3 /Fermilab /SLAC /York U., Canada /Brookhaven /UC, Irvine /INFN, Rome /Rome U. /Valencia U., IFIC /INFN, Padua /Padua U. /Munich, Max Planck Inst. /Barcelona U. /Warwick U. /Tata Inst. /Frascati /Mainz U., Inst. Phys. /Vienna U. /KEK, Tsukuba /Orsay, LPT /Frascati /Munich, Tech. U. /Brookhaven /Bern U. /CERN /Mainz U., Inst. Phys. /Wayne State U. /Valencia U., IFIC /CERN /Kentucky U. /Oxford U. /Iowa State U. /Bristol U. /INFN, Rome /Rutherford /CERN /Orsay, LAL /Glasgow U. /INFN, Padua /Queen Mary, U. of London /Texas U. /LPHE, Lausanne /Fermilab /UC, Santa Cruz /Vienna, OAW /Cincinnati U. /Frascati /Orsay, LAL /Ohio State U. /Purdue U. /Novosibirsk, IYF /Frascati /INFN, Rome /Padua U. /INFN, Rome /Bern U. /Karlsruhe U. /Brookhaven /CERN /Paris U., VI-VII /Zurich, ETH /Pisa U. /Frascati /Oxford U. /Orsay, LAL /INFN, Rome2 /INFN, Rome /INFN, Rome3 /Princeton U. /Fermilab /Queen's U., Kingston /KEK, Tsukuba /Melbourne U. /Brookhaven /Indiana U. /INFN, Rome /Rome U. /Pisa U. /Mainz U., Inst. Phys. /Karlsruhe U. /Oxford U. /Cambridge U., DAMTP /Edinburgh U. /CERN
2010-08-26
In the past decade, one of the major challenges of particle physics has been to gain an in-depth understanding of the role of quark flavor. In this time frame, measurements and the theoretical interpretation of their results have advanced tremendously. A much broader understanding of flavor particles has been achieved, apart from their masses and quantum numbers, there now exist detailed measurements of the characteristics of their interactions allowing stringent tests of Standard Model predictions. Among the most interesting phenomena of flavor physics is the violation of the CP symmetry that has been subtle and difficult to explore. In the past, observations of CP violation were confined to neutral K mesons, but since the early 1990s, a large number of CP-violating processes have been studied in detail in neutral B mesons. In parallel, measurements of the couplings of the heavy quarks and the dynamics for their decays in large samples of K,D, and B mesons have been greatly improved in accuracy and the results are being used as probes in the search for deviations from the Standard Model. In the near future, there will be a transition from the current to a new generation of experiments, thus a review of the status of quark flavor physics is timely. This report is the result of the work of the physicists attending the 5th CKM workshop, hosted by the University of Rome 'La Sapienza', September 9-13, 2008. It summarizes the results of the current generation of experiments that is about to be completed and it confronts these results with the theoretical understanding of the field which has greatly improved in the past decade.
First Look at Heavy-Light Mesons with a Dressed Quark-Gluon Vertex
NASA Astrophysics Data System (ADS)
Gómez-Rocha, María; Hilger, Thomas; Krassnigg, Andreas
2015-09-01
Following up on earlier work, we investigate possible effects of a dressed quark-gluon vertex in heavy-light mesons. In particular, we study corrections to the popular rainbow-ladder truncation of the Dyson-Schwinger-Bethe-Salpeter equation system. We adopt a simple interaction kernel which reduces the resulting set of coupled integral equations to a set of coupled algebraic equations, which are solved numerically. In this way, we extend previous studies to quark-antiquark systems with unequal current-quark masses, at first for the pseudoscalar case, and investigate the resulting set of problems and solutions. We attempt to find patterns in—as well as to quantify corrections to—the rainbow-ladder truncation. In addition, we open this approach to phenomenological predictions of the heavy quark symmetry.
Impact of a magnetic field on the thermodynamics of magnetized quark matter
NASA Astrophysics Data System (ADS)
Farias, R. L. S.; Timóteo, V. S.; Avancini, S.; Pinto, M. B.; Krein, G.
2016-04-01
We investigate the effect of a magnetic field on the thermodynamics of magnetized quark matter at finite temperature. By using the Nambu Jona-Lasino (NJL) model, we show that the lattice results for the quark consensate can be reproduced when the coupling constant G of the model decreases with the magnetic field and the temperature. Our results show that thermodynamic quantities and quark condensates are very sensitive to the dependence of G with the temperature, even in the absence of a magnetic field.
Bound Nucleon Form Factors, Quark-Hadron Duality, and the Nuclear EMC Effect
K. Tsushima; D.H. Lu; W. Melnitchouk; K. Saito; A.W. Thomas
2002-09-13
We discuss the electromagnetic form factors, axial form factors, and structure functions of a nucleon bound in the quark-meson coupling (QMC) model. Free space nucleon form factors are calculated using the improved cloudy bag model (ICBM). After describing finite nuclei and nuclear matter in the quark-based (EMC) model, the in-medium modification of the bound nucleon form factors is calculated in the same model. Finally, the bound nucleon structure function, F2, is extracted using the calculated in-medium electromagnetic form factors and Bloom-Gilman (quark-hadron) duality.
Top Quark Properties in Little Higgs Models
Berger, C.F.; Perelstein, M.; Petriello, F.; /Wisconsin U., Madison
2005-12-08
Identifying the mechanism which breaks electroweak symmetry and generates fermion masses is one of the main physics goals for both the LHC and the ILC. Studies of the top quark have the potential to illuminate this issue; since it is the heaviest of the Standard Model (SM) fermions, the top is expected to couple strongly to the symmetry-breaking sector. Consequently, the structure of that sector can have significant, potentially observable effects on the properties of the top. for example, it is well known that the vector and axial t{bar t}Z form factors receive large corrections (of order 5-10%) in certain models of dynamical electroweak symmetry breaking [1]. At future colliders such as the LHC and the ILC, we will be able to pursue a program of precision top physics, similar to the program studying the Z at LEP and SLC. In this manuscript, they study the corrections to the top quark properties in ''Little Higgs'' models of electroweak symmetry breaking [2], and compare the expected deviations from the SM predictions with expected sensitivities of experiments at the LHC and the ILC. In the Little Higgs models, electroweak symmetry is driven by the radiative effects from the top sector, including the SM-like top and its heavy counterpart, a TeV-scale ''heavy top'' T. Probing this structure experimentally is quite difficult. While the LHC should be able to discover the T quark, its potential for studying its couplings is limited [3,4]. Direct production of the T will likely be beyond the kinematic reach of the ILC. However, we will show below that the corrections to the gauge couplings of the SM top, induced by its mixing with the T, will be observable at the ILC throughout the parameter range consistent with naturalness. Measuring these corrections will provide a unique window on the top sector of the Little Higgs. Many Little Higgs models have been proposed in the literature. We will consider two examples in this study, the ''Littlest Higgs'' model [5], and its
Progress in Understanding the Nuclear Equation of State at the Quark Level
A.W. Thomas; P.A.M. Guichon
2007-01-03
At the present time there is a lively debate within the nuclear community concerning the relevance of quark degrees of freedom in understanding nuclear structure. We outline the key issues and review the impressive progress made recently within the framework of the quark-meson coupling model. In particular, we explain in quite general terms how the modification of the internal structure of hadrons in-medium leads naturally to three- and four-body forces, or equivalently, to density dependent effective interactions.
Strange Quark Matter Status and Prospects
NASA Technical Reports Server (NTRS)
Sandweiss, J.
2004-01-01
The existence of quark states with more than three quarks is allowed in QCD. The stability of such quark matter states has been studied with lattice QCD and phenomenological bag models, but is not well constrained by theory. The addition of strange quarks to the system allows the quarks to be in lower energy states despite the additional mass penalty. There is additional stability from reduced Coulomb repulsion. SQM is expected to have a low Z/A. Stable or metastable massive multiquark states contain u, d, and s quarks.
Petite unification of quarks and leptons
Hung, P.Q.; Buras, A.J.; Bjorken, J.D.
1982-02-01
A general discussion of a quark-lepton unification characterized by the gauge group G/sub S/xG/sub W/ with two coupling constants g/sub S/ and g/sub W/ and by the unification mass scale M = 10/sup 5plus-or-minus1/ GeV is presented. The choice of G/sub W/ is quite restricted by the measured value of sin/sup 2/theta/sub W/. The minimal model of such a unification turns out to be SU(4)/sub PS/xSU(2)/sub L/xSU(2)/sub R/xSU(2)/sub L/'xSU(2)/sub R/', where the first three factors constitute the well-known Pati-Salam group. The presence of SU(2)/sub L/'xSU(2)/sub R/' is required by the measured value of sin/sup 2/theta/sub W/ and it implies the existence of mirror fermions whose masses may range from 20--30 GeV to a few TeV. The lightest mirror femion might be relatively long lived when compared to an ordinary sequential heavy fermion. The model accommodating all known quark and lepton generations gives the correct sin/sup 2/theta/sub W/roughly-equal0.22 and at the same time can be made consistent with the experimental bounds on rare transitions induced by leptoquark exchanges.
Stability of superfluid vortices in dense quark matter
NASA Astrophysics Data System (ADS)
Alford, Mark G.; Mallavarapu, S. Kumar; Vachaspati, Tanmay; Windisch, Andreas
2016-04-01
Superfluid vortices in the color-flavor-locked (CFL) phase of dense quark matter are known to be energetically disfavored relative to well-separated triplets of so-called semi-superfluid color flux tubes. However, the short-range interaction (metastable versus unstable) has not been established. In this paper we perform numerical calculations using the effective theory of the condensate field, mapping the regions in the parameter space of coupling constants where the vortices are metastable versus unstable. For the case of zero-gauge coupling we analytically identify a candidate for the unstable mode and show that it agrees well with the results of the numerical calculations. We find that in the region of the parameter space that seems likely to correspond to real-world CFL quark matter the vortices are unstable, indicating that if such matter exists in neutron star cores it is very likely to contain semi-superfluid color flux tubes rather than superfluid vortices.
NASA Astrophysics Data System (ADS)
Xiao, C. W.; Ozpineci, A.; Oset, E.
2015-10-01
Using a coupled channel unitary approach, combining the heavy quark spin symmetry and the dynamics of the local hidden gauge, we investigate the meson-meson interaction with hidden beauty. We obtain several new states of isospin I = 0: six bound states, and weakly bound six more possible states which depend on the influence of the coupled channel effects.
Nuclear matter from effective quark-quark interaction.
Baldo, M; Fukukawa, K
2014-12-12
We study neutron matter and symmetric nuclear matter with the quark-meson model for the two-nucleon interaction. The Bethe-Bruckner-Goldstone many-body theory is used to describe the correlations up to the three hole-line approximation with no extra parameters. At variance with other nonrelativistic realistic interactions, the three hole-line contribution turns out to be non-negligible and to have a substantial saturation effect. The saturation point of nuclear matter, the compressibility, the symmetry energy, and its slope are within the phenomenological constraints. Since the interaction also reproduces fairly well the properties of the three-nucleon system, these results indicate that the explicit introduction of the quark degrees of freedom within the considered constituent quark model is expected to reduce the role of three-body forces. PMID:25541769
Shining a gluon beam through quark-gluon plasma
NASA Astrophysics Data System (ADS)
Chesler, Paul M.; Ho, Ying-Yu; Rajagopal, Krishna
2012-06-01
We compute the energy density radiated by a quark undergoing circular motion in strongly coupled N=4 supersymmetric Yang-Mills plasma. If it were in vacuum, this quark would radiate a beam of strongly coupled radiation whose angular distribution has been characterized and is very similar to that of synchrotron radiation produced by an electron in circular motion in electrodynamics. Here, we watch this beam of gluons getting quenched by the strongly coupled plasma. We find that a beam of gluons of momenta ˜q≫πT is attenuated rapidly, over a distance ˜q1/3(πT)-4/3 in a plasma with temperature T. As the beam propagates through the plasma at the speed of light, it sheds trailing sound waves with momenta ≲πT. Presumably these sound waves would thermalize in the plasma if they were not hit soon after their production by the next pulse of gluons from the lighthouselike rotating quark. At larger and larger q, the trailing sound wave becomes less and less prominent. The outward-going beam of gluon radiation itself shows no tendency to spread in angle or to shift toward larger wavelengths, even as it is completely attenuated. In this regard, the behavior of the beam of gluons which we analyze is reminiscent of the behavior of jets produced in heavy ion collisions at the LHC which lose a significant fraction of their energy without appreciable change in their angular distribution or their momentum distribution as they plow through the strongly coupled quark-gluon plasma produced in these collisions.
Meson phenomenology and phase transitions in nonlocal chiral quark models
NASA Astrophysics Data System (ADS)
Carlomagno, J. P.; Gomez Dumm, D.; Pagura, V.; Scoccola, N. N.
2015-07-01
We study the features of nonlocal chiral quark models that include wave function renormalization. Model parameters are determined from meson phenomenology, considering different nonlocal form factor shapes. In this context we analyze the characteristics of the deconfinement and chiral restoration transitions at finite temperature and chemical potential, introducing the couplings of fermions to the Polyakov loop for different Polyakov potentials. The results for various thermodynamical quantities are compared with data obtained from lattice QCD calculations.
Running couplings and operator mixing in the gravitational corrections to coupling constants
Anber, Mohamed M.; Donoghue, John F.; El-Houssieny, Mohamed
2011-06-15
The use of a running coupling constant in renormalizable theories is well known, but the implementation of this idea for effective field theories with a dimensional coupling constant is, in general, less useful. Nevertheless, there are multiple attempts to define running couplings, including the effects of gravity, with varying conclusions. We sort through many of the issues involved, most particularly the idea of operator mixing and also the kinematics of crossing, using calculations in Yukawa and {lambda}{phi}{sup 4} theories as illustrative examples. We remain in the perturbative regime. In some theories with a high permutation symmetry, such as {lambda}{phi}{sup 4}, a reasonable running coupling can be defined. However, in most cases, such as Yukawa and gauge theories, a running coupling fails to correctly account for the energy dependence of the interaction strength. As a by-product we also contrast on-shell and off-shell renormalization schemes and show that operators which are normally discarded, such as those that vanish by the equations of motion, are required for off-shell renormalization of effective field theories. Our results suggest that the inclusion of gravity in the running of couplings is not useful or universal in the description of physical processes.
The Top Quark as a Window to Beyond the Standard Model Physics
Yu, Chiu-Tien
2013-01-01
The top quark was the last of the Standard Model quarks to be discovered, and is of considerable interest. The closeness of the top quark mass to the electroweak scale is suggestive that the top quark could be closely related to the mechanisms for electroweak symmetry breaking. Any new physics in electroweak symmetry breaking models could then preferentially couple to the top quark, making the top quark a promising probe for new physics. In this thesis, we will explore two aspects of the top quark as a harbinger to new physics: the top forward-backward asymmetry as seen at the Tevatron and the search for stops. In this thesis, we will discuss the Asymmetric Left-Right Model (ALRM), a model that is based on the gauge group $U'(1)\\times SU(2)\\times SU'(2)$ with couplings $g_1^\\prime, g_2^\\prime,$ and $g'$ associated with the fields $B',W,W'$, respectively, and show how this model can explain the top forward-backward asymmetry. We will then explore the scalar sector of the ALRM, and provide a specific Higgs mechanism that provides the masses for the $W'$ and $Z'$ bosons. The top forward-backward asymmetry is a test of invariance of charge-conjugation. Thus, we look at the $X$-gluon model, a model that was motivated by the top forward-backward asymmetry, and show that one can look at the longitudinal polarization of the top-quark to test parity conservation. Finally, we investigate searches for stop squarks, the supersymmetric partner of the top quark, at the Large Hadron Collider (LHC) using shape-based analyses.
The Top Quark as a Window to Beyond the Standard Model Physics
NASA Astrophysics Data System (ADS)
Yu, Chiu-Tien
The top quark was the last of the Standard Model quarks to be discovered, and is of considerable interest. The closeness of the top quark mass to the electroweak scale is suggestive that the top quark could be closely related to the mechanisms for electroweak symmetry breaking. Any new physics in electroweak symmetry breaking models could then preferentially couple to the top quark, making the top quark a promising probe for new physics. In this thesis, we will explore two aspects of the top quark as a harbinger to new physics: the top forward-backward asymmetry as seen at the Tevatron and the search for stops. In this thesis, we will discuss the Asymmetric Left-Right Model (ALRM), a model that is based on the gauge group U'(1) x SU(2) x SU'(2) with couplings g' 1,g'2; and g' associated with the fields B',W,W', respectively, and show how this model can explain the top forwardbackward asymmetry. We will then explore the scalar sector of the ALRM, and provide a specific Higgs mechanism that provides the masses for the W' and Z' bosons. The top forward-backward asymmetry is a test of invariance of chargeconjugation. Thus, we look at the X-gluon model, a model that was motivated by the top forward-backward asymmetry, and show that one can look at the longitudinal polarization of the top-quark to test parity conservation. Finally, we investigate searches for stop squarks, the supersymmetric partner of the top quark, at the Large Hadron Collider (LHC) using shape-based analyses.
Anarchic Yukawas and top partial compositeness: the flavour of a successful marriage
NASA Astrophysics Data System (ADS)
Cacciapaglia, Giacomo; Cai, Haiying; Flacke, Thomas; Lee, Seung J.; Parolini, Alberto; Serôdio, Hugo
2015-06-01
The top quark can be naturally singled out from other fermions in the Standard Model due to its large mass, of the order of the electroweak scale. We follow this reasoning in models of pseudo Nambu Goldstone Boson composite Higgs, which may derive from an underlying confining dynamics. We consider a new class of flavour models, where the top quark obtains its mass via partial compositeness, while the lighter fermions acquire their masses by a deformation of the dynamics generated at a high flavour scale. One interesting feature of such scenario is that it can avoid all the flavour constraints without the need of flavour symmetries, since the flavour scale can be pushed high enough. We show that both flavour conserving and violating constraints can be satisfied with top partial compositeness without invoking any flavour symmetry for the up-type sector, in the case of the minimal SO(5)/SO(4) coset with top partners in the four-plet and singlet of SO(4). In the down-type sector, some degree of alignment is required if all down-type quarks are elementary. We show that taking the bottom quark partially composite provides a dynamical explanation for the hierarchy causing this alignment. We present explicit realisations of this mechanism which do not require to include additional bottom partner fields. Finally, these conclusions are generalised to scenarios with non-minimal cosets and top partners in larger representations.
NASA Astrophysics Data System (ADS)
Horn, D.
2015-03-01
The quark model emerged from the Gell-Mann-Ne'eman flavor SU(3) symmetry. Its development, in the context of strong interactions, took place in a heuristic theoretical framework, referred to as the Bootstrap Era. Setting the background for the dominant ideas in strong interaction of the early 1960s, we outline some aspects of the constituent quark model. An independent theoretical development was the emergence of hadron duality in 1967, leading to a realization of the Bootstrap idea by relating hadron resonances (in the s-channel) with Regge pole trajectories (in t- and u-channels). The synthesis of duality with the quark-model has been achieved by duality diagrams, serving as a conceptual framework for discussing many aspects of hadron dynamics toward the end of the 1960s.
NASA Astrophysics Data System (ADS)
Horn, D.
2014-12-01
The quark model emerged from the Gell-Mann-Ne'eman flavor SU(3) symmetry. Its development, in the context of strong interactions, took place in a heuristic theoretical framework, referred to as the Bootstrap Era. Setting the background for the dominant ideas in strong interaction of the early 1960s, we outline some aspects of the constituent quark model. An independent theoretical development was the emergence of hadron duality in 1967, leading to a realization of the Bootstrap idea by relating hadron resonances (in the s-channel) with Regge pole trajectories (in t- and u-channels). The synthesis of duality with the quark-model has been achieved by duality diagrams, serving as a conceptual framework for discussing many aspects of hadron dynamics toward the end of the 1960s.
Heavy quark spectroscopy and decay
Schindler, R.H.
1987-01-01
The understanding of q anti q systems containing heavy, charmed, and bottom quarks has progressed rapidly in recent years, through steady improvements in experimental techniques for production and detection of their decays. These lectures are meant to be an experimentalist's review of the subject. In the first of two lectures, the existing data on the spectroscopy of the bound c anti c and b anti b systems will be discussed. Emphasis is placed on comparisons with the theoretical models. The second lecture covers the rapidly changing subject of the decays of heavy mesons (c anti q and b anti q), and their excited states. In combination, the spectroscopy and decays of heavy quarks are shown to provide interesting insights into both the strong and electroweak interactions of the heavy quarks. 103 refs., 39 figs.
Boosted top quarks and jet structure
NASA Astrophysics Data System (ADS)
Schätzel, Sebastian
2015-09-01
The Large Hadron Collider is the first particle accelerator that provides high enough energy to produce large numbers of boosted top quarks. The decay products of these top quarks are confined to a cone in the top quark flight direction and can be clustered into a single jet. Top quark reconstruction then amounts to analysing the structure of the jet and looking for subjets that are kinematically compatible with top quark decay. Many techniques have been developed in this context to identify top quarks in a large background of non-top jets. This article reviews the results obtained using data recorded in the years 2010-2012 by the experiments ATLAS and CMS. Studies of Standard Model top quark production and searches for new massive particles that decay to top quarks are presented.
Fein, D.K.; D0 Collaboration
1997-01-01
Recent results in heavy quark physics from the D0 experiment at the Fermilab Tevatron Collider are reported. Topics included are top quark production and mass determination, bottom production and correlations, and charmonium production. 20 refs., 10 figs., 2 tabs.
Effective field theories of baryons and mesons, or, what do quarks do?
Keaton, G.L.
1995-06-26
This thesis is an attempt to understand the properties of the protons, pions and other hadrons in terms of their fundamental building blocks. In the first chapter the author reviews several of the approaches that have already been developed. The Nambu-Jona-Lasinio model offers the classic example of a derivation of meson properties from a quark Lagrangian. The chiral quark model encodes much of the intuition acquired in recent decades. The author also discusses the non-linear sigma model, the Skyrme model, and the constituent quark model, which is one of the oldest and most successful models. In the constituent quark model, the constituent quark appears to be different from the current quark that appears in the fundamental QCD Lagrangian. Recently it was proposed that the constituent quark is a topological soliton. In chapter 2 the author investigates this soliton, calculating its mass, radius, magnetic moment, color magnetic moment, and spin structure function. Within the approximations used, the magnetic moments and spin structure function cannot simultaneously be made to agree with the constituent quark model. In chapter 3 the author uses a different plan of attack. Rather than trying to model the constituents of the baryon, he begins with an effective field theory of baryons and mesons, with couplings and masses that are simply determined phenomenologically. Meson loop corrections to baryon axial currents are then computed in the 1/N expansion. It is already known that the one-loop corrections are suppressed by a factor 1/N; here it is shown that the two-loop corrections are suppressed by 1/N{sup 2}. To leading order, these corrections are exactly the same as would be calculated in the constituent quark model. This method therefore offers a different approach to the constituent quark.
Top quark production at the Tevatron
Varnes, Erich W.; /Arizona U.
2010-09-01
The Fermilab Tevatron has, until recently, been the only accelerator with sufficient energy to produce top quarks. The CDF and D0 experiments have collected large samples of top quarks. We report on recent top quark production measurements of the single top and t{bar t} production cross sections, as well as studies of the t{bar t} invariant mass distribution and a search for highly boosted top quarks.
Quark propagators in confinement and deconfinement phases
Hamada, Masatoshi; Yahiro, Masanobu; Kouno, Hiroaki; Nakamura, Atsushi; Saito, Takuya
2010-05-01
We study quark propagators near the confinement/deconfinement phase transition temperature in quenched-lattice simulation of QCD. We find that there is no qualitative change for the quark propagators in both phases. In the confinement phase, those effective quark masses in units of the critical temperature behave as a constant as a function of the temperature, while above the critical temperature, the value of the effective quark mass drops to circa half value.
Top Quark Spin Correlations - Theory
Parke, Stephen J.; /Fermilab
2012-02-01
The top quark decay width (G{sub F}m{sub t}{sup 3} {approx} 1 GeV) is much larger than the QCD hadronization scale ({Lambda}{sub QCD} {approx} 0.1 GeV) and much larger than the spin decorrelation scale ({Lambda}{sub QCD}{sup 2}/m{sub t} {approx} 0.1 MeV). Therefore, spin correlations in top quark pair production are reflected in angular correlations of the decay products, see [1] and [2].
NASA Astrophysics Data System (ADS)
Patel, Smruti J.; Vinodkumar, P. C.
2016-05-01
We study the mass spectra of hexaquark states as di-hadronic molecules with Yukawa potential in a semi-relativistic scheme. We have solved numerically the relevant equation using mathematica notebook of Range-Kutta method including effective Yukawa like potential between two baryons to model the two-body interaction and have calculated their masses and binding energy. We have been able to assign the JP values for many of the exotic states according to their compositions. We have predicted some of the di-baryonic exotic states for which experimental as well as theoretical data are not available and we look forward to see the experimental support in favour of our predictions. So in the absence of such results our predictions can be used as guidelines for future experimental and theoretical analysis of exotic states.
Bulk Properties and Collective Flow of Quark Gluon Plasma
NASA Astrophysics Data System (ADS)
Kapusta, Joseph
2007-10-01
Quantum Chromodynamics predicts a transition from a hadronic phase at temperatures less than 150-200 MeV to a quark gluon plasma phase at higher temperatures. Lattice calculations show a big increase in the entropy density in this vicinity. Whether the transition is first or second order or a smooth rapid crossover depends upon the values of the up, down and strange quark masses. The goal of the heavy ion experimental program at RHIC is to observe this transition and to study the nature of the quark gluon plasma quantitatively. Two big surprises arose from these experiments: Substantial collective flow has been observed, as evidenced by single-particle transverse momentum distributions and by azimuthal correlations among the produced particles, and the degree to which high energy jets are attenuated in the produced matter. A variety of theoretical models of these collisions require initial energy densities more than a factor of 10 greater than in neutron star cores and more than a factor of 100 greater than within atomic nuclei. Taken together this body of work implies a strongly interacting phase of quarks and gluons beyond the capabilities of perturbation theory. This has motivated approaches based on gauge theories with gravity duals where physical observables may be calculated in a strong coupling limit. This in turn has stimulated interest from members of the string theory community who are currently bringing their expertise to bear on the problem.
Some aspects of three-quark potentials
NASA Astrophysics Data System (ADS)
Andreev, Oleg
2016-05-01
We analytically evaluate the expectation value of a baryonic Wilson loop in a holographic model of an S U (3 ) pure gauge theory. We then discuss three aspects of a static three-quark potential: an aspect of universality which concerns properties independent of a geometric configuration of quarks, a heavy diquark structure, and a relation between the three- and two-quark potentials.
Exotic heavy-quark states at Belle
NASA Astrophysics Data System (ADS)
Wang, Xiaolong; Belle Collaboration
2016-03-01
The search for multi-quark states beyond the meson (quark-antiquark) and baryon (three-quark) has resulted in the discovery of many new exotic states of matter, starting with the X(3872) discovery by Belle in 2003. We report selected recent results on searches for such states at Belle. supported by the Department of Energy Office of Science.
LATTICE QCD THERMODYNAMICS WITH WILSON QUARKS.
EJIRI,S.
2007-11-20
We review studies of QCD thermodynamics by lattice QCD simulations with dynamical Wilson quarks. After explaining the basic properties of QCD with Wilson quarks at finite temperature including the phase structure and the scaling properties around the chiral phase transition, we discuss the critical temperature, the equation of state and heavy-quark free energies.
NASA Astrophysics Data System (ADS)
Ikot, Akpan N.; Maghsoodi, Elham; Hassanabadi, Hassan; Obu, Joseph A.
2014-05-01
In this paper, we obtain the approximate analytical bound-state solutions of the Dirac particle with the generalized Yukawa potential within the framework of spin and pseudospin symmetries for the arbitrary к state with a generalized tensor interaction. The generalized parametric Nikiforov-Uvarov method is used to obtain the energy eigenvalues and the corresponding wave functions in closed form. We also report some numerical results and present figures to show the effect of the tensor interaction.
Does the b quark decay left-handedly
Gronau, M. ); Wakaizumi, S. )
1992-03-23
The left-handedness of the {ital b} quark weak couplings has not yet been tested experimentally. We present an SU(2){sub {ital L}}{times}SU(2){sub {ital R}}{times}U(1) model with purely right-handed {ital b} decay couplings. We show that the model is consistent with the quite severe existing experimental constraints from {ital B} decays, from {ital B}{sup 0-}{ital {bar B}} {sup 0} mixing, from the neutral {ital K} mass difference, and from {ital CP} violation in the kaon system. We point out a difficulty in distinguishing our scheme from the standard model in semileptonic {ital B} decays.
R-parity violation in flavor-changing neutral current processes and top quark decays
NASA Astrophysics Data System (ADS)
Agashe, K.; Graesser, M.
1996-10-01
We show that supersymmetric R-parity-breaking (R/p) interactions always result in flavor changing neutral current processes. Within a single coupling scheme, these processes can be avoided in either the charge +2/3 or the charge -1/3 quark sector, but not both. These processes are used to place constraints on R/p couplings. The constraints on the first and the second generations are better than those existing in the literature. The R/p interactions may result in new top quark decays. Some of these violate electron-muon universality or produce a surplus of b quark events in tt¯ decays. Results from the CDF experiment are used to bound these R/p couplings.
Barberis, Emanuela; /Northeastern U.
2006-05-01
A summary of the results on the measurement of the Top Quark mass and the study of the kinematics of the t{bar t} system at the Tevatron collider is presented here. Results from both the CDF and D0 collaborations are reported.
DOE R&D Accomplishments Database
Kim, S. B.
1995-08-01
Top quark production is observed in{bar p}p collisions at{radical}s= 1.8 TeV at the Fermilab Tevatron. The Collider Detector at Fermilab (CDF) and D{O} observe signals consistent with t{bar t} to WWb{bar b}, but inconsistent with the background prediction by 4.8{sigma} (CDF), 4.6a (D{O}). Additional evidence for the top quark Is provided by a peak in the reconstructed mass distribution. The kinematic properties of the excess events are consistent with the top quark decay. They measure the top quark mass to be 176{plus_minus}8(stat.){plus_minus}10(sys.) GeV/c{sup 2} (CDF), 199{sub -21}{sup+19}(stat.){plus_minus}22(sys.) GeV/c{sup 2} (D{O}), and the t{bar t} production cross section to be 6.8{sub -2.4}{sup+3.6}pb (CDF), 6.4{plus_minus}2.2 pb (D{O}).
Greenlee, H.; D0 Collaboration
1995-05-01
The DO collaboration reports on a search for the Standard Model top quark in p{bar p} collisions at {radical}s = 1.8 TeV at the Fermilab Tevatron, with an integrated luminosity of approximately 50 pb{sup {minus}1}. We have searched for t{bar t} production in the dilepton and single-lepton decay channels, with and without tagging of b quark jets. We observe 17 events with an expected background of 3.8 {plus_minus} 0.6 events. The probability for an upward fluctuation of the background to produce the observed signal is 2 {times} 10{sup {minus}6} (equivalent to 4.6 standard deviations). The kinematic properties of the excess events are consistent with top quark decay. We conclude that we have observed the top quark and measure its mass to be 199{sub {minus}21}{sup +19} (stat.) {plus_minus}22 (syst.) GeV/c{sup 2} and its production cross section to be 6.4 {plus_minus} 2.2 pb.
ERIC Educational Resources Information Center
Young, Robert D.
1973-01-01
Discusses the charge independence, wavefunctions, magnetic moments, and high-energy scattering of hadrons on the basis of group theory and nonrelativistic quark model with mass spectrum calculated by first-order perturbation theory. The presentation is explainable to advanced undergraduate students. (CC)
NASA Astrophysics Data System (ADS)
Brown, Laurie Mark; Dresden, Max; Hoddeson, Lillian
2009-01-01
Part I. Introduction; 1. Pions to quarks: particle physics in the 1950s Laurie M Brown, Max Dresden and Lillian Hoddeson; 2. Particle physics in the early 1950s Chen Ning Yang; 3. An historian's interest in particle physics J. L. Heilbron; Part II. Particle discoveries in cosmic rays; 4. Cosmic-ray cloud-chamber contributions to the discovery of the strange particles in the decade 1947-1957 George D. Rochester; 5. Cosmic-ray work with emulsions in the 1940s and 1950s Donald H. Perkins; Part III. High-energy nuclear physics; Learning about nucleon resonances with pion photoproduction Robert L. Walker; 7. A personal view of nucleon structure as revealed by electron scattering Robert Hofstadter; 8. Comments on electromagnetic form factors of the nucleon Robert G. Sachs and Kameshwar C. Wali; Part IV. The new laboratory; 9. The making of an accelerator physicist Matthew Sands; 10. Accelerator design and construction in the 1950s John P. Blewett; 11. Early history of the Cosmotron and AGS Ernest D. Courant; 12. Panel on accelerators and detectors in the 1950s Lawrence W. Jones, Luis W. Alvarez, Ugo Amaldi, Robert Hofstadter, Donald W. Kerst, Robert R. Wilson; 13. Accelerators and the Midwestern Universities Research Association in the 1950s Donald W. Kerst; 14. Bubbles, sparks and the postwar laboratory Peter Galison; 15. Development of the discharge (spark) chamber in Japan in the 1950s Shuji Fukui; 16. Early work at the Bevatron: a personal account Gerson Goldhaber; 17. The discovery of the antiproton Owen Chamberlain; 18. On the antiproton discovery Oreste Piccioni; Part V. The Strange Particles; 19. The hydrogen bubble chamber and the strange resonances Luis W. Alvarez; 20. A particular view of particle physics in the fifties Jack Steinberger; 21. Strange particles William Chinowsky; 22. Strange particles: production by Cosmotron beams as observed in diffusion cloud chambers William B. Fowler; 23. From the 1940s into the 1950s Abraham Pais; Part VI. Detection of the
NASA Astrophysics Data System (ADS)
Kim, Tae Jeong
2014-04-01
In 2011, an integrated luminosity of more than 5 fb-1 at 7 TeV has been delivered by the LHC. The measurement of the cross section in top quark pair production and in single top quark production, top quark mass, top quark properties and new physics searches in top quark decays have been performed at the CMS experiment with various integrated luminosities. An overview of the latest results of these measurements and searches by the time of ICFP 2012 conference will be presented.
Synthesis of baryons from unconfined quarks
Dicus, D.A.; Pati, J.C.; Teplitz, V.L.
1980-02-15
We calculate, for a number of cases, the cosmic temperature at which primordial quarks condense into baryons, within a field theory of partially confined quarks that enjoys temporary asymptotic freedom. We assume that the mass of a quark in a dense quark-antiquark medium is a monotonic function of the medium: that is, we assume the validity of the so-called ''Archimedes effect.'' We show that, within such models, unbound-quark lifetimes are larger than the age of the universe at the time of the transition.
Peters, Reinhild Yvonne
2014-11-26
Years after its discovery in 1995 by CDF and D0, the top quark still undergoes intense investigations at the Tevatron. Using up to the full Run II data sample, new measurements of top quark production and properties by the D0 Collaboration are presented. In particular, the first observation of single top quark s-channel production, the measurement of differential tbar t distributions, forward-backward tbar t asymmetry, a new measurement of the top quark mass, and a measurement of the top quark charge are discussed.
Measurements of top quark properties at CDF
Kraan, Aafke C.; /Pennsylvania U.
2006-11-01
The top quark with its mass of about 172 GeV/c{sup 2} is the most massive fundamental particle observed by experiment. In this talk they highlight the most recent measurements of several top quark properties performed with the CDF detector based on data samples corresponding to integrated luminosities up to 1 fb{sup -1}. These results include a search for top quark pair production via new massive resonances, measurements of the helicity of the W boson from top-quark decay, and a direct limit on the lifetime of the top quark.
Transport properties for an electroneutral Yukawa-type fluid in the MSA
NASA Astrophysics Data System (ADS)
Montes-Perez, J.; Herrera, J. N.
2014-01-01
In the framework of a linear response theory, in which Onsager’s continuity equations are combined with the Mean Spherical Approximation (MSA) from the theory of correlation functions in equilibrium, and using a Green’s function formalism, we consider the transport properties of electrolytes. The interaction between the ions in the electrolyte is represented by an intermolecular Yukawa potential which satisfies the electroneutrality condition. The model contains an adjustable parameter z which takes into account the effects of the solvent. Transport processes in an ionic solution are determined by two dominant forces: the relaxation and the electrophoretic forces; their contributions to the transport properties are calculated using the Fuoss-Onsager theory. We find the conductivity and the self-diffusion coefficient for a family of electrolytes using the linear response theory. The predictions of our model can be adjusted by means of the parameter z. The electrophoretic effect, due to the hydrodynamic interaction between the ions, is calculated using the Rotne-Prager tensor. Our theoretical results are in good agreement with experimental data for electrolytes 1-1, even for high concentrations. We applied this theory also to two unsymmetrical electrolytes, namely the aqueous solutions of MgCl2 and CaCl2, with results in good accord with experimental data.
Higgs-Yukawa model with higher dimension operators via extended mean field theory
NASA Astrophysics Data System (ADS)
Akerlund, Oscar; de Forcrand, Philippe
2016-02-01
Using extended mean field theory (EMFT) on the lattice, we study properties of the Higgs-Yukawa model as an approximation of the standard model Higgs sector, and the effect of higher dimension operators. We remark, as has been noted before, that the discussion of vacuum stability is completely modified in the presence of a ϕ6 term, and that the Higgs mass no longer appears fine tuned. We also study the finite temperature transition. Without higher dimension operators the transition is found to be second order (crossover with gauge fields) for the experimental value of the Higgs mass Mh=125 GeV . By taking a ϕ6 interaction in the Higgs potential as a proxy for a UV completion of the standard model, the transition becomes stronger and turns first order if the scale of new physics, i.e., the mass of the lightest mediator particle, is around 1.5 TeV. This implies that electroweak baryogenesis may be viable in models which introduce new particles around that scale.
Sparticle spectroscopy with neutralino dark matter from t-b-{tau} quasi-Yukawa unification
Dar, Shahida; Gogoladze, Ilia; Shafi, Qaisar; Uen, Cem Salih
2011-10-15
We consider two classes of t-b-{tau} quasi-Yukawa unification scenarios which can arise from realistic supersymmetric SO(10) and SU(4){sub C}xSU(2){sub L}xSU(2){sub R} models. We show that these scenarios can be successfully implemented in the nonuniversal Higgs model with m{sub H{sub u}}=m{sub H{sub d}}{ne}m{sub 0} and the constrained minimal sumersymmetric model frameworks, and they yield a variety of sparticle spectra with Wilkinson Microwave Anisotropy Probe compatible neutralino dark matter. In the nonuniversal Higgs model with m{sub H{sub u}}=m{sub H{sub d}}{ne}m{sub 0}, we find bino-Higgsino dark matter as well as the stau coannihilation and A-funnel solutions. The constrained minimal sumersymmetric model case yields the stau coannihilation and A-funnel solutions. The gluino and squark masses are found to lie in the TeV range.
Yukawa corrections to {gamma}{gamma}{yields}bb in the topcolor assisted technicolor models
Huang Jinshu; Lu Gongru
2008-08-01
We study the Yukawa corrections to the {gamma}{gamma}{yields}bb cross section in the topcolor assisted technicolor models at the photon-photon colliders. We find that, for the favorable parameters, the relative corrections from pseudo-Goldstone bosons give out a 3.2%{approx}5.9% decrement of the cross section from the tree level when {radical}(s)=500 GeV, the contributions from new extended technicolor gauge bosons Z* and colored gauge bosons B are negligibly small, and the relative correction arising from new color-singlet heavy gauge boson Z{sup '} is less than -3.2%. Therefore, the total relative corrections are significantly larger than the corresponding corrections in the standard model, the general two Higgs doublet model, and the minimal supersymmetric standard model. Since these corrections are obvious for the International Linear Colliders, the process {gamma}{gamma}{yields}bb is really interesting in testing the standard model and searching for the signs of technicolor.
Yukawa unification in an SO(10) SUSY GUT: SUSY on the edge
NASA Astrophysics Data System (ADS)
Poh, Zijie; Raby, Stuart
2015-07-01
In this paper we analyze Yukawa unification in a three family SO(10) SUSY GUT. We perform a global χ2 analysis and show that supersymmetry (SUSY) effects do not decouple even though the universal scalar mass parameter at the grand unified theory (GUT) scale, m16, is found to lie between 15 and 30 TeV with the best fit given for m16≈25 TeV . Note, SUSY effects do not decouple since stops and bottoms have mass of order 5 TeV, due to renormalization group running from MGUT. The model has many testable predictions. Gauginos are the lightest sparticles and the light Higgs boson is very much standard model-like. The model is consistent with flavor and C P observables with the BR (μ →e γ ) close to the experimental upper bound. With such a large value of m16 we clearly cannot be considered "natural" SUSY nor are we "split" SUSY. We are thus in the region in between or "SUSY on the edge."
Quark number fluctuations at high temperatures
Petreczky, P.; Hegde, P.; Velytsky, A.
2009-11-01
We calculate the second, fourth and sixth order quark number fluctuations in the deconfined phase of 2+1 flavor QCD using lattices with temporal extent N{sub t} = 4,6,8 and 12. We consider light, strange and charm quarks. We use p4 action for valence quarks and gauge configurations generated with p4 action with physical value of the strange quark mass and light quark mass m{sub q} = 0.1 m{sub s} generated by the RBC-Bielefeld collaboration. We observe that for all quark masses the quark number fluctuations rapidly get close to the corresponding ideal gas limits. We compare our results to predictions of a quasi-particle model and resummed high temperature perturbative calculations. We also investigate correlations among different flavor channels.
Nonequilibrium hadronization and constituent quark number scaling
Zschocke, Sven; Horvat, Szabolcs; Mishustin, Igor N.; Csernai, Laszlo P.
2011-04-15
The constituent quark number scaling of elliptic flow is studied in a nonequilibrium hadronization and freeze-out model with rapid dynamical transition from ideal, deconfined, and chirally symmetric quark-gluon plasma, to final noninteracting hadrons. In this transition a bag model of constituent quarks is considered, where the quarks gain constituent quark mass while the background bag field breaks up and vanishes. The constituent quarks then recombine into simplified hadron states, while chemical, thermal, and flow equilibrium break down one after the other. In this scenario the resulting temperatures and flow velocities of baryons and mesons are different. Using a simplified few source model of the elliptic flow, we are able to reproduce the constituent quark number scaling, with assumptions on the details of the nonequilibrium processes.
QCD constraints on the shape of polarized quark and gluon distributions
NASA Astrophysics Data System (ADS)
Brodsky, Stanley J.; Burkardt, Matthias; Schmidt, Ivan
1995-02-01
We develop simple analytic representations of the polarized quark and gluon distributions in the nucleon at low Q2 which incorporate general constraints obtained from the requirements of color coherence of gluon couplings at x ˜ 0 and the helicity retention properties of perturbative QCD couplings at x ˜ 1. The unpolarized predictions are similar to the Do' distributions given by Martin, Roberts, and Stirling. The predictions for the quark helicity distributions are compared with polarized structure functions measured by the E142 experiment at SLAC and the SMC experiment at CERN.
Z -peaked excess from heavy gluon decays to vectorlike quarks
NASA Astrophysics Data System (ADS)
Vignaroli, Natascia
2015-06-01
A 3 sigma excess has been recently announced by ATLAS in events with Z -peaked dilepton pairs, jets, and large transverse missing energy. We interpret this finding in the context of composite Higgs/Randall-Sundrum theories. We find that composite Higgs theories with custodial symmetry protection to the Z b b ¯ coupling predict a significant contribution to Z Z b b (and to h h b b ) final states coming from heavy gluon decays to pairs of bottom partner vectorlike quarks. The heavy gluon to vectorlike quark signal is largely accepted by the ATLAS selection if one of the Z bosons in the Z Z b b final state decays leptonically and the other to neutrinos. For a bottom partner of ˜900 GeV , we find that the ATLAS excess can be reproduced by composite Higgs models, in an experimentally allowed parameter space, for heavy gluon masses roughly in a range 1.87-2.15 TeV and for heavy gluon couplings to light quarks within ˜(0.3 - 0.65 )gS . We briefly discuss the implication of this result for future experimental tests.
NASA Astrophysics Data System (ADS)
Bouzas, Antonio O.; Larios, F.
2015-11-01
We study the DIS and photo-production modes of pairs at the proposed LHeC and its potential to probe the electromagnetic and weak dipole moments (MDM and EDM for ttγ) of the top quark. A framework of eight independent gauge invariant dimension six operators involving the top quark and the electroweak gauge bosons is used. Four of those operators modify the charged tbW coupling which can be probed through the single (anti) top production mode as reported in the literature. One generates ttγ(Z) as well as tbW couplings, while other two do not generate tbW but only ttγ(Z). Our focus is on the MDM and EDM of the top quark for which the photo-production mode of can be an excellent probe. At the proposed electron energies of Ee = 60 and 140 GeV the LHeC could set constraints stronger than the indirect limits from b → sγ and the potential limits of the LHC through production[1].
Energy change of a heavy quark in a viscous quark-gluon plasma with fluctuations
NASA Astrophysics Data System (ADS)
Jiang, Bing-feng; Hou, De-fu; Li, Jia-rong
2016-09-01
When a heavy quark travels through the quark-gluon plasma, the polarization and fluctuating chromoelectric fields will be produced simultaneously in the plasma. The drag force due to those fields exerting in return on the moving heavy quark will cause energy change to it. Based on the dielectric functions derived from the viscous chromohydrodynamics, we have studied the collisional energy change of a heavy quark traversing the viscous quark-gluon plasma including fluctuations of chromoelectric field. Numerical results indicate that the chromoelectric field fluctuations lead to an energy gain of the moving heavy quark. Shear viscosity suppresses the fluctuation-induced energy gain and the viscous suppression effect for the charm quark is much more remarkable than that for the bottom quark. While, the fluctuation energy gain is much smaller than the polarization energy loss in magnitude and the net energy change for the heavy quark is at loss.
Single Spin Asymmetry in Strongly Correlated Quark Model
Musulmanbekov, G.
2007-06-13
The Single Transverse - Spin Asymmetry (SSA) is analysed in the framework of the Strongly Correlated Quark Model proposed by author, where the proton spin emerges from the orbital momenta of quark and qluon condensates circulating around the valence quarks. It is shown that dominating factors of appearance of SSA are the orbiting around the valence quarks sea quark and qluon condensates and spin dependent quark-quark cross sections.
One-Loop β Functions for Yukawa Couplings in the Electroweak-Scale Right-Handed Neutrino Model
NASA Astrophysics Data System (ADS)
Nhu Le, Nguyen; Quang Hung, Pham
2014-09-01
Fermions in the model of electroweak-scale right-handed neutrinos (EWRH) with masses of the order of 300 GeV or more could result in dynamical electroweak symmetry breaking by forming condensates through the exchange of a fundamental Higgs scalar doublet or triplet. These condensates are dynamically studied within the framework of the Schwinger- Dyson equation. With the electroweak symmetry broken by condensates, the fully worked-out model of EWRH in which there are two doublets and two triplets, one of which is composite and the others being the original fundamental scalar doublet and triplet could be suitable for recent LHC discovery of the 125 GeV scalar particle.
Quark-Gluon Soup -- The Perfectly Liquid Phase of QCD
NASA Astrophysics Data System (ADS)
Heinz, Ulrich
2015-03-01
At temperatures above about 150 MeV and energy densities exceeding 500 MeV/fm3, quarks and gluons exist in the form of a plasma of free color charges that is about 1000 times hotter and a billion times denser than any other plasma ever created in the laboratory. This quark-gluon plasma (QGP) turns out to be strongly coupled, flowing like a liquid. About 35 years ago, the nuclear physics community started a program of relativistic heavy-ion collisions with the goal of producing and studying QGP under controlled laboratory conditions. This article recounts the story of its successful creation in collider experiments at Brookhaven National Laboratory and CERN and the subsequent discovery of its almost perfectly liquid nature, and reports on the recent quantitatively precise determination of its thermodynamic and transport properties.
QCD phase transition with chiral quarks and physical quark masses.
Bhattacharya, Tanmoy; Buchoff, Michael I; Christ, Norman H; Ding, H-T; Gupta, Rajan; Jung, Chulwoo; Karsch, F; Lin, Zhongjie; Mawhinney, R D; McGlynn, Greg; Mukherjee, Swagato; Murphy, David; Petreczky, P; Renfrew, Dwight; Schroeder, Chris; Soltz, R A; Vranas, P M; Yin, Hantao
2014-08-22
We report on the first lattice calculation of the QCD phase transition using chiral fermions with physical quark masses. This calculation uses 2+1 quark flavors, spatial volumes between (4 fm)(3) and (11 fm)(3) and temperatures between 139 and 196 MeV. Each temperature is calculated at a single lattice spacing corresponding to a temporal Euclidean extent of N(t) = 8. The disconnected chiral susceptibility, χ(disc) shows a pronounced peak whose position and height depend sensitively on the quark mass. We find no metastability near the peak and a peak height which does not change when a 5 fm spatial extent is increased to 10 fm. Each result is strong evidence that the QCD "phase transition" is not first order but a continuous crossover for m(π) = 135 MeV. The peak location determines a pseudocritical temperature T(c) = 155(1)(8) MeV, in agreement with earlier staggered fermion results. However, the peak height is 50% greater than that suggested by previous staggered results. Chiral SU(2)(L) × SU(2)(R) symmetry is fully restored above 164 MeV, but anomalous U(1)(A) symmetry breaking is nonzero above T(c) and vanishes as T is increased to 196 MeV. PMID:25192088
Measurement of parity violation in electron–quark scattering
Wang, D.; Pan, K.; Subedi, R.; Deng, X.; Ahmed, Z.; Allada, K.; Aniol, K. A.; Armstrong, D. S.; Arrington, J.; Bellini, V.; Beminiwattha, R.; Benesch, J.; Benmokhtar, F.; Bertozzi, W.; Camsonne, A.; Canan, M.; Cates, G. D.; Chen, J.-P.; Chudakov, E.; Cisbani, E.; Dalton, M. M.; de Jager, C. W.; De Leo, R.; Deconinck, W.; Deur, A.; Dutta, C.; El Fassi, L.; Erler, J.; Flay, D.; Franklin, G. B.; Friend, M.; Frullani, S.; Garibaldi, F.; Gilad, S.; Giusa, A.; Glamazdin, A.; Golge, S.; Grimm, K.; Hafidi, K.; Hansen, J.-O.; Higinbotham, D. W.; Holmes, R.; Holmstrom, T.; Holt, R. J.; Huang, J.; Hyde, C. E.; Jen, C. M.; Jones, D.; Kang, Hoyoung; King, P. M.; Kowalski, S.; Kumar, K. S.; Lee, J. H.; LeRose, J. J.; Liyanage, N.; Long, E.; McNulty, D.; Margaziotis, D. J.; Meddi, F.; Meekins, D. G.; Mercado, L.; Meziani, Z.-E.; Michaels, R.; Mihovilovic, M.; Muangma, N.; Myers, K. E.; Nanda, S.; Narayan, A.; Nelyubin, V.; Nuruzzaman,; Oh, Y.; Parno, D.; Paschke, K. D.; Phillips, S. K.; Qian, X.; Qiang, Y.; Quinn, B.; Rakhman, A.; Reimer, P. E.; Rider, K.; Riordan, S.; Roche, J.; Rubin, J.; Russo, G.; Saenboonruang, K.; Saha, A.; Sawatzky, B.; Shahinyan, A.; Silwal, R.; Sirca, S.; Souder, P. A.; Suleiman, R.; Sulkosky, V.; Sutera, C. M.; Tobias, W. A.; Urciuoli, G. M.; Waidyawansa, B.; Wojtsekhowski, B.; Ye, L.; Zhao, B.; Zheng, X.
2014-02-05
Symmetry permeates nature and is fundamental to all laws of physics. One example is parity (mirror) symmetry, which implies that flipping left and right does not change the laws of physics. Laws for electromagnetism, gravity and the subatomic strong force respect parity symmetry, but the subatomic weak force does not. Historically, parity violation in electron scattering has been important in establishing (and now testing) the standard model of particle physics. One particular set of quantities accessible through measurements of parity-violating electron scattering are the effective weak couplings C2q, sensitive to the quarks chirality preference when participating in the weak force, which have been measured directly3, 4 only once in the past 40?years. Here we report a measurement of the parity-violating asymmetry in electron-quark scattering, which yields a determination of 2C2u???C2d (where u and d denote up and down quarks, respectively) with a precision increased by a factor of five relative to the earlier result. These results provide evidence with greater than 95 per cent confidence that the C2q couplings are non-zero, as predicted by the electroweak theory. They lead to constraints on new parity-violating interactions beyond the standard model, particularly those due to quark chirality. Whereas contemporary particle physics research is focused on high-energy colliders such as the Large Hadron Collider, our results provide specific chirality information on electroweak theory that is difficult to obtain at high energies. Our measurement is relatively free of ambiguity in its interpretation, and opens the door to even more precise measurements in the future.
Measurement of parity violation in electron-quark scattering
NASA Astrophysics Data System (ADS)
The Jefferson Lab Pvdis Collaboration; Wang, D.; Pan, K.; Subedi, R.; Deng, X.; Ahmed, Z.; Allada, K.; Aniol, K. A.; Armstrong, D. S.; Arrington, J.; Bellini, V.; Beminiwattha, R.; Benesch, J.; Benmokhtar, F.; Bertozzi, W.; Camsonne, A.; Canan, M.; Cates, G. D.; Chen, J.-P.; Chudakov, E.; Cisbani, E.; Dalton, M. M.; de Jager, C. W.; de Leo, R.; Deconinck, W.; Deur, A.; Dutta, C.; El Fassi, L.; Erler, J.; Flay, D.; Franklin, G. B.; Friend, M.; Frullani, S.; Garibaldi, F.; Gilad, S.; Giusa, A.; Glamazdin, A.; Golge, S.; Grimm, K.; Hafidi, K.; Hansen, J.-O.; Higinbotham, D. W.; Holmes, R.; Holmstrom, T.; Holt, R. J.; Huang, J.; Hyde, C. E.; Jen, C. M.; Jones, D.; Kang, Hoyoung; King, P. M.; Kowalski, S.; Kumar, K. S.; Lee, J. H.; Lerose, J. J.; Liyanage, N.; Long, E.; McNulty, D.; Margaziotis, D. J.; Meddi, F.; Meekins, D. G.; Mercado, L.; Meziani, Z.-E.; Michaels, R.; Mihovilovic, M.; Muangma, N.; Myers, K. E.; Nanda, S.; Narayan, A.; Nelyubin, V.; Nuruzzaman; Oh, Y.; Parno, D.; Paschke, K. D.; Phillips, S. K.; Qian, X.; Qiang, Y.; Quinn, B.; Rakhman, A.; Reimer, P. E.; Rider, K.; Riordan, S.; Roche, J.; Rubin, J.; Russo, G.; Saenboonruang, K.; Saha, A.; Sawatzky, B.; Shahinyan, A.; Silwal, R.; Sirca, S.; Souder, P. A.; Suleiman, R.; Sulkosky, V.; Sutera, C. M.; Tobias, W. A.; Urciuoli, G. M.; Waidyawansa, B.; Wojtsekhowski, B.; Ye, L.; Zhao, B.; Zheng, X.
2014-02-01
Symmetry permeates nature and is fundamental to all laws of physics. One example is parity (mirror) symmetry, which implies that flipping left and right does not change the laws of physics. Laws for electromagnetism, gravity and the subatomic strong force respect parity symmetry, but the subatomic weak force does not. Historically, parity violation in electron scattering has been important in establishing (and now testing) the standard model of particle physics. One particular set of quantities accessible through measurements of parity-violating electron scattering are the effective weak couplings C2q, sensitive to the quarks' chirality preference when participating in the weak force, which have been measured directly only once in the past 40years. Here we report a measurement of the parity-violating asymmetry in electron-quark scattering, which yields a determination of 2C2u-C2d (where u and d denote up and down quarks, respectively) with a precision increased by a factor of five relative to the earlier result. These results provide evidence with greater than 95 per cent confidence that the C2q couplings are non-zero, as predicted by the electroweak theory. They lead to constraints on new parity-violating interactions beyond the standard model, particularly those due to quark chirality. Whereas contemporary particle physics research is focused on high-energy colliders such as the Large Hadron Collider, our results provide specific chirality information on electroweak theory that is difficult to obtain at high energies. Our measurement is relatively free of ambiguity in its interpretation, and opens the door to even more precise measurements in the future.
Measurement of parity violation in electron-quark scattering.
2014-02-01
Symmetry permeates nature and is fundamental to all laws of physics. One example is parity (mirror) symmetry, which implies that flipping left and right does not change the laws of physics. Laws for electromagnetism, gravity and the subatomic strong force respect parity symmetry, but the subatomic weak force does not. Historically, parity violation in electron scattering has been important in establishing (and now testing) the standard model of particle physics. One particular set of quantities accessible through measurements of parity-violating electron scattering are the effective weak couplings C2q, sensitive to the quarks' chirality preference when participating in the weak force, which have been measured directly only once in the past 40 years. Here we report a measurement of the parity-violating asymmetry in electron-quark scattering, which yields a determination of 2C2u - C2d (where u and d denote up and down quarks, respectively) with a precision increased by a factor of five relative to the earlier result. These results provide evidence with greater than 95 per cent confidence that the C2q couplings are non-zero, as predicted by the electroweak theory. They lead to constraints on new parity-violating interactions beyond the standard model, particularly those due to quark chirality. Whereas contemporary particle physics research is focused on high-energy colliders such as the Large Hadron Collider, our results provide specific chirality information on electroweak theory that is difficult to obtain at high energies. Our measurement is relatively free of ambiguity in its interpretation, and opens the door to even more precise measurements in the future. PMID:24499917
Quark eigenmodes and lattice QCD
NASA Astrophysics Data System (ADS)
Liu, Guofeng
In this thesis, we study a number of topics in lattice QCD through the low-lying quark eigenmodes in the domain wall fermion (DWF) formulation in the quenched approximation. Specifically, we present results for the chiral condensate measured from these eigenmodes; we investigate the QCD vacuum structure by looking at the correlation between the magnitude of the chirality density, |psi†(x)gamma5psi( x)|, and the normal density, psi†( x)psi(x), for these states; we study the behavior of DWF formulation at large quark masses by investigating the mass dependence of the eigenvalues of the physical four dimensional-states as well as the bulk, five-dimensional states.
STAR: Characterizing hot quark matter
NASA Astrophysics Data System (ADS)
Van Buren, G.; STAR Collaboration
2013-04-01
With discovery of Quark Gluon Plasma well-established at RHIC, the STAR Experiment continues to work toward a more complete understanding of properties of the produced matter, and the conditions necessary for the phase change. We will present recent progress on characterizing quark matter at high temperature through a wide variety of measurement techniques in STAR's repertoire: from observing species suppression and correlations, to determining statistical moments and prospecting for symmetry-breaking. RHIC has further embarked on a program to study this matter through a range of conditions achieved by varying the collision energies, which are hoped to span and locate the QCD critical point. We will show how STAR's toolkit is already providing intriguing results from the the first phase of this program and discuss possible future directions for the program.
DOE R&D Accomplishments Database
Walsh, Karen McNulty
2011-03-28
Near-light-speed collisions of gold ions provide a recipe for in-depth explorations of matter and fundamental forces. The Relativistic Heavy Ion Collider (RHIC) has produced the most massive antimatter nucleus ever discovered—and the first containing an anti-strange quark. The presence of strange antimatter makes this antinucleus the first to be entered below the plane of the classic Periodic Table of Elements, marking a new frontier in physics.
Fluctuation Probes of Quark Deconfinement
Asakawa, Masayuki; Heinz, Ulrich; Mueller, Berndt
2000-09-04
The size of the average fluctuations of net baryon number and electric charge in a finite volume of hadronic matter differs widely between the confined and deconfined phases. These differences may be exploited as indicators of the formation of a quark-gluon plasma in relativistic heavy-ion collisions, because fluctuations created in the initial state survive until freeze-out due to the rapid expansion of the hot fireball. (c) 2000 The American Physical Society.
C. Paus
2002-11-13
The contribution summarizes the latest results from CDF on heavy quark production. Results from top, bottom and charm production are included. Some new analysis using Run I (1991-1994) data have become available. More importantly there are a number of results using Run II data which began in April 2001. The data indicate the potential of CDF for bottom and charm production physics in the near future.
Magnetism in Dense Quark Matter
NASA Astrophysics Data System (ADS)
Ferrer, Efrain J.; de la Incera, Vivian
We review the mechanisms via which an external magnetic field can affect the ground state of cold and dense quark matter. In the absence of a magnetic field, at asymptotically high densities, cold quark matter is in the Color-Flavor-Locked (CFL) phase of color superconductivity characterized by three scales: the superconducting gap, the gluon Meissner mass, and the baryonic chemical potential. When an applied magnetic field becomes comparable with each of these scales, new phases and/or condensates may emerge. They include the magnetic CFL (MCFL) phase that becomes relevant for fields of the order of the gap scale; the paramagnetic CFL, important when the field is of the order of the Meissner mass, and a spin-one condensate associated to the magnetic moment of the Cooper pairs, significant at fields of the order of the chemical potential. We discuss the equation of state (EoS) of MCFL matter for a large range of field values and consider possible applications of the magnetic effects on dense quark matter to the astrophysics of compact stars.
Lifetimes and heavy quark expansion
NASA Astrophysics Data System (ADS)
Lenz, Alexander
2015-04-01
Kolya Uraltsev was one of the inventors of the Heavy Quark Expansion (HQE), that describes inclusive weak decays of hadrons containing heavy quarks and in particular lifetimes. Besides giving a pedagogic introduction to the subject, we review the development and the current status of the HQE, which just recently passed several non-trivial experimental tests with an unprecedented precision. In view of many new experimental results for lifetimes of heavy hadrons, we also update several theory predictions: τ (B+)/τ (Bd) = 1.04+0.05-0.01 ± 0.02 ± 0.01, τ(Bs)/τ(Bd) = 1.001 ±0.002, τ(Λb)/τ(Bd) = 0.935 ±0.054 and \\bar {τ } (Ξ b0)/\\bar {τ } (Ξ b+) = 0.95 ± 0.06. The theoretical precision is currently strongly limited by the unknown size of the non-perturbative matrix elements of four-quark operators, which could be determined with lattice simulations.
Electrically charged strange quark stars
Negreiros, Rodrigo Picanco; Weber, Fridolin; Malheiro, Manuel; Usov, Vladimir
2009-10-15
The possible existence of compact stars made of absolutely stable strange quark matter--referred to as strange stars--was pointed out by Witten almost a quarter of a century ago. One of the most amazing features of such objects concerns the possible existence of ultrastrong electric fields on their surfaces, which, for ordinary strange matter, is around 10{sup 18} V/cm. If strange matter forms a color superconductor, as expected for such matter, the strength of the electric field may increase to values that exceed 10{sup 19} V/cm. The energy density associated with such huge electric fields is on the same order of magnitude as the energy density of strange matter itself, which, as shown in this paper, alters the masses and radii of strange quark stars at the 15% and 5% levels, respectively. Such mass increases facilitate the interpretation of massive compact stars, with masses of around 2M{sub {center_dot}}, as strange quark stars.
Quark masses and their hierarchies
NASA Astrophysics Data System (ADS)
Ida, M.
1987-12-01
Electroweak symmetry breaking is attributed to dynamical generation of quark masses. Quarks q (and leptons l) are assumed to be produced by hypercolor confinement of preons at an intermediate scale Λ hc. Hierarchies observed in the q mass spectra can be explained by a BCS mechanism if the color interaction is enough asymptotically free and if residual ones emerging by the confinement are medium strong. The former assumption claims that N≦4, where N is the family number of q and l. Dynamical equations to determine q masses and mixings are given, but they require knowledge on the physics at Λ hc. A phenomenological approach is also made on the basis of an SU(7)× SU(7) chiral preon model with N=4. The mass ratio m t/ mb is related to ( m c/ m s)ηB with η B≃1.1 and m t'/ mb' to ( m u/ m d)ηA with η A≃1.4. In this scheme the fourth down quark is the heaviest (˜ 110 GeV) and contributes dominantly to F 2, where F is the Fermi scale.
NASA Astrophysics Data System (ADS)
Khan, Saki
2016-06-01
We present a minimal renormalizable non-supersymmetric S O(10) grand unified model with a symmetry breaking sector consisting of Higgs fields in the 54H + 126H + 10H representations. This model admits a single intermediate scale associated with Pati-Salam symmetry along with a discrete parity. Spontaneous symmetry breaking, the unification of gauge couplings and proton lifetime estimates are studied in detail in this framework. Including threshold corrections self-consistently, obtained from a full analysis of the Higgs potential, we show that the model is compatible with the current experimental bound on proton lifetime. The model generally predicts an upper bound of few times 1035 yrs for proton lifetime, which is not too far from the present Super-Kamiokande limit of τp ≳ 1.29 × 1034 yrs. With the help of a Pecci-Quinn symmetry and the resulting axion, the model provides a suitable dark matter candidate while also solving the strong CP problem. The intermediate scale, MI ≈ (1013 - 1014) GeV which is also the B - L scale, is of the right order for the right-handed neutrino mass which enables a successful description of light neutrino masses and oscillations. The Yukawa sector of the model consists of only two matrices in family space and leads to a predictive scenario for quark and lepton masses and mixings. The branching ratios for proton decay are calculable with the leading modes being p → e+π0 and p →v ¯π+ . Even though the model predicts no new physics within the reach of LHC, the next generation proton decay detectors and axion search experiments have the capability to pass verdict on this minimal scenario.
Revision of FMM-Yukawa: An adaptive fast multipole method for screened Coulomb interactions
NASA Astrophysics Data System (ADS)
Zhang, Bo; Huang, Jingfang; Pitsianis, Nikos P.; Sun, Xiaobai
2010-12-01
FMM-YUKAWA is a mathematical software package primarily for rapid evaluation of the screened Coulomb interactions of N particles in three dimensional space. Since its release, we have revised and re-organized the data structure, software architecture, and user interface, for the purpose of enabling more flexible, broader and easier use of the package. The package and its documentation are available at http://www.fastmultipole.org/, along with a few other closely related mathematical software packages. New version program summaryProgram title: FMM-Yukawa Catalogue identifier: AEEQ_v2_0 Program summary URL:http://cpc.cs.qub.ac.uk/summaries/AEEQ_v2_0.html Program obtainable from: CPC Program Library, Queen's University, Belfast, N. Ireland Licensing provisions: GNU GPL 2.0 No. of lines in distributed program, including test data, etc.: 78 704 No. of bytes in distributed program, including test data, etc.: 854 265 Distribution format: tar.gz Programming language: FORTRAN 77, FORTRAN 90, and C. Requires gcc and gfortran version 4.4.3 or later Computer: All Operating system: Any Classification: 4.8, 4.12 Catalogue identifier of previous version: AEEQ_v1_0 Journal reference of previous version: Comput. Phys. Comm. 180 (2009) 2331 Does the new version supersede the previous version?: Yes Nature of problem: To evaluate the screened Coulomb potential and force field of N charged particles, and to evaluate a convolution type integral where the Green's function is the fundamental solution of the modified Helmholtz equation. Solution method: The new version of fast multipole method (FMM) that diagonalizes the multipole-to-local translation operator is applied with the tree structure adaptive to sample particle locations. Reasons for new version: To handle much larger particle ensembles, to enable the iterative use of the subroutines in a solver, and to remove potential contention in assignments for parallelization. Summary of revisions: The software package FMM-Yukawa has been
Constraints on top quark flavor changing neutral currents using diphoton events at the LHC
NASA Astrophysics Data System (ADS)
Khatibi, Sara; Mohammadi Najafabadi, Mojtaba
2016-08-01
In this paper we show that the diphoton mass spectrum in proton-proton collisions at the LHC is sensitive to the top quark flavor changing neutral current in the vertices of tuγ and tcγ. The diphoton mass spectrum measured by the CMS experiment at the LHC at a center-of-mass energy of 8 TeV and an integrated luminosity of 19.5 fb-1 is used as an example to set limits on these FCNC couplings. It is also shown that the angular distribution of the diphotons is sensitive to anomalous tuγ and tcγ couplings and it is a powerful tool to probe any value of the branching fraction of top quark rare decay to an up-type quark plus a photon down to the order of 10-4.
Pion form factor using domain wall valence quarks and asqtad sea quarks
George Fleming; Frederic Bonnet; Robert Edwards; Randal Lewis; David Richards
2004-09-01
We compute the pion electromagnetic form factor in a hybrid calculation with domain wall valence quarks and improved staggered (asqtad) sea quarks. This method can easily be extended to rho-to-gamma-pi transition form factors.
Physics of the nucleon sea quark distributions
Vogt, R.
2000-03-10
Sea quark distributions in the nucleon have naively been expected to be generated perturbatively by gluon splitting. In this case, there is no reason for the light quark and anti-quark sea distributions to be different. No asymmetries in the strange or heavy quark sea distributions are predicted in the improved parton model. However,recent experiments have called these naive expectations into question. A violation of the Gottfried sum rule has been measured in several experiments, suggesting that (bar u) < (bar d) in the proton. Additionally, other measurements, while not definitive, show that there may be an asymmetry in the strange and anti-strange quark sea distributions. These effects may require nonperturbative explanations. In this review we first discuss the perturbative aspects of the sea quark distributions. We then describe the experiments that could point to nonperturbative contributions to the nucleon sea. Current phenomenological models that could explain some of these effects are reviewed.
Gluonic structure of the constituent quark
NASA Astrophysics Data System (ADS)
Kochelev, Nikolai; Lee, Hee-Jung; Zhang, Baiyang; Zhang, Pengming
2016-06-01
Based on both the constituent quark picture and the instanton model for QCD vacuum, we calculate the unpolarized and polarized gluon distributions in the constituent quark and in the nucleon. Our approach consists of the two main steps. At the first step, we calculate the gluon distributions inside the constituent quark generated by the perturbative quark-gluon interaction, the non-perturbative quark-gluon interaction, and the non-perturbative quark-gluon-pion anomalous chromomagnetic interaction. The non-perturbative interactions are related to the existence of the instantons, strong topological fluctuations of gluon fields, in the QCD vacuum. At the second step, the convolution model is applied to derive the gluon distributions in the nucleon. A very important role of the pion field in producing the unpolarized and the polarized gluon distributions in the hadrons is discovered. We discuss a possible solution of the proton spin problem.
Planets orbiting Quark Nova compact remnants
NASA Astrophysics Data System (ADS)
Keränen, P.; Ouyed, R.
2003-08-01
We explore planet formation in the Quark Nova scenario. If a millisecond pulsar explodes as a Quark Nova, a protoplanetary disk can be formed out of the metal rich fall-back material. The propeller mechanism transfers angular momentum from the born quark star to the disk that will go through viscous evolution with later plausible grain condensation and planet formation. As a result, earth-size planets on circular orbits may form within short radii from the central quark star. The planets in the PSR 1257+12 system can be explained by our model if the Quark Nova compact remnant is born with a period of ~ 0.5 ms following the explosion. We suggest that a good portion of the Quark Nova remnants may harbour planetary systems.
The CGC and the Glasma: Two Lectures at the Yukawa Institute
McLerran, L.
2010-08-10
These lectures present the theory of the Color Glass Condensate (CGC) and the Glasma in an elementary and intuitive manner. This matter controls the high energy limit of QCD. The CGC is the universal limit for the components of a hadron wavefunction important for high energy scattering processes. It is a highly coherent, extremely high energy density ensemble of gluon states. The Glasma is matter produced in the collision of CGCs of two hadrons. It has properties much different from those of the CGC, and is produced in a very short time after the collision. It eventually evolves from the the Color Glass Condensate initial conditions into a Quark Gluon Plasma. We can visualize the collision of two high energy hadrons as shown in Fig. 1. Before the collision, two hadrons appear as Lorentz contracted sheets approaching one another at near light speed. These we will later describe as two sheets of Colored Glass. In a very short time, the sheets of Color Glass interpenetrate one another. This we think of as the initial singularity for the collision. This is of course not a real singularity for finite collision energy, but we will see it becomes one in the limit of infinite energy. After the initial singularity, a Glasma is formed. This is composed of highly coherent gluon fields of very high energy density. If we imagine that the sheets of Colored Glass have passed through one another largely intact, the Glasma forms in the region between the receding sheets. As time goes on, the Glasma evolves into a Quark Gluon Plasma, and eventually into a gas of ordinary hadrons. These lectures are about the earliest stages of these collisions, and will describe neither the Quark Gluon Plasma nor the Hadron Gas. I will motivate the CGC and Glasma from simple physical considerations, and provide a sketchy derivation from QCD. There will be some discussion of experimental tests of these ideas.