Goldman, T.
1991-01-01
Two dibaryons, one with high strangeness, the other with the quantum numbers of a spin excitation of the deuteron, are found in essentially all models of QCD. Experimental proof that they are not produced at levels well below the predicted cross sections would require major revisions of our understanding of QCD. 14 refs., 4 tabs.
NASA Technical Reports Server (NTRS)
Olinto, Angela V.; Haensel, Pawel; Frieman, Joshua A.
1991-01-01
The effects are studied of H-dibaryons on the structure of neutron stars. It was found that H particles could be present in neutron stars for a wide range of dibaryon masses. The appearance of dibaryons softens the equations of state, lowers the maximum neutron star mass, and affects the transport properties of dense matter. The parameter space is constrained for dibaryons by requiring that a 1.44 solar mass neutron star be gravitationally stable.
Dibaryons from Exceptional Collections
NASA Astrophysics Data System (ADS)
Herzog, Christopher P.; Walcher, Johannes
2003-09-01
We discuss aspects of the dictionary between brane configurations in del Pezzo geometries and dibaryons in the dual superconformal quiver gauge theories. The basis of fractional branes defining the quiver theory at the singularity has a K-theoretic dual exceptional collection of bundles which can be used to read off the spectrum of dibaryons in the weakly curved dual geometry. Our prescription identifies the R-charge R and all baryonic U(1) charges QI with divisors in the del Pezzo surface without any Weyl group ambiguity. As one application of the correspondence, we identify the cubic anomaly trRQIQJ as an intersection product for dibaryon charges in large-N superconformal gauge theories. Examples can be given for all del Pezzo surfaces using three- and four-block exceptional collections. Markov-type equations enforce consistency among anomaly equations for three-block collections.
NN and Nd Scattering with Intermediate Dibaryons
NASA Astrophysics Data System (ADS)
Platonova, Maria N.
2017-03-01
Excitation of intermediate dibaryon resonances in hadronic processes accompanied by high momentum transfers is considered. It is shown that some basic features of NN inelastic scattering with single- or double-pion production can be effectively described by taking into account the short-range s-channel dibaryon excitation along with peripheral t-channel meson-exchange processes. In particular, isovector dibaryons with I(J^P)=1(2^+), 1(3^-) and 1(2^-) are shown to play an important role in reproducing the cross sections and especially polarization observables in the basic single-pion production reaction pp → dπ ^+, while an isoscalar I(J^P)=0(3^+) dibaryon is crucial for describing the basic double-pion production process pn → d (π π )_0. Possible generalization of resonance (dibaryon) mechanisms considered in NN scattering to Nd elastic and inelastic scattering is also discussed.
Holographic QCD for H-dibaryon (uuddss)
NASA Astrophysics Data System (ADS)
Suganuma, Hideo; Matsumoto, Kohei
2017-03-01
The H-dibaryon (uuddss) is studied in holographic QCD for the first time. In holographic QCD, four-dimensional QCD, i.e., SU(Nc) gauge theory with chiral quarks, can be formulated with S1-compactified D4/D8/\\overline {{{D8}}} -brane system. In holographic QCD with large (Nc, all the baryons appear as topological chiral solitons of Nambu-Goldstone bosons and (axial) vector mesons, and the H-dibaryon can be described as an SO(3)-type topological soliton with B = 2. We derive the low-energy effective theory to describe the H-dibaryon in holographic QCD. The H-dibaryon mass is found to be twice of the B = 1 hedgehog-baryon mass, MH ≃ 2.00MB=1HH, and is estimated about 1.7GeV, which is smaller than mass of two nucleons (flavor-octet baryons), in the chiral limit.
Search for an isospin I = 3 dibaryon
NASA Astrophysics Data System (ADS)
Adlarson, P.; Augustyniak, W.; Bardan, W.; Bashkanov, M.; Bergmann, F. S.; Berłowski, M.; Bhatt, H.; Bondar, A.; Büscher, M.; Calén, H.; Ciepał, I.; Clement, H.; Czerwiński, E.; Demmich, K.; Engels, R.; Erven, A.; Erven, W.; Eyrich, W.; Fedorets, P.; Föhl, K.; Fransson, K.; Goldenbaum, F.; Goswami, A.; Grigoryev, K.; Gullström, C.-O.; Heijkenskjöld, L.; Hejny, V.; Hüsken, N.; Jarczyk, L.; Johansson, T.; Kamys, B.; Kemmerling, G.; Khan, F. A.; Khatri, G.; Khoukaz, A.; Khreptak, O.; Kirillov, D. A.; Kistryn, S.; Kleines, H.; Kłos, B.; Krzemień, W.; Kulessa, P.; Kupść, A.; Kuzmin, A.; Lalwani, K.; Lersch, D.; Lorentz, B.; Magiera, A.; Maier, R.; Marciniewski, P.; Mariański, B.; Morsch, H.-P.; Moskal, P.; Ohm, H.; Perez del Rio, E.; Piskunov, N. M.; Prasuhn, D.; Pszczel, D.; Pysz, K.; Pyszniak, A.; Ritman, J.; Roy, A.; Rudy, Z.; Rundel, O.; Sawant, S.; Schadmand, S.; Schätti-Ozerianska, I.; Sefzick, T.; Serdyuk, V.; Shwartz, B.; Sitterberg, K.; Skorodko, T.; Skurzok, M.; Smyrski, J.; Sopov, V.; Stassen, R.; Stepaniak, J.; Stephan, E.; Sterzenbach, G.; Stockhorst, H.; Ströher, H.; Szczurek, A.; Trzciński, A.; Varma, R.; Wolke, M.; Wrońska, A.; Wüstner, P.; Yamamoto, A.; Zabierowski, J.; Zieliński, M. J.; Zink, A.; Złomańczuk, J.; Żuprański, P.; Żurek, M.
2016-11-01
Various theoretical calculations based on QCD or hadronic interactions predict that in addition to the recently observed dibaryon resonance d* (2380) with I (JP) = 0 (3+) there should also exist a dibaryon resonance with mirrored quantum numbers I (JP) = 3 (0+). We report here on a search for such a NN-decoupled state in data on the pp → ppπ+π+π-π- reaction. Since no clear-cut evidence has been found, we give upper limits for the production cross section of such a resonance in the mass range 2280-2500 MeV.
On the history of dibaryons and their final observation
NASA Astrophysics Data System (ADS)
Clement, H.
2017-03-01
A review is given about the long-standing search for dibaryons, i.e. six-quark objects, from the early days until present, when the first dibaryon resonance has been established, which has the potential of constituting a compact six-quark object.
A Study of the H-dibaryon in Holographic QCD
NASA Astrophysics Data System (ADS)
Matsumoto, Kohei; Nakagawa, Yuya; Suganuma, Hideo
We study the H-dibaryon (uuddss) in holographic QCD for the first time. Holographic QCD is derived from a QCD-equivalent D-brane system (S1-compactified D4/D8/overline{D8}) in the superstring theory via the gauge/gravity correspondence. In holographic QCD, all baryons appear as topological chiral solitons of Nambu-Goldstone bosons and (axial) vector mesons. In this framework, the H-dibaryon can be described as an SO(3)-type hedgehog state. We present the formalism of the H-dibaryon in holographic QCD, and perform the calculation to investigate its properties in the chiral limit.
Evidence for a bound H-dibaryon using lattice QCD
Will Detmold
2012-04-01
The H-dibaryon, a J = 0 state with the valence quark content udsuds, has long been hypothesized to exist because of the attractive nature of color magnetic gluon exchange in the flavor- singlet channel. Using lattice QCD the NPLQCD collaboration have investigated this system and evidence is presented for the existence of a stable H-dibaryon, albeit at a quark mass somewhat larger than that in nature. This calculation is reviewed and combined with subsequent calculations by the HALQCD collaboration at the SU(3) flavor symmetric point to identify bounds on the H-dibaryon mass at the physical quark masses.
Experimental evidence for the exotic dibaryon d^{ast }1
NASA Astrophysics Data System (ADS)
Khrykin, A. S.
2016-12-01
We provide strong experimental evidence for the existence of a nonstrange exotic dibaryon with a mass of about 1956 MeV called d^{ast }1(1956). This dibaryon is expected to be stable against strong decay and decays predominantly into two nucleons ( NN) via the isospin-conserving radiative process d^{ast }1 to NN γ . First, we present the experimental evidence for the d^{ast }1(1956) found in the energy spectrum of the coincident photons emitted at ±900 from the reaction p p → p p γ γ at 216 MeV. Then we give an explanation why the WASA/CELSIUS Collaboration did not find signatures of this dibaryon in its proton-proton bremsstrahlung data measured at 310 and 200 MeV. We also present signatures of this dibaryon found in experimental invariant mass spectra of photon pairs from the p p → p p γ γ reaction measured by this collaboration at 1360 and 1200 MeV. These signatures provide very substantial confirmation of the existence of the d^{ast }1(1956).
Quark models of dibaryon resonances in nucleon-nucleon scattering
Ping, J. L.; Huang, H. X.; Pang, H. R.; Wang Fan; Wong, C. W.
2009-02-15
We look for {delta}{delta} and N{delta} resonances by calculating NN scattering phase shifts of two interacting baryon clusters of quarks with explicit coupling to these dibaryon channels. Two phenomenological nonrelativistic chiral quark models giving similar low-energy NN properties are found to give significantly different dibaryon resonance structures. In the chiral quark model (ChQM), the dibaryon system does not resonate in the NNS waves, in agreement with the experimental SP07 NN partial-wave scattering amplitudes. In the quark delocalization and color screening model (QDCSM), the S-wave NN resonances disappear when the nucleon size b falls below 0.53 fm. Both quark models give an IJ{sup P}=03{sup +}{delta}{delta} resonance. At b=0.52 fm, the value favored by the baryon spectrum, the resonance mass is 2390 (2420) MeV for the ChQM with quadratic (linear) confinement, and 2360 MeV for the QDCSM. Accessible from the {sup 3}D{sub 3}{sup NN} channel, this resonance is a promising candidate for the known isoscalar ABC structure seen more clearly in the pn{yields}d{pi}{pi} production cross section at 2410 MeV in the recent preliminary data reported by the CELSIUS-WASA Collaboration. In the isovector dibaryon sector, our quark models give a bound or almost bound {sup 5}S{sub 2}{sup {delta}}{sup {delta}} state that can give rise to a {sup 1}D{sub 2}{sup NN} resonance. None of the quark models used have bound N{delta}P states that might generate odd-parity resonances.
Dibaryon octet strong decay coupling constants sum rules with first-order SU(3) symmetry breaking
NASA Astrophysics Data System (ADS)
Polanco-Euán, E. N.; Sánchez-Colón, G.; Gupta, V.
2017-03-01
The SU(3) octet states with baryon number B = 2, hexaquark dibaryons, are considered. We extend previous work and determine strong decay coupling constants sum rules with first-order SU(3) symmetry breaking for dibaryon octet into two ordinary baryon octets and into a baryon octet plus a baryon decuplet. Possibilities for the experimental observation of multibaryon and anti-multibaryon states are pointed out.
Search for the H-dibaryon. A proposal to E871
Fitch, V.; Klein, J.; May, M.
1998-10-01
This report consists of vugraphs for a lecture on the search for the H-dibaryon. The physics importance of this search are: (1) low energy test of QCD; (2) new form of matter; (3) missing link between normal hadronic matter and strange matter; (4) astrophysical explanations; and (5) cosmology and dark matter. The author reviews past experiments searching for H-dibaryon. Finally he discusses search methods at E871.
Kukulin, V.I.; Grabmayr, P.; Faessler, A.; Abraamyan, Kh.U.; Bashkanov, M.; Clement, H.; Skorodko, T.; Pomerantsev, V.N.
2010-06-15
Numerous theoretical and experimental arguments in favor of the generation of intermediate {sigma}-dressed dibaryon in NN interaction at middle and short distances are presented. We argue that this intermediate dibaryon should be responsible for the strong middle-range attraction and the short-range repulsion in the NN interaction, and also for the short-range correlations in nuclei. The suggested mechanism for the {sigma}-dressing of the dibaryon is identical to that which explains the Roper-resonance structure, its dominant decay mode and its extraordinary low mass. It is arguing that the (partial) chiral symmetry restoration effects, common for the Roper resonance and dressed dibaryon, are responsible for strong renormalizing of their masses and widths and the observed {sigma}-meson mass and decay width as well. The new experimental data on 2{pi}-production in the scalar-isoscalar channel produced in pn- and pd-collisions and recent data on {gamma}{gamma} correlations in pC and dC scattering in the GeV region seems to corroborate the existence of the {sigma}-dressed dibaryon in two- and three-nucleon interactions. A similar transformation mechanism from the glue to the scalar field can be valid also in some J/{Psi} decays and in enormous {sigma}-meson production in central pp collisions at high energies.
Present constraints on the H-dibaryon at the physical point from Lattice QCD
Beane, S. R.; Chang, E.; Detmold, W.; Joo, B.; Lin, H. -W.; Luu, T. C.; Orginos, K.; Parreno, A.; Savage, M. J.; Torok, A.; Walker-Loud, A.
2011-11-10
The current constraints from Lattice QCD on the existence of the H-dibaryon are discussed. With only two significant Lattice QCD calculations of the H-dibaryon binding energy at approximately the same lattice spacing, the form of the chiral and continuum extrapolations to the physical point are not determined. In this brief report, an extrapolation that is quadratic in the pion mass, motivated by low-energy effective field theory, is considered. An extrapolation that is linear in the pion mass is also considered, a form that has no basis in the effective field theory, but is found to describe the light-quark mass dependence observed in Lattice QCD calculations of the octet baryon masses. In both cases, the extrapolation to the physical pion mass allows for a bound H-dibaryon or a near-threshold scattering state.
Present constraints on the H-dibaryon at the physical point from Lattice QCD
Beane, S. R.; Chang, E.; Detmold, W.; ...
2011-11-10
The current constraints from Lattice QCD on the existence of the H-dibaryon are discussed. With only two significant Lattice QCD calculations of the H-dibaryon binding energy at approximately the same lattice spacing, the form of the chiral and continuum extrapolations to the physical point are not determined. In this brief report, an extrapolation that is quadratic in the pion mass, motivated by low-energy effective field theory, is considered. An extrapolation that is linear in the pion mass is also considered, a form that has no basis in the effective field theory, but is found to describe the light-quark mass dependencemore » observed in Lattice QCD calculations of the octet baryon masses. In both cases, the extrapolation to the physical pion mass allows for a bound H-dibaryon or a near-threshold scattering state.« less
Novel six-quark hidden-color dibaryon states in QCD
Bashkanov, M.; Brodsky, Stanley J.; Clement, H.
2013-12-01
The recent observation of a hadronic resonance d* in the proton–neutron system with isospin I=0 and spin-parity J^{P}=3^{+} raises the possibility of producing other novel six-quark dibaryon configurations allowed by QCD.
Bound H Dibaryon in Flavor SU(3) Limit of Lattice QCD
Inoue, Takashi; Ishii, Noriyoshi; Aoki, Sinya; Doi, Takumi; Sasaki, Kenji; Hatsuda, Tetsuo; Ikeda, Yoichi; Murano, Keiko; Nemura, Hidekatsu
2011-04-22
The flavor-singlet H dibaryon, which has strangeness -2 and baryon number 2, is studied by the approach recently developed for the baryon-baryon interactions in lattice QCD. The flavor-singlet central potential is derived from the spatial and imaginary-time dependence of the Nambu-Bethe-Salpeter wave function measured in N{sub f}=3 full QCD simulations with the lattice size of L{approx_equal}2,3,4 fm. The potential is found to be insensitive to the volume, and it leads to a bound H dibaryon with the binding energy of 30-40 MeV for the pseudoscalar meson mass of 673-1015 MeV.
Evidence for a Bound $H$ Dibaryon from Lattice QCD
Beane, S. R.; Chang, E.; Detmold, W.; Joo, B.; Lin, H. W.; Luu, T. C.; Orginos, K.; Parreño, A.; Savage, M. J.; Torok, A.; Walker-Loud, A.
2011-04-20
We present evidence for the existence of a bound H-dibaryon, an I = 0, J = 0, s = -2 state with valence quark structure uuddss, at a pion mass of m$_{\\pi}$ ~389 MeV. Extrapolating the results of lattice QCD calculations performed on four ensembles of anisotropic clover gauge-field configurations, with spatial extents of L ~ 2.0, 2.5, 3.0 and 3.9 fm at a spatial lattice spacing of b_{s} ~ 0.123 fm, we find an H-dibaryon bound by B$H\\atop{\\infty}$ = 16.6 ± 2.1 ± 4.6 MeV at a pion mass of m$_{\\pi}$ ~ 389 MeV.
Bound H dibaryon in flavor SU(3) limit of lattice QCD.
Inoue, Takashi; Ishii, Noriyoshi; Aoki, Sinya; Doi, Takumi; Hatsuda, Tetsuo; Ikeda, Yoichi; Murano, Keiko; Nemura, Hidekatsu; Sasaki, Kenji
2011-04-22
The flavor-singlet H dibaryon, which has strangeness -2 and baryon number 2, is studied by the approach recently developed for the baryon-baryon interactions in lattice QCD. The flavor-singlet central potential is derived from the spatial and imaginary-time dependence of the Nambu-Bethe-Salpeter wave function measured in N(f)=3 full QCD simulations with the lattice size of L≃2,3,4 fm. The potential is found to be insensitive to the volume, and it leads to a bound H dibaryon with the binding energy of 30-40 MeV for the pseudoscalar meson mass of 673-1015 MeV.
Bolger, J.; Boschitz, E.; Mathie, E.L.; Smith, G.R.; Meyer, M.; Vogler, F.; Mango, S.; Konter, J.A.; Mutchler, G.S.; Arvieux, J.
1982-06-14
The vector analyzing power (iT/sub 11/) in elastic ..pi..-d scattering has been measured for several angles at T/sub ..pi../ = 219, 256, 275, and 294 MeV. Strong oscillations are confirmed at 256 MeV. The data are compared with Faddeev calculations; Faddeev amplitudes plus the /sup 3/F/sub 3/(2220) dibaryon resonance only; and Faddeev amplitudes plus the /sup 1/G/sub 4/(2430) dibaryon resonance only. At 219 MeV the Faddeev calculations are consistant with the data, while at the higher energies the general trend of the data favors the admixing of the /sup 1/G/sub 4/ dibaryon resonance. The forward angle data at 294 MeV are not well described by an existing calculation.
Quark-mass dependence of the H dibaryon in Λ Λ scattering
NASA Astrophysics Data System (ADS)
Yamaguchi, Yasuhiro; Hyodo, Tetsuo
2016-12-01
We study the quark mass dependence of the H dibaryon in the strangeness S =-2 baryon-baryon scattering. A low-energy effective field theory is used to describe the coupled-channel scattering, in which the quark mass dependence is incorporated so as to reproduce the lattice QCD data by the HAL QCD collaboration in the SU(3) limit. We point out the existence of the Castillejo-Dalitz-Dyson pole in the Λ Λ scattering amplitude below the threshold in the SU(3) limit, which may cause the Ramsauer-Townsend effect near the N Ξ threshold at the physical point. The H dibaryon is unbound at the physical point, and a resonance appears just below the N Ξ threshold. As a consequence of the coupled-channel dynamics, the pole associated with the resonance is not continuously connected to the bound state in the SU(3) limit. Through the extrapolation in quark masses, we show that the unitary limit of the Λ Λ scattering is achieved between the physical point and the SU(3) limit. We discuss the possible realization of the "H matter" in the unphysical quark mass region.
From CELSIUS to COSY: on the observation of a dibaryon resonance
NASA Astrophysics Data System (ADS)
Clement, H.; Bashkanov, M.; Skorodko, T.
2015-11-01
Using a high-quality beam of storage rings in combination with a pellet target and a hermetic WASA detector covering practically the full solid angle, two-pion production in nucleon-nucleon collisions has been systematically studied by exclusive and kinematically complete measurements—first at CELSIUS and subsequently at COSY. These measurements resulted in a detailed understanding of the two-pion production mechanism by t-channel meson exchange. The investigation of the ABC effect, which denotes an unusual low-mass enhancement in the ππ-invariant mass spectrum, in double-pionic fusion reactions led the trace to the observation of a narrow dibaryon resonance with I({J}P)=0({3}+) about 80 MeV below the nominal mass of the conventional Δ Δ system. New neutron-proton scattering data, taken with a polarized beam at COSY, produced a pole in the coupled {}3{D}3-3{G}3 partial waves at (2380+/- 10\\-\\i\\40+/- 5) MeV, establishing thus the first observation of a genuine s-channel dibaryon resonance.
All strange and terrible events: A search for the H dibaryon
Ware, B.
1995-12-01
No six-quark bound hadron, (other than the loosely bound deuteron) has been observed, despite several experimental searches. Some models of quark dynamics predict the existence of such a state, the doubly-strange six-quark H dibaryon (uuddss) being the most likely. The mass of the H would be between that of the deuteron and the 2m{sub {Lambda}} strong interaction decay threshold. In 1992, Experiment E888 at Brookhaven National Lab`s Alternating Gradient Synchrotron collected data to search for this particle. The detector consisted of a two-arm spectrometer with drift chamber tracking and two magnets for momentum analysis, scintillator hodoscope triggering, Cerenkov particle identification, an electromagnetic calorimeter, and a muon hodoscope and rangefinder. The experiment searched for the decay {Lambda} {yields} p{pi}{sup -} from the weak decays of H {yields} {Lambda}n and H {yields} {Sigma}{sup 0}n (followed by {Sigma}{sup 0} {yields} {Lambda}{gamma}). This search was sensitive to weakly decaying H dibaryons with lifetimes from 6-230 us with production cross-sections greater than {approximately}2 {mu}b/steradian.
The search for the H dibaryon with the BNL 2. 0 GeV/c kaon beam
Quinn, B.P.
1991-01-01
The status is given for two experiments being carried out to search for evidence of the H dibaryon. BNL experiments E813 and E836 will use the new 2 GeV/c kaon beam line. The former has recently begun data taking. They cover complementary regions of mass-sensitivity and promise to provide sensitive tests of the existence of the H. 12 refs.
Evidence for a dibaryon signal in the measurement of elastic. pi. /sup +/-d/sub pol/ scattering
Bolger, J.; Boschitz, E.; Proebstle, G.; Smith, G.R.; Mango, S.; Vogler, F.; Johnson, R.R.; Arvieux, J.
1981-01-19
The vector analyzing power (iT/sub 11/) in elastic ..pi..-d/sub pol/ scattering has been measured for several angles at T/sub ..pi../=142 and 256 MeV. The results are compared with calculations reported in the literature. At the lower energies, Faddeev calculations agree fairly well with the data. At the higher energies, the experimental results differ markedly from any conventional calculation, but agree surprisingly well with predictions in which effects of dibaryon resonances are explicitly included.
NASA Astrophysics Data System (ADS)
Shin, Jae Won; Hyun, Chang Ho
2016-09-01
We develop a new hadronic model for GEANT4 that is specialized for the disintegration of the deuteron by photons, dγ → np. For the description of two-nucleon interactions, we employ a pionless effective field theory with dibaryon fields (dEFT). We apply the new model of GEANT4 (G4dEFT) to the calculations of the total and the differential cross sections in dγ → np and compare the results with empirical data. As an application of the new model, we calculate the neutron yield from the γ+CD2 process. G4dEFT predicts peaks for the neutron yield, but the existing model of GEANT4 does not show such behavior.
Search for supernarrow dibaryons via the pd{yields}ppX and pd{yields}pdX reactions
Kuboki, H.; Hatano, M.; Saito, T.; Sakai, H.; Sasano, M.; Yako, K.; Tamii, A.; Fujita, K.; Hatanaka, K.; Sakemi, Y.; Shimizu, Y.; Tameshige, Y.; Kamiya, J.; Kudoh, T.; Sagara, K.; Shimomoto, S.; Shiota, M.; Wakasa, T.; Maeda, Y.; Uesaka, T.
2006-09-15
Supernarrow dibaryons (SNDs) have been searched for by the pd{yields}ppX and pd{yields}pdX reactions at E{sub p}=295 MeV over a mass range of 1898 to 1953 MeV, where three candidates of SNDs were found at the Moscow Meson Factory. The experiment was carried out at the Research Center for Nuclear Physics using a two-arm magnetic spectrometer system and a liquid deuterium target. A good mass resolution of 1 MeV and a low background condition were achieved. No resonance structure was observed in the missing mass spectra. Upper limits of the SND production cross section were determined.
NASA Astrophysics Data System (ADS)
Hwang, Sanghoon; Imai, Kenichi; Ahn, Jung Keun
We the E42 collaboration proposed to search for the H-dibaryon in ΛΛ production from (K-, K-) reaction off nuclei by using a high-intensity K- beam at J-PARC with 100 times better statistics than KEK-E224 and E552 experiments. Our proposed experiment will be designed to confirm if the enhancement is due to the H-dibaryon as a ΛΛ resonance or a virtual bound state or ΛΛ final state interaction. We plan to construct a large-acceptance hyperon spectrometer with a Time-Projection-Chamber (HypTPC) to detector ΛΛ particles, simultaneously K+ particle is measured by the KURAMA spectrometer. We expect to collect 11000 ΛΛ events with a mass resolution of 1.0 MeV/c2 near the ΛΛ threshold. The sensitivity of the detector shows two orders of magitude improvement from the present limit.
NASA Astrophysics Data System (ADS)
Deinet, Werner; Teilab, Khaled; Giacosa, Francesco; Rischke, Dirk H.
2016-10-01
We calculate the total and the differential cross section for n p scattering at low energies in the isospin I =1 channel within the so-called extended linear sigma model. This model contains conventional (pseudo)scalar and (axial-)vector mesons, as well as the nucleon and its chiral partner within the mirror assignment. In order to obtain good agreement with experimental data analysis results we need to consider two additional resonances: the lightest scalar state f0(500 ) and a dibaryon state with quantum numbers I =1 ,JP=0+ (also known as S10 resonance). The resonance f0(500 ) is coupled to nucleons in a chirally invariant way through the mirror assignment and is crucial for a qualitatively correct description of the shape of the differential cross section. On the other hand, the dibaryon is exchanged in the s channel and is responsible of the large cross section close to threshold. We compare our results to data analysis results performed by the said program of the CNS Data Analysis Center (in the following "said results").
YAMAZAKI, Toshimitsu; AKAISHI, Yoshinori; HASSANVAND, Maryam
2011-01-01
A recent successful observation of a dense and deeply bound 𝐾̄ nuclear system, K−pp, in the p + p → K+ + K−pp reaction in a DISTO experiment indicates that the double-𝐾̄ dibaryon, K−K−pp, which was predicted to be a dense nuclear system, can also be formed in p + p collisions. We find theoretically that the K−-K− repulsion plays no significant role in reducing the density and binding energy of K−K−pp and that, when two Λ(1405) resonances are produced simultaneously in a short-range p + p collision, they act as doorways to copious formation of K−K−pp, if and only if K−K−pp is a dense object, as predicted. PMID:21670568
NASA Astrophysics Data System (ADS)
Wagner, Gerhard J.; Bilger, R.; Clement, H.; Denig, A.; Foehl, K.; Graeter, J.; Kluge, W.; Paetzold, J.; Meier, R.; Schepkin, M.; Wagne, G. J.; Amaudruz, P. A.; Ambardar, A.; Bilger, R.; Bonutti, F.; Camerini, P.; Clark, J.; Clement, H.; Felawka, L.; Friedman, E.; Graeter, J.; Grion, N.; Hofman, G. J.; Hong, P.; Kermani, M.; Mathie, E. L.; Meier, R.; Ottewell, D.; Patarakin, O.; Rui, R.; Schepkin, M.; Sevior, M. E.; Smith, G. R.; Tacik, R.; Tagliente, G.; Wagner, G. J.; Bilger, R.; Brodowski, W.; Calen, H.; Clement, H.; Ekstroem, C.; Foehl, K.; Fransson, K.; Gustafsson, L.; Haeggstroem, S.; Hoeistad, B.; Johansson, A.; Johansson, T.; Kilian, K.; Kullander, S.; Kupsc, A.; Kurz, G.; Marciniewski, P.; Morosov, B.; Moehn, J.; Moertsell, A.; Oelert, W.; Renken, V.; Ruber, R.; Schepkin, M. G.; Siodlaczek, U.; Stepaniak, J.; Sukhanov, A.; Turowiecki, A.; Wagner, G. J.; Wilhelmi, Z.; Zabierowski, J.; Zernov, A.; Zlomanczuk, J.
1998-09-01
In order to explain the resonance-like excitation functions of pionic double-charge-exchange reactions near 50 MeV the existence of a narrow πNN-resonance d' with a mass of about 2.06 GeV has been postulated. The status of the various experiments that have been performed to establish the existence of the d' is reported.
Search for dibaryons in measurements of the. pi. d(pol) system
Smith, G.R.; Mathie, E.L.; Boschitz, E.T.; Ottermann, C.R.; Gyles, W.; List, W.; Mango, S.; Konter, J.A.; Van der Brandt, B.; Olszewski, R.
1984-11-15
Comprehensive measurements of the vector analyzing power iT/sub 11/ have recently been completed in the elastic, absorption, and breakup channels of the ..pi..d system using a polarized deuteron target and a TOF detection system at SIN. Discrepancies between the experimental data and the predictions of Faddeev calculations appear with varying severity in all three channels.
Skorodko, T.; Bashkanov, M.; Clement, H.; Doroshkevich, E.; Khakimova, O.; Kren, F.; Pricking, A.; Wagner, G. J.
2010-08-05
The two-pion production in nucleon-nucleon collisions has been studied by exclusive and kinematically complete experiments from threshold up to T{sub p} = 1.36 GeV at CELSIUS-WASA. At near-threshold energies the total and differential distributions for the {pi}{sup +{pi}-} and {pi}{sup 0{pi}0} channels are dominated by Roper excitation and its decay into N{sigma}s and {Delta}{pi} channels. At beam energies T{sub p}>1.1 GeV the {Delta}{Delta} excitation governs the two-pion production process. In the {pi}{sup +{pi}+} channel evidence is found for the excitation of a higher-lying I =3/2 resonance, favorably the {Delta}(1600). The isovector fusion processes leading to the deuteron and to quasi-stable {sup 2}He, respectively, exhibit no or only a modest ABC-effect, i.e. low-mass enhancement in the {pi}{pi}-invariant mass spectrum, and can be described by conventional t-channel {Delta}{Delta} excitation. On the other hand, the isoscalar fusion process to the deuteron exhibits a dramatic ABC-effect correlated with a narrow resonance-like energy dependence in the total cross section with a width of only 50 MeV and situated at a mass 90 MeV below the {Delta}{Delta} mass.
Case for exotic baryon-baryon states
Thomas, G.H.
1980-01-01
Three main points are presented. (1) Current theoretical prejudices are presented for why dibaryon states are interesting, and why they should be expected. (2) A review is given of some of the unsettled experimental issues which have emerged during this conference concerning dibaryons. (3) Phenomenological issues are raised which are critical to understanding whether dibaryon states are observable in the medium energy NN system.
K meson-nucleus interactions: strangeness and nuclear matter
Kahana, S.
1985-01-01
A brief review is provided of some straightforward K-nuclear and ..lambda..-hypernuclear systems. A discussion of less straightforward speculations on H-dibaryons and strange quark matter by many authors, is also given. 28 refs., 6 figs.
NASA Astrophysics Data System (ADS)
Adam, J.; Adamová, D.; Aggarwal, M. M.; Aglieri Rinella, G.; Agnello, M.; Agrawal, N.; Ahammed, Z.; Ahmed, I.; Ahn, S. U.; Aimo, I.; Aiola, S.; Ajaz, M.; Akindinov, A.; Alam, S. N.; Aleksandrov, D.; Alessandro, B.; Alexandre, D.; Alfaro Molina, R.; Alici, A.; Alkin, A.; Alme, J.; Alt, T.; Altinpinar, S.; Altsybeev, I.; Alves Garcia Prado, C.; Andrei, C.; Andronic, A.; Anguelov, V.; Anielski, J.; Antičić, T.; Antinori, F.; Antonioli, P.; Aphecetche, L.; Appelshäuser, H.; Arcelli, S.; Armesto, N.; Arnaldi, R.; Aronsson, T.; Arsene, I. C.; Arslandok, M.; Augustinus, A.; Averbeck, R.; Azmi, M. D.; Bach, M.; Badalà, A.; Baek, Y. W.; Bagnasco, S.; Bailhache, R.; Bala, R.; Baldisseri, A.; Ball, M.; Baltasar Dos Santos Pedrosa, F.; Baral, R. C.; Barbano, A. M.; Barbera, R.; Barile, F.; Barnaföldi, G. G.; Barnby, L. S.; Barret, V.; Bartalini, P.; Bartke, J.; Bartsch, E.; Basile, M.; Bastid, N.; Basu, S.; Bathen, B.; Batigne, G.; Batista Camejo, A.; Batyunya, B.; Batzing, P. C.; Bearden, I. G.; Beck, H.; Bedda, C.; Behera, N. K.; Belikov, I.; Bellini, F.; Bello Martinez, H.; Bellwied, R.; Belmont, R.; Belmont-Moreno, E.; Belyaev, V.; Bencedi, G.; Beole, S.; Berceanu, I.; Bercuci, A.; Berdnikov, Y.; Berenyi, D.; Bertens, R. A.; Berzano, D.; Betev, L.; Bhasin, A.; Bhat, I. R.; Bhati, A. K.; Bhattacharjee, B.; Bhom, J.; Bianchi, L.; Bianchi, N.; Bianchin, C.; Bielčík, J.; Bielčíková, J.; Bilandzic, A.; Biswas, S.; Bjelogrlic, S.; Blanco, F.; Blau, D.; Blume, C.; Bock, F.; Bogdanov, A.; Bøggild, H.; Boldizsár, L.; Bombara, M.; Book, J.; Borel, H.; Borissov, A.; Borri, M.; Bossú, F.; Botje, M.; Botta, E.; Böttger, S.; Braun-Munzinger, P.; Bregant, M.; Breitner, T.; Broker, T. A.; Browning, T. A.; Broz, M.; Brucken, E. J.; Bruna, E.; Bruno, G. E.; Budnikov, D.; Buesching, H.; Bufalino, S.; Buncic, P.; Busch, O.; Buthelezi, Z.; Buxton, J. T.; Caffarri, D.; Cai, X.; Caines, H.; Calero Diaz, L.; Caliva, A.; Calvo Villar, E.; Camerini, P.; Carena, F.; Carena, W.; Castillo Castellanos, J.; Castro, A. J.; Casula, E. A. R.; Cavicchioli, C.; Ceballos Sanchez, C.; Cepila, J.; Cerello, P.; Chang, B.; Chapeland, S.; Chartier, M.; Charvet, J. L.; Chattopadhyay, S.; Chattopadhyay, S.; Chelnokov, V.; Cherney, M.; Cheshkov, C.; Cheynis, B.; Chibante Barroso, V.; Chinellato, D. D.; Chochula, P.; Choi, K.; Chojnacki, M.; Choudhury, S.; Christakoglou, P.; Christensen, C. H.; Christiansen, P.; Chujo, T.; Chung, S. U.; Cicalo, C.; Cifarelli, L.; Cindolo, F.; Cleymans, J.; Colamaria, F.; Colella, D.; Collu, A.; Colocci, M.; Conesa Balbastre, G.; Conesa del Valle, Z.; Connors, M. E.; Contreras, J. G.; Cormier, T. M.; Corrales Morales, Y.; Cortés Maldonado, I.; Cortese, P.; Cosentino, M. R.; Costa, F.; Crochet, P.; Cruz Albino, R.; Cuautle, E.; Cunqueiro, L.; Dahms, T.; Dainese, A.; Danu, A.; Das, D.; Das, I.; Das, S.; Dash, A.; Dash, S.; De, S.; De Caro, A.; de Cataldo, G.; de Cuveland, J.; De Falco, A.; De Gruttola, D.; De Marco, N.; De Pasquale, S.; Deisting, A.; Deloff, A.; Dénes, E.; D'Erasmo, G.; Di Bari, D.; Di Mauro, A.; Di Nezza, P.; Diaz Corchero, M. A.; Dietel, T.; Dillenseger, P.; Divià, R.; Djuvsland, Ø.; Dobrin, A.; Dobrowolski, T.; Domenicis Gimenez, D.; Dönigus, B.; Dordic, O.; Dubey, A. K.; Dubla, A.; Ducroux, L.; Dupieux, P.; Ehlers, R. J.; Elia, D.; Engel, H.; Erazmus, B.; Erhardt, F.; Eschweiler, D.; Espagnon, B.; Estienne, M.; Esumi, S.; Evans, D.; Evdokimov, S.; Eyyubova, G.; Fabbietti, L.; Fabris, D.; Faivre, J.; Fantoni, A.; Fasel, M.; Feldkamp, L.; Felea, D.; Feliciello, A.; Feofilov, G.; Ferencei, J.; Fernández Téllez, A.; Ferreiro, E. G.; Ferretti, A.; Festanti, A.; Figiel, J.; Figueredo, M. A. S.; Filchagin, S.; Finogeev, D.; Fionda, F. M.; Fiore, E. M.; Fleck, M. G.; Floris, M.; Foertsch, S.; Foka, P.; Fokin, S.; Fragiacomo, E.; Francescon, A.; Frankenfeld, U.; Fuchs, U.; Furget, C.; Furs, A.; Fusco Girard, M.; Gaardhøje, J. J.; Gagliardi, M.; Gago, A. M.; Gallio, M.; Gangadharan, D. R.; Ganoti, P.; Gao, C.; Garabatos, C.; Garcia-Solis, E.; Gargiulo, C.; Gasik, P.; Germain, M.; Gheata, A.; Gheata, M.; Ghosh, P.; Ghosh, S. K.; Gianotti, P.; Giubellino, P.; Giubilato, P.; Gladysz-Dziadus, E.; Glässel, P.; Gomez Ramirez, A.; González-Zamora, P.; Gorbunov, S.; Görlich, L.; Gotovac, S.; Grabski, V.; Graczykowski, L. K.; Grelli, A.; Grigoras, A.; Grigoras, C.; Grigoriev, V.; Grigoryan, A.; Grigoryan, S.; Grinyov, B.; Grion, N.; Grosse-Oetringhaus, J. F.; Grossiord, J.-Y.; Grosso, R.; Guber, F.; Guernane, R.; Guerzoni, B.; Gulbrandsen, K.; Gulkanyan, H.; Gunji, T.; Gupta, A.; Gupta, R.; Haake, R.; Haaland, Ø.; Hadjidakis, C.; Haiduc, M.; Hamagaki, H.; Hamar, G.; Hanratty, L. D.; Hansen, A.; Harris, J. W.; Hartmann, H.; Harton, A.; Hatzifotiadou, D.; Hayashi, S.; Heckel, S. T.; Heide, M.; Helstrup, H.; Herghelegiu, A.; Herrera Corral, G.; Hess, B. A.; Hetland, K. F.; Hilden, T. E.; Hillemanns, H.; Hippolyte, B.; Hristov, P.; Huang, M.; Humanic, T. J.; Hussain, N.; Hussain, T.; Hutter, D.; Hwang, D. S.; Ilkaev, R.; Ilkiv, I.; Inaba, M.; Ionita, C.; Ippolitov, M.; Irfan, M.; Ivanov, M.; Ivanov, V.; Izucheev, V.; Jachołkowski, A.; Jacobs, P. M.; Jahnke, C.; Jang, H. J.; Janik, M. A.; Jayarathna, P. H. S. Y.; Jena, C.; Jena, S.; Jimenez Bustamante, R. T.; Jones, P. G.; Jung, H.; Jusko, A.; Kalinak, P.; Kalweit, A.; Kamin, J.; Kang, J. H.; Kaplin, V.; Kar, S.; Karasu Uysal, A.; Karavichev, O.; Karavicheva, T.; Karpechev, E.; Kebschull, U.; Keidel, R.; Keijdener, D. L. D.; Keil, M.; Khan, K. H.; Khan, M. M.; Khan, P.; Khan, S. A.; Khanzadeev, A.; Kharlov, Y.; Kileng, B.; Kim, B.; Kim, D. W.; Kim, D. J.; Kim, H.; Kim, J. S.; Kim, M.; Kim, M.; Kim, S.; Kim, T.; Kirsch, S.; Kisel, I.; Kiselev, S.; Kisiel, A.; Kiss, G.; Klay, J. L.; Klein, C.; Klein, J.; Klein-Bösing, C.; Kluge, A.; Knichel, M. L.; Knospe, A. G.; Kobayashi, T.; Kobdaj, C.; Kofarago, M.; Köhler, M. K.; Kollegger, T.; Kolojvari, A.; Kondratiev, V.; Kondratyeva, N.; Kondratyuk, E.; Konevskikh, A.; Kouzinopoulos, C.; Kovalenko, V.; Kowalski, M.; Kox, S.; Koyithatta Meethaleveedu, G.; Kral, J.; Králik, I.; Kravčáková, A.; Krelina, M.; Kretz, M.; Krivda, M.; Krizek, F.; Kryshen, E.; Krzewicki, M.; Kubera, A. M.; Kučera, V.; Kucheriaev, Y.; Kugathasan, T.; Kuhn, C.; Kuijer, P. G.; Kulakov, I.; Kumar, J.; Kumar, L.; Kurashvili, P.; Kurepin, A.; Kurepin, A. B.; Kuryakin, A.; Kushpil, S.; Kweon, M. J.; Kwon, Y.; La Pointe, S. L.; La Rocca, P.; Lagana Fernandes, C.; Lakomov, I.; Langoy, R.; Lara, C.; Lardeux, A.; Lattuca, A.; Laudi, E.; Lea, R.; Leardini, L.; Lee, G. R.; Lee, S.; Legrand, I.; Lehnert, J.; Lemmon, R. C.; Lenti, V.; Leogrande, E.; León Monzón, I.; Leoncino, M.; Lévai, P.; Li, S.; Li, X.; Lien, J.; Lietava, R.; Lindal, S.; Lindenstruth, V.; Lippmann, C.; Lisa, M. A.; Ljunggren, H. M.; Lodato, D. F.; Loenne, P. I.; Loggins, V. R.; Loginov, V.; Loizides, C.; Lopez, X.; López Torres, E.; Lowe, A.; Lu, X.-G.; Luettig, P.; Lunardon, M.; Luparello, G.; Maevskaya, A.; Mager, M.; Mahajan, S.; Mahmood, S. M.; Maire, A.; Majka, R. D.; Malaev, M.; Maldonado Cervantes, I.; Malinina, L.; Mal'Kevich, D.; Malzacher, P.; Mamonov, A.; Manceau, L.; Manko, V.; Manso, F.; Manzari, V.; Marchisone, M.; Mareš, J.; Margagliotti, G. V.; Margotti, A.; Margutti, J.; Marín, A.; Markert, C.; Marquard, M.; Martashvili, I.; Martin, N. A.; Martin Blanco, J.; Martinengo, P.; Martínez, M. I.; Martínez García, G.; Martinez Pedreira, M.; Martynov, Y.; Mas, A.; Masciocchi, S.; Masera, M.; Masoni, A.; Massacrier, L.; Mastroserio, A.; Matyja, A.; Mayer, C.; Mazer, J.; Mazzoni, M. A.; Mcdonald, D.; Meddi, F.; Menchaca-Rocha, A.; Meninno, E.; Mercado Pérez, J.; Meres, M.; Miake, Y.; Mieskolainen, M. M.; Mikhaylov, K.; Milano, L.; Milosevic, J.; Minervini, L. M.; Mischke, A.; Mishra, A. N.; Miśkowiec, D.; Mitra, J.; Mitu, C. M.; Mohammadi, N.; Mohanty, B.; Molnar, L.; Montaño Zetina, L.; Montes, E.; Morando, M.; Moretto, S.; Morreale, A.; Morsch, A.; Muccifora, V.; Mudnic, E.; Mühlheim, D.; Muhuri, S.; Mukherjee, M.; Müller, H.; Mulligan, J. D.; Munhoz, M. G.; Murray, S.; Musa, L.; Musinsky, J.; Nandi, B. K.; Nania, R.; Nappi, E.; Naru, M. U.; Nattrass, C.; Nayak, K.; Nayak, T. K.; Nazarenko, S.; Nedosekin, A.; Nellen, L.; Ng, F.; Nicassio, M.; Niculescu, M.; Niedziela, J.; Nielsen, B. S.; Nikolaev, S.; Nikulin, S.; Nikulin, V.; Noferini, F.; Nomokonov, P.; Nooren, G.; Norman, J.; Nyanin, A.; Nystrand, J.; Oeschler, H.; Oh, S.; Oh, S. K.; Ohlson, A.; Okatan, A.; Okubo, T.; Olah, L.; Oleniacz, J.; Oliveira Da Silva, A. C.; Oliver, M. H.; Onderwaater, J.; Oppedisano, C.; Ortiz Velasquez, A.; Oskarsson, A.; Otwinowski, J.; Oyama, K.; Ozdemir, M.; Pachmayer, Y.; Pagano, P.; Paić, G.; Pajares, C.; Pal, S. K.; Pan, J.; Pandey, A. K.; Pant, D.; Papikyan, V.; Pappalardo, G. S.; Pareek, P.; Park, W. J.; Parmar, S.; Passfeld, A.; Paticchio, V.; Paul, B.; Pawlak, T.; Peitzmann, T.; Pereira Da Costa, H.; Pereira De Oliveira Filho, E.; Peresunko, D.; Pérez Lara, C. E.; Peskov, V.; Pestov, Y.; Petráček, V.; Petrov, V.; Petrovici, M.; Petta, C.; Piano, S.; Pikna, M.; Pillot, P.; Pinazza, O.; Pinsky, L.; Piyarathna, D. B.; Płoskoń, M.; Planinic, M.; Pluta, J.; Pochybova, S.; Podesta-Lerma, P. L. M.; Poghosyan, M. G.; Polichtchouk, B.; Poljak, N.; Poonsawat, W.; Pop, A.; Porteboeuf-Houssais, S.; Porter, J.; Pospisil, J.; Prasad, S. K.; Preghenella, R.; Prino, F.; Pruneau, C. A.; Pshenichnov, I.; Puccio, M.; Puddu, G.; Pujahari, P.; Punin, V.; Putschke, J.; Qvigstad, H.; Rachevski, A.; Raha, S.; Rajput, S.; Rak, J.; Rakotozafindrabe, A.; Ramello, L.; Raniwala, R.; Raniwala, S.; Räsänen, S. S.; Rascanu, B. T.; Rathee, D.; Razazi, V.; Read, K. F.; Real, J. S.; Redlich, K.; Reed, R. J.; Rehman, A.; Reichelt, P.; Reicher, M.; Reidt, F.; Ren, X.; Renfordt, R.; Reolon, A. R.; Reshetin, A.; Rettig, F.; Revol, J.-P.; Reygers, K.; Riabov, V.; Ricci, R. A.; Richert, T.; Richter, M.; Riedler, P.; Riegler, W.; Riggi, F.; Ristea, C.; Rivetti, A.; Rocco, E.; Rodríguez Cahuantzi, M.; Rodriguez Manso, A.; Røed, K.; Rogochaya, E.; Rohr, D.; Röhrich, D.; Romita, R.; Ronchetti, F.; Ronflette, L.; Rosnet, P.; Rossi, A.; Roukoutakis, F.; Roy, A.; Roy, C.; Roy, P.; Rubio Montero, A. J.; Rui, R.; Russo, R.; Ryabinkin, E.; Ryabov, Y.; Rybicki, A.; Sadovsky, S.; Šafařík, K.; Sahlmuller, B.; Sahoo, P.; Sahoo, R.; Sahoo, S.; Sahu, P. K.; Saini, J.; Sakai, S.; Saleh, M. A.; Salgado, C. A.; Salzwedel, J.; Sambyal, S.; Samsonov, V.; Sanchez Castro, X.; Šándor, L.; Sandoval, A.; Sano, M.; Santagati, G.; Sarkar, D.; Scapparone, E.; Scarlassara, F.; Scharenberg, R. P.; Schiaua, C.; Schicker, R.; Schmidt, C.; Schmidt, H. R.; Schuchmann, S.; Schukraft, J.; Schulc, M.; Schuster, T.; Schutz, Y.; Schwarz, K.; Schweda, K.; Scioli, G.; Scomparin, E.; Scott, R.; Seeder, K. S.; Seger, J. E.; Sekiguchi, Y.; Selyuzhenkov, I.; Senosi, K.; Seo, J.; Serradilla, E.; Sevcenco, A.; Shabanov, A.; Shabetai, A.; Shadura, O.; Shahoyan, R.; Shangaraev, A.; Sharma, A.; Sharma, N.; Shigaki, K.; Shtejer, K.; Sibiriak, Y.; Siddhanta, S.; Sielewicz, K. M.; Siemiarczuk, T.; Silvermyr, D.; Silvestre, C.; Simatovic, G.; Simonetti, G.; Singaraju, R.; Singh, R.; Singha, S.; Singhal, V.; Sinha, B. C.; Sinha, T.; Sitar, B.; Sitta, M.; Skaali, T. B.; Slupecki, M.; Smirnov, N.; Snellings, R. J. M.; Snellman, T. W.; Søgaard, C.; Soltz, R.; Song, J.; Song, M.; Song, Z.; Soramel, F.; Sorensen, S.; Spacek, M.; Spiriti, E.; Sputowska, I.; Spyropoulou-Stassinaki, M.; Srivastava, B. K.; Stachel, J.; Stan, I.; Stefanek, G.; Steinpreis, M.; Stenlund, E.; Steyn, G.; Stiller, J. H.; Stocco, D.; Strmen, P.; Suaide, A. A. P.; Sugitate, T.; Suire, C.; Suleymanov, M.; Sultanov, R.; Šumbera, M.; Symons, T. J. M.; Szabo, A.; Szanto de Toledo, A.; Szarka, I.; Szczepankiewicz, A.; Szymanski, M.; Takahashi, J.; Tanaka, N.; Tangaro, M. A.; Tapia Takaki, J. D.; Tarantola Peloni, A.; Tariq, M.; Tarzila, M. G.; Tauro, A.; Tejeda Muñoz, G.; Telesca, A.; Terasaki, K.; Terrevoli, C.; Teyssier, B.; Thäder, J.; Thomas, D.; Tieulent, R.; Timmins, A. R.; Toia, A.; Trogolo, S.; Trubnikov, V.; Trzaska, W. H.; Tsuji, T.; Tumkin, A.; Turrisi, R.; Tveter, T. S.; Ullaland, K.; Uras, A.; Usai, G. L.; Utrobicic, A.; Vajzer, M.; Vala, M.; Valencia Palomo, L.; Vallero, S.; Van Der Maarel, J.; Van Hoorne, J. W.; van Leeuwen, M.; Vanat, T.; Vande Vyvre, P.; Varga, D.; Vargas, A.; Vargyas, M.; Varma, R.; Vasileiou, M.; Vasiliev, A.; Vauthier, A.; Vechernin, V.; Veen, A. M.; Veldhoen, M.; Velure, A.; Venaruzzo, M.; Vercellin, E.; Vergara Limón, S.; Vernet, R.; Verweij, M.; Vickovic, L.; Viesti, G.; Viinikainen, J.; Vilakazi, Z.; Villalobos Baillie, O.; Vinogradov, A.; Vinogradov, L.; Vinogradov, Y.; Virgili, T.; Vislavicius, V.; Viyogi, Y. P.; Vodopyanov, A.; Völkl, M. A.; Voloshin, K.; Voloshin, S. A.; Volpe, G.; von Haller, B.; Vorobyev, I.; Vranic, D.; Vrláková, J.; Vulpescu, B.; Vyushin, A.; Wagner, B.; Wagner, J.; Wang, H.; Wang, M.; Wang, Y.; Watanabe, D.; Weber, M.; Weber, S. G.; Wessels, J. P.; Westerhoff, U.; Wiechula, J.; Wikne, J.; Wilde, M.; Wilk, G.; Wilkinson, J.; Williams, M. C. S.; Windelband, B.; Winn, M.; Yaldo, C. G.; Yamaguchi, Y.; Yang, H.; Yang, P.; Yano, S.; Yasnopolskiy, S.; Yin, Z.; Yokoyama, H.; Yoo, I.-K.; Yurchenko, V.; Yushmanov, I.; Zaborowska, A.; Zaccolo, V.; Zaman, A.; Zampolli, C.; Zanoli, H. J. C.; Zaporozhets, S.; Zarochentsev, A.; Závada, P.; Zaviyalov, N.; Zbroszczyk, H.; Zgura, I. S.; Zhalov, M.; Zhang, H.; Zhang, X.; Zhang, Y.; Zhao, C.; Zhigareva, N.; Zhou, D.; Zhou, Y.; Zhou, Z.; Zhu, H.; Zhu, J.; Zhu, X.; Zichichi, A.; Zimmermann, A.; Zimmermann, M. B.; Zinovjev, G.; Zyzak, M.
2016-01-01
We present results of a search for two hypothetical strange dibaryon states, i.e. the H-dibaryon and the possible Λn ‾ bound state. The search is performed with the ALICE detector in central (0-10%) Pb-Pb collisions at √{sNN} = 2.76 TeV, by invariant mass analysis in the decay modes Λn ‾ → d ‾π+ and H-dibaryon → Λpπ-. No evidence for these bound states is observed. Upper limits are determined at 99% confidence level for a wide range of lifetimes and for the full range of branching ratios. The results are compared to thermal, coalescence and hybrid UrQMD model expectations, which describe correctly the production of other loosely bound states, like the deuteron and the hypertriton.
Strange experiments at the AGS
Chrien, R.
1990-01-01
The purpose of this review is to report recent progress in nuclear experiments involving strangeness which have been carried out at the Brookhaven Alternating Gradient Synchrotron over the past three years. These recent developments are noted in three areas: few body systems and dibaryons; strange probes of the nucleus; and associated production of hypernuclei. 9 refs., 3 figs.
Examination of the nature of the ABC effect
NASA Astrophysics Data System (ADS)
Bashkanov, M.; Clement, H.; Skorodko, T.
2017-02-01
Recently it has been shown by exclusive and kinematically complete experiments that the appearance of a narrow resonance structure in double-pionic fusion reactions is strictly correlated with the appearance of the so-called ABC effect, which denotes a pronounced low-mass enhancement in the ππ-invariant mass spectrum. Whereas the resonance structure got its explanation by the d* (2380) dibaryonic resonance, a satisfactory explanation for the ABC effect is still pending. In this paper we discuss possible explanations of the ABC effect and their consequences for the internal structure of the d* dibaryon. To this end we examine and review a variety of proposed explanations for the ABC effect, add a new hypothesis and confront all of them with the experimental results for the np → dπ0π0 and np → npπ0π0 reactions, which are the most challenging ones for this topic.
Foundations of strangeness nuclear physics derived from chiral effective field theory
NASA Astrophysics Data System (ADS)
Meißner, Ulf-G.; Haidenbauer, Johann
Dense compact objects like neutron stars or black holes have always been one of Gerry Brown’s favorite research topics. This is closely related to the effects of strangeness in nuclear physics. Here, we review the chiral Effective Field Theory approach to interactions involving nucleons and hyperons, the possible existence of strange dibaryons, the fate of hyperons in nuclear matter and the present status of three-body forces involving hyperons and nucleons.
Experimental Medium Energy Physics
Not Available
1992-01-01
This report discusses the following topics: Search for the H Dibaryon at the AGS; hypernuclear weak decay studies at the LAGS; search for strangelets using the 2 GeV/c beam line; experiment to detect double lambda hypernuclei; hyperon photoproduction at CEBAF; the region 1 drift chambers for the CLAS spectrometer; parity violating electron scattering from the proton: the G{sup 0}experiment at CEBAF; and relativistic heavy ion - nucleus collisions at the SPS.
The 4He(π+,π-) reaction at low energies
NASA Astrophysics Data System (ADS)
Chaos Collaboration; Gräter, J.; Bilger, R.; Clement, H.; Meier, R.; Wagner, G. J.; Friedman, E.; Schepkin, M.; Amaudruz, P. A.; Felawka, L.; Ottewell, D.; Smith, G. R.; Ambardar, A.; Hofman, G. J.; Kermani, M.; Tagliente, G.; Bonutti, F.; Camerini, P.; Grion, N.; Rui, R.; Hong, P.; Mathie, E. L.; Tacik, R.; Clark, J.; Sevior, M. E.; Patarakin, O.
1998-02-01
Using the CHAOS spectrometer at TRIUMF the total cross sections and outgoing pion momentum distributions for the 4He(π+,π-) reaction were measured for π+ kinetic energies from 70 to 130 MeV. At energies around 100 MeV the total cross sections show an excess by a factor 3 over conventional model calculations which could be ascribed to a contribution from a hypothetical d' dibaryon.
Smith, G.R.; Mathie, E.L.; Boschitz, E.T.; Ottermann, C.R.; Mango, S.; Konter, J.A.; Daum, M.; Meyer, M.; Olszewski, R.; Vogler, F.
1984-06-01
The vector analyzing power iT/sub 11/ has been measured for the ..pi..d elastic scattering reaction at 12 incident pion energies between 117 and 325 MeV, using a vector polarized deuteron target. The results cover an average of 14 angles per incident pion energy. A detailed comparison with existing Faddeev calculations is made. The effect of including dibaryon resonances with one of these predictions is investigated.
Experimental Medium Energy Physics. Annual progress report, June 1991--May 1992
Not Available
1992-09-01
This report discusses the following topics: Search for the H Dibaryon at the AGS; hypernuclear weak decay studies at the LAGS; search for strangelets using the 2 GeV/c beam line; experiment to detect double lambda hypernuclei; hyperon photoproduction at CEBAF; the region 1 drift chambers for the CLAS spectrometer; parity violating electron scattering from the proton: the G{sup 0}experiment at CEBAF; and relativistic heavy ion - nucleus collisions at the SPS.
Bunce, G.
1984-05-30
Is all hadronic physics ultimately describable by QCD. Certainly, many disparate phenomena can be understood within the QCD framework. Also certainly, there are important questions which are open, both theoretically (little guidance, as yet) and experimentally, regarding confinement. Are there dibaryons, baryonium, glueballs. In addition, there are experimental results which at present do not have an explanation. This talk, after a short section on QCD successes and difficulties, will emphasize two experimental topics which have recent results - glueball spectroscopy and exclusive reactions at large momentum transfer. Both are experimentally accessible in the AGS/LAMPF II/AGS II/TRIUMF II/SIN II energy domain.
Energy dependence of the 4He(π+,π-) total cross section
NASA Astrophysics Data System (ADS)
Gräter, J.; Bilger, R.; Clement, H.; Meier, R.; Wagner, G. J.; Friedman, E.; Schepkin, M.; Amaudruz, P. A.; Felawka, L.; Ottewell, D.; Smith, G. R.; Ambardar, A.; Hofman, G. J.; Kermani, M.; Tagliente, G.; Bonutti, F.; Camerini, P.; Grion, N.; Rui, R.; Hong, P.; Mathie, E. L.; Tacik, R.; Clark, J.; Sevior, M. E.; Patarakin, O.
1998-09-01
The total cross section of the 4He(π+,π-) reaction was measured for π+ kinetic energies ranging from 70 to 130 MeV using the CHAOS spectrometer at TRIUMF and a liquid 4He target. Around Tπ=90 MeV, total cross sections exceed conventional model predictions by a factor of 3, whereas at Tπ=70 MeV and for Tπ>130 MeV the data are consistent with these calculations. An attempt is made to understand this behavior by assuming the production of the hypothetical d' dibaryon.
({lambda}, p) Spectrum Analysis in p+A Interactions at 10 GeV/c
Aslanyan, P. Zh.; Emelyanenko, V. N.
2007-06-13
Experimental data from the 2m propane bubble chamber have been analyzed for exotic baryon states search. A number of peculiarities were found in the effective mass spectra of: {lambda}{pi}+({sigma}*+(1382),PDG), {lambda}p and {lambda}pp subsystems. A few events detected on the photographs of the propane bubble chamber exposed to a 10 GeV/c proton beam, were interpreted as S=-2 H0 light(
Tensor analyzing power in πd elastic scattering
NASA Astrophysics Data System (ADS)
Smith, G. R.; Altman, A.; Delheij, P.; Gill, D. R.; Healey, D.; Johnson, R. R.; Jones, G.; Ottewell, D.; Rozon, F. M.; Sevior, M. E.; Tervisidis, F.; Trelle, R. P.; Wait, G. D.; Walden, P.; Mathie, E. L.; Lolos, G. J.; Naqvi, S. I.; Boschitz, E. T.; Ottermann, C. R.; Kyle, G. S.; Amaudruz, P. A.
1986-08-01
A tensor-polarized deuteron target has been employed for the first measurements of the tensor analyzing power, T20, in πd elastic scattering. Data at six angles were measured at pion bombarding energies of 133.8 and 150.9 MeV. The results settle a long-standing controversy over conflicting measurements of the tensor polarization t20, and dispute evidence for dibaryon resonances predicated on one of these t20 measurements. The data are shown to be in reasonable agreement with recent Faddeev calculations which have reduced contributions from pion absorption.
On the determination of Ω - Ω scattering amplitudes from finite volume spectra
NASA Astrophysics Data System (ADS)
Li, Ning; Wu, Ya-Jie
2016-12-01
The elastic scattering phase shifts to the two-particle energy levels in a finite cubic box is related by the Lüscher’s formula. In this paper, based on the nonrelativistic quantum mechanics model which is usually assumed to be the low energy scattering case in lattice simulations, we confirmed the generalized Lüscher’s formula for the case of two-particle scattering with arbitrary spin in Ref. 1. In particular, Lüscher’s formula is synthesized for two-spin-3/2-particle scattering, i.e. Ω - Ω scattering on lattice that may help us study the promising dibaryon states.
NASA Astrophysics Data System (ADS)
Batty, C. J.; Friedman, E.; Gal, A.
1999-01-01
Experiments with Ξ- atoms are proposed in order to study the nuclear interaction of Ξ hyperons. The production of Ξ- in the (K-,K+) reaction, the Ξ- stopping in matter, and its atomic cascade are incorporated within a realistic evaluation of the results expected for Ξ- x-ray spectra across the periodic table, using an assumed Ξ-nucleus optical potential Vopt. Several optimal targets for measuring the strong-interaction shift and width of the x-ray transition to the ``last'' atomic level observed are singled out: F, Cl, I, and Pb. The sensitivity of these observables to the parameters of Vopt is considered. The relevance of such experiments is discussed in the context of strangeness -2 nuclear physics and multistrange nuclear matter. Finally, with particular reference to searches for the H dibaryon, the properties of Ξ-d atoms are also discussed. The role of Stark mixing and its effect on S and P state capture of Ξ- by the deuteron together with estimates of the resulting probability for producing the H dibaryon are considered in detail.
Crawford, H.J.; Engelage, J.
1998-11-01
The program is an investigation of the hadronization process through experimental measurement of rare particle production in high energy nuclear interactions. These interactions provide an environment similar in energy density to the conditions in the Big Bang. The authors are currently involved in two major experiments to study this environment, E896 at the AGS and STAR at RHIC. They have completed the first physics running of E896, a search for the H dibaryon and measurement of hyperon production in AuAu collisions, and are in the process of analyzing the data. They have prototyped the STAR trigger and are in the process of fabricating its components and installing them in the STAR detector.
Investigation of Rare Particle Production in High Energy Nuclear Collisions
1999-09-02
Our program is an investigation of the hadronization process through measurement of rare particle production in high energy nuclear interactions. Such collisions of heavy nuclei provide an environment similar in energy density to the conditions in the Big Bang. We are currently involved in two major experiments to study this environment, E896 at the AGS and STAR at RHIC. We have completed our physics running of E896, a search for the H dibaryon and measurement of hyperon production in AuAu collisions, and are in the process of analyzing the data. We have produced the electronics and software for the STAR trigger and will begin to use these tools to search for anti-nuclei and strange hadrons when RHIC turns on later this year.
Light Nuclei and HyperNuclei from Quantum Chromodynamics in the Limit of SU(3) Flavor Symmetry
Beane, S R; Cohen, S D; Detmold, W; Lin, H W; Luu, T C; Orginos, K; Parreno, A; Savage, M J; Walker-Loud, A
2013-02-01
The binding energies of a range of nuclei and hypernuclei with atomic number A <= 4 and strangeness |s| <= 2, including the deuteron, di-neutron, H-dibaryon, {sup 3}He, {sub {Lambda}}{sup 3}He, {sub {Lambda}}{sup 4}He, and {sub {Lambda}{Lambda}}{sup 4}He, are calculated in the limit of flavor-SU(3) symmetry at the physical strange quark mass with quantum chromodynamics (without electromagnetic interactions). The nuclear states are extracted from Lattice QCD calculations performed with n{sub f}=3 dynamical light quarks using an isotropic clover discretization of the quark-action in three lattice volumes of spatial extent L ~ 3.4 fm, 4.5 fm and 6.7 fm, and with a single lattice spacing b ~ 0.145 fm.
Nuclear structure studies with medium energy probes. [Northwestern Univ
Seth, Kamal K.
1980-01-01
Progress in the continuing program of experimental research in nuclear structure with medium-energy probes during the year 1979-1980 is reviewed, and the research activities planned for the year 1980-1981 are discussed. In the study of pion-induced reactions emphasis is placed on investigation of isovector characteristics of nuclear excitations and on double charge exchange reactions. Pion production studies form the major part of the program of experiments with proton beams of 400 to 800 MeV at LAMPF. Current emphasis is on the bearing of these investigations on di-baryon existence. The study of high-spin states and magnetic scattering constitute the main goals of the electron scattering program at Bates. Representative results are presented; completed work is reported in the usual publications. (RWR)
Rusek, A.; Bassalleck, B.; Fischer, H.; Berdoz, A.; Franklin, G.B.; Buerger, T.; Burger, M.; Chrien, R.E.; Diebold, G.E.; En`yo, H.
1995-12-31
During the 1993 AGS heavy ion run, experiment E886 conducted a strangelet search in Au + Pt reactions, with beam momentum of 10.8 GeV/c per nucleon. Presented here are the upper limit for strangelet production, invariant cross sections for p, t, d, {sup 3}He, {sup 4}He, {sup 6}He, {sup 8}He, {sup 6}Li, {sup 7}Li, {sup 8}Li and {sup 7}Be, along with a demonstration of their agreement with a coalescence model fit to data collected by E886 during the 1992 engineering run, and upper limits for production cross sections for other rare objects, such as (H dibaryon)-nucleus systems. All results reported are preliminary.
Thomas-Fermi Quark Model and Techniques to Improve Lattice QCD Calculation
NASA Astrophysics Data System (ADS)
Liu, Quan
Two topics are discussed separately in this thesis. In the first part a semiclassical quark model, called the Thomas-Fermi quark model, is reviewed. After a modified approach to spin in the model is introduced, I present the calculation of the spectra of octet and decuplet baryons. The six-quark doubly strange H-dibaryon state is also investigated. In the second part, two numerical techniques which improve latice QCD calculations are covered. The first one, which we call Polynomial-Preconditioned GMRES-DR(PP-GMRESDR), is used to speed up the calculation of large systems of linear equations in LQCD. The second one, called the Polynomial-Subtraction method, is used to help reduce the noise variance of the calculations for disconnected loops in LQCD.
1 to 2 GeV/c beam line for hypernuclear and kaon research
Chrien, R.E.
1985-02-15
A kaon beam line operating in the range from 1.0 to 2.0 GeV/c is proposed. The line is meant for kaon and pion research in a region hitherto inaccessible to experimenters. Topics in hypernuclear and kaon physics of high current interest include the investigation of doubly strange nuclear systems with the K/sup -/,K/sup +/ reaction, searching for dibaryon resonances, hyperon-nucleon interactions, hypernuclear ..gamma.. rays, and associated production of excited hypernuclei. The beam line would provide separated beams of momentum analyzed kaons at intensities greater than 10/sup 6/ particles per spill with a momentum determined to one part in a thousand. This intensity is an order of magnitude greater than that currently available. 63 references.
pp{yields}p{Lambda}K{sup +} reaction in search for the K{sup -}pp state - quest for a kaonic nuclei
Suzuki, Ken; Kienle, Paul; Maggiora, Marco; Yamazaki, Toshimitsu
2011-10-21
The dibaryonic kaonic nuclear bound state, K{sup -}pp is searched by studying an exclusive p+p{yields}p+{Lambda}+K{sup +} process at several beam energies. A signature of the K{sup -}pp is explored in a p+p{yields}X({identical_to}K{sup -}pp)+K{sup +} reaction that follows a decay of the X into p+{Lambda}. We found in a missing-mass {Delta}M(K{sup +}) spectrum and a {Lambda}p invariant-mass M({Lambda}p) spectrum of DISTO data at 2.85 GeV a resonance with M = 2267 MeV/c{sup 2} and {Gamma} = 118 MeV. Those events are found to be associated with a mono energetic kaon. We investigate this resonance as a candidate of the K{sup -}pp further also with a different beam energies.
Measurement of the Branching Fraction and Lambda-bar Polarization in B0 -> Lambda-par p pi-
Aubert, B.; Karyotakis, Y.; Lees, J.P.; Poireau, V.; Prencipe, E.; Prudent, X.; Tisserand, V.; Garra Tico, J.; Grauges, E.; Martinelli, M.; Palano, A.; Pappagallo, M.; Eigen, G.; Stugu, B.; Sun, L.; Battaglia, M.; Brown, D.N.; Kerth, L.T.; Kolomensky, Yu.G.; Lynch, G.; Osipenkov, I.L.; /LBL, Berkeley /UC, Berkeley /Birmingham U. /Ruhr U., Bochum /British Columbia U. /Brunel U. /Novosibirsk, IYF /UC, Irvine /UC, Riverside /UC, San Diego /UC, Santa Barbara /UC, Santa Cruz /Caltech /Cincinnati U. /Colorado U. /Colorado State U. /Dortmund U. /Dresden, Tech. U. /Ecole Polytechnique /Edinburgh U. /INFN, Ferrara /Ferrara U. /INFN, Ferrara /INFN, Ferrara /Ferrara U. /INFN, Ferrara /INFN, Ferrara /Ferrara U. /Frascati /INFN, Genoa /Genoa U. /INFN, Genoa /INFN, Genoa /Genoa U. /INFN, Genoa /INFN, Genoa /Genoa U. /Harvard U. /Heidelberg U. /Humboldt U., Berlin /Imperial Coll., London /Iowa U. /Iowa State U. /Johns Hopkins U. /Orsay, LAL /LLNL, Livermore /Liverpool U. /Queen Mary, U. of London /Royal Holloway, U. of London /Louisville U. /Mainz U., Inst. Kernphys. /Manchester U. /Maryland U. /Massachusetts U., Amherst /MIT, LNS /McGill U. /INFN, Milan /Milan U. /INFN, Milan /INFN, Milan /Milan U. /Mississippi U. /Montreal U. /Mt. Holyoke Coll. /INFN, Naples /Naples U. /INFN, Naples /INFN, Naples /Naples U. /NIKHEF, Amsterdam /Notre Dame U. /Ohio State U. /Oregon U. /INFN, Padua /Padua U. /INFN, Padua /INFN, Padua /Padua U. /Paris U., VI-VII /Pennsylvania U. /INFN, Perugia /Perugia U. /INFN, Pisa /Pisa U. /INFN, Pisa /Pisa, Scuola Normale Superiore /INFN, Pisa /Pisa U. /INFN, Pisa /Princeton U. /INFN, Rome /INFN, Rome /Rome U. /INFN, Rome /INFN, Rome /Rome U. /INFN, Rome /INFN, Rome /Rome U. /INFN, Rome /INFN, Rome /Rome U. /INFN, Rome /Rostock U. /Rutherford /DAPNIA, Saclay /SLAC /South Carolina U. /Stanford U., Phys. Dept. /SUNY, Albany /Tel Aviv U. /Tennessee U. /Texas U. /Texas U., Dallas /INFN, Turin /Turin U. /INFN, Trieste /Trieste U. /Valencia U., IFIC /Victoria U. /Warwick U. /Wisconsin U., Madison
2009-08-03
We present a measurement of the B{sup 0} {yields} {bar {Lambda}}p{pi}{sup -} branching fraction performed using the BABAR detector at the PEP-II asymmetric e{sup +}e{sup -} collider. Based on a sample of 467 x 10{sup 6} B{bar B} pairs we measure {Beta}(B{sup 0} {yields} {bar {Lambda}}p{pi}{sup -}) [3.07 {+-} 0.31(stat.) {+-} 0.23(syst.)] x 10{sup -6}. The measured differential spectrum as a function of the dibaryon invariant mass m({bar {Lambda}}p) shows a near-threshold enhancement similar to that observed in other baryonic B decays. We study the {bar {Lambda}} polarization as a function of {bar {Lambda}} energy in the B{sup 0} rest frame (E*{sub {bar {Lambda}}}) and compare it with theoretical expectations of fully longitudinally right-polarized {bar {Lambda}} at large E*{sub {bar {Lambda}}}.
Effect of in-medium properties on heavy-ion collisions
Schaffner-Bielich, J.
2000-07-20
The properties of strange hadrons, i.e. of kaons and hyperons, in the nuclear medium--are discussed in connection with neutron star properties and relativistic heavy-ion collisions. Firstly, the relevant medium modifications of a kaon in a medium as provided by heavy-ion collisions is critically examined within a coupled channel calculation. We demonstrate, that particle ratios for kaons are not a sensitive probe of in-medium effects while the K{sup {minus}} flow is more suited to pin down the K{sup {minus}} optical potential in dense matter. Secondly, the interaction between hyperons is studied and may form bound states which can be produced in relativistic heavy-ion collisions. Signals for the detection of strange dibaryons by their decay topology and/or in the invariant mass spectra are outlined.
The Thomas–Fermi quark model: Non-relativistic aspects
Liu, Quan Wilcox, Walter
2014-02-15
The first numerical investigation of non-relativistic aspects of the Thomas–Fermi (TF) statistical multi-quark model is given. We begin with a review of the traditional TF model without an explicit spin interaction and find that the spin splittings are too small in this approach. An explicit spin interaction is then introduced which entails the definition of a generalized spin “flavor”. We investigate baryonic states in this approach which can be described with two inequivalent wave functions; such states can however apply to multiple degenerate flavors. We find that the model requires a spatial separation of quark flavors, even if completely degenerate. Although the TF model is designed to investigate the possibility of many-quark states, we find surprisingly that it may be used to fit the low energy spectrum of almost all ground state octet and decuplet baryons. The charge radii of such states are determined and compared with lattice calculations and other models. The low energy fit obtained allows us to extrapolate to the six-quark doubly strange H-dibaryon state, flavor symmetric strange states of higher quark content and possible six quark nucleon–nucleon resonances. The emphasis here is on the systematics revealed in this approach. We view our model as a versatile and convenient tool for quickly assessing the characteristics of new, possibly bound, particle states of higher quark number content. -- Highlights: • First application of the statistical Thomas–Fermi quark model to baryonic systems. • Novel aspects: spin as generalized flavor; spatial separation of quark flavor phases. • The model is statistical, but the low energy baryonic spectrum is successfully fit. • Numerical applications include the H-dibaryon, strange states and nucleon resonances. • The statistical point of view does not encourage the idea of bound many-quark baryons.
Ambrose, D.; Betts, W.; Coffey, P.; Glass, G.; McDonough, J.; Riley, P.; Tang, J.L.
1998-08-01
This document is a final technical report describing the accomplishments of the medium/high energy nuclear physics research program at the University of Texas at Austin. The research program had four main thrusts, only one of which can be considered as measurements of N-N parameters: (1) finishing the data analyses associated with recent LAMPF and TRIUMPF N-N experiments, whose overall purpose has been the determination of the nucleon-nucleon amplitudes, both for isospin 0 and 1 at medium energies; (2) continuing work on BNL E871, a search for rare decay modes of the K{sub L}; (3) work on the RHIC-STAR project, an experiment to create and study a quark gluon plasma and nuclear matter at high energy density; (4) beginning a new AGS experiment (E896) which will search for the lowest mass state of the predicted strange di-baryons, the Ho, and other exotic states of nuclear matter through nucleus-nucleus collisions.
Nuclear physics and astrophysics. Progress report for period June 15, 1992--June 14, 1993
Schramm, D.N.; Olinto, A.V.
1993-06-01
The authors report on recent progress of research at the interface of nuclear physics and astrophysics. During the past year, the authors continued to work on Big Bang and stellar nucleosynthesis, the solar neutrino problem, the equation of state for dense matter, the quark-hadron phase transition, and the origin of gamma-ray bursts; and began studying the consequences of nuclear reaction rates in the presence of strong magnetic fields. They have shown that the primordial production of B and Be cannot explain recent detections of these elements in halo stars and have looked at spallation as the likely source of these elements. By looking at nucleosynthesis with inhomogeneous initial conditions, they concluded that the Universe must have been very smooth before nucleosynthesis. They have also constrained neutrino oscillations and primordial magnetic fields by Big Bang nucleosynthesis. On the solar neutrino problem, they have analyzed the implications of the SAGE and GALLEX experiments. They also showed that the presence of dibaryons in neutron stars depends weakly on uncertainties of nuclear equations of state. They have started to investigate the consequences of strong magnetic fields on nuclear reactions and implications for neutron star cooling and supernova nucleosynthesis.
Observation of B^{0}→pΛ[over ¯]D^{(*)-}.
Chang, Y-Y; Wang, M-Z; Abdesselam, A; Adachi, I; Adamczyk, K; Aihara, H; Al Said, S; Asner, D M; Atmacan, H; Aushev, T; Babu, V; Badhrees, I; Bakich, A M; Barberio, E; Bhuyan, B; Biswal, J; Bobrov, A; Bozek, A; Bračko, M; Browder, T E; Červenkov, D; Chekelian, V; Chen, A; Cheon, B G; Chilikin, K; Chistov, R; Chobanova, V; Choi, S-K; Choi, Y; Cinabro, D; Dalseno, J; Danilov, M; Dingfelder, J; Doležal, Z; Drásal, Z; Dutta, D; Eidelman, S; Farhat, H; Fast, J E; Ferber, T; Fulsom, B G; Gaur, V; Gabyshev, N; Ganguly, S; Garmash, A; Gillard, R; Glattauer, R; Goh, Y M; Goldenzweig, P; Greenwald, D; Grzymkowska, O; Haba, J; Hayasaka, K; Hayashii, H; He, X H; Hou, W-S; Hsu, C-L; Iijima, T; Inami, K; Ishikawa, A; Itoh, R; Iwasaki, Y; Jacobs, W W; Jaegle, I; Joffe, D; Joo, K K; Kawasaki, T; Kim, D Y; Kim, H J; Kim, J B; Kim, J H; Kim, K T; Kim, M J; Kim, S H; Kim, Y J; Kinoshita, K; Korpar, S; Križan, P; Krokovny, P; Kuhr, T; Kumita, T; Kuzmin, A; Kwon, Y-J; Lai, Y-T; Lee, I S; Li, L; Li, Y; Libby, J; Liventsev, D; Lukin, P; Masuda, M; Matvienko, D; Miyabayashi, K; Miyake, H; Miyata, H; Mizuk, R; Mohanty, G B; Mohanty, S; Moll, A; Moon, H K; Mori, T; Nakano, E; Nakao, M; Nanut, T; Nayak, M; Nishida, S; Ogawa, S; Ozaki, H; Pakhlov, P; Pakhlova, G; Pal, B; Park, C W; Pedlar, T K; Pestotnik, R; Petrič, M; Piilonen, L E; Rauch, J; Ribežl, E; Ritter, M; Rostomyan, A; Ryu, S; Sahoo, H; Sakai, Y; Sandilya, S; Santelj, L; Sanuki, T; Savinov, V; Schneider, O; Schnell, G; Schwanda, C; Seino, Y; Senyo, K; Seong, I S; Sevior, M E; Shebalin, V; Shen, C P; Shibata, T-A; Shiu, J-G; Simon, F; Sohn, Y-S; Starič, M; Stypula, J; Sumihama, M; Sumisawa, K; Sumiyoshi, T; Tamponi, U; Tanida, K; Teramoto, Y; Uglov, T; Unno, Y; Uno, S; Usov, Y; Van Hulse, C; Vanhoefer, P; Varner, G; Vorobyev, V; Vossen, A; Wagner, M N; Wang, C H; Wang, P; Watanabe, M; Watanabe, Y; Williams, K M; Won, E; Yamaoka, J; Yashchenko, S; Yelton, J; Yusa, Y; Zhang, Z P; Zhilich, V; Zhulanov, V; Zupanc, A
2015-11-27
We report the first observation of the decays B^{0}→pΛ[over ¯]D^{(*)-}. The data sample of 711 fb^{-1} used in this analysis corresponds to 772×10^{6} BB[over ¯] pairs, collected at the ϒ(4S) resonance by the Belle detector at the KEKB asymmetric-energy e^{+}e^{-} collider. We observe 19.8σ and 10.8σ excesses of events for the two decay modes and measure the branching fractions of B^{0}→pΛ[over ¯]D^{-} and B^{0}→pΛ[over ¯]D^{*-} to be (25.1±2.6±3.5)×10^{-6} and (33.6±6.3±4.4)×10^{-6}, respectively, where the first uncertainties are statistical and the second are systematic. These results are not compatible with the predictions based on the generalized factorization approach. In addition, a threshold enhancement in the dibaryon (pΛ[over ¯]) system is observed, consistent with that observed in similar B decays.
Spin structure in high energy processes: Proceedings
DePorcel, L.; Dunwoodie, C.
1994-12-01
This report contains papers as the following topics: Spin, Mass, and Symmetry; physics with polarized Z{sup 0}s; spin and precision electroweak physics; polarized electron sources; polarization phenomena in quantum chromodynamics; polarized lepton-nucleon scattering; polarized targets in high energy physics; spin dynamics in storage rings and linear accelerators; spin formalism and applications to new physics searches; precision electroweak physics at LEP; recent results on heavy flavor physics from LEP experiments using 1990--1992 data; precise measurement of the left-right cross section asymmetry in Z boson production by electron-positron collisions; preliminary results on heavy flavor physics at SLD; QCD tests with SLD and polarized beams; recent results from TRISTAN at KEK; recent B physics results from CLEO; searching for the H dibaryon at Brookhaven; recent results from the compton observatory; the spin structure of the deuteron; spin structure of the neutron ({sup 3}HE) and the Bjoerken sum rule; a consumer`s guide to lattice QCD results; top ten models constrained by b {yields} sy; a review of the Fermilab fixed target program; results from the D0 experiment; results from CDF at FNAL; quantum-mechanical suppression of bremsstrahlung; report from the ZEUS collaboration at HERA; physics from the first year of H1 at HERA, and hard diffraction. These papers have been cataloged separately elsewhere.
Not Available
1992-10-01
Progress in the various components of the UCLA High-Energy Physics Research program is summarized, including some representative figures and lists of resulting presentations and published papers. Principal efforts were directed at the following: (I) UCLA hadronization model, PEP4/9 e{sup +}e{sup {minus}} analysis, {bar P} decay; (II) ICARUS and astroparticle physics (physics goals, technical progress on electronics, data acquisition, and detector performance, long baseline neutrino beam from CERN to the Gran Sasso and ICARUS, future ICARUS program, and WIMP experiment with xenon), B physics with hadron beams and colliders, high-energy collider physics, and the {phi} factory project; (III) theoretical high-energy physics; (IV) H dibaryon search, search for K{sub L}{sup 0} {yields} {pi}{sup 0}{gamma}{gamma} and {pi}{sup 0}{nu}{bar {nu}}, and detector design and construction for the FNAL-KTeV project; (V) UCLA participation in the experiment CDF at Fermilab; and (VI) VLPC/scintillating fiber R & D.
Experimental and theoretical high energy physics research. [UCLA
Buchanan, Charles D.; Cline, David B.; Byers, N.; Ferrara, S.; Peccei, R.; Hauser, Jay; Muller, Thomas; Atac, Muzaffer; Slater, William; Cousins, Robert; Arisaka, Katsushi
1992-01-01
Progress in the various components of the UCLA High-Energy Physics Research program is summarized, including some representative figures and lists of resulting presentations and published papers. Principal efforts were directed at the following: (I) UCLA hadronization model, PEP4/9 e{sup +}e{sup {minus}} analysis, {bar P} decay; (II) ICARUS and astroparticle physics (physics goals, technical progress on electronics, data acquisition, and detector performance, long baseline neutrino beam from CERN to the Gran Sasso and ICARUS, future ICARUS program, and WIMP experiment with xenon), B physics with hadron beams and colliders, high-energy collider physics, and the {phi} factory project; (III) theoretical high-energy physics; (IV) H dibaryon search, search for K{sub L}{sup 0} {yields} {pi}{sup 0}{gamma}{gamma} and {pi}{sup 0}{nu}{bar {nu}}, and detector design and construction for the FNAL-KTeV project; (V) UCLA participation in the experiment CDF at Fermilab; and (VI) VLPC/scintillating fiber R D.
Study of the quasi-free np → np π+π- reaction with a deuterium beam at 1.25 GeV/nucleon
NASA Astrophysics Data System (ADS)
Agakishiev, G.; Balanda, A.; Belver, D.; Belyaev, A. V.; Blanco, A.; Böhmer, M.; Boyard, J. L.; Braun-Munzinger, P.; Cabanelas, P.; Castro, E.; Chernenko, S.; Christ, T.; Destefanis, M.; Díaz, J.; Dohrmann, F.; Dybczak, A.; Fabbietti, L.; Fateev, O. V.; Finocchiaro, P.; Fonte, P.; Friese, J.; Fröhlich, I.; Galatyuk, T.; Garzón, J. A.; Gernhäuser, R.; Gil, A.; Gilardi, C.; Göbel, K.; Golubeva, M.; González-Díaz, D.; Guber, F.; Gumberidze, M.; Hennino, T.; Holzmann, R.; Ierusalimov, A.; Iori, I.; Ivashkin, A.; Jurkovic, M.; Kämpfer, B.; Karavicheva, T.; Kirschner, D.; Koenig, I.; Koenig, W.; Kolb, B. W.; Kotte, R.; Krizek, F.; Krücken, R.; Kühn, W.; Kugler, A.; Kurepin, A.; Kurilkin, A.; Kurilkin, P.; Ladygin, V.; Lang, S.; Lange, J. S.; Lapidus, K.; Liu, T.; Lopes, L.; Lorenz, M.; Maier, L.; Mangiarotti, A.; Markert, J.; Metag, V.; Michalska, B.; Michel, J.; Morinière, E.; Mousa, J.; Müntz, C.; Naumann, L.; Otwinowski, J.; Pachmayer, Y. C.; Palka, M.; Parpottas, Y.; Pechenov, V.; Pechenova, O.; Pietraszko, J.; Przygoda, W.; Ramstein, B.; Reshetin, A.; Rustamov, A.; Sadovsky, A.; Salabura, P.; Schmah, A.; Schwab, E.; Sobolev, Yu. G.; Spataro, S.; Spruck, B.; Ströbele, H.; Stroth, J.; Sturm, C.; Tarantola, A.; Teilab, K.; Tlusty, P.; Traxler, M.; Trebacz, R.; Tsertos, H.; Wagner, V.; Vasiliev, T.; Weber, M.; Wisniowski, M.; Wojcik, T.; Wüstenfeld, J.; Yurevich, S.; Zanevsky, Y.; Zhou, P.
2015-11-01
The tagged quasi-free np → np π+π- reaction has been studied experimentally with the High Acceptance Di-Electron Spectrometer (HADES) at GSI at a deuteron incident beam energy of 1.25 GeV/nucleon (√{ s} ∼ 2.42 GeV / c for the quasi-free collision). For the first time, differential distributions of solid statistics for π+π- production in np collisions have been collected in the region corresponding to the large transverse momenta of the secondary particles. The invariant mass and angular distributions for the np → np π+π- reaction are compared with different models. This comparison confirms the dominance of the t-channel with ΔΔ contribution. It also validates the changes previously introduced in the Valencia model to describe two-pion production data in other isospin channels, although some deviations are observed, especially for the π+π- invariant mass spectrum. The extracted total cross section is also in much better agreement with this model. Our new measurement puts useful constraints for the existence of the conjectured dibaryon resonance at mass M ∼ 2.38 GeV and with width Γ ∼ 70 MeV.
Cline, D.B.
1993-10-01
Progress on seven tasks is reported. (I)UCLA hadronization model, antiproton decay, PEP4/9 e{sup +}e{sup {minus}} analysis: In addition to these topics, work on CP and CPT phenomenology at a {phi} factory and letters of support on the hadronization project are included. (II)ICARUS detector and rare B decays with hadron beams and colliders: Developments are summarized and some typcial events as shown; in addition, the RD5 collaboration at CERN and the asymmetric {phi} factory project are sketched. (III)Theoretical physics: Feynman diagram calculations in gauge theory; supersymmetric standard model; effects of quantum gravity in breaking of global symmetries; models of quark and lepton substructure; renormalized field theory; large-scale structure in the universe and particle-astrophysics/early universe cosmology. (IV)H dibaryon search at BNL, kaon experiments (E799/KTeV) at Fermilab: Project design and some scatterplots are given. (V)UCLA participation in the experiment CDF at Fermilab. (VI)Detectors for hadron physics at ultrahigh energy colliders: Scintillating fiber and visible light photon counter research. (VII)Administrative support and conference organization.
NASA Astrophysics Data System (ADS)
Sharma, Natasha
2016-12-01
The excellent particle identification capabilities of the ALICE detector, using the time projection chamber and the time-of-flight detector, allow the detection of light nuclei and anti-nuclei. Furthermore, the high tracking resolution provided by the inner tracking system enables the separation of primary nuclei from those coming from the decay of heavier systems. This allows for the reconstruction of decays such as the hypertriton mesonic weak decay (H3Λ →3He +π-), the decay of a hypothetical bound state of a Λn into a deuteron and pion or the H-dibaryon decaying into a Λ, a proton and a π-. An overview of the production of stable nuclei and anti-nuclei in proton-proton, proton-lead and, in particular, lead-lead collisions is presented. Hypernuclei production rates in Pb-Pb are also shown, together with the upper limits estimated on the production of hypothetical exotica candidates. The results are compared with predictions for the production in thermal (statistical) and coalescence models.
Strange Particles and Heavy Ion Physics
Bassalleck, Bernd; Fields, Douglas
2016-04-28
This very long-running grant has supported many experiments in nuclear and particle physics by a group from the University of New Mexico. The gamut of these experiments runs from many aspects of Strangeness Nuclear Physics, to rare Kaon decays, to searches for exotic Hadrons such as Pentaquark or H-Dibaryon, and finally to Spin Physics within the PHENIX collaboration at RHIC. These experiments were performed at a number of laboratories worldwide: first and foremost at Brookhaven National Lab (BNL), but also at CERN, KEK, and most recently at J-PARC. In this Final Technical Report we summarize progress and achievements for this award since our last Progress Report, i.e. for the period of fall 2013 until the award’s termination on November 30, 2015. The report consists of two parts, representing our two most recent experimental efforts, participation in the Nucleon Spin Physics program of the PHENIX experiment at RHIC, the Relativistic Heavy Ion Collider at BNL – Task 1, led by Douglas Fields; and participation in several Strangeness Nuclear Physics experiments at J-PARC, the Japan Proton Accelerator Research Center in Tokai-mura, Japan – Task 2, led by Bernd Bassalleck.
Radiative neutron capture on a proton at big-bang nucleosynthesis energies
Ando, S.; Cyburt, R. H.; Hong, S. W.; Hyun, C. H.
2006-08-15
The total cross section for radiative neutron capture on a proton, np{yields}d{gamma}, is evaluated at big-bang nucleosynthesis (BBN) energies. The electromagnetic transition amplitudes are calculated up to next-to-leading-order within the framework of pionless effective field theory with dibaryon fields. We also calculate the d{gamma}{yields}np cross section and the photon analyzing power for the d{gamma}(vector sign){yields}np process from the amplitudes. The values of low-energy constants that appear in the amplitudes are estimated by a Markov Chain Monte Carlo analysis using the relevant low-energy experimental data. Our result agrees well with those of other theoretical calculations except for the np{yields}d{gamma} cross section at some energies estimated by an R-matrix analysis. We also study the uncertainties in our estimation of the np{yields}d{gamma} cross section at relevant BBN energies and find that the estimated cross section is reliable to within {approx}1% error.
High Statistics Analysis using Anisotropic Clover Lattices: (III) Baryon-Baryon Interactions
Silas Beane; Detmold, William; Lin, Huey-Wen; Luu, Thomas C.; Orginos, Kostas; Savage, Martin; Torok, Aaron M.; Walker-Loud, Andre
2010-03-01
Low-energy baryon-baryon interactions are calculated in a high-statistics lattice QCD study on a single ensemble of anisotropic clover gauge-field configurations at a pion mass of m_pi ~ 390 MeV, a spatial volume of L^3 ~ (2.5 fm)^3, and a spatial lattice spacing of b ~ 0.123 fm. Luscher’s method is used to extract nucleon-nucleon, hyperon-nucleon and hyperon-hyperon scattering phase shifts at one momentum from the one- and two-baryon ground-state energies in the lattice volume. The N-Sigma interactions are found to be highly spin-dependent, and the interaction in the ^3 S _1 channel is found to be strong. In contrast, the N-Lambda interactions are found to be spin-independent, within the uncertainties of the calculation, consistent with the absence of one-pion-exchange. The only channel for which a negative energy-shift is found is Lambda-Lambda, indicating that the Lambda-Lambda interaction is attractive, as anticipated from model-dependent discussions regarding the H-dibaryon. The NN scattering lengths are found to be small, clearly indicating the absence of any fine-tuning in the NN-sector at this pion mass. This is consistent with our previous Lattice QCD calculation of the NN interactions. The behavior of the signal-to-noise ratio in the baryon-baryon correlation functions, and in the ratio of correlation functions that yields the ground-state energy splitting
High statistics analysis using anisotropic clover lattices: (III) Baryon-baryon interactions
Beane, S; Detmold, W; Lin, H; Luu, T; Orginos, K; Savage, M; Torok, A; Walker-Loud, A
2010-01-19
Low-energy baryon-baryon interactions are calculated in a high-statistics lattice QCD study on a single ensemble of anisotropic clover gauge-field configurations at a pion mass of m{sub {pi}} {approx} 390 MeV, a spatial volume of L{sup 3} {approx} (2.5 fm){sup 3}, and a spatial lattice spacing of b {approx} 0.123 fm. Luescher's method is used to extract nucleon-nucleon, hyperon-nucleon and hyperon-hyperon scattering phase shifts at one momentum from the one- and two-baryon ground-state energies in the lattice volume. The isospin-3/2 N{Sigma} interactions are found to be highly spin-dependent, and the interaction in the {sup 3}S{sub 1} channel is found to be strong. In contrast, the N{Lambda} interactions are found to be spin-independent, within the uncertainties of the calculation, consistent with the absence of one-pion-exchange. The only channel for which a negative energy-shift is found is {Lambda}{Lambda}, indicating that the {Lambda}{Lambda} interaction is attractive, as anticipated from model-dependent discussions regarding the H-dibaryon. The NN scattering lengths are found to be small, clearly indicating the absence of any fine-tuning in the NN-sector at this pion mass. This is consistent with our previous Lattice QCD calculation of NN interactions. The behavior of the signal-to-noise ratio in the baryon-baryon correlation functions, and in the ratio of correlation functions that yields the ground-state energy splitting is explored. In particular, focus is placed on the window of time slices for which the signal-to-noise ratio does not degrade exponentially, as this provides the opportunity to extract quantitative information about multi-baryon systems.
Electroproduction of kaons and light hypernuclei
Geesaman, D.F.; Jackson, H.E.; Jones, C.E.
1995-08-01
A detailed investigation of the basic hyperon-nucleon interactions in nuclei is one of the aims of Experiment 91-016, approved with high priority at CEBAF, to study the electroproduction of kaons on targets of deuterium, {sup 3}He, and {sup 4}He. Inasmuch as both the electron and K{sup +} are particles that interact relatively weakly with nucleons, electroproduction of light hypernuclei provides a low-distortion method for investigating the fundamental interactions between nucleons, {Alpha}`s, and {Epsilon}`s in few-body systems. In particular, the (e,e`K{sup +}) reactions on cryogenic targets of D, {sup 3}He, and {sup 4}He will be studied at incident electron energies near 3 GeV with coincident detection of the emergent e and K{sup +} in the HMS and SOS magnetic spectrometers in Hall C. Construction of the He target, operating at {approximately}10 atm, {approximately}50 K and capable of dissipating {approximately}30 W, is expected to be complete prior to commencement of production runs in Hall C. The first data runs for E91-016, expected to begin late in FY 1995, will also be the basis for a doctoral thesis at Hampton University. In addition to providing new information on the phases of hyperon-nucleon interactions, measurements of cross sections for hypernuclear formation, and interference phenomena, the data may provide evidence for the presence of bound {Epsilon}`s and strange di-baryonic states that are the subject of considerable theoretical discussion.
Experimental studies of nucleon-nucleon and pion-nucleus interactions at intermediate energies
Not Available
1990-10-01
This report summarizes the work on experimental research in intermediate energy nuclear and particle physics carried out by New Mexico State University in 1988--91. Most of these studies have involved investigations of neutron-proton and pion-nucleus interactions. The neutron-proton research is part of a program of studies of interactions between polarized nucleons that we have been involved with for more than ten years. Its purpose has been to help complete the determination of the full set of ten complex nucleon-nucleon amplitudes at energies up to 800 MeV, as well as to continue investigating the possibility of the existence of dibaryon resonances. The give complex isospin-one amplitudes have been fairly well determined, partly as a result of this work. Our work in this period has involved measurements and analysis of data on elastic scattering and total cross sections for polarized neutrons on polarized protons. The pion-nucleus research continues our studies of this interaction in regions where it has not been well explored. One set of experiments includes studies of pion elastic and double-charge-exchange scattering at energies between 300 and 550 MeV, where our data is unique. Another involves elastic and single-charge-exchange scattering of pions from polarized nuclear targets, a new field of research which will give the first extensive set of information on spin-dependent pion-nucleus amplitudes. Still another involves the first set of detailed studies of the kinematic correlations among particles emitted following pion absorption in nuclei.
Auerbach, L.B.; Highland, V.L.; McFarlane, K.W.; Kettell, S.H.
1992-07-12
The major emphasis of this project continues to be on fundamental symmetries and parameters of the Standard Model. A test of a quark model prediction was also done. The projects in the current period have been the following: LSND, a neutrino oscillation experiment at LAMPF; E791, a search for the decays K{sub L}{sup 0} {yields} {mu}e and K{sub L}{sup 0} {yields} ee; E871, tests and preparations for an upgrade proposal; and E888, a search for the H dibaryon. The LSND (Large Scintillator Neutrino Detector) is under construction at this time. Progress in the construction schedule has been accelerated with the expectation of being ready to accept beam in March 1993. The automated system for testing photomultiplier tubes is in full production, and should be able to certify a fun complement of tubes for installation by October 1992. Results of an earlier LAMPF experiment, E764, on the interaction of muon neutrinos with carbon nuclei have been submitted for publication. A thorough `blind` analysis of the E791 data set has just been brought to completion. Final results for the upper limits (90% C.L.) on the branching ratios for the decays K{sub L}{sup 0} {yields} {mu}e and K{sub L}{sup 0} {yields} ee are 3.3 {times} 10{sup {minus}11} and 4.1 {times} 10{sup {minus}11}, respectively. The final result for the branching ratio for K{sub L}{sup 0} {yields} {mu}{mu} from all the data (720 events) is (7.0 {plus_minus} 0.4 {plus_minus} 0.2) {times} 10{sup {minus}9}. The potential of the E791 detector for rare K decays has reached its limit. Before disassembly it was used to mount a search (E888) for a possible long-lived six-quark state, the H. At the same time studies have been made of an upgraded version of the experiment (E871) that will make use of a portion of the existing apparatus.
Auerbach, L.B.; Highland, V.L.; McFarlane, K.W.; Kettell, S.H.
1992-07-12
The major emphasis of this project continues to be on fundamental symmetries and parameters of the Standard Model. A test of a quark model prediction was also done. The projects in the current period have been the following: LSND, a neutrino oscillation experiment at LAMPF; E791, a search for the decays K{sub L}{sup 0} {yields} {mu}e and K{sub L}{sup 0} {yields} ee; E871, tests and preparations for an upgrade proposal; and E888, a search for the H dibaryon. The LSND (Large Scintillator Neutrino Detector) is under construction at this time. Progress in the construction schedule has been accelerated with the expectation of being ready to accept beam in March 1993. The automated system for testing photomultiplier tubes is in full production, and should be able to certify a fun complement of tubes for installation by October 1992. Results of an earlier LAMPF experiment, E764, on the interaction of muon neutrinos with carbon nuclei have been submitted for publication. A thorough 'blind' analysis of the E791 data set has just been brought to completion. Final results for the upper limits (90% C.L.) on the branching ratios for the decays K{sub L}{sup 0} {yields} {mu}e and K{sub L}{sup 0} {yields} ee are 3.3 {times} 10{sup {minus}11} and 4.1 {times} 10{sup {minus}11}, respectively. The final result for the branching ratio for K{sub L}{sup 0} {yields} {mu}{mu} from all the data (720 events) is (7.0 {plus minus} 0.4 {plus minus} 0.2) {times} 10{sup {minus}9}. The potential of the E791 detector for rare K decays has reached its limit. Before disassembly it was used to mount a search (E888) for a possible long-lived six-quark state, the H. At the same time studies have been made of an upgraded version of the experiment (E871) that will make use of a portion of the existing apparatus.
NASA Astrophysics Data System (ADS)
Lai, X. Y.; Gao, C. Y.; Xu, R. X.
2013-06-01
The study of dense matter at ultrahigh density has a very long history, which is meaningful for us to understand not only cosmic events in extreme circumstances but also fundamental laws of physics. It is well known that the state of cold matter at supranuclear density depends on the non-perturbative nature of quantum chromodynamics (QCD) and is essential for modelling pulsars. A so-called H-cluster matter is proposed in this paper as the nature of dense matter in reality. In compact stars at only a few nuclear densities but low temperature, quarks could be interacting strongly with each other there. That might render quarks grouped in clusters, although the hypothetical quark clusters in cold dense matter have not been confirmed due to the lack of both theoretical and experimental evidence. Motivated by recent lattice QCD simulations of the H-dibaryons (with structure uuddss), we therefore consider here a possible kind of quark clusters, H-clusters, that could emerge inside compact stars during their initial cooling as the dominant components inside (the degree of freedom could then be H-clusters there). Taking into account the in-medium stiffening effect, we find that at baryon densities of compact stars H-cluster matter could be more stable than nuclear matter. We also find that for the H-cluster matter with lattice structure, the equation of state could be so stiff that it would seem to be `superluminal' in the most dense region. However, the real sound speed for H-cluster matter is in fact difficult to calculate, so at this stage we do not put constraints on our model from the usual requirement of causality. We study the stars composed of H-clusters, i.e. H-cluster stars, and derive the dependence of their maximum mass on the in-medium stiffening effect, showing that the maximum mass could be well above 2 M⊙ as observed and that the resultant mass-radius relation fits the measurement of the rapid burster under reasonable parameters. Besides a general
Nuclear Structure in China 2010
NASA Astrophysics Data System (ADS)
Bai, Hong-Bo; Meng, Jie; Zhao, En-Guang; Zhou, Shan-Gui
2011-08-01
Personal view on nuclear physics research / Jie Meng -- High-spin level structures in [symbol]Zr / X. P. Cao ... [et al.] -- Constraining the symmetry energy from the neutron skin thickness of tin isotopes / Lie-Wen Chen ... [et al.] -- Wobbling rotation in atomic nuclei / Y. S. Chen and Zao-Chun Gao -- The mixing of scalar mesons and the possible nonstrange dibaryons / L. R. Dai ... [et al.] -- Net baryon productions and gluon saturation in the SPS, RHIC and LHC energy regions / Sheng-Qin Feng -- Production of heavy isotopes with collisions between two actinide nuclides / Z. Q. Feng ... [et al.] -- The projected configuration interaction method / Zao-Chun Gao and Yong-Shou Chen -- Applications of Nilsson mean-field plus extended pairing model to rare-earth nuclei / Xin Guan ... [et al.] -- Complex scaling method and the resonant states / Jian-You Guo ... [et al.] -- Probing the equation of state by deep sub-barrier fusion reactions / Hong-Jun Hao and Jun-Long Tian -- Doublet structure study in A[symbol]105 mass region / C. Y. He ... [et al.] -- Rotational bands in transfermium nuclei / X. T. He -- Shape coexistence and shape evolution [symbol]Yb / H. Hua ... [et al.] -- Multistep shell model method in the complex energy plane / R. J. Liotta -- The evolution of protoneutron stars with kaon condensate / Ang Li -- High spin structures in the [symbol]Lu nucleus / Li Cong-Bo ... [et al.] -- Nuclear stopping and equation of state / QingFeng Li and Ying Yuan -- Covariant description of the low-lying states in neutron-deficient Kr isotopes / Z. X. Li ... [et al.] -- Isospin corrections for superallowed [symbol] transitions / HaoZhao Liang ... [et al.] -- The positive-parity band structures in [symbol]Ag / C. Liu ... [et al.] -- New band structures in odd-odd [symbol]I and [symbol]I / Liu GongYe ... [et al.] -- The sd-pair shell model and interacting boson model / Yan-An Luo ... [et al.] -- Cross-section distributions of fragments in the calcium isotopes projectile