Science.gov

Sample records for lambda particles

  1. {Lambda} single-particle energies

    SciTech Connect

    Bodmer, A.R.; Usmani, Q.N.; Sami, M.

    1995-08-01

    We are continuing our work on the {Lambda} hyperon single-particle (s.p.) energies and their interpretation in terms of the basic {Lambda}-nuclear interactions. In particular we are interpreting the results obtained by S.C. Pieper, A. Usmani and Q.N. Usmani. We obtain about 30 MeV for the repulsive contribution of the three-body {Lambda}NN forces in nuclear matter. We are able to exclude purely {open_quotes}dispersive{close_quotes} {Lambda}NN forces. We are investigating the mix of dispersive and two-pion-exchange {Lambda}NN forces which provide a fit to the s.p. data. For interactions, which provide a fit to the s.p. data, the {Lambda} binding energy as a function of the nuclear matter density shows characteristic saturation features with a maximum at a density not very different from that of normal nuclear matter. We obtain a more precise measure of the space-exchange part of the {Lambda}-nuclear force than was previously available, corresponding to an exchange parameter {approx_equal} 0.32. The space-exchange force is rather directly related to the effective mass of a {Lambda} in the nuclear medium and turns out to be about 70% of its free mass. As a result, we also obtain a much better value for the p-state {Lambda}-nucleus potential which is about 40% of the s-state potential. The A binding to nuclear matter is determined to be {approx_equal} 28 MeV.

  2. Immunogenicity of bacteriophage lambda particles displaying porcine Circovirus 2 (PCV2) capsid protein epitopes.

    PubMed

    Gamage, Lakshman N A; Ellis, John; Hayes, Sidney

    2009-11-01

    Phage lambda particles displaying four immunodominant regions of porcine Circovirus 2 (PCV2) capsid protein (LDP-D-CAP) was shown to be immunogenic in pigs. The immunodominant regions were fused to the carboxyl-terminal of lambda head protein D. Expression of D-CAP on lambda display particles was demonstrated by ELISA and Western blots. Pigs receiving LDP-D-CAP, without incorporating adjuvant, showed significant anti-PCV2 immune response following the primary vaccination. The LDP-D-CAP preparation induced PCV2 neutralizing antibodies. Delayed type hypersensitivity (DTH) reaction scores revealed that the immunized pigs were hypersensitive to both lambda phage and PCV2 antigens. The LDP-D-CAP elicited both cellular and humoral immune responses. Neither LDP-D-CAP nor the lambda control elicited any untoward local or systemic reactions following immunization. These studies produced the first potential phage vaccine to porcine Circovirus 2. PMID:19712770

  3. Action of Penicillin G on Endosymbiote Lambda Particles of Paramecium aurelia

    PubMed Central

    Soldo, Anthony T.; Musil, George; Godoy, Gustavo A.

    1970-01-01

    The kinetics of loss from the cytoplasm and changes in ultrastructure of symbiont lambda particles after treatment of axenically cultivated lambda-bearing Paramecium aurelia with penicillin G was investigated. Low concentrations (1 to 2 unit/ml) of the antibiotic caused many particles within the cell to become filamentous; high concentrations (2,000 unit/ml) caused lysis of the particles without noticeably affecting the protozoan. The ED50 value (2 to 3 unit/ml) was within the range of values found to cause lysis of many gram-negative bacteria. Rapidly dividing lambda were more vulnerable to the action of the antibiotic than slowly dividing particles. Nondividing particles were not affected by exposure to the antibiotic. Ultrastructural changes observed in lambda during lysis by penicillin G were consistent with the view that penicillin interferes with the synthesis of a vital component of the cell envelope of the particle, possibly a peptidoglycan similar to that found in the cell walls of bacteria. The deoxyribonucleic acid of lambda was dispersed throughout the particle as electron dense fibers enclosed within electron transparent areas. The cell envelope appeared to consist of at least two morphologically distinguishable layers, an inner layer homologous to the plasma membrane of bacteria and an outer layer homologous to the bacterial cell wall. Lambda may be regarded as a randomly distributed population of bacteria growing and dividing synchronously within the collective cytoplasm of its protozoan host. Images PMID:4099102

  4. Alpha particles accompanying the weak decay of {sub {lambda}}{sup 10}Be and {sub {lambda}}{sup 10}B hypernuclei

    SciTech Connect

    Majling, L. Kuzmin, V. A. Tetereva, T. V.

    2006-05-15

    The possibility of a detailed investigation of weak {lambda}N interaction in the {sub {lambda}}{sup 10}Be and {sub {lambda}}{sub /10}B hypernuclei, which stand out owing to their {alpha}{alpha}N{lambda} cluster structure, is discussed. The detection of a few groups of correlated {alpha}{alpha} pairs will furnish information about decays to specific states of product nuclei ({sup 8}Be*, {sup 8}Li, {sup 8}B), thereby paving the way to a phenomenological analysis of the weak decays of p-shell hypernuclei. The ratios of the intensities of individual alpha-particle groups to be measured in experiments at the cyclotron of the Joint Institute for Nuclear Research (JINR, Dubna) will provide a useful criterion for choosing an appropriate model of weak {lambda}N interaction. The current state of hypernuclear physics is briefly reviewed.

  5. Measurement of Lambda and Lambda(macro) particles in Au+Au collisions at the square root of S(NN) = 130 GeV.

    PubMed

    Adcox, K; Adler, S S; Ajitanand, N N; Akiba, Y; Alexander, J; Aphecetche, L; Arai, Y; Aronson, S H; Averbeck, R; Awes, T C; Barish, K N; Barnes, P D; Barrette, J; Bassalleck, B; Bathe, S; Baublis, V; Bazilevsky, A; Belikov, S; Bellaiche, F G; Belyaev, S T; Bennett, M J; Berdnikov, Y; Botelho, S; Brooks, M L; Brown, D S; Bruner, N; Bucher, D; Buesching, H; Bumazhnov, V; Bunce, G; Burward-Hoy, J; Butsyk, S; Carey, T A; Chand, P; Chang, J; Chang, W C; Chavez, L L; Chernichenko, S; Chi, C Y; Chiba, J; Chiu, M; Choudhury, R K; Christ, T; Chujo, T; Chung, M S; Chung, P; Cianciolo, V; Cole, B A; D'Enterria, D G; David, G; Delagrange, H; Denisov, A; Deshpande, A; Desmond, E J; Dietzsch, O; Dinesh, B V; Drees, A; Durum, A; Dutta, D; Ebisu, K; Efremenko, Y V; el-Chenawi, K; En'yo, H; Esumi, S; Ewell, L; Ferdousi, T; Fields, D E; Fokin, S L; Fraenkel, Z; Franz, A; Frawley, A D; Fung, S-Y; Garpman, S; Ghosh, T K; Glenn, A; Godoi, A L; Goto, Y; Greene, S V; Grosse Perdekamp, M; Gupta, S K; Guryn, W; Gustafsson, H-A; Haggerty, J S; Hamagaki, H; Hansen, A G; Hara, H; Hartouni, E P; Hayano, R; Hayashi, N; He, X; Hemmick, T K; Heuser, J M; Hibino, M; Hill, J C; Ho, D S; Homma, K; Hong, B; Hoover, A; Ichihara, T; Imai, K; Ippolitov, M S; Ishihara, M; Jacak, B V; Jang, W Y; Jia, J; Johnson, B M; Johnson, S C; Joo, K S; Kametani, S; Kang, J H; Kann, M; Kapoor, S S; Kelly, S; Khachaturov, B; Khanzadeev, A; Kikuchi, J; Kim, D J; Kim, H J; Kim, S Y; Kim, Y G; Kinnison, W W; Kistenev, E; Kiyomichi, A; Klein-Boesing, C; Klinksiek, S; Kochenda, L; Kochetkov, V; Koehler, D; Kohama, T; Kotchetkov, D; Kozlov, A; Kroon, P J; Kurita, K; Kweon, M J; Kwon, Y; Kyle, G S; Lacey, R; Lajoie, J G; Lauret, J; Lebedev, A; Lee, D M; Leitch, M J; Li, X H; Li, Z; Lim, D J; Liu, M X; Liu, X; Liu, Z; Maguire, C F; Mahon, J; Makdisi, Y I; Manko, V I; Mao, Y; Mark, S K; Markacs, S; Martinez, G; Marx, M D; Masaike, A; Matathias, F; Matsumoto, T; McGaughey, P L; Melnikov, E; Merschmeyer, M; Messer, F; Messer, M; Miake, Y; Miller, T E; Milov, A; Mioduszewski, S; Mischke, R E; Mishra, G C; Mitchell, J T; Mohanty, A K; Morrison, D P; Moss, J M; Mühlbacher, F; Mukhopadhyay, D; Muniruzzaman, M; Murata, J; Nagamiya, S; Nagasaka, Y; Nagle, J L; Nakada, Y; Nandi, B K; Newby, J; Nikkinen, L; Nilsson, P; Nishimura, S; Nyanin, A S; Nystrand, J; O'Brien, E; Ogilvie, C A; Ohnishi, H; Ojha, I D; Ono, M; Onuchin, V; Oskarsson, A; Osterman, L; Otterlund, I; Oyama, K; Paffrath, L; Pal, D; Palounek, A P T; Pantuev, V S; Papavassiliou, V; Pate, S F; Peitzmann, T; Petridis, A N; Pinkenburg, C; Pisani, R P; Pitukhin, P; Plasil, F; Pollack, M; Pope, K; Purschke, M L; Ravinovich, I; Read, K F; Reygers, K; Riabov, V; Riabov, Y; Rosati, M; Rose, A A; Ryu, S S; Saito, N; Sakaguchi, A; Sakaguchi, T; Sako, H; Sakuma, T; Samsonov, V; Sangster, T C; Santo, R; Sato, H D; Sato, S; Sawada, S; Schlei, B R; Schutz, Y; Semenov, V; Seto, R; Shea, T K; Shein, I; Shibata, T-A; Shigaki, K; Shiina, T; Shin, Y H; Sibiriak, I G; Silvermyr, D; Sim, K S; Simon-Gillo, J; Singh, C P; Singh, V; Sivertz, M; Soldatov, A; Soltz, R A; Sorensen, S; Stankus, P W; Starinsky, N; Steinberg, P; Stenlund, E; Ster, A; Stoll, S P; Sugioka, M; Sugitate, T; Sullivan, J P; Sumi, Y; Sun, Z; Suzuki, M; Takagui, E M; Taketani, A; Tamai, M; Tanaka, K H; Tanaka, Y; Taniguchi, E; Tannenbaum, M J; Thomas, J; Thomas, J H; Thomas, T L; Tian, W; Tojo, J; Torii, H; Towell, R S; Tserruya, I; Tsuruoka, H; Tsvetkov, A A; Tuli, S K; Tydesjö, H; Tyurin, N; Ushiroda, T; Van Hecke, H W; Velissaris, C; Velkovska, J; Velkovsky, M; Vinogradov, A A; Volkov, M A; Vorobyov, A; Vznuzdaev, E; Wang, H; Watanabe, Y; White, S N; Witzig, C; Wohn, F K; Woody, C L; Xie, W; Yagi, K; Yokkaichi, S; Young, G R; Yushmanov, I E; Zajc, W A; Zhang, Z; Zhou, S; Zhou, S

    2002-08-26

    We present results on the measurement of Lambda and Lambda(macro) production in Au+Au collisions at square root of (S (NN) = 130 GeV with the PHENIX detector at the Relativistic Heavy Ion Collider. The transverse momentum spectra were measured for minimum bias and for the 5% most central events. The Lambda;/Lambda ratios are constant as a function of p(T) and the number of participants. The measured net Lambda density is significantly larger than predicted by models based on hadronic strings (e.g., HIJING) but in approximate agreement with models which include the gluon-junction mechanism. PMID:12190391

  6. Existence of {sub {lambda}}{sub {lambda}}{sup 4}H: A variational Monte Carlo search

    SciTech Connect

    Shoeb, Mohammad

    2005-02-01

    A variational Monte Carlo (VMC) calculation for the binding energy B{sub {lambda}}{sub {lambda}} of the lightest hypernucleus {sub {lambda}}{sub {lambda}}{sup 4}H has been performed in the four-body {lambda}{lambda}pn model. A range of input {lambda}{lambda} potentials of moderate strength produce a particle-stable {sub {lambda}}{sub {lambda}}{sup 4}H for the simulated NSC97e and f {lambda}N potentials, whereas the phenomenological Minnesota {lambda}N potential needs a much stronger {lambda}{lambda} potential to bind. The VMC results for B{sub {lambda}}{sub {lambda}} agree with the prediction of the stochastic variational model but contradict the recent Faddeev-Yakubovsky calculation. As reported earlier, B{sub {lambda}}{sub {lambda}} is sensitive to the triplet {lambda}N channel for a given {lambda}{lambda} potential. The B{sub {lambda}}{sub {lambda}} of {sub {lambda}}{sub {lambda}}{sup 4}H in the three-body {lambda}{lambda}d cluster model is consistent with but slightly lower than the Faddeev calculation. The VMC method predicts a stable {sub {lambda}}{sub {lambda}}{sup 4}H system in both models and thus offers the possibility of identifying {sub {lambda}}{sub {lambda}}{sup 4}H in a future extension of E906 or of a related experiment at KEK, provided the simulated potentials are true representations of realistic Nijmegen potentials.

  7. Dual expression system for assembling phage lambda display particle (LDP) vaccine to porcine Circovirus 2 (PCV2).

    PubMed

    Hayes, Sidney; Gamage, Lakshman N A; Hayes, Connie

    2010-09-24

    The bacteriophage lambda small capsid protein D forms trimers on the phage head. D-fusion polypeptides can be expressed from plasmids in E. coli and remain soluble without aggregation. We report a dual expression system for the display of four immunodominant regions of porcine Circovirus 2 (PCV2) capsid protein (CAP) as D-CAP fusions on lambda display particles (LDP). The LDP-D-CAP preparation proved an effective vaccine in pigs, eliciting both cellular and humoral immune responses and PCV2 neutralizing antibodies. In our dual system wild type D expression was encoded by a heteroimmune infecting phage. The D-fusion protein expression in the infected cells was from an inducible plasmid, enabling the deferral of D-fusion expression until needed. The effective vaccine preparation depended upon the gradient purification of very high concentration, essentially tail-less display particles, not previously described. PMID:20674873

  8. lambda lambda. hypernuclei and the. lambda lambda. interaction

    SciTech Connect

    Bodmer, A.R.; Usmani, Q.N.

    1986-01-01

    Variational calculations of ..cap alpha..-cluster models for /sup 6//sub ..lambda lambda../He, /sup 9//sub ..lambda lambda../Be have been made. These calculations require a knowledge of the ..cap alpha lambda.. potential which is obtained in several ways including the use of five-body Monte Carlo (MC) calculations of /sup 5//sub ..lambda../He. We discuss the ..lambda lambda.. interaction strengths and the relation between the /sup 6//sub ..lambda lambda../He and /sup 10//sub ..lambda lambda../Be binding energies and, in particular, the dependence of these on the ..cap alpha lambda.. potential. For all our ..cap alpha lambda.. potentials the binding energy of /sup 6//sub ..lambda lambda../He predicted from /sup 10//sub ..lambda lambda../Be is 1 MeV or more below the experimental value. A brief discussion is given of the implication of the phenomenological strength of ..lambda lambda.. interaction we obtain and also the implication of ..lambda lambda.. hypernuclei for the H-dibaryon. 19 refs., 2 figs., 1 tab.

  9. Five-Body Cluster Structure of the Double-{Lambda} Hypernucleus {sub {Lambda}{Lambda}}{sup 11}Be

    SciTech Connect

    Hiyama, E.; Kamimura, M.; Yamamoto, Y.; Motoba, T.

    2010-05-28

    Energy levels of the double {Lambda} hypernucleus, {sub {Lambda}{Lambda}}{sup 11}Be are calculated within the framework of a {alpha}{alpha}n{Lambda}{Lambda} five-body model. Interactions between constituent particles are determined so as to reproduce reasonably the observed low-energy properties of the {alpha}{alpha}, {alpha}{alpha}n nuclei and the existing data for {Lambda}-binding energies of the {alpha}{Lambda}, {alpha}{alpha}{Lambda}, {alpha}n{Lambda}, and {alpha}{alpha}n{Lambda} systems. An effective {Lambda}{Lambda} interaction is constructed so as to reproduce, within the {alpha}{Lambda}{Lambda} three-body model, the B{sub {Lambda}{Lambda}}of {sub {Lambda}{Lambda}}{sup 6}He, which was extracted from the emulsion experiment, the NAGARA event. With no adjustable parameters for the {alpha}{alpha}n{Lambda}{Lambda} system, B{sub {Lambda}{Lambda}}of the ground and bound excited states of {sub {Lambda}{Lambda}}{sup 11}Be are calculated with the Gaussian expansion method. The Hida event, recently observed at KEK-E373 experiment, is interpreted as an observation of the ground state of the {sub {Lambda}{Lambda}}{sup 11}Be.

  10. Spin correlations in the {Lambda}{Lambda} and {Lambda}{Lambda}-bar systems generated in relativistic heavy-ion collisions

    SciTech Connect

    Lyuboshitz, V. L.; Lyuboshitz, V. V.

    2010-05-15

    Spin correlations for the {Lambda}{Lambda} and {Lambda}{Lambda}-bar pairs, generated in relativistic heavy-ion collisions, and related angular correlations at the joint registration of hadronic decays of two hyperons, in which space parity is not conserved, are analyzed. The correlation tensor components can be derived from the double angular distribution of products of two decays by the method of 'moments'. The properties of the 'trace' of the correlation tensor (a sum of three diagonal components), determining the relative fractions of the triplet states and singlet state of respective pairs, are discussed. Spin correlations for two identical particles ({Lambda}{Lambda}) and two nonidentical particles ({Lambda}{Lambda}-bar) are considered from the viewpoint of the conventional model of one-particle sources. In the framework of this model, correlations vanish at sufficiently large relative momenta. However, under these conditions, in the case of two nonidentical particles ({Lambda}{Lambda}-bar) a noticeable role is played by two-particle annihilation (two-quark, two-gluon) sources, which lead to the difference of the correlation tensor from zero. In particular, such a situation may arise when the system passes through the 'mixed phase.'

  11. Lambda Vision

    NASA Astrophysics Data System (ADS)

    Czajkowski, Michael

    2014-06-01

    There is an explosion in the quantity and quality of IMINT data being captured in Intelligence Surveillance and Reconnaissance (ISR) today. While automated exploitation techniques involving computer vision are arriving, only a few architectures can manage both the storage and bandwidth of large volumes of IMINT data and also present results to analysts quickly. Lockheed Martin Advanced Technology Laboratories (ATL) has been actively researching in the area of applying Big Data cloud computing techniques to computer vision applications. This paper presents the results of this work in adopting a Lambda Architecture to process and disseminate IMINT data using computer vision algorithms. The approach embodies an end-to-end solution by processing IMINT data from sensors to serving information products quickly to analysts, independent of the size of the data. The solution lies in dividing up the architecture into a speed layer for low-latent processing and a batch layer for higher quality answers at the expense of time, but in a robust and fault-tolerant way. This approach was evaluated using a large corpus of IMINT data collected by a C-130 Shadow Harvest sensor over Afghanistan from 2010 through 2012. The evaluation data corpus included full motion video from both narrow and wide area field-of-views. The evaluation was done on a scaled-out cloud infrastructure that is similar in composition to those found in the Intelligence Community. The paper shows experimental results to prove the scalability of the architecture and precision of its results using a computer vision algorithm designed to identify man-made objects in sparse data terrain.

  12. Shell-model predictions for Lambda Lambda hypernuclei

    SciTech Connect

    Gal, A.; Millener, D.

    2011-06-02

    It is shown how the recent shell-model determination of {Lambda}N spin-dependent interaction terms in {Lambda} hypernuclei allows for a reliable deduction of {Lambda}{Lambda} separation energies in {Lambda}{Lambda} hypernuclei across the nuclear p shell. Comparison is made with the available data, highlighting {sub {Lambda}{Lambda}}{sup 11}Be and {sub {Lambda}{Lambda}}{sup 12}Be which have been suggested as possible candidates for the KEK-E373 HIDA event.

  13. Study of {Lambda}-{Lambda} oscillation in quantum coherent {Lambda}{Lambda} by using J/{psi}{yields}{Lambda}{Lambda} decay

    SciTech Connect

    Kang Xianwei; Li Haibo; Lu Gongru

    2010-03-01

    We discuss the possibility of searching for the {Lambda}-{Lambda} oscillations for coherent {Lambda}{Lambda} production in the J/{psi}{yields}{Lambda}{Lambda} decay process. The sensitivity of measurement of {Lambda}-{Lambda} oscillation in the external field at BES-III experiment is considered. These considerations indicate an alternative way to probe the {Delta}B=2 amplitude in addition to neutron oscillation experiments. Both coherent and time-dependent information can be used to extract the {Lambda}-{Lambda} oscillation parameter. With one year's luminosity at BES-III, we can set an upper limit of {delta}m{sub {Lambda}{Lambda}<}10{sup -15} MeV at 90% confidence level, corresponding to about 10{sup -6} s of {Lambda}-{Lambda} oscillation time.

  14. Search for supersymetric particles desintegrant itself in R-parite violee (coupling lambda_121) in a final state has three leptons

    SciTech Connect

    Magnan, Anne-Marie

    2005-07-01

    This thesis is dedicated to the study of the first data taken by the D0 detector during the Run II of the Tevatron. Supersymmetric particles have been search for in proton-antiproton collisions, with a center of mass energy of 1.96 TeV. In the framework of supersymmetry with R-parity violation, I have studied the pair production of Gauginos, leading to a pair of LSP ({chi}{sub 1}{sup 0}), each one decaying into ee{nu}{sub {mu}} or e{mu}{nu}{sub e} with a {lambda}{sub 121} coupling. The final state contains at least two electrons: I have thus paid special attention in this work to the methods concerning identification and mis-identification of electromagnetic particles, as well as reconstruction, triggering, and correction (of the reconstructed energy). In a selection of trileptons, with at least two electrons, and some transverse missing energy, we observed 0 event in the 350 pb{sup -1} of analyzed data, for 0,4{sub -0,05}{sup +0,35}(stat) {+-} 0,16 (sys) expected from the Standard Model contributions. In the signal considered in this analysis, the selection efficiency is around 12%. Results have been studied in two models: mSUGRA and MSSM. In mSUGRA model, limits on m{sub 1/2} and lightest gauginos's masses have been obtained, with tan{beta} = 5, A{sub 0} = 0, m{sub 0} = 100 and 1000 GeV.c{sup -2} and both signs of {mu}. In MSSM, with the hypothesis of massive sfermions (1000 GeV.c{sup -2}), we can exclude, at 95% Confidence Level, the region m{sub {chi}{sub 1}}{+-} < 200 GeV.c{sup -2}, for all masses of {chi}{sub 1}{sup 0} LSP.

  15. The Dependence of Cirrus Gamma Size Distributions Expressed as Volumes in N(sub 0)-Lambda-Mu Phase Space and Bulk Cloud Properties on Environmental Conditions: Results from the Small Ice Particles in Cirrus Experiment (SPARTICUS)

    NASA Technical Reports Server (NTRS)

    Jackson, Robert C.; McFarquhar, Greg M.; Fridlind, Ann M.; Atlas, Rachel

    2015-01-01

    The variability of cirrus ice microphysical properties is investigated using observations obtained during the Small Particles in Cirrus (SPARTICUS) campaign. An existing approach that represents a size distribution (SD) as a single gamma function using an ellipsoid of equally realizable solutions in (N(sub 0), lambda, mu) phase space is modified to automatically identify multiple modes in SDs and characterize each mode by such an ellipsoid. The modified approach is applied to ice crystals with maximum dimension D greater than15 micrometers collected by the 2-D stereo and 2-D precipitation probes on the Stratton Park Engineering Company Learjet. The dependencies of N(sub 0), mu, and lambda from each mode, total number concentration, bulk extinction, ice water content (IWC), and mass median maximum dimension D(sub mm) as a function of temperature T and cirrus type are then analyzed. The changes in the observed codependencies between N(sub 0), mu, and lambda, bulk extinction, IWC, and D(sub mm) with environmental conditions indicate that particles were larger at higher T during SPARTICUS. At most two modes were observed in any SD during SPARTICUS, with the average boundary between them at 115 micrometers, similar to past studies not using probes with shatter mitigating tips and artifact removal algorithms. The bimodality of the SDs increased with T. This and the differences in N(sub 0), mu, and lambda between the modes suggest that particles with smaller D nucleated more recently than particles with larger D, which grew via vapor deposition and aggregation. Because smaller crystals, whose concentrations are uncertain, make marginal contributions to higher order moments, the use of higher moments for evaluating model fields is suggested.

  16. Study of the decay asymmetry parameter and CP violation parameter in the Lambda(c)+ ---> Lambda pi+ decay

    SciTech Connect

    Link, J.M.; Yager, P.M.; Anjos, J.C.; Bediaga, I.; Castromonte, C.; Machado, A.A.; Magnin, J.; Massafferri, A.; de Miranda, J.M.; Pepe, I.M.; Polycarpo, E.; dos Reis, A.C.; Carrillo, S.; Casimiro, E.; Cuautle, E.; Sanchez-Hernandez, A.; Uribe, C.; Vazquez, F.; Agostino, L.; Cinquini, L.; Cumalat, J.P.; /Colorado U. /Fermilab /Frascati /Guanajuato U. /Illinois U., Urbana /Indiana U. /Korea U. /Kyungpook Natl. U. /INFN, Milan /Milan U. /North Carolina U. /Pavia U. /INFN, Pavia /Rio de Janeiro, Pont. U. Catol. /Puerto Rico U., Mayaguez /South Carolina U. /Tennessee U. /Vanderbilt U. /Wisconsin U., Madison

    2005-09-01

    Using data from the FOCUS (E831) experiment at Fermilab, we present a new measurement of the weak decay-asymmetry parameter a{sub {Lambda}{sub c}} in {Lambda}{sub c}{sup +} {yields} {Lambda}{pi}{sup +} decay. Comparing particle with antiparticle decays, we obtain the first measurement of the CP violation parameter {Alpha} {triple_bond} a{sub {Lambda}{sub c}} + a{sub {ovr {Lambda}{sub c}}}/a{sub {Lambda}{sub c}} - a{sub {ovr {Lambda}{sub c}}}. We obtain a{sub {Lambda}{sub c}} = -0.78 {+-} 0.16 {+-} 0.13 and {Alpha} = -0.07 {+-} 0.19 {+-} 0.12 where errors are statistical and systematic.

  17. {lambda}(1520) {yields} {lambda}{gamma} Radiative-Decay Width

    SciTech Connect

    Vavilov, D.V.; Antipov, Yu.M.; Artamonov, A.V.; Batarin, V.A.; Victorov, V.A.; Golovkin, S.V.; Gorin, Yu.P.; Eroshin, O.V.; Kozhevnikov, A.P.; Konstantinov, A.S.; Kubarovsky, V.P.; Kurshetsov, V.F.; Landsberg, L.G.; Leontiev, V.M.; Molchanov, V.V.; Mukhin, V.A.; Patalakha, D.I.; Petrenko, S.V.; Petrukhin, A.I.; Kolganov, V.Z.

    2005-03-01

    The radiative decay {lambda}(1520) {yields} {lambda}{gamma} was recorded in the exclusive reaction p + N {yields} {lambda}(1520)K{sup +} + N at the SPHINX facility. The branching ratio for this decay and the corresponding partial width were found to be, respectively, Br[{lambda}(1520) {yields} {lambda}{gamma}] = (1.02 {+-} 0.21) x 10{sup -2} and {gamma}[{lambda}(1520) {yields} {lambda}{gamma}] = 159 {+-} 35 keV (the quoted errors are purely statistical, the systematic errors being within 15%)

  18. Measurement of the Lambda b lifetime in the exclusive decay Lambda b --> J/psi Lambda.

    PubMed

    Abazov, V M; Abbott, B; Abolins, M; Acharya, B S; Adams, M; Adams, T; Aguilo, E; Ahn, S H; Ahsan, M; Alexeev, G D; Alkhazov, G; Alton, A; Alverson, G; Alves, G A; Anastasoaie, M; Ancu, L S; Andeen, T; Anderson, S; Andrieu, B; Anzelc, M S; Arnoud, Y; Arov, M; Arthaud, M; Askew, A; Asman, B; Jesus, A C S Assis; Atramentov, O; Autermann, C; Avila, C; Ay, C; Badaud, F; Baden, A; Bagby, L; Baldin, B; Bandurin, D V; Banerjee, P; Banerjee, S; Barberis, E; Barfuss, A-F; Bargassa, P; Baringer, P; Barreto, J; Bartlett, J F; Bassler, U; Bauer, D; Beale, S; Bean, A; Begalli, M; Begel, M; Belanger-Champagne, C; Bellantoni, L; Bellavance, A; Benitez, J A; Beri, S B; Bernardi, G; Bernhard, R; Berntzon, L; Bertram, I; Besançon, M; Beuselinck, R; Bezzubov, V A; Bhat, P C; Bhatnagar, V; Biscarat, C; Blazey, G; Blekman, F; Blessing, S; Bloch, D; Bloom, K; Boehnlein, A; Boline, D; Bolton, T A; Borissov, G; Bos, K; Bose, T; Brandt, A; Brock, R; Brooijmans, G; Bross, A; Brown, D; Buchanan, N J; Buchholz, D; Buehler, M; Buescher, V; Burdin, S; Burke, S; Burnett, T H; Buszello, C P; Butler, J M; Calfayan, P; Calvet, S; Cammin, J; Caron, S; Carvalho, W; Casey, B C K; Cason, N M; Castilla-Valdez, H; Chakrabarti, S; Chakraborty, D; Chan, K; Chan, K M; Chandra, A; Charles, F; Cheu, E; Chevallier, F; Cho, D K; Choi, S; Choudhary, B; Christofek, L; Christoudias, T; Cihangir, S; Claes, D; Clément, B; Clément, C; Coadou, Y; Cooke, M; Cooper, W E; Corcoran, M; Couderc, F; Cousinou, M-C; Crépé-Renaudin, S; Cutts, D; Cwiok, M; da Motta, H; Das, A; Davies, G; De, K; de Jong, P; de Jong, S J; De La Cruz-Burelo, E; De Oliveira Martins, C; Degenhardt, J D; Déliot, F; Demarteau, M; Demina, R; Denisov, D; Denisov, S P; Desai, S; Diehl, H T; Diesburg, M; Dominguez, A; Dong, H; Dudko, L V; Duflot, L; Dugad, S R; Duggan, D; Duperrin, A; Dyer, J; Dyshkant, A; Eads, M; Edmunds, D; Ellison, J; Elvira, V D; Enari, Y; Eno, S; Ermolov, P; Evans, H; Evdokimov, A; Evdokimov, V N; Ferapontov, A V; Ferbel, T; Fiedler, F; Filthaut, F; Fisher, W; Fisk, H E; Ford, M; Fortner, M; Fox, H; Fu, S; Fuess, S; Gadfort, T; Galea, C F; Gallas, E; Galyaev, E; Garcia, C; Garcia-Bellido, A; Gavrilov, V; Gay, P; Geist, W; Gelé, D; Gerber, C E; Gershtein, Y; Gillberg, D; Ginther, G; Gollub, N; Gómez, B; Goussiou, A; Grannis, P D; Greenlee, H; Greenwood, Z D; Gregores, E M; Grenier, G; Gris, Ph; Grivaz, J-F; Grohsjean, A; Grünendahl, S; Grünewald, M W; Guo, F; Guo, J; Gutierrez, G; Gutierrez, P; Haas, A; Hadley, N J; Haefner, P; Hagopian, S; Haley, J; Hall, I; Hall, R E; Han, L; Hanagaki, K; Hansson, P; Harder, K; Harel, A; Harrington, R; Hauptman, J M; Hauser, R; Hays, J; Hebbeker, T; Hedin, D; Hegeman, J G; Heinmiller, J M; Heinson, A P; Heintz, U; Hensel, C; Herner, K; Hesketh, G; Hildreth, M D; Hirosky, R; Hobbs, J D; Hoeneisen, B; Hoeth, H; Hohlfeld, M; Hong, S J; Hooper, R; Hossain, S; Houben, P; Hu, Y; Hubacek, Z; Hynek, V; Iashvili, I; Illingworth, R; Ito, A S; Jabeen, S; Jaffré, M; Jain, S; Jakobs, K; Jarvis, C; Jesik, R; Johns, K; Johnson, C; Johnson, M; Jonckheere, A; Jonsson, P; Juste, A; Käfer, D; Kahn, S; Kajfasz, E; Kalinin, A M; Kalk, J M; Kalk, J R; Kappler, S; Karmanov, D; Kasper, J; Kasper, P; Katsanos, I; Kau, D; Kaur, R; Kaushik, V; Kehoe, R; Kermiche, S; Khalatyan, N; Khanov, A; Kharchilava, A; Kharzheev, Y M; Khatidze, D; Kim, H; Kim, T J; Kirby, M H; Kirsch, M; Klima, B; Kohli, J M; Konrath, J-P; Kopal, M; Korablev, V M; Kothari, B; Kozelov, A V; Krop, D; Kryemadhi, A; Kuhl, T; Kumar, A; Kunori, S; Kupco, A; Kurca, T; Kvita, J; Lam, D; Lammers, S; Landsberg, G; Lazoflores, J; Lebrun, P; Lee, W M; Leflat, A; Lehner, F; Lellouch, J; Lesne, V; Leveque, J; Lewis, P; Li, J; Li, L; Li, Q Z; Lietti, S M; Lima, J G R; Lincoln, D; Linnemann, J; Lipaev, V V; Lipton, R; Liu, Y; Liu, Z; Lobo, L; Lobodenko, A; Lokajicek, M; Lounis, A; Love, P; Lubatti, H J; Lyon, A L; Maciel, A K A; Mackin, D; Madaras, R J; Mättig, P; Magass, C; Magerkurth, A; Makovec, N; Mal, P K; Malbouisson, H B; Malik, S; Malyshev, V L; Mao, H S; Maravin, Y; Martin, B; McCarthy, R; Melnitchouk, A; Mendes, A; Mendoza, L; Mercadante, P G; Merkin, M; Merritt, K W; Meyer, A; Meyer, J; Michaut, M; Millet, T; Mitrevski, J; Molina, J; Mommsen, R K; Mondal, N K; Moore, R W; Moulik, T; Muanza, G S; Mulders, M; Mulhearn, M; Mundal, O; Mundim, L; Nagy, E; Naimuddin, M; Narain, M; Naumann, N A; Neal, H A; Negret, J P; Neustroev, P; Nilsen, H; Noeding, C; Nomerotski, A; Novaes, S F; Nunnemann, T; O'dell, V; O'neil, D C; Obrant, G; Ochando, C; Onoprienko, D; Oshima, N; Osta, J; Otec, R; Otero Y Garzón, G J; Owen, M; Padley, P; Pangilinan, M; Panikashvili, N; Parashar, N; Park, S-J; Park, S K; Parsons, J; Partridge, R; Parua, N; Patwa, A; Pawloski, G; Perea, P M; Peters, K; Peters, Y; Pétroff, P; Petteni, M; Piegaia, R; Piper, J; Pleier, M-A; Podesta-Lerma, P L M; Podstavkov, V M; Pogorelov, Y; Pol, M-E; Pompos, A; Pope, B G; Popov, A V; Potter, C; Prado da Silva, W L; Prosper, H B; Protopopescu, S; Qian, J; Quadt, A; Quinn, B; Rakitine, A; Rangel, M S; Rani, K J; Ranjan, K; Ratoff, P N; Renkel, P; Reucroft, S; Rich, P; Rijssenbeek, M; Ripp-Baudot, I; Rizatdinova, F; Robinson, S; Rodrigues, R F; Royon, C; Rubinov, P; Ruchti, R; Safronov, G; Sajot, G; Sánchez-Hernández, A; Sanders, M P; Santoro, A; Savage, G; Sawyer, L; Scanlon, T; Schaile, D; Schamberger, R D; Scheglov, Y; Schellman, H; Schieferdecker, P; Schliephake, T; Schmitt, C; Schwanenberger, C; Schwartzman, A; Schwienhorst, R; Sekaric, J; Sengupta, S; Severini, H; Shabalina, E; Shamim, M; Shary, V; Shchukin, A A; Shivpuri, R K; Shpakov, D; Siccardi, V; Simak, V; Sirotenko, V; Skubic, P; Slattery, P; Smirnov, D; Smith, R P; Snow, G R; Snow, J; Snyder, S; Söldner-Rembold, S; Sonnenschein, L; Sopczak, A; Sosebee, M; Soustruznik, K; Souza, M; Spurlock, B; Stark, J; Steele, J; Stolin, V; Stone, A; Stoyanova, D A; Strandberg, J; Strandberg, S; Strang, M A; Strauss, M; Ströhmer, R; Strom, D; Strovink, M; Stutte, L; Sumowidagdo, S; Svoisky, P; Sznajder, A; Talby, M; Tamburello, P; Tanasijczuk, A; Taylor, W; Telford, P; Temple, J; Tiller, B; Tissandier, F; Titov, M; Tokmenin, V V; Tomoto, M; Toole, T; Torchiani, I; Trefzger, T; Tsybychev, D; Tuchming, B; Tully, C; Tuts, P M; Unalan, R; Uvarov, L; Uvarov, S; Uzunyan, S; Vachon, B; van den Berg, P J; van Eijk, B; Van Kooten, R; van Leeuwen, W M; Varelas, N; Varnes, E W; Vartapetian, A; Vasilyev, I A; Vaupel, M; Verdier, P; Vertogradov, L S; Verzocchi, M; Villeneuve-Seguier, F; Vint, P; Von Toerne, E; Voutilainen, M; Vreeswijk, M; Wagner, R; Wahl, H D; Wang, L; Wang, M H L S; Warchol, J; Watts, G; Wayne, M; Weber, G; Weber, M; Weerts, H; Wenger, A; Wermes, N; Wetstein, M; White, A; Wicke, D; Wilson, G W; Wimpenny, S J; Wobisch, M; Wood, D R; Wyatt, T R; Xie, Y; Yacoob, S; Yamada, R; Yan, M; Yasuda, T; Yatsunenko, Y A; Yip, K; Yoo, H D; Youn, S W; Yu, C; Yu, J; Yurkewicz, A; Zatserklyaniy, A; Zeitnitz, C; Zhang, D; Zhao, T; Zhou, B; Zhu, J; Zielinski, M; Zieminska, D; Zieminski, A; Zivkovic, L; Zutshi, V; Zverev, E G

    2007-10-01

    We have measured the Lambda b lifetime using the exclusive decay Lambda b --> J/psi Lambda, based on 1.2 fb(-1) of data collected with the D0 detector during 2002-2006. From 171 reconstructed Lambda b decays, where the J/psi and Lambda are identified via the decays J/psi --> mu+ mu- and Lambda --> ppi, we measured the Lambda b lifetime to be tau(Lambda b)=1.218 (+0.130)/(-0.115) (stat) +/- 0.042(syst) ps. We also measured the B0 lifetime in the decay B0 --> J/psi(mu+ mu-)K(0)/(S)(pi+ pi-) to be tau(B0)=1.501 (+0.078)/(-0.074) (stat) +/- 0.050(syst) ps, yielding a lifetime ratio of tau(Lambda b)/tau(B0)=0.811 (+0.096)/(-0.087) (stat) +/- 0.034(syst). PMID:17930660

  19. Life of Lambda

    ERIC Educational Resources Information Center

    Futhey, Tracy

    2005-01-01

    In this column, the author discusses the four key questions related to the National LambdaRail (NLR) networking technology. NLR uses Dense Wave Division Multiplexing (DWDM) to enable multiple networks to coexist on a national fiber footprint, and is owned and operated not by carriers, but by the research and education community. The NLR Board…

  20. Transverse polarization of {lambda} and {lambda} hyperons in quasireal photoproduction

    SciTech Connect

    Airapetian, A.; Akopov, N.; Akopov, Z.; Avakian, R.; Avetissian, A.; Elbakian, G.; Gharibyan, V.; Marukyan, H.; Rostomyan, A.; Taroian, S.; Zohrabian, H.; Amarian, M.; Ammosov, V. V.; Gapienko, G.; Gapienko, V.; Tchuiko, B.; Andrus, A.; Bailey, P.; Bouwhuis, M.; Chiang, H. C.

    2007-11-01

    The HERMES experiment has measured the transverse polarization of {lambda} and {lambda} hyperons produced inclusively in quasireal photoproduction at a positron beam energy of 27.6 GeV. The transverse polarization P{sub n}{sup {lambda}} of the {lambda} hyperon is found to be positive while the observed {lambda} polarization is compatible with zero. The values averaged over the kinematic acceptance of HERMES are P{sub n}{sup {lambda}}=0.078{+-}0.006(stat){+-}0.012(syst) and P{sub n}{sup {lambda}}=-0.025{+-}0.015(stat){+-}0.018(syst) for {lambda} and {lambda}, respectively. The dependences of P{sub n}{sup {lambda}} and P{sub n}{sup {lambda}} on the fraction {zeta} of the beam's light-cone momentum carried by the hyperon and on the hyperon's transverse momentum p{sub T} were investigated. The measured {lambda} polarization rises linearly with p{sub T} and exhibits a different behavior for low and high values of {zeta}, which approximately correspond to the backward and forward regions in the center-of-mass frame of the {gamma}*N reaction.

  1. Reinvestigating the Lambda Boo Stars

    NASA Astrophysics Data System (ADS)

    Cheng, Kwang-Ping; Corbally, C. J.; Gray, R. O.; Murphy, S.; Neff, J. E.; Desai, A.; Newsome, I.; Steele, P.

    2014-01-01

    The peculiar nature of Lambda Bootis was first introduced in 1943. Subsequently, Lambda Boo stars have been slowly recognized as a group of A-type Population I dwarfs that show mild to extreme deficiencies of iron-peak elements, although C, N, O, and S can be near solar. MK classification criteria include broad hydrogen lines, a weak metallic-line spectrum compared to MK standards, coupled with a particularly weak Mg II 4481 line. This intriguing stellar class has recently regained the spotlight because of the directly imaged planets around a confirmed Lambda Boo star-HR 8799 and a probable Lambda Boo star-Beta Pictoris. The possible link between Lambda Boo stars and planet-bearing stars motivates us to study Lambda Boo stars systematically. However, Lambda Boo candidates published in the literature have been selected using widely different criteria. The Lambda Boo class has become somewhat of a "grab bag" for any peculiar A-type stars that didn't fit elsewhere. In order to determine the origin of Lambda Boo stars’ low abundances and to better discriminate between theories explaining the Lambda Boo phenomenon, a refined working definition of Lambda Boo stars is needed. We have re-evaluated all published Lambda Boo candidates and their existing spectra. After applying a consistent set of optical/UV classification criteria, we identified over 60 confirmed and over 20 probable Lambda Boo stars among all stars that have been suggested as Lambda Boo candidates. We are obtaining new observations for those probable Lambda Boo stars. We also have explored the possible link between debris disks and Lambda Boo Stars.

  2. Lambda Calculi: A Guide

    NASA Astrophysics Data System (ADS)

    Hankin, Chris

    One of the universal notions of programming languages is functional abstraction. The methods of Java and the functions defined and used in functional programming languages, such as Haskell, are instances of this general notion. The inspiration for this form of abstraction mechanism comes from Mathematical Logic; notably Church's λ(lambda)-calculi and Schönfinkel's and Curry's Combinatory Logic. A proper study of these foundations leads to a better understanding of some of the fundamental issues in Computer Science.

  3. Structure of A=7 iso-triplet {lambda} hypernuclei studied with the four-body cluster model

    SciTech Connect

    Hiyama, E.; Yamamoto, Y.; Motoba, T.; Kamimura, M.

    2009-11-15

    The structure of the T=1 isotriplet hypernuclei, {sub {lambda}}{sup 7}He, {sub {lambda}}{sup 7}Li, and {sub {lambda}}{sup 7}Be within the framework of an {alpha}+{lambda}+N+N four-body cluster model is studied. Interactions between the constituent subunits are determined so as to reproduce reasonably well the observed low-energy properties of the {alpha}N, {alpha}{lambda}, {alpha}NN, and {alpha}{lambda}N subsystems. Furthermore, the two-body {lambda}N interaction is adjusted so as to reproduce the 0{sup +}-1{sup +} splitting of {sub {lambda}}{sup 4}H. Also, a phenomenological {lambda}N charge symmetry breaking (CSB) interaction is introduced. The {lambda} binding energy of the ground state in {sub {lambda}}{sup 7}He is predicted to be 5.16(5.36) MeV with (without) the CSB interaction. The calculated energy splittings of the 3/2{sup +}-5/2{sup +} states in {sub {lambda}}{sup 7}He and {sub {lambda}}{sup 7}Li are around 0.1 MeV. We point out that there is a three-layer structure of the matter distribution, {alpha} particle, {lambda} skin, and proton or neutron halo, in the {sub {lambda}}{sup 7}He(J=5/2{sup +}), {sub {lambda}}{sup 7}Li(J=5/2{sup +}), and {sub {lambda}}{sup 7}Be(J=1/2{sup +}) states.

  4. {Lambda}* hypernuclei with chiral dynamics

    SciTech Connect

    Uchino, Toshitaka; Hyodo, Tetsuo; Oka, Makoto

    2011-10-21

    As a strangeness S = -1 and baryon number B = 2 system, the two-body bound state of {Lambda}* = {Lambda}(1405) and a nucleon is studied. To solve the {Lambda}*N system, we construct the {Lambda}*N potential by extending the Juelich model with couplings estimated in the chiral unitary approach. We have the {Lambda}*N quasi-bound state with the mass, M{sub {Lambda}}*N{approx}2366 MeV which is shallowly bound with the binding energy B{approx}9 MeV in terms of the K-barNN system. Decay width of the fall apart process, where the {Lambda}*N resonance decays to {pi}{Sigma}N with a nucleon being as a spectator, is estimated to be {Gamma}{sub F.A}{approx}49 MeV.

  5. Shell and cluster states of {sub {Lambda}}{sup 21}Ne studied with antisymmetrized molecular dynamics

    SciTech Connect

    Isaka, Masahiro; Kimura, Masaaki; Dote, Akinobu; Ohnishi, Akira

    2011-05-15

    The low-lying states of {sub {Lambda}}{sup 21}Ne are studied with antisymmetrized molecular dynamics for hypernuclei. We have obtained ten rotational bands where the number of bands are increased compared to {sup 20}Ne by adding a {Lambda} hyperon. Among them, we focus on the K{sup {pi}=}0{sub 1}{sup +} x {Lambda}{sub s} and K{sup {pi}=}0{sub 1}{sup -} x {Lambda}{sub s} bands. The former has a shell-model-like structure that has {Lambda} in an s wave coupled to the ground band of {sup 20}Ne. The latter is a cluster state that has a {alpha}+{sub {Lambda}}{sup 17}O dicluster structure. The difference between their structures leads to the binding energy of {Lambda} particle B{sub {Lambda}} and reduction of the E2 transition probabilities B(E2).

  6. Production of cumulative. lambda. hyperons in. pi. /sup -/C interactions at 40 GeV/c

    SciTech Connect

    Kladnitskaya, E.N.; Popova, V.M.

    1984-02-01

    We report the results of a study of the cumulative production of ..lambda.. hyperons in ..pi../sup -/C interactions at a ..pi../sup -/-meson momentum 40 GeV/c. The cross section for production of cumulative ..lambda.. hyperons is found to be sigma/sup ..lambda..//sub cum/ = 0.7 +- 0.2 mb. The fraction of ..lambda../sub cum/ is 5 +- 1% of all ..lambda.. hyperons in ..pi../sup -/C interactions at 40 GeV/c. Average values are given for the kinematic parameters of the ..lambda.. hyperons, together with the distribution of ..lambda.. hyperons in cumulative number and the dependence of the invariant cross sections on the kinetic energy and on the transverse momentum of the cumulative ..lambda.. hyperons. The results are compared with data of other studies at various primary-particle energies.

  7. PROTON - LAMBDA CORRELATIONS IN AU-AU COLLISIONS AT SQUARE ROOT NN = 200 GEV FROM THE STAR EXPERIMENT.

    SciTech Connect

    RENAULT,G.

    2004-03-15

    The space-time evolution of the source of particles formed in the collision of nuclei can be studied through particle correlations. The STAR experiment is dedicated to study ultra-relativistic heavy ions collisions and allows to measure non-identical strange particle correlations. The source size can be extracted by studying p - {Lambda}, {bar p} - {bar {Lambda}}, {bar p} - {Lambda} and p - {bar {Lambda}} correlation functions. Strong interaction potential has been studied for these systems using an analytical model. Final State Interaction (FSI) parameters have been determined and has shown a significant annihilation process present in {bar p} - {Lambda} and p - {bar {Lambda}} systems not present in p - {Lambda} and {bar p} - {bar {Lambda}}.

  8. Suppression of the {Lambda}-{Sigma} coupling in nuclear matter

    SciTech Connect

    Bodmer, A.R.; Usmani, Q.N.

    1995-08-01

    We initiated a study of the modification of the coupling of the {Lambda}N to the {Sigma}N channel in nuclear matter with the Fermi hypernetted-chain variational approach. This modification of the {Lambda}N-{Sigma}N coupling is a central problem in hypernuclear physics and is related closely to the strongly repulsive three-body forces which are needed to account for hypernuclear binding energies. All earlier calculations have only considered this problem in the so-called G-matrix approximation which neglects important higher-order effects. An important result of this work will be a better understanding of the density dependence of {Lambda} binding in nuclear matter, which can then be tested in the calculation of the {Lambda} single-particle energies.

  9. HERMES measurements of {lambda} polarization

    SciTech Connect

    Rith, Klaus

    2007-06-13

    The HERMES experiment at DESY has measured the transfer of polarization from longitudinally polarized 27.6 GeV positrons to {lambda} hyperons produced in semi-inclusive deep-inelastic scattering from unpolarized gas targets internal to the electron/positron ring of the HERA collider. The longitudinal spin transfer coefficient is found to be D{sub LL'}{sup {lambda}} = 0.11 {+-} 0.10 (stat) {+-} 0.03 (syst) at an average fractional energy carried by the {lambda} hyperon = 0.45.

  10. Variational calculations of the {Lambda}-separation energy of the {sub {Lambda}}{sup 17}O hypernucleus

    SciTech Connect

    Usmani, A.A.; Pieper, S.C.; Usmani, Q.N.

    1995-05-01

    Variational Monte Carlo calculations have been made for the {sub {Lambda}}{sup 17}O hypernucleus using realistic two- and three-baryon interactions. A two-pion exchange potential with spin- and space-exchange components is used for the {Lambda}{ital N} potential. Three-body two-pion exchange and strongly repulsive dispersive {Lambda}{ital NN} interactions are also included. The trial wave function is constructed from pair- and triplet-correlation operators acting on a single-particle determinant. These operators consist of central, spin, isospin, tensor, and three-baryon potential components. A cluster Monte Carlo method is developed for noncentral correlations and is used with up to four-baryon clusters in our calculations. The three-baryon {Lambda}{ital NN} force is discussed.

  11. Experimental Studies of Hypernuclear Structure and the {lambda}N and {lambda}NN Interactions

    SciTech Connect

    Tamura, H.

    2008-04-29

    The {lambda}NN three-body force, through {lambda}N-{sigma}N coupling, plays an important role in the structure of {lambda} hypernuclei. We have been studying the {lambda}N interaction via hypernuclear {gamma}-ray spectroscopy experiments and obtained the effective interaction strengths of the spin-dependent {lambda}N interactions. In addition, a possible effect of the {lambda}NN three-body force is being investigated from precise level schemes of light {lambda} hypernuclei. The {lambda}NN three-body force can also be studied from the structure of neutron-rich {lambda} hypernuclei by using the ({pi}{sup -},K{sup +}) reaction.

  12. Measurements of J/{psi} and {psi}(2S) decays into {lambda}{lambda}{pi}{sup 0} and {lambda}{lambda}{eta}

    SciTech Connect

    Ablikim, M.; Bai, J. Z.; Cai, X.; Chen, H. S.; Chen, H. X.; Chen, J. C.; Chen, Jin; Chen, Y. B.; Chu, Y. P.; Deng, Z. Y.; Du, S. X.; Fang, J.; Fang, S. S.; Gao, C. S.; Gu, S. D.; Guo, Y. N.; He, K. L.; Heng, Y. K.; Hu, H. M.; Hu, T.

    2007-11-01

    Using 58x10{sup 6} J/{psi} and 14x10{sup 6} {psi}(2S) events collected by the BESII detector at the BEPC, branching fractions or upper limits for the decays J/{psi} and {psi}(2S){yields}{lambda}{lambda}{pi}{sup 0} and {lambda}{lambda}{eta} are measured. For the isospin violating decays, the upper limits are determined to be B(J/{psi}{yields}{lambda}{lambda}{pi}{sup 0})<6.4x10{sup -5} and B[{psi}(2S){yields}{lambda}{lambda}{pi}{sup 0}]<4.9x10{sup -5} at the 90% confidence level. The isospin conserving process J/{psi}{yields}{lambda}{lambda}{eta} is observed for the first time, and its branching fraction is measured to be B(J/{psi}{yields}{lambda}{lambda}{eta})=(2.62{+-}0.60{+-}0.44)x10{sup -4}, where the first error is statistical and the second one is systematic. No {lambda}{lambda}{eta} signal is observed in {psi}(2S) decays, and B[{psi}(2S){yields}{lambda}{lambda}{eta}]<1.2x10{sup -4} is set at the 90% confidence level. Branching fractions of J/{psi} decays into {sigma}{sup +}{pi}{sup -}{lambda} and {sigma}{sup -}{pi}{sup +}{lambda} are also reported, and the sum of these branching fractions is determined to be B(J/{psi}{yields}{sigma}{sup +}{pi}{sup -}{lambda}+c.c.)=(1.52{+-}0.08{+-}0.16)x10{sup -3}.

  13. {Lambda}K*{Lambda}(1116) photoproduction and nucleon resonances

    SciTech Connect

    Kim, Sang-Ho; Kim, Hyun-Chul; Nam, Seung-il; Oh, Yongseok

    2011-10-21

    In this presentation, we report our recent studies on the {Lambda}K*{Lambda}(1116) photoproduction off the proton target, using the tree-level Born approximation, via the effective Lagrangian approach. In addition, we include the nine (three- or four-star confirmed) nucleon resonances below the threshold {radical}(s{sub th}){approx_equal}2008 MeV, to interpret the discrepancy between the experiment and previous theoretical studies, in the vicinity of the threshold region. From the numerical studies, we observe that the S{sub 11}(1535) and S11(1650) play an important role for the cross-section enhancement near the {radical}(s{sub th}). It also turns out that, in order to reproduce the data, we have the vector coupling constants gK*S{sub 11}(1535){Lambda} = (7.0{approx}9.0) and gK*S{sub 11}(1650){Lambda} (5.0{approx}6.0).

  14. A new three-baryon-force in {lambda}{lambda} hypernuclei

    SciTech Connect

    Nemura, Hidekatsu

    2008-04-29

    We describe a few-body calculation of {sub {lambda}}{sub {lambda}}{sup 5}H as well as {sub {lambda}}{sub {lambda}}{sup 4}H and {sub {lambda}}{sub {lambda}}{sup 6}He taking account fully coupled-channel two-baryon potentials acting among the octet of baryons. The wave function includes not only pnn{lambda}{lambda} and ppnn{xi}{sup -} components but also pnn{lambda}{sigma}{sup 0}, ppn{lambda}{sigma}{sup -}, pnn{sigma}{sup 0}{sigma}{sup 0} and ppn{sigma}{sup 0}{sigma}{sup -}. An effective YY potential based on Nijmegen model D is used. We find that the pnn{lambda}{sigma}{sup 0} and ppn{lambda}{sigma}{sup -} components play an important role in producing the {sub {lambda}}{sub {lambda}}{sup 5}H bound state. The present result requires the introduction of a new coupled-channel three-body-force, N{lambda}{lambda}--NN{xi}, if the intermediate pnn{lambda}{sigma}{sup 0} and ppn{lambda}{sigma}{sup -} states are eliminated from the model space.

  15. Six-Body variational Monte Carlo study of {sub {lambda}}{sub {lambda}}{sup 6}He

    SciTech Connect

    Usmani, Q.N.; Sharma, Bhupali; Bodmer, A.R.

    2004-12-01

    Variational Monte Carlo calculations are carried out for {sub {lambda}}{sub {lambda}}{sup 6}He using realistic NN, NNN, and phenomenological {lambda}N and {lambda}NN interactions. For the {lambda}{lambda} interaction we employ the various phase equivalent Nijmegen interactions. By incorporating the various components of {lambda}-nuclear interactions in stages, and keeping B{sub {lambda}}({sub {lambda}}{sup 5}He) around 3.12 MeV, it is demonstrated that the incremental energy {delta}B{sub {lambda}}{sub {lambda}} for {sub {lambda}}{sub {lambda}}{sup 6}He is sensitive to the three-body {lambda}NN force and the exchange part of the {lambda}N interaction. The {lambda}{lambda} interaction obtained is only somewhat weaker than the {lambda}N interaction. We also report the results for the rearrangement energy of the {alpha} core. We discuss the implications of our results.

  16. Study of B{yields}{lambda}{sub c}{lambda}{sub c} and B{yields}{lambda}{sub c}{lambda}{sub c}K

    SciTech Connect

    Cheng, H.-Y.; Hsiao, Y.-K.; Chua, C.-K.

    2009-06-01

    We study the doubly charmful two-body and three-body baryonic B decays B{yields}{lambda}{sub c}{sup +}{lambda}{sub c}{sup -} and B{yields}{lambda}{sub c}{sup +}{lambda}{sub c}{sup -}K. As pointed out before, a naive estimate of the branching ratio O(10{sup -8}) for the latter decay is too small by 3 to 4 orders of magnitude compared to experiment. Previously, it has been shown that a large enhancement for the {lambda}{sub c}{sup +}{lambda}{sub c}{sup -}K production can occur due to a charmoniumlike resonance (e.g. X(4630) discovered by Belle) with a mass near the {lambda}{sub c}{lambda}{sub c} threshold. Motivated by the BABAR's observation of a resonance in the {lambda}{sub c}K system with a mass of order 2930 MeV, we study in this work the contribution to B{yields}{lambda}{sub c}{sup +}{lambda}{sub c}{sup -}K from the intermediate state {xi}{sub c}(2980) which is postulated to be a first positive-parity excited D-wave charmed baryon state. Assuming that a soft qq quark pair is produced through the {sigma} and {pi} meson exchanges in the configuration for B{yields}{xi}{sub c}(2980){lambda}{sub c} and {lambda}{sub c}{lambda}{sub c}, it is found that branching ratios of B{yields}{lambda}{sub c}{sup +}{lambda}{sub c}{sup -}K and B{yields}{lambda}{sub c}{sup +}{lambda}{sub c}{sup -} are of order 3.5x10{sup -4} and 5x10{sup -5}, respectively, in agreement with experiment except that the prediction for the {lambda}{sub c}{lambda}{sub c}K{sup -} is slightly smaller. In conjunction with our previous analysis, we conclude that the enormously large rate of B{yields}{lambda}{sub c}{sup +}{lambda}{sub c}{sup -}K arises from the resonances {xi}{sub c}(2980) and X(4630)

  17. Longitudinal Polarization of {lambda} and {lambda}-bar Hyperons in Deep-Inelastic Scattering at COMPASS

    SciTech Connect

    Sapozhnikov, M. G.

    2007-06-13

    The longitudinal polarization of {lambda} and {lambda}-bar hyperons produced in deep-inelastic scattering of 160 GeV/c polarized positive muons is studied in the COMPASS (CERN NA58) experiment. Preliminary results on the longitudinal polarization of {lambda} and {lambda}-bar from data collected during the 2003 run are presented.

  18. {lambda}NN Three-Body Force due to Coherent {lambda}-{sigma} Coupling

    SciTech Connect

    Akaishi, Yoshinori; Myint, Khin Swe

    2008-04-29

    The overbinding problem of {sub {lambda}}{sup 5}He is solved by introducing a concept of coherent {lambda}-{sigma} coupling which is equivalent to a {lambda}NN three-body force. This three-body force is coherently enhanced in the 0{sup +} states of {sub {lambda}}{sup 4}H and {sub {lambda}}{sup 4}He. The 0{sup +}-1{sup +} splitting in these hypernuclei is mainly due to coherent {lambda}-{sigma} coupling and partly due to the {lambda}N spin-spin interaction. A {lambda}NN three-body potential is derived from the coupled-channel treatment. The origin of the repulsive and attractive nature of the three-body force is discussed. Coherent {lambda}-{sigma} coupling becomes more important in neutron-rich hypernuclei and especially in neutron-star matter at high densities. The possible existence of ''hyperheavy hydrogen'', {sub {lambda}}{sup 6}H, is suggested.

  19. Observation of B{sup 0}{yields}{lambda}{lambda}K{sup 0} and B{sup 0}{yields}{lambda}{lambda}K*{sup 0} at Belle

    SciTech Connect

    Chang, Y.-W.; Wang, M.-Z.; Chao, Y.; Hou, W.-S.; Lin, S.-W.; Shiu, J.-G.; Wei, J.-T.; Adachi, I.; Dalseno, J.; Hazumi, M.; Iwasaki, Y.; Kichimi, H.; Nakao, M.; Nishida, S.; Ozaki, H.; Sakai, Y.; Sumisawa, K.; Tanaka, M.; Uehara, S.; Uno, S.

    2009-03-01

    We study the charmless decays B{yields}{lambda}{lambda}h, where h stands for {pi}{sup +}, K{sup +}, K{sup 0},K*{sup +}, or K*{sup 0}, using a 605 fb{sup -1} data sample collected at the {upsilon}(4S) resonance with the Belle detector at the KEKB asymmetric energy e{sup +}e{sup -} collider. We observe B{sup 0}{yields}{lambda}{lambda}K{sup 0} and B{sup 0}{yields}{lambda}{lambda}K*{sup 0} with branching fractions of (4.76{sub -0.68}{sup +0.84}(stat){+-}0.61(syst))x10{sup -6} and (2.46{sub -0.72}{sup +0.87}{+-}0.34)x10{sup -6}, respectively. The significances of these signals in the threshold-mass enhanced mass region, M{sub {lambda}}{sub {lambda}}<2.85 GeV/c{sup 2}, are 12.4{sigma} and 9.3{sigma}, respectively. We also update the branching fraction B(B{sup +}{yields}{lambda}{lambda}K{sup +})=(3.38{sub -0.36}{sup +0.41}{+-}0.41)x10{sup -6} with better accuracy, and report the following measurement or 90% confidence level upper limit in the threshold-mass-enhanced region: B(B{sup +}{yields}{lambda}{lambda}K*{sup +})=(2.19{sub -0.88}{sup +1.13}{+-}0.33)x10{sup -6} with 3.7{sigma} significance; B(B{sup +}{yields}{lambda}{lambda}{pi}{sup +})<0.94x10{sup -6}. A related search for B{sup 0}{yields}{lambda}{lambda}D{sup 0} yields a branching fraction B(B{sup 0}{yields}{lambda}{lambda}D{sup 0})=(1.05{sub -0.44}{sup +0.57}{+-}0.14)x10{sup -5}. This may be compared with the large, {approx}10{sup -4}, branching fraction observed for B{sup 0}{yields}ppD{sup 0}. The M{sub {lambda}}{sub {lambda}} enhancements near threshold and related angular distributions for the observed modes are also reported.

  20. Photoproduction of the Lambda*(1520) Hyperon

    SciTech Connect

    Z. W. Zhao, H. Y. Lu, L. Graham, K. Park, R. W. Gothe

    2010-08-01

    The photoproduction of the Lambda*(1520) on both the proton and neutron have been studied by using the CLAS eg3 run data set. The reactions are gammad-->K+Lambda*(n) and gammad-->K0Lambda*(p) with Lambda*-->pK-. Preliminary total and differential cross sections have been extracted in the photon energy region 1.75 GeVLambda*(1520) on the neutron is reported, and we will extend the results on the proton to higher energies than in previous studies.

  1. Superfluidity of {Lambda} hyperons in neutron stars

    SciTech Connect

    Wang, Y. N.; Shen, H.

    2010-02-15

    We study the {sup 1}S{sub 0} superfluidity of {Lambda} hyperons in neutron star matter and neutron stars. We use the relativistic mean field (RMF) theory to calculate the properties of neutron star matter. In the RMF approach, the meson-hyperon couplings are constrained by reasonable hyperon potentials that include the updated information from recent developments in hypernuclear physics. To examine the {sup 1}S{sub 0} pairing gap of {Lambda} hyperons, we employ several {Lambda}{Lambda} interactions based on the Nijmegen models and used in double-{Lambda} hypernuclei studies. It is found that the maximal pairing gap obtained is a few tenths of a MeV. The magnitude and the density region of the pairing gap are dependent on the {Lambda}{Lambda} interaction and the treatment of neutron star matter. We calculate neutron star properties and find that whether the {sup 1}S{sub 0} superfluidity of {Lambda} hyperons exists in the core of neutron stars mainly depends on the {Lambda}{Lambda} interaction used.

  2. Serologically defined V region subgroups of human lambda light chains.

    PubMed

    Solomon, A; Weiss, D T

    1987-08-01

    The availability of numerous antisera prepared against lambda-type Bence Jones proteins and lambda chains of known amino acid sequence has led to the differentiation and classification of human lambda light chains into one of five V lambda subgroups. The five serologically defined subgroups, V lambda I, V lambda II, V lambda III, V lambda IV, and V lambda VI, correspond to the chemical classification that is based on sequence homologies in the first framework region (FR1). Proteins designated by sequence as lambda V react with specific anti-lambda II antisera and are thus included in the V lambda II subgroup classification. The isotypic nature of the five V lambda subgroups was evidenced through analyses of lambda-type light chains that were isolated from the IgG of normal individuals. Based on analyses of 116 Bence Jones proteins, the frequency of distribution of the lambda I, lambda II/V, lambda III, lambda IV, and lambda VI proteins in the normal lambda chain population is estimated to be 27%, 37%, 23%, 3%, and 10%, respectively. This distribution of V lambda subgroups was comparable to that found among 82 monoclonal Ig lambda proteins. Considerable V lambda intragroup antigenic heterogeneity was also apparent. At least two sub-subgroups were identified among each of the five major V lambda subgroups, implying the existence of multiple genes in the human V lambda genome. The V lambda classification of 54 Ig lambda proteins obtained from patients with primary or multiple myeloma-associated amyloidosis substantiated the preferential association of lambda VI light chains with amyloidosis AL and the predominance of the normally rare V lambda VI subgroup in this disease. PMID:3110284

  3. First Observation of the {Lambda}(1405) Line Shape in Electroproduction

    SciTech Connect

    Iowa State U.; Carnegie Mellon U.

    2013-10-01

    We report the first observation of the line shape of the {Lambda}(1405) from electroproduction, and show that it is not a simple Breit-Wigner resonance. Electroproduction of K{sup +}{Lambda}(1405) off the proton was studied by using data from CLAS at Jefferson Lab in the range 1.0Lambda}(1405) and p{pi}{sup 0} of the {Sigma}{sup +}. Neither the standard Particle Data Group resonance parameters, nor free parameters fitting to a single Breit-Wigner resonance represent the line shape. In our fits, the line shape corresponds approximately to predictions of a two-pole meson-baryon picture of the {Lambda}(1405), with a lower mass pole near 1368 MeV/c{sup 2} and a higher mass pole near 1423 MeV/c{sup 2}. Furthermore, with increasing photon virtuality the mass distribution shifts toward the higher mass pole.

  4. Measurement of the Lambda 0(b) -> Lambda +(c) pi- branching ratio

    SciTech Connect

    Le, Yi; /Johns Hopkins U.

    2003-01-01

    The authors present a measurement of the {Lambda}{sub b}{sup 0} {yields} {Lambda}{sub c}{sup +} {pi}{sup -} branching ratio in p{bar p} collisions at {radical}s = 1.96 TeV using 65 pb{sup -1} data collected by the Collider Detector at Fermilab (CDF). The measurement starts from reconstructing two decay modes: {Lambda}{sub b}{sup 0} {yields} {Lambda}{sub c}{sup +}{pi}{sup -}, where {Lambda}{sub c}{sup +} {yields} p K{sup -} {pi}{sup +}; and {bar B}{sup 0} {yields} D{sup +}{pi}{sup -}, where D{sup +} {yields} {pi}{sup +} K{sup -} {pi}{sup +}. The authors obtained 96 {+-} 13 {Lambda}{sub b}{sup 0} and 321 {+-} 22 {bar B}{sup 0} candidates from the CDF Run II Two-Track Hadronic Trigger data sample. The relative branching ratio of the two decays is then measured based on the equation: f{sub {Lambda}{sub b}} BR({Lambda}{sub b} {yields} {Lambda}{sub c}{sup +} {pi}{sup -})/f{sub d} BR({bar B}{sup 0} {yields} D{sup +} {pi}{sup -}) = BR(D{sup +} {yields} K{pi}{pi}) N{sub {Lambda}{sub b}} {epsilon}{sub B{sup 0}}/BR({Lambda}{sub c}{sup +} {yields} pK{pi}) N{sub {bar B}{sup 0}} {epsilon}{sub {Lambda}{sub b}}. The measurement gives f{sub {Lambda}{sub b}} BR({Lambda}{sub b} {yields} {Lambda}{sub c}{sup +}{pi}{sup -})/f{sub d} BR({bar B}{sup 0} {yields} D{sup +}{pi}{sup -}) = 0.66 {+-} 0.11(stat) {+-} 0.09(syst) {+-} 0.18(BR). The {Lambda}{sub b}{sup 0} {yields} {Lambda}{sub c}{sup +}{pi}{sup -} branching ratio is then extracted, giving BR({Lambda}{sub b}{sup 0} {yields} {Lambda}{sub c}{sup +}{pi}{sup -}) = (6.6 {+-} 1.2(stat.) {+-} 0.9(syst.) {+-} 2.3(BR+FR)) x 10{sup -3}. The {Lambda}{sub b}{sup 0} sample they reconstructed in this analysis is the largest fully reconstructed {Lambda}{sub b}{sup 0} sample in existence. The result they report here on the {Lambda}{sub b}{sup 0} {yields} {Lambda}{sub c}{sup +}{pi}{sup -} branching ratio is the world's first such measurement.

  5. Ultraviolet flare on Lambda Andromedae

    NASA Technical Reports Server (NTRS)

    Baliunas, S. L.; Guinan, E. F.; Dupree, A. K.

    1984-01-01

    On November 5, 6, 1982, a luminous, flarelike brightening of the ultraviolet emissions was observed with IUE from the active RS CVn type star Lambda And during the phase of rotation period corresponding to maximum area coverage of the visible hemisphere by starspots and active regions. Enhancements during the flare in the ultraviolet emission lines as large as factors of several and in the ultraviolet continuum up to 80 percent persisted for over 5 hours. The bulk of the radiative output of the flare occurred in Mg II h and k and H I Ly-alpha. Because of the long duration and extreme luminosity of the event, the energy radiated by the flare alone is in excess of 10 to the 35th ergs just in the ultraviolet region. This is the most energetic stellar flare ever recorded in the ultraviolet. In addition, it is the first ultraviolet flare observed from a giant star. In comparison to the largest solar flares, the flare on Lambda And is at least three orders of magnitude more energetic in similar emission lines.

  6. Bacteriophage lambda-based expression vectors.

    PubMed

    Christensen, A C

    2001-03-01

    Bacteriophage lambda has been in use as a cloning vector for over 25 years, and has been used extensively as an expression vector. The efficiency of packaging and infection, and the simplicity of plaque screening are advantages of lambda as a cloning vector. A number of ingenious modifications help overcome the disadvantages associated with its mode of growth and its size. Some lambda vectors have been designed to be readily converted into plasmids or phagemids, and there are a variety of promoters and fusions that can be used to drive expression of foreign genes. Screening lambda libraries with antibodies or ligands is a powerful way of identifying novel genes. PMID:11434310

  7. Measurement of the forward-backward asymmetry of $$\\Lambda$$ and $$\\bar{\\Lambda}$$ production in $$p \\bar{p}$$ collisions

    DOE PAGESBeta

    Abazov, Victor Mukhamedovich

    2016-02-09

    Here, we studymore » $$\\Lambda$$ and $$\\bar{\\Lambda}$$ production asymmetries in $$p \\bar{p} \\rightarrow \\Lambda (\\bar{\\Lambda}) X$$, $$p \\bar{p} \\rightarrow J/\\psi \\Lambda (\\bar{\\Lambda}) X$$, and $$p \\bar{p} \\rightarrow \\mu^\\pm \\Lambda (\\bar{\\Lambda}) X$$ events recorded by the D0 detector at the Fermilab Tevatron collider at $$\\sqrt{s} = 1.96$$ TeV. We find an excess of $$\\Lambda$$'s ($$\\bar{\\Lambda}$$'s) produced in the proton (antiproton) direction. This forward-backward asymmetry is measured as a function of rapidity. We confirm that the $$\\bar{\\Lambda}/\\Lambda$$ production ratio, measured by several experiments with various targets and a wide range of energies, is a universal function of "rapidity loss", i.e., the rapidity difference of the beam proton and the lambda.« less

  8. Polarization Effects in Lambda and Anti-Lambda Production at HERMES

    SciTech Connect

    Belostotski, S. L.

    2009-08-04

    Study of the LAMBDA and LAMBDA hyperon production in the HERMES experiment is discussed. The data were collected using a 27.6 GeV longitudinally polarized positron (or electron) beam of the HERA accelerator and a polarized or unpolarized target. The transverse polarizations (perpendicular to the production plane) of the LAMBDA and LAMBDA hyperons have been measured. The spin transfer K{sub LL} from the longitudinally polarized target has been found for inclusively detected LAMBDA and LAMBDA events. Longitudinal spin transfer D{sub LL} from the beam to the LAMBDA hyperon in the deep inelastic scattering regime has been analyzed. The D{sub LL} for LAMBDA has been measured for the first time.

  9. Study of Lambda+(c) Cabibbo favored decays containing a Lambda baryon in the final state

    SciTech Connect

    Link, J.M.; Yager, P.M.; Anjos, J.C.; Bediaga, I.; Castromonte, C.; Machado, A.A.; Magnin, J.; Massafferri, A.; de Miranda, J.M.; Pepe, I.M.; Polycarpo, E.; dos Reis, A.C.; Carrillo, S.; Casimiro, E.; Cuautle, E.; Sanchez-Hernandez, A.; Uribe, C.; Vazquez, F.; Agostino, L.; Cinquini, L.; Cumalat, J.P.; /Colorado U. /Fermilab /Frascati /Guanajuato U. /Illinois U., Urbana /Indiana U. /Korea U. /Kyungpook Natl. U. /INFN, Milan /Milan U. /North Carolina U. /Pavia U. /INFN, Pavia /Rio de Janeiro, Pont. U. Catol. /Puerto Rico U., Mayaguez /South Carolina U. /Tennessee U. /Vanderbilt U. /Wisconsin U., Madison

    2005-05-01

    Using data from the FOCUS experiment (FNAL-E831), they study the decay of {Lambda}{sub c}{sup +} baryons into final states contain a {Lambda} hyperon. The branching fractions of {Lambda}{sub c}{sup +} into {Lambda}{pi}{sup +}, {Lambda}{pi}{sup +}{pi}{sup +}{pi}{sup -} and {Lambda}{bar K}{sup 0}K{sup +} relative to that into pK{sup -} {pi}{sup +} are measured to be 0.217 {+-} 0.013 {+-} 0.020, 0.508 {+-} 0.024 {+-} 0.024 and 0.142 {+-} 0.018 {+-} 0.022, respectively. New measurements are also reported. Further, an analysis of the subresonant structure for the {Lambda}{sub c}{sup +} {yields} {Lambda}{pi}{sup +}{pi}{sup +}{pi}{sup -} decay mode is presented.

  10. Evidence for the Heavy Baryon Resonance State $\\Lambda_{b}^{\\ast0}$ Observed with the CDF II Detector, and Studies of New Particle Tracking Technologies Using the LANSCE Proton Beam

    SciTech Connect

    Palni, Prabhakar

    2014-05-01

    To discover and probe the properties of new particles, we need to collide highly energetic particles. The Tevatron at Fermilab has collided protons and anti-protons at very high energies. These collisions produce short lived and stable particles, some known and some previously unknown. The CDF detector is used to study the products of such collisions and discover new elementary particles. To study the interaction between high energy charged particles and the detector materials often requires development of new instruments. Thus this dissertation involves a measurement at a contemporary experiment and development of technologies for related future experiments that will build on the contemporary one.

  11. Transverse polarization of {Lambda} and {bar {Lambda}} hyperons in quasireal photoproduction.

    SciTech Connect

    Airapetian, A.; Akopov, N.; Amarian, M.; Ammosov, V. V.; Andrus, A.; Elalaoui-Moulay, A.; Hafidi, K.; Jackson, H. E.; Potterveld, D. H.; Reimer, P. E.; Sanjiev, I.; Physics; Yerevan Physics Inst.; Inst. Nazionaled di Fisica Nucleare; Inst. High Energy Physics

    2007-11-01

    The HERMES experiment has measured the transverse polarization of Lambda and {ovr Lambda} hyperons produced inclusively in quasireal photoproduction at a positron beam energy of 27.6 GeV. The transverse polarization P{sub n}{sup Lambda} of the Lambda hyperon is found to be positive while the observed {ovr Lambda} polarization is compatible with zero. The values averaged over the kinematic acceptance of HERMES are P{sub n}{sup Lambda} =0.078 {+-} 0.006(stat) {+-} 0.012(syst) and P{sub n}{sup {ovr Lambda}} = -0.025 {+-} 0.015(stat) {+-} 0.018(syst) for Lambda and {ovr Lambda}, respectively. The dependences of P{sub n}{sup Lambda} and P{sub n}{sup {ovr Lambda}} on the fraction zeta of the beam's light-cone momentum carried by the hyperon and on the hyperon's transverse momentum p{sub T} were investigated. The measured Lambda polarization rises linearly with p{sub T} and exhibits a different behavior for low and high values of zeta, which approximately correspond to the backward and forward regions in the center-of-mass frame of the gamma*N reaction.

  12. Double Lambda and Xi hypernuclei

    NASA Astrophysics Data System (ADS)

    Nakazawa, Kazuma

    2014-09-01

    Nuclei with double strangeness (S = -2) provide the key information to understand Baryon-Baryon interaction under the SU(3)f symmetry. Therefore we have carried out the experiments at KEK for quarter a century. Recently, the interaction in S = -2 sector is noted to derive the information of the EOS of neutron star. The Lambda-Lambda interaction has been presented to be weak attractive by NAGARA event which showed the production and decay of 6He double-hypernucleus. The event also presented the lower mass limit of H dibaryon. In other five events, we obtained the knowledge about an excitation level of 10Be double-hypernucleus under the consistency with NAGARA event. Moreover, very recently, we have discovered a Xi-14N system which was deeply bound far from the atomic 3D level (0.17 MeV) for a captured Xi hyperon. Since a 8Li nucleus was associated with the decay of one of twin-hypernuclei, the event was uniquely identified as Xi- + 14N ==> 10BeL + 5HeL. The system was selected from 8 million pictures on the test running for development of ``Overall Scanning'' to be used in the coming experiment. This is the first evidence of Xi hypernucleus to be bound and it is impacting for the study of Xi-N interaction. At J-PARC facility, for the further study of hyperon-hyperon interaction, we plan to perform the E07 experiment at J-PARC. In the workshop, we will review the above knowledge obtained by the experiments at KEK-PS, and discuss developed technologies to detected 102 or more double-hypernuclei in the E07 experiment at J-PARC. Nuclei with double strangeness (S = -2) provide the key information to understand Baryon-Baryon interaction under the SU(3)f symmetry. Therefore we have carried out the experiments at KEK for quarter a century. Recently, the interaction in S = -2 sector is noted to derive the information of the EOS of neutron star. The Lambda-Lambda interaction has been presented to be weak attractive by NAGARA event which showed the production and decay of 6He

  13. Recent developments in Lambda networking

    NASA Astrophysics Data System (ADS)

    de Laat, C.; Grosso, P.

    About 6 years ago the first baby-steps were made on opening up dark fiber and DWDM infrastructure for direct use by ISP's after the transformation of the old style Telecom sector into a market driven business. Since then Lambda workshops, community groups like GLIF and a number of experiments have led to many implementations of hybrid national research and education networks and lightpath-based circuit exchanges as pioneered by SURFnet in GigaPort and NetherLight in collaboration with StarLight in Chicago and Canarie in Canada. This article looks back on those developments, describes some current open issues and research developments and proposes a concept of terabit networking.

  14. Alternatives to Goodman and Kruskal's Lambda.

    ERIC Educational Resources Information Center

    Stavig, Gordon R.

    1979-01-01

    Lambda and kappa coefficients of nominal scale association are developed for research hypotheses that involve predictions of modality, agreement, or some theoretically specified configuration. The proposed new coefficient is offered as an alternative to Goodman and Kruskal's lambda. (Author/CTM)

  15. Photoproduction of the {Lambda}*(1520) Hyperon

    SciTech Connect

    Zhao, Z. W.; Lu, H. Y.; Graham, L.; Park, K.; Gothe, R. W.

    2010-08-05

    The photoproduction of the {Lambda}*(1520) on both the proton and neutron have been studied by using the CLAS eg3 run data set. The reactions are {gamma}d{yields}K{sup +{Lambda}}*(n) and {gamma}d{yields}K{sup 0{Lambda}}*(p) with {Lambda}*{yields}pK{sup -}. Preliminary total and differential cross sections have been extracted in the photon energy region 1.75 GeVLambda}*(1520) on the neutron is reported, and we will extend the results on the proton to higher energies than in previous studies.

  16. Bacteriophage Lambda: a Paradigm Revisited ▿

    PubMed Central

    Fogg, Paul C. M.; Allison, Heather E.; Saunders, Jon R.; McCarthy, Alan J.

    2010-01-01

    Bacteriophage lambda has an archetypal immunity system, which prevents the superinfection of its Escherichia coli lysogens. It is now known that superinfection can occur with toxigenic lambda-like phages at a high frequency, and here we demonstrate that the superinfection of a lambda lysogen can lead to the acquisition of additional lambda genomes, which was confirmed by Southern hybridization and quantitative PCR. As many as eight integration events were observed but at a very low frequency (6.4 × 10−4) and always as multiple insertions at the established primary integration site in E. coli. Sequence analysis of the complete immunity region demonstrated that these multiply infected lysogens were not immunity mutants. In conclusion, although lambda superinfection immunity can be confounded, it is a rare event. PMID:20375161

  17. Polarization of Lambda0 and anti-Lambda0 inclusively produced by 610-GeV/c Sigma- and 525-GeV/c proton beams

    SciTech Connect

    Sanchez-Lopez, J.L.; Nelson, K.D.; Engelfried, J.; Akgun, U.; Alkhazov, G.; Amaro-Reyes, J.; Atamantchouk, A.G.; Ayan, A.S.; Balatz, M.Y.; Blanco-Covarrubias, A.; Bondar, N.F.; /Ball State U. /Bogazici U. /Carnegie Mellon U. /Rio de Janeiro, CBPF /Fermilab /Serpukhov, IHEP /Beijing, Inst. High Energy Phys. /Moscow, ITEP /Heidelberg, Max Planck Inst. /Moscow State U. /St. Petersburg, INP

    2007-06-01

    We have measured the polarization of {Lambda}{sup 0} and {bar {Lambda}{sup 0}} inclusively produced by 610 GeV/c {Sigma}{sup -} and 525 GeV/c proton beams in the experiment SELEX during the 1996/7 fixed target run at Fermilab. The polarization was measured as a function of the {Lambda} longitudinal momentum fraction x{sub F} and transverse momentum p{sub t}. For the {Lambda}{sup 0} produced by {Sigma}{sup -} the polarization is increasing with x{sub F} , from slightly negative at x{sub F} {approx} 0 to about 15% at large x{sub F} ; it shows a non-monotonic behavior as a function of p{sub t}. For the proton beam, the {Lambda}{sup 0} polarization is negative and decreasing as a function of x{sub F} and p{sub t}. The {bar {Lambda}{sup 0}} polarization is compatible with 0 for both beam particles over the full kinematic range. The target dependence was examined but no statistically significant difference was found.

  18. Internal structure of the resonant {Lambda}(1405) state in chiral dynamics

    SciTech Connect

    Sekihara, Takayasu; Hyodo, Tetsuo; Jido, Daisuke

    2011-05-15

    The internal structure of the resonant {Lambda}(1405) state is investigated based on meson-baryon coupled-channels chiral dynamics by evaluating density distributions obtained from the form factors of the {Lambda}(1405) state. The form factors are defined as an extension of the ordinary stable particles and are directly evaluated from the current-coupled meson-baryon scattering amplitude, paying attention to the charge conservation of the probe interactions. For the resonant {Lambda}(1405) state we calculate the density distributions in two ways. One is on the pole position of the {Lambda}(1405) in the complex energy plane, which evaluates the resonant {Lambda}(1405) structure without contamination from nonresonant backgrounds, and another is on the real energy axis around the {Lambda}(1405) resonance energy, which may be achieved in experiments. Using several probe interactions and channel decomposition, we separate the various contributions to the internal structure of the {Lambda}(1405). As a result, we find that the resonant {Lambda}(1405) state is composed of widely spread K-bar around N, which gives dominant component inside the {Lambda}(1405), with escaping {pi}{Sigma} component. Furthermore, we consider K-barN bound state without decay channels, with which we can observe the internal structure of the bound state within real numbers. We also study the dependence of the form factors on the binding energy and meson mass. This verifies that the form factor defined through the current-coupled scattering amplitude serves as a natural generalization of the form factor for the resonance state. The relation between the interaction strength and the meson mass shows that the physical kaon mass appears to be within the suitable range to form a molecular bound state with the nucleon through the chiral SU(3) interaction.

  19. Bacteriophage lambda: Early pioneer and still relevant.

    PubMed

    Casjens, Sherwood R; Hendrix, Roger W

    2015-05-01

    Molecular genetic research on bacteriophage lambda carried out during its golden age from the mid-1950s to mid-1980s was critically important in the attainment of our current understanding of the sophisticated and complex mechanisms by which the expression of genes is controlled, of DNA virus assembly and of the molecular nature of lysogeny. The development of molecular cloning techniques, ironically instigated largely by phage lambda researchers, allowed many phage workers to switch their efforts to other biological systems. Nonetheless, since that time the ongoing study of lambda and its relatives has continued to give important new insights. In this review we give some relevant early history and describe recent developments in understanding the molecular biology of lambda's life cycle. PMID:25742714

  20. Bacteriophage lambda: early pioneer and still relevant

    PubMed Central

    Casjens, Sherwood R.; Hendrix, Roger W.

    2015-01-01

    Molecular genetic research on bacteriophage lambda carried out during its golden age from the mid 1950's to mid 1980's was critically important in the attainment of our current understanding of the sophisticated and complex mechanisms by which the expression of genes is controlled, of DNA virus assembly and of the molecular nature of lysogeny. The development of molecular cloning techniques, ironically instigated largely by phage lambda researchers, allowed many phage workers to switch their efforts to other biological systems. Nonetheless, since that time the ongoing study of lambda and its relatives have continued to give important new insights. In this review we give some relevant early history and describe recent developments in understanding the molecular biology of lambda's life cycle. PMID:25742714

  1. Large palindromes in the lambda phage genome are preserved in a rec/sup +/ host by inhibiting lambda DNA replication

    SciTech Connect

    Shurvinton, C.E.; Stahl, M.M.; Stahl, F.W.

    1987-03-01

    A large palindrome carried by phage lambda has been shown to prevent growth of the phage on a rec/sup +/ strain of Escherichia coli. The phage do form plaques on recBC sbcB strains, but the palindrome is not stable - deletions that either destroy the palindrome or diminish its size overgrow the original engineered palindrome-containing phage. The authors have prepared stocks of lambda carrying a palindrome that is 2 x 4200 base pairs long. lambda phage were density labeled by UV induction of lysogens grown in minimal medium containing (/sup 13/C) glucose and /sup 15/NH/sub 4/Cl. These phage stocks are produced by induction of a lysogen in which the two halves of the palindrome are stored at opposite ends of the prophage and are of sufficient titer (10/sup 9/ phage per ml) to enable one-step growth experiments with replication-blocked phage. They find that the large palindrome as well as a lesser palindrome of 2 x 265 base pairs are recovered intact among particles carrying unreplicated chromosomes following such an infection of a rec/sup +/ host. they propose that DNA replication drives the extrusion of palindromic sequences in vivo, forming secondary structures that are substrates for the recBC and sbcB gene products.

  2. Azimuthal anisotropy of K(0)(S) and Lambda+Lambda production at midrapidity from Au+Au collisions at sqrt[s(NN)]=130 GeV.

    PubMed

    Adler, C; Ahammed, Z; Allgower, C; Amonett, J; Anderson, B D; Anderson, M; Averichev, G S; Balewski, J; Barannikova, O; Barnby, L S; Baudot, J; Bekele, S; Belaga, V V; Bellwied, R; Berger, J; Bichsel, H; Billmeier, A; Bland, L C; Blyth, C O; Bonner, B E; Boucham, A; Brandin, A; Bravar, A; Cadman, R V; Caines, H; Calderón de la Barca Sánchez, M; Cardenas, A; Carroll, J; Castillo, J; Castro, M; Cebra, D; Chaloupka, P; Chattopadhyay, S; Chen, Y; Chernenko, S P; Cherney, M; Chikanian, A; Choi, B; Christie, W; Coffin, J P; Cormier, T M; Cramer, J G; Crawford, H J; Deng, W S; Derevschikov, A A; Didenko, L; Dietel, T; Draper, J E; Dunin, V B; Dunlop, J C; Eckardt, V; Efimov, L G; Emelianov, V; Engelage, J; Eppley, G; Erazmus, B; Fachini, P; Faine, V; Filimonov, K; Finch, E; Fisyak, Y; Flierl, D; Foley, K J; Fu, J; Gagliardi, C A; Gagunashvili, N; Gans, J; Gaudichet, L; Germain, M; Geurts, F; Ghazikhanian, V; Grachov, O; Grigoriev, V; Guedon, M; Gushin, E; Hallman, T J; Hardtke, D; Harris, J W; Henry, T W; Heppelmann, S; Herston, T; Hippolyte, B; Hirsch, A; Hjort, E; Hoffmann, G W; Horsley, M; Huang, H Z; Humanic, T J; Igo, G; Ishihara, A; Ivanshin, Yu I; Jacobs, P; Jacobs, W W; Janik, M; Johnson, I; Jones, P G; Judd, E G; Kaneta, M; Kaplan, M; Keane, D; Kiryluk, J; Kisiel, A; Klay, J; Klein, S R; Klyachko, A; Konstantinov, A S; Kopytine, M; Kotchenda, L; Kovalenko, A D; Kramer, M; Kravtsov, P; Krueger, K; Kuhn, C; Kulikov, A I; Kunde, G J; Kunz, C L; Kutuev, R Kh; Kuznetsov, A A; Lakehal-Ayat, L; Lamont, M A C; Landgraf, J M; Lange, S; Lansdell, C P; Lasiuk, B; Laue, F; Lebedev, A; Lednický, R; Leontiev, V M; LeVine, M J; Li, Q; Lindenbaum, S J; Lisa, M A; Liu, F; Liu, L; Liu, Z; Liu, Q J; Ljubicic, T; Llope, W J; LoCurto, G; Long, H; Longacre, R S; Lopez-Noriega, M; Love, W A; Ludlam, T; Lynn, D; Ma, J; Majka, R; Margetis, S; Markert, C; Martin, L; Marx, J; Matis, H S; Matulenko, Yu A; McShane, T S; Meissner, F; Melnick, Yu; Meschanin, A; Messer, M; Miller, M L; Milosevich, Z; Minaev, N G; Mitchell, J; Moiseenko, V A; Moore, C F; Morozov, V; de Moura, M M; Munhoz, M G; Nelson, J M; Nevski, P; Nikitin, V A; Nogach, L V; Norman, B; Nurushev, S B; Odyniec, G; Ogawa, A; Okorokov, V; Oldenburg, M; Olson, D; Paic, G; Pandey, S U; Panebratsev, Y; Panitkin, S Y; Pavlinov, A I; Pawlak, T; Perevoztchikov, V; Peryt, W; Petrov, V A; Planinic, M; Pluta, J; Porile, N; Porter, J; Poskanzer, A M; Potrebenikova, E; Prindle, D; Pruneau, C; Putschke, J; Rai, G; Rakness, G; Ravel, O; Ray, R L; Razin, S V; Reichhold, D; Reid, J G; Retiere, F; Ridiger, A; Ritter, H G; Roberts, J B; Rogachevski, O V; Romero, J L; Rose, A; Roy, C; Rykov, V; Sakrejda, I; Salur, S; Sandweiss, J; Saulys, A C; Savin, I; Schambach, J; Scharenberg, R P; Schmitz, N; Schroeder, L S; Schüttauf, A; Schweda, K; Seger, J; Seliverstov, D; Seyboth, P; Shahaliev, E; Shestermanov, K E; Shimanskii, S S; Shvetcov, V S; Skoro, G; Smirnov, N; Snellings, R; Sorensen, P; Sowinski, J; Spinka, H M; Srivastava, B; Stephenson, E J; Stock, R; Stolpovsky, A; Strikhanov, M; Stringfellow, B; Struck, C; Suaide, A A P; Sugarbaker, E; Suire, C; Sumbera, M; Surrow, B; Symons, T J M; Szanto de Toledo, A; Szarwas, P; Tai, A; Takahashi, J; Tang, A H; Thomas, J H; Thompson, M; Tikhomirov, V; Tokarev, M; Tonjes, M B; Trainor, T A; Trentalange, S; Tribble, R E; Trofimov, V; Tsai, O; Ullrich, T; Underwood, D G; Van Buren, G; VanderMolen, A M; Vasilevski, I M; Vasiliev, A N; Vigdor, S E; Voloshin, S A; Wang, F; Ward, H; Watson, J W; Wells, R; Westfall, G D; Whitten, C; Wieman, H; Willson, R; Wissink, S W; Witt, R; Wood, J; Xu, N; Xu, Z; Yakutin, A E; Yamamoto, E; Yang, J; Yepes, P; Yurevich, V I; Zanevski, Y V; Zborovský, I; Zhang, H; Zhang, W M; Zoulkarneev, R; Zubarev, A N

    2002-09-23

    We report STAR results on the azimuthal anisotropy parameter v(2) for strange particles K(0)(S), Lambda, and Lambda at midrapidity in Au+Au collisions at sqrt[s(NN)]=130 GeV at the Relativistic Heavy Ion Collider. The value of v(2) as a function of transverse momentum, p(t), of the produced particle and collision centrality is presented for both particles up to p(t) approximately 3.0 GeV/c. A strong p(t) dependence in v(2) is observed up to 2.0 GeV/c. The v(2) measurement is compared with hydrodynamic model calculations. The physics implications of the p(t) integrated v(2) magnitude as a function of particle mass are also discussed. PMID:12225018

  3. Efficient Attosecond Phenomena in the Relativistic {lambda}3 Regime

    SciTech Connect

    Naumova, Natalia; Mourou, Gerard; Nees, John

    2006-04-07

    Particle-in-cell simulations of relativistically strong laser pulses interacting with overdense plasma targets predict that coherent motion of electrons leads to the efficient generation of strong attosecond electromagnetic pulses and dense attosecond electron bunches. The optimal conditions for these attosecond phenomena are achieved in the {lambda}3 regime, when few-cycle laser pulses are focused to a wavelength-limited spot, producing maximal intensity and maximal gradients with a given energy. The natural synchronism of these attosecond phenomena should enable a kind of relativistic attosecond optoelectronics.

  4. Study ofe+e- to Lambda anti-Lambda, Lambda anti-Sigma^0,Sigma^0 anti-Sigma^0 using Initial State Radiation with BaBar

    SciTech Connect

    Aubert, B.

    2007-09-14

    We study the e+e- --> Lambda anti-Lambda gamma, Lambda anti-Sigma0 gamma, Sigma0 anti-Sigma0 gamma processes using 230 fb-1 of integrated luminosity collected by the BaBar detector at e+e- center-of-mass energy of 10.58 GeV. From the analysis of the baryon-antibaryon mass spectra the cross sections for e+e- --> Lambda anti-Lambda, Lambda anti-Sigma0, Sigma0 anti-Sigma0 are measured in the dibaryon mass range from threshold up to 3 GeV/c{sup 2}. The ratio of electric and magnetic form factors, |G{sub E}/G{sub M}|, is measured for e+e- --> Lambda anti-Lambda, and limits on the relative phase between Lambda form factors are obtained. We also measure the J/psi --> Lambda anti-Lambda, Sigma0 anti-Sigma0 and psi(2S) --> Lambda anti-Lambda branching fractions.

  5. The Heavy Mass Expansion lambda(sub)b -> lambda(sub)c Decays

    SciTech Connect

    Mannel, Thomas; Roberts, Winston

    1992-11-01

    We point out that in the decays of the lambda(sub)b to lambda(sub)c one can find predictions which - in the framework of the 1/m(sub)c expansion - do not receive corrections in any order of 1/m(sub)c. We discuss QCD corrections to these predictions and examine some of the consequences for nonleptonic decays.

  6. Binding energy of (Lambda)He-7 and test of charge symmetry breaking in the Lambda N interaction potential

    SciTech Connect

    Hashimoto, O; Honda, D; Kaneta, M; Kato, F; Kawama, D; Maruyama, N; Matsumura, A; Nakamura, S N; Nomura, H; Nonaka, K; Ohtani, A; Okayasu, Y; Osaka, M; Oyamada, M; Sumihama, M; Tamura, H; Baker, O K; Cole, L; Christy, M; Gueye, P; Keppel, C; Tang, L; Yuan, L; Acha, A; Baturin, P; Boeglin, W; Kramer, L; Markowitz, P; Pamela, P; Perez, N; Raue, B; Reinhold, J; Rivera, R; Kato, S; Sato, Y; Takahashi, T; Daniel, A; Hungerford, Ed V; Ispiryan, M; Kalantarians, N; Lan, K J; Li, Y; Miyoshi, T; Randeniya, S; Rodriguez, V M; Bosted, P; Carlini, R; Ent, R; Fenker, H; Gaskell, D; Jones, M; Mack, D; Roche, J; Smith, G; Tvaskis, V; Vulcan, W; Wood, S; Yan, C; Asaturyan, A; Asaturyan, R; Egiyan, K; Mkrtchyan, H; Margaryan, A; Navasardyan, T; Tadevosyan, V; Zamkochian, S; Hu, B; Song, Y; Luo, W; Androic, D; Furic, M; Petkovic, T; Seva, T; Ahmidouch, A; Danagoulian, S; Gasparian, A; Halkyard, R; Johnson, K; Simicevic, N; Wells, S; Niculescu, G; Niculescu, M I; Gan, L; Benmokhtar, F; Horn, T; Elassar, M; Gibson, E F

    2011-09-01

    The binding energy of 7LambdaHe has been obtained for the first time with reaction spectroscopy using the (e, e'K+) reaction at Jefferson Lab's Hall C. A comparison among the binding energies of the A = 7 T = l iso-triplet hypernuclei, 7LambdaHe, 7LambdaLi*and 7LambdaBe, is made and possible charge symmetry breaking (CSB) in the LambdaN potential is discussed. For 7LambdaHe and 7LambdaBe, the shifts in binding energies are opposite to those predicted by a recent cluster model calculation, which assumes that the unexplained part of the binding energy difference between 4LambdaH and 4LambdaHe, is due to the CSB of the LambdaN potential. Further examination of CSB in light hypernuclear systems is required both experimentally and theoretically.

  7. Measurement of the Production Fraction Times Branching Fraction f(b -> \\Lambda_b) x B(\\Lambda_b -> J/\\psi \\Lambda)

    SciTech Connect

    Heredia-De La Cruz, I.; /CINVESTAV, IPN

    2011-09-01

    A new measurement of the b {yields} {Lambda}{sub b} production fraction multiplied by the {Lambda}{sub b} {yields} J/{psi}{Lambda} branching fraction was performed by the D0 experiment using 6.1 fb{sup -1} of p{bar p} collisions at {radical}s = 1.96 TeV. The result of this measurement, f(b {yields} {Lambda}{sub b}) {center_dot} {Beta}({Lambda}{sub b} {yields} J/{psi}{Lambda}) = [6.01 {+-} 0.60 (stat.) {+-} 0.58 (syst.) {+-} 0.28 (PDG)] x 10{sup -5}, represents an improvement in precision by about a factor of three with respect to the current world average. We give an estimate of {Beta}({Lambda}{sub b} {yields} J/{psi}{Lambda}), which takes into account correlations among the different b-hadron production fractions and other weakly decaying baryons.

  8. Nonlinear stability control and lambda-bifurcation

    SciTech Connect

    Erneux, T.; Reiss, E.L.; Magnan, J.F.; Jayakumar, P.K.

    1987-12-01

    Passive techniques for nonlinear stability control are presented for a model of fluidelastic instability. They employ the phenomena of lambda-bifurcation and a generalization of it. lambda-bifurcation occurs when a branch of flutter solutions bifurcates supercritically from a basic solution and terminates with an infinite period orbit at a branch of divergence solutions which bifurcates subcritically from the basic solution. The shape of the bifurcation diagram then resembles the greek letter lambda. When the system parameters are in the range where flutter occurs by lambda-bifurcation, then as the flow velocity increase the flutter amplitude also increases, but the frequencies of the oscillations decrease to zero. This diminishes the damaging effects of structural fatigue by flutter, and permits the flow speed to exceed the critical flutter speed. If generalized lambda-bifurcation occurs, then there is a jump transition from the flutter states to a divergence state with a substantially smaller amplitude, when the flow speed is sufficiently larger than the critical flutter speed.

  9. Does lambda sub 2,2 vary?

    NASA Technical Reports Server (NTRS)

    Wagner, C. A.

    1971-01-01

    An attempt has been made to find a secular drift in lambda sub 2,2, or the phase of the low order and degree portion of the geogravity field. This portion may be associated with mass anomalies near the core-mantle boundary. From the geomagnetic evidence, such anomalies might have westward drifts on the order of 0.5 degrees/year. Tracking data on 8 synchronous satellite over a period of 6 years were examined for residual accelerations which might be explained by a drift of the lambda sub 2,2 gravity phase angle. No conclusive movement of lambda sub 2,2 was detected. But a measured upper bound on the drift of less than 0.05 degrees/year is still compatible with possible slow moving irregularities in the region of the core-mantle boundary.

  10. {lambda}(1405)-induced nonmesonic decay in kaonic nuclei

    SciTech Connect

    Sekihara, T.; Jido, D.; Kanada-En'yo, Y.

    2009-06-15

    Nonmesonic decay of kaonic nuclei is investigated under a {lambda}(1405) doorway picture in which the K absorptions in nuclei take place through the {lambda}(1405) resonance. Calculating {lambda}(1405)N{yields}YN transitions with one-meson exchange, we find that the nonmesonic decay ratio {gamma}{sub {lambda}}{sub N}/{gamma}{sub {sigma}{sup 0}}{sub N} depends strongly on the ratio of the couplings {lambda}(1405)-KN and {lambda}(1405)-{pi}{sigma}. Especially, a larger {lambda}(1405)-KN coupling leads to enhancement of the decay to {lambda}N. Using the chiral unitary approach for description of the KN amplitudes, we obtain {gamma}{sub {lambda}}{sub N}/{gamma}{sub {sigma}{sup 0}}{sub N}{approx_equal}1.2 almost independently of the nucleon density and find the total nonmesonic decay width calculated in uniform nuclear matter to be 22 MeV at the normal density.

  11. Associated {Lambda} production at Jefferson Lab

    SciTech Connect

    Niculescu, G.; Baker, O.K. |; Avery, S.; E93018 Collaboration

    1997-12-31

    The {sup 1}H(e, e{prime}K{sup +}){Lambda} and {sup 1}H(e, e{prime}K{sup +}){Sigma}{sup 0} reactions were studied as a function of the squared four-momentum-transfer, Q{sup 2}, and the virtual photon polarization, {var_epsilon}, thus enabling the separation of the longitudinal and transverse parts of the cross section. The existence of a sensibly large longitudinal component for the {sup 1}H(e, e{prime}K{sup +}){Lambda} reaction seems to be sustained by these data.

  12. Lambda Exonuclease Digestion of CGG Trinucleotide Repeats

    PubMed Central

    Conroy, R.S.; Koretsky, A.P.; Moreland, J.

    2011-01-01

    Fragile X syndrome and other triplet repeat diseases are characterized by an elongation of a repeating DNA triplet. The ensemble-averaged lambda exonuclease digestion rate of different substrates, including one with an elongated FMR1 gene containing 120 CGG repeats, was measured using absorption and fluorescence spectroscopy. Using magnetic tweezers sequence-dependent digestion rates and pausing was measured for individual lambda exonucleases. Within the triplet repeats a lower average and narrower distribution of rates and a higher frequency of pausing was observed. PMID:19562332

  13. Neutral kaon and lambda production in electron-positron annihilation at 29 GeV and the Z boson resonance

    SciTech Connect

    Fordham, C.S.

    1990-10-01

    The production of K{sup 0} and {Lambda} in the hadronization of q{bar q} events from e{sup +}e{sup {minus}} collisions at 29 GeV and the Z{sup 0} resonance is studied using the Mark II detector as upgraded for running at the Stanford Linear Collider. Hadronization processes cannot presently be calculated with Quantum Chromodynamics; instead, hadronization models must be used in comparisons with data. In these models, hadronization occurs at local energy scales of a few GeV, a level at which small differences in quark and diquark mass significantly affect the production of particles such as K{sup 0} and {Lambda}, the lightest neutral meson and baryon containing strange quarks. Their production and behavior in hadronic events is a test for the accuracy of our understanding of hadronization. Two-charged- particle decays of the K{sup 0} and {Lambda} are isolated within the hadronic event sample. The resulting distribution of K{sup 0} and {Lambda} are corrected for inefficiencies and generalized to include all K{sup 0} and {Lambda}. Various kinematic distributions of the strange particles are examined. These distributions include the momentum and scaled momentum of the particles. The kinematics of the particles with respect to the original quark direction are examined through the distributions of rapidity and momentum transverse to the thrust both in and out of the event plane. The dependence of K{sup 0} and {Lambda} production on the sphericity of the hadronic events is also examined. All these distributions show that the behavior of K{sup 0} and {Lambda} in hadronic events is consistent with the hadronization models.

  14. The Lambda Point Experiment in Microgravity

    NASA Technical Reports Server (NTRS)

    Lipa, J. A.; Swanson, D. R.; Nissen, J. A.; Chui, T. C. P.

    1993-01-01

    In October 1992 a low temperature experiment was flown on the Space Shuttle in low earth orbit, using the JPL low temperature research facility. The objective of the mission was to measure the heat capacity and thermal relaxation of helium very close to the lambda point with the smearing effect of gravity removed.

  15. The Lambda Orionis association. [star cluster anomalies

    NASA Technical Reports Server (NTRS)

    Murdin, P.; Penston, M. V.

    1977-01-01

    The Lambda Orionis association has the photometric properties of a typical young cluster with an age of about 4 million yr. Its distance is 400 + or - 40 pc. Attention is drawn to the lack of a dense molecular cloud and associated infrared sources in this young grouping

  16. {lambda}{sub b}{yields}p, {lambda} transition form factors from QCD light-cone sum rules

    SciTech Connect

    Wang Yuming; Lue Caidian; Shen Yuelong

    2009-10-01

    Light-cone sum rules for the {lambda}{sub b}{yields}p, {lambda} transition form factors are derived from the correlation functions expanded by the twist of the distribution amplitudes of the {lambda}{sub b} baryon. In terms of the {lambda}{sub b} three-quark distribution amplitude models constrained by the QCD theory, we calculate the form factors at small momentum transfers and compare the results with those estimated in the conventional light-cone sum rules (LCSR) and perturbative QCD approaches. Our results indicate that the two different versions of sum rules can lead to the consistent numbers of form factors responsible for {lambda}{sub b}{yields}p transition. The {lambda}{sub b}{yields}{lambda} transition form factors from LCSR with the asymptotic {lambda} baryon distribution amplitudes are found to be almost 1 order larger than those obtained in the {lambda}{sub b}-baryon LCSR, implying that the preasymptotic corrections to the baryonic distribution amplitudes are of great importance. Moreover, the SU(3) symmetry breaking effects between the form factors f{sub 1}{sup {lambda}{sub b}}{sup {yields}}{sup p} and f{sub 1}{sup {lambda}{sub b}}{sup {yields}}{sup {lambda}} are computed as 28{sub -8}{sup +14}% in the framework of {lambda}{sub b}-baryon LCSR.

  17. Excited states of {sub {lambda}}{sup 9}Be and {sub {lambda}}{sub {lambda}}{sup 10}Be in an {alpha} cluster model

    SciTech Connect

    Shoeb, Mohammad

    2006-12-15

    The energies of the degenerate spin-flip doublet (3{sup +}/2,5{sup +}/2) of {sub {lambda}}{sup 9}Be and of the 2{sup +} state of {sub {lambda}}{sub {lambda}}{sup 10}Be are analyzed in the {alpha} cluster model using a phenomenological dispersive three-body {lambda}{alpha}{alpha} force that reproduces the ground state energy of {sub {lambda}}{sup 9}Be. Two types of phenomenological {lambda}{alpha} and {alpha}{alpha} potentials and a few s-state {lambda}{lambda} potentials are taken as input. The energies of the excited states of the hypernuclei, treated as three- and four-body systems, calculated using the Variational Monte Carlo method, are in good agreement with the experimental values. Our results demonstrate that the existing data are insensitive to whether one employs a dispersive {lambda}{alpha}{alpha} force along with potentials in the relative angular momentum state l=0 and 2 as in the present work or whether one uses nonlocal {lambda}{alpha} potential as in earlier analyses.

  18. The Hyperon {Lambda}(1405) in p+p reactions

    SciTech Connect

    Siebenson, Johannes

    2011-10-21

    We present an analysis of the hyperon {Lambda}(1405) for p+p reactions at 3.5 GeV kinetic beam energy. The data were taken with the High Acceptance Di-Electron Spectrometer (HADES). A {Lambda}(1405) signal could be reconstructed in both charged decay channels ({Lambda}(1405){yields}{Sigma}{sup {+-}}{pi}{sup {+-}}).

  19. Measurement of the Branching Fraction and Lambda-bar Polarization in B0 -> Lambda-par p pi-

    SciTech Connect

    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}}}.

  20. Reevaluation of the reported observation of the {sub {lambda}}{sub {lambda}}{sup 4}H hypernucleus

    SciTech Connect

    Randeniya, S. D.; Hungerford, E. V.

    2007-12-15

    The results of experiment E906, undertaken at the Alternating Gradient Synchrotron of the Brookhaven National Laboratory (BNL-AGS), were reanalyzed to clarify the signature of the decays of the double- and single-{lambda} hypernuclei that could have been produced in this experiment. This reanalysis indicates that instead of the reported decay of {sub {lambda}}{sub {lambda}}{sup 4}H through a proposed resonance in {sub {lambda}}{sup 4}He, it is more probable that the decay of the {sub {lambda}}{sub {lambda}}{sup 7}He hypernucleus was observed. This decay was accompanied by a background of coincident decays of pairs of the single hypernuclear fragments {sub {lambda}}{sup 3}H with {sub {lambda}}{sup 4}H, {sub {lambda}}{sup 3}H with {sub {lambda}}{sup 3}H, and {sub {lambda}}{sup 4}H with {sub {lambda}}{sup 4}H. An attempt was also made to determine if any other double or coincident single hypernuclear species could be observed in the data.

  1. {lambda}-{sigma} coupling effect in the neutron-rich {lambda} hypernucleus {sub {lambda}}{sup 10}Li in a microscopic shell-model calculation

    SciTech Connect

    Umeya, A.; Harada, T.

    2009-02-15

    We investigate the structure of the neutron-rich {lambda}-hypernucleus {sub {lambda}}{sup 10}Li by using microscopic shell-model calculations considering a {lambda}-{sigma} coupling effect. The calculated {sigma}-mixing probability in the {sub {lambda}}{sup 10}Li ground state is found to be about 0.34% that is coherently enhanced by the {lambda}-{sigma} coupling configurations, leading to the energy shift 0.28 MeV that is about 3 times larger than that in {sub {lambda}}{sup 7}Li. The importance of the {sigma} configuration obtained by the {sigma}N interaction and the potentiality of the neutron-rich environment are discussed.

  2. The lambda point experiment in microgravity

    NASA Technical Reports Server (NTRS)

    Lipa, J. A.

    1988-01-01

    The motivation and potential for performing very high resolution measurements of the heat capacity singularity at the lambda point of helium in microgravity conditions was briefly discussed. It is clear that tests extending deep into the asymptotic region can be performed, where the theoretical predictions take on their simplest form. This advantageous situation should lead to a major improvement in the understanding of the range of applicability of current theoretical ideas in this field. The lambda transition holds out the prospect of giving the maximum advance of any system, and with the application of cryogenic techniques, the potential of this system can be realized. The technology for the initial experiments is already developed, and results could be obtained in 1990.

  3. The {Lambda}(1405) in Full QCD

    SciTech Connect

    Menadue, Benjamin J.; Kamleh, Waseem; Leinweber, Derek B.; Mahbub, M. Selim

    2011-12-14

    At 1405.1 MeV, the lowest-lying negative-parity state of the {Lambda} baryon lies surprising low. Indeed, this is lower than the lowest negative-parity state of the nucleon, even though the {Lambda}(1405) possesses a valence strange quark. However, previous Lattice QCD studies have been unable to identify such a low-lying state. Using the PACS-CS (2+1)-flavour full-QCD ensembles, available through the ILDG, we utilise a variational analysis with source and sink smearing to isolate this elusive state. We find three low-lying odd-parity states, and for the first time reproduce the correct level ordering with respect to the nearby scattering thresholds.

  4. Fully correlated study of {sub {lambda}}{sub {lambda}}{sup 6}He hypernucleus including {lambda}N space-exchange correlations

    SciTech Connect

    Usmani, A. A.; Hasan, Z.

    2006-09-15

    We present a fully correlated study of the six-body {sub {lambda}}{sub {lambda}}{sup 6}He hypernucleus. The wave function involves all relevant dynamic correlations as well as the space-exchange correlation (SEC). Calculations for energy breakdown, {lambda}{lambda}-separation energy, nuclear core polarization, and point proton radius have been performed. The baryon density profiles have also been calculated. Effect of SEC on all these physical observables is found to be significant. The findings suggest that a study ignoring SEC would be deficient.

  5. Trivalent iron induced gelation in lambda-carrageenan

    SciTech Connect

    Running, Cordelia A.; Falshaw, Ruth; Janaswamy, Srinivas

    2012-05-24

    This communication reports gelation of lambda-carrageenan, for the first time, in the presence of trivalent iron ions. Kappa-, iota- and lambda-carrageenans are sulfated polysaccharides used extensively in food, pharmaceutical and medical applications. Kappa- and iota-carrageenans show gelation in the presence of mono- and di-valent ions, but lambda-carrageenan yields only viscous solutions. Our results show that gelation in lambda-carrageenan indeed is possible, but with trivalent ions. X-ray fiber diffraction patterns of iron (III)-lambda-carrageenan are characteristic of highly oriented and polycrystalline fibers containing well resolved Bragg reflections. The elastic modulus (G*) of the product is far greater than the loss modulus (G*) indicating the thermal stability of lambda-carrageenan in the presence of iron (III) ions. This novel finding has potential to expand lambda-carrageenan's current utility beyond a viscosifying agent.

  6. MASS FUNCTION PREDICTIONS BEYOND {Lambda}CDM

    SciTech Connect

    Bhattacharya, Suman; Lukic, Zarija; Habib, Salman; Heitmann, Katrin; White, Martin; Wagner, Christian

    2011-05-10

    The statistics of dark matter halos is an essential component of precision cosmology. The mass distribution of halos, as specified by the halo mass function, is a key input for several cosmological probes. The sizes of N-body simulations are now such that, for the most part, results need no longer be statistics-limited, but are still subject to various systematic uncertainties. Discrepancies in the results of simulation campaigns for the halo mass function remain in excess of statistical uncertainties and of roughly the same size as the error limits set by near-future observations; we investigate and discuss some of the reasons for these differences. Quantifying error sources and compensating for them as appropriate, we carry out a high-statistics study of dark matter halos from 67 N-body simulations to investigate the mass function and its evolution for a reference {Lambda}CDM cosmology and for a set of wCDM cosmologies. For the reference {Lambda}CDM cosmology (close to WMAP5), we quantify the breaking of universality in the form of the mass function as a function of redshift, finding an evolution of as much as 10% away from the universal form between redshifts z = 0 and z = 2. For cosmologies very close to this reference we provide a fitting formula to our results for the (evolving) {Lambda}CDM mass function over a mass range of 6 x 10{sup 11}-3 x 10{sup 15} M{sub sun} to an estimated accuracy of about 2%. The set of wCDM cosmologies is taken from the Coyote Universe simulation suite. The mass functions from this suite (which includes a {Lambda}CDM cosmology and others with w {approx_equal} -1) are described by the fitting formula for the reference {Lambda}CDM case at an accuracy level of 10%, but with clear systematic deviations. We argue that, as a consequence, fitting formulae based on a universal form for the mass function may have limited utility in high-precision cosmological applications.

  7. Differential Photoproduction Cross Sections of the Sigma0(1385), Lambda(1405), and Lambda(1520)

    SciTech Connect

    Moriya, Kei; Schumacher, Reinhard A.

    2013-10-01

    We report the exclusive photoproduction cross sections for the Sigma(1385), Lambda(1405), and Lambda(1520) in the reactions gamma + p -> K+ + Y* using the CLAS detector for energies from near the respective production thresholds up to a center-of-mass energy W of 2.85 GeV. The differential cross sections are integrated to give the total exclusive cross sections for each hyperon. Comparisons are made to current theoretical models based on the effective Lagrangian approach and fitted to previous data. The accuracy of these models is seen to vary widely. The cross sections for the Lambda(1405) region are strikingly different for the Sigma+pi-, Sigma0 pi0, and Sigma- pi+ decay channels, indicating the effect of isospin interference, especially at W values close to the threshold.

  8. Measurement of transverse {lambda} and {lambda}-bar polarization at COMPASS

    SciTech Connect

    Ferrero, A.

    2007-06-13

    New data on hyperon polarization in semi-inclusive deep inelastic scattering have been collected by the COMPASS collaboration at CERN during the years 2002-2004, using a beam of longitudinally polarized muons of 160 GeV/c and a 6LiD target that can be polarized both longitudinally and transversely. The various combinations of beam and target polarizations allow for the study of a wide variety of hyperon polarization effects. Here we present preliminary results on the transverse polarization of {lambda} and {lambda}-bar produced both with unpolarized and transversely polarized deuteron targets.

  9. T(sub lambda) Depression by a Heat Current Along the lambda-Line

    NASA Technical Reports Server (NTRS)

    Liu, Yuanming; Larson, Melora; Iraelsson, Ulf E.

    1999-01-01

    We report measurements of the depression of the superfluid transition temperature by a heat current (1 less than or = Q less than or = 100 microW/sq cm) along the lambda-line (SVP less than or = P less than or = 21.6 bar). At P = 21.6 bar, measurements were also performed in a reduced gravity (0.2g). Experimental results show that the pressure dependence of the depression and the gravity effect on the measurements are small, in qualitative agreement with theoretical predictions. Keywords: superfluid helium; Lambda transition; heat current

  10. Lambda Baryon a Production in 91 GEV Positron - Collisions

    NASA Astrophysics Data System (ADS)

    Routenburg, Paul

    1992-01-01

    An analysis of Lambda + | Lambda production in the data collected with the OPAL detector during 1990 is presented. A total inclusive rate is determined and checked through detailed systematic studies. This rate is found to be 0.356 +/- 0.011 (stat.) +/- 0.028 (syst.) per multihadron event. The inclusive cross sections as a function of the fractional Lambda energy (x _{E}) and xi (xi = ln(1/x_{p }), where x_{p} is the fractional Lambda momentum) are determined and compared to the predictions of the HERWIG 5.0 and JETSET 7.2 Monte Carlos as tuned to agree with global event shapes at an average centre-of-mass energy of 91 GeV. The overall Lambda rate is in agreement with the JETSET prediction but less than that predicted by HERWIG. The fragmentation function observed is softer than predicted by either Monte Carlo. Scaling violations are observed in the x_{E } distribution compared to the observations between 29 and 35 GeV. This is attributed to increased gluon radiation. A study is then made of the Lambda decay length distribution, and of the production and decay angles. Reasonable agreement is found between the data and the expectations. There is some indication that the Lambda rate increases faster with event sphericity than does the charged multiplicity. This effect is thought to be due to increased baryon production in gluon fragmentation. Finally, an investigation into Lambda - | Lambda, Lambda - Lambda and | Lambda - | Lambda production in the same event is presented. The results support local baryon number conservation and agree with the JETSET prediction. It is also shown that an additional meson is produced between the baryon and the antibaryon a significant fraction of the time.

  11. Measurement of the Lambda0b lifetime in the decay lambda0b--> J/psiLambda0 with the D0 detector.

    PubMed

    Abazov, V M; Abbott, B; Abolins, M; Acharya, B S; Adams, M; Adams, T; Agelou, M; Agram, J-L; Ahn, S H; Ahsan, M; Alexeev, G D; Alkhazov, G; Alton, A; Alverson, G; Alves, G A; Anastasoaie, M; Anderson, S; Andrieu, B; Arnoud, Y; Askew, A; Asman, B; Atramentov, O; Autermann, C; Avila, C; Badaud, F; Baden, A; Baldin, B; Balm, P W; Banerjee, S; Barberis, E; Bargassa, P; Baringer, P; Barnes, C; Barreto, J; Bartlett, J F; Bassler, U; Bauer, D; Bean, A; Beauceron, S; Begel, M; Bellavance, A; Beri, S B; Bernardi, G; Bernhard, R; Bertram, I; Besançon, M; Beuselinck, R; Bezzubov, V A; Bhat, P C; Bhatnagar, V; Binder, M; Black, K M; Blackler, I; Blazey, G; Blekman, F; Blessing, S; Bloch, D; Blumenschein, U; Boehnlein, A; Boeriu, O; Bolton, T A; Borcherding, F; Borissov, G; Bos, K; Bose, T; Brandt, A; Brock, R; Brooijmans, G; Bross, A; Buchanan, N J; Buchholz, D; Buehler, M; Buescher, V; Burdin, S; Burnett, T H; Busato, E; Butler, J M; Bystricky, J; Carvalho, W; Casey, B C K; Cason, N M; Castilla-Valdez, H; Chakrabarti, S; Chakraborty, D; Chan, K M; Chandra, A; Chapin, D; Charles, F; Cheu, E; Chevalier, L; Cho, D K; Choi, S; Christiansen, T; Christofek, L; Claes, D; Clément, B; Clément, C; Coadou, Y; Cooke, M; Cooper, W E; Coppage, D; Corcoran, M; Coss, J; Cothenet, A; Cousinou, M-C; Crépé-Renaudin, S; Cristetiu, M; Cummings, M A C; Cutts, D; da Motta, H; Davies, B; Davies, G; Davis, G A; De, K; de Jong, P; de Jong, S J; De La Cruz-Burelo, E; De Oliveira Martins, C; Dean, S; Déliot, F; Delsart, P A; Demarteau, M; Demina, R; Demine, P; Denisov, D; Denisov, S P; Desai, S; Diehl, H T; Diesburg, M; Doidge, M; Dong, H; Doulas, S; Duflot, L; Dugad, S R; Duperrin, A; Dyer, J; Dyshkant, A; Eads, M; Edmunds, D; Edwards, T; Ellison, J; Elmsheuser, J; Eltzroth, J T; Elvira, V D; Eno, S; Ermolov, P; Eroshin, O V; Estrada, J; Evans, D; Evans, H; Evdokimov, A; Evdokimov, V N; Fast, J; Fatakia, S N; Feligioni, L; Ferbel, T; Fiedler, F; Filthaut, F; Fisher, W; Fisk, H E; Fortner, M; Fox, H; Freeman, W; Fu, S; Fuess, S; Gadfort, T; Galea, C F; Gallas, E; Galyaev, E; Garcia, C; Garcia-Bellido, A; Gardner, J; Gavrilov, V; Gay, P; Gelé, D; Gelhaus, R; Genser, K; Gerber, C E; Gershtein, Y; Ginther, G; Golling, T; Gómez, B; Gounder, K; Goussiou, A; Grannis, P D; Greder, S; Greenlee, H; Greenwood, Z D; Gregores, E M; Gris, Ph; Grivaz, J-F; Groer, L; Grünendahl, S; Grünewald, M W; Gurzhiev, S N; Gutierrez, G; Gutierrez, P; Haas, A; Hadley, N J; Hagopian, S; Hall, I; Hall, R E; Han, C; Han, L; Hanagaki, K; Harder, K; Harrington, R; Hauptman, J M; Hauser, R; Hays, J; Hebbeker, T; Hedin, D; Heinmiller, J M; Heinson, A P; Heintz, U; Hensel, C; Hesketh, G; Hildreth, M D; Hirosky, R; Hobbs, J D; Hoeneisen, B; Hohlfeld, M; Hong, S J; Hooper, R; Houben, P; Hu, Y; Huang, J; Iashvili, I; Illingworth, R; Ito, A S; Jabeen, S; Jaffré, M; Jain, S; Jain, V; Jakobs, K; Jenkins, A; Jesik, R; Johns, K; Johnson, M; Jonckheere, A; Jonsson, P; Jöstlein, H; Juste, A; Kado, M M; Käfer, D; Kahl, W; Kahn, S; Kajfasz, E; Kalinin, A M; Kalk, J; Karmanov, D; Kasper, J; Kau, D; Kehoe, R; Kermiche, S; Kesisoglou, S; Khanov, A; Kharchilava, A; Kharzheev, Y M; Kim, K H; Klima, B; Klute, M; Kohli, J M; Kopal, M; Korablev, V M; Kotcher, J; Kothari, B; Koubarovsky, A; Kozelov, A V; Kozminski, J; Krzywdzinski, S; Kuleshov, S; Kulik, Y; Kunori, S; Kupco, A; Kurca, T; Lager, S; Lahrichi, N; Landsberg, G; Lazoflores, J; Le Bihan, A-C; Lebrun, P; Lee, S W; Lee, W M; Leflat, A; Lehner, F; Leonidopoulos, C; Lewis, P; Li, J; Li, Q Z; Lima, J G R; Lincoln, D; Linn, S L; Linnemann, J; Lipaev, V V; Lipton, R; Lobo, L; Lobodenko, A; Lokajicek, M; Lounis, A; Lubatti, H J; Lueking, L; Lynker, M; Lyon, A L; Maciel, A K A; Madaras, R J; Mättig, P; Magerkurth, A; Magnan, A-M; Makovec, N; Mal, P K; Malik, S; Malyshev, V L; Mao, H S; Maravin, Y; Martens, M; Mattingly, S E K; Mayorov, A A; McCarthy, R; McCroskey, R; Meder, D; Melanson, H L; Melnitchouk, A; Merkin, M; Merritt, K W; Meyer, A; Miettinen, H; Mihalcea, D; Mitrevski, J; Mokhov, N; Molina, J; Mondal, N K; Montgomery, H E; Moore, R W; Muanza, G S; Mulders, M; Mutaf, Y D; Nagy, E; Narain, M; Naumann, N A; Neal, H A; Negret, J P; Nelson, S; Neustroev, P; Noeding, C; Nomerotski, A; Novaes, S F; Nunnemann, T; Nurse, E; O'dell, V; O'Neil, D C; Oguri, V; Oliveira, N; Oshima, N; Otero Y Garzón, G J; Padley, P; Parashar, N; Park, J; Park, S K; Parsons, J; Partridge, R; Parua, N; Patwa, A; Perea, P M; Perez, E; Peters, O; Pétroff, P; Petteni, M; Phaf, L; Piegaia, R; Podesta-Lerma, P L M; Podstavkov, V M; Pogorelov, Y; Pope, B G; da Silva, W L Prado; Prosper, H B; Protopopescu, S; Przybycien, M B; Qian, J; Quadt, A; Quinn, B; Rani, K J; Rapidis, P A; Ratoff, P N; Reay, N W; Reucroft, S; Rijssenbeek, M; Ripp-Baudot, I; Rizatdinova, F; Royon, C; Rubinov, P; Ruchti, R; Sajot, G; Sánchez-Hernández, A; Sanders, M P; Santoro, A; Savage, G; Sawyer, L; Scanlon, T; Schamberger, R D; Schellman, H; Schieferdecker, P; Schmitt, C; Schukin, A A; Schwartzman, A; Schwienhorst, R; Sengupta, S; Severini, H; Shabalina, E; Shamim, M; Shary, V; Shephard, W D; Shpakov, D; Sidwell, R A; Simak, V; Sirotenko, V; Skubic, P; Slattery, P; Smith, R P; Smolek, K; Snow, G R; Snow, J; Snyder, S; Söldner-Rembold, S; Song, X; Song, Y; Sonnenschein, L; Sopczak, A; Sosebee, M; Soustruznik, K; Souza, M; Spurlock, B; Stanton, N R; Stark, J; Steele, J; Steinbrück, G; Stevenson, K; Stolin, V; Stone, A; Stoyanova, D A; Strandberg, J; Strang, M A; Strauss, M; Ströhmer, R; Strovink, M; Stutte, L; Sumowidagdo, S; Sznajder, A; Talby, M; Tamburello, P; Taylor, W; Telford, P; Temple, J; Tentindo-Repond, S; Thomas, E; Thooris, B; Tomoto, M; Toole, T; Torborg, J; Towers, S; Trefzger, T; Trincaz-Duvoid, S; Tuchming, B; Tully, C; Turcot, A S; Tuts, P M; Uvarov, L; Uvarov, S; Uzunyan, S; Vachon, B; Van Kooten, R; van Leeuwen, W M; Varelas, N; Varnes, E W; Vasilyev, I A; Vaupel, M; Verdier, P; Vertogradov, L S; Verzocchi, M; Villeneuve-Seguier, F; Vlimant, J-R; Von Toerne, E; Vreeswijk, M; Vu Anh, T; Wahl, H D; Walker, R; Wang, L; Wang, Z-M; Warchol, J; Warsinsky, M; Watts, G; Wayne, M; Weber, M; Weerts, H; Wegner, M; Wermes, N; White, A; White, V; Whiteson, D; Wicke, D; Wijngaarden, D A; Wilson, G W; Wimpenny, S J; Wittlin, J; Wobisch, M; Womersley, J; Wood, D R; Wyatt, T R; Xu, Q; Xuan, N; Yamada, R; Yan, M; Yasuda, T; Yatsunenko, Y A; Yen, Y; Yip, K; Youn, S W; Yu, J; Yurkewicz, A; Zabi, A; Zatserklyaniy, A; Zdrazil, M; Zeitnitz, C; Zhang, D; Zhang, X; Zhao, T; Zhao, Z; Zhou, B; Zhu, J; Zielinski, M; Zieminska, D; Zieminski, A; Zitoun, R; Zutshi, V; Zverev, E G; Zylberstejn, A

    2005-03-18

    We present measurements of the Lambda(0)(b) lifetime in the exclusive decay channel Lambda(0)(b)--> J/psiLambda(0), with J/psi--> mu(+)mu(-) and Lambda(0)--> ppi(-), the B0 lifetime in the decay B0-->J/psiK(0)(S) with J/psi--> mu(+)mu(-) and K(0)(S)-->pi(+)pi(-), and the ratio of these lifetimes. The analysis is based on approximately 250 pb(-1) of data recorded with the D0 detector in pp collisions at sqrt[s] = 1.96 TeV. The Lambda(0)(b) lifetime is determined to be tau(Lambda(0)(b)) = 1.22(+0.22)(-0.18)(stat) +/- 0.04(syst) ps, the B0 lifetime tau(B0) = 1.40(+0.11)(-0.10)(stat) +/- 0.03(syst) ps, and the ratio tau(Lambda(0)(b))/tau(B0) = 0.87(+0.17)(-0.14)(stat) +/- 0.03(syst). In contrast with previous measurements using semileptonic decays, this is the first determination of the Lambda(0)(b) lifetime based on a fully reconstructed decay channel. PMID:15783476

  12. Spectroscopy of 28Al(Lambda), 12B(Lambda), 7He(Lambda) by the (e,e'K+) Reaction

    SciTech Connect

    Akihiko Matsumura

    2010-06-30

    Hypernuclear spectroscopy by the $(e,e^{\\prime}K^+)$ reaction is one of the powerful tools to investigate precise structures of hypernuclei and to study $\\Lambda$N interaction. The second generation hypernuclear experiment at JLab Hall C(E01-011) was successfully performed in 2005, introducing the two novel experimental configurations, High resolution and large acceptance Kaon Spectrometer(HKS) and Tilt method. Thanks to these new configurations, various hypernuclei such as $^{28}_{\\Lambda}$Al, $^{12}_{\\Lambda}$B and $^{7}_{\\Lambda}$He were measured with precise energy resolution of 500 keV (FWHM). Obtained absolute binding energies and cross sections were compared with other experimental data and recent theoretical calculations based on shell model and cluster model. The results of this study provided new information on $\\Lambda$N interaction.

  13. Rabi resonances in the {lambda} excitation scheme

    SciTech Connect

    Godone, Aldo; Micalizio, Salvatore; Levi, Filippo

    2002-12-01

    We consider the interaction of a three-level system with phase-modulated resonant fields in the {lambda} excitation scheme. We treat theoretically the case of a sinusoidal phase modulation, a phase step perturbation, and a stochastic phase modulation. The appearance of a Rabi resonance both in the spectrum of the optical transmitted signal (electromagnetically induced transparency) and in the spectrum of the microwave emission (coherent population trapping maser) is considered in detail. All the theoretical results are compared with the analogous ones reported for the two-level system and with our experimental observations obtained for the case of rubidium in a buffer gas.

  14. {Lambda}(1520) photoproduction with Regge contribution

    SciTech Connect

    Nam, Seung-il; Yu, Byung-Geel; Kao, Chung-Wen

    2011-10-21

    In this talk, we report our recent progresses on the {Lambda}(1520) photoproduction using the effective Lagrangian approach. In addition to the tree-level Born diagrams, we take into account the Regge-trajectories for the possible strange-meson exchanges in the t channel. We compute the angular and energy dependences of the production process, including polarization observables, such as the photon-beam asymmetry and the polarization-transfer coefficients, resulting in good qualitative agreement with current experimental data. We also compute the K{sup -} angle distribution function in the Gottfried-Jackson frame, using the polarization-transfer coefficients in the z direction.

  15. Aetherizing Lambda: Barotropic fluids as dark energy

    SciTech Connect

    Linder, Eric V.; Scherrer, Robert J.

    2009-07-15

    We examine the class of barotropic fluid models of dark energy, in which the pressure is an explicit function of the density, p=f({rho}). Through general physical considerations we constrain the asymptotic past and future behaviors and show that this class is equivalent to the sum of a cosmological constant and a decelerating perfect fluid, or 'aether', with w{sub AE}{>=}0. Barotropic models give substantially disjoint predictions from quintessence, except in the limit of {lambda}CDM. They are also interesting in that they simultaneously can ameliorate the coincidence problem and yet 'predict' a value of w{approx_equal}-1.

  16. Carbon/lambda-MnO{sub 2} composites for supercapacitor electrodes

    SciTech Connect

    Malak-Polaczyk, A.; Matei-Ghimbeu, C.; Vix-Guterl, C.; Frackowiak, E.

    2010-04-15

    In the present work a composite of carbon with lambda-MnO{sub 2} have been synthesized by a simple two-step route. In the first step, to obtain LiMn{sub 2}O{sub 4}/carbon material, mesoporous activated carbon was impregnated with the solution of precursor metal salts and heated subsequently. As-prepared materials were acid treated which resulted in the formation of lambda-MnO{sub 2}/carbon. Physical properties, structure and specific surface area of electrode materials were studied by TEM, X-ray diffraction and nitrogen sorption measurements. Voltammetry cycling, galvanostatic charge/discharge and impedance spectroscopy measurements performed in two- and three-electrode cells have been applied in order to measure electrochemical parameters. TEM images confirmed well dispersed lambda-MnO{sub 2} particles on the surface of carbon material. The carbon in the composite plays an important role as the surface area enhancing component and a support of pseudocapacitive material. Furthermore, the through-connected porosity serves as a continuous pathway for electrolyte transport. A synergetic effect of the porous carbon framework and of the redox properties of the lambda-MnO{sub 2} is at the origin of improvement of specific capacitance values which has been observed for composites after delithiation. - Comparison of capacitance characteristics for initial carbon and synthesised composites for CB in 1 mol L{sup -1} Na{sub 2}SO{sub 4} solution.

  17. Measurement of the Lambda/b lifetime in Lambda/b to Lambda/c pi decays at the Collider Detector at Fermilab

    SciTech Connect

    Mumford, Jonathan Reid; /Johns Hopkins U.

    2008-10-01

    The lifetime of the {Lambda}{sub b}{sup 0} baryon (consisting of u, d and b quarks) is the theoretically most interesting of all b-hadron lifetimes. The lifetime of {Lambda}{sub b}{sup 0} probes our understanding of how baryons with one heavy quark are put together and how they decay. Experimentally however, measurements of the {Lambda}{sub b}{sup 0} lifetime have either lacked precision or have been inconsistent with one another. This thesis describes the measurement of {Lambda}{sub b}{sup 0} lifetime in proton-antiproton collisions with center of mass energy of 1.96 TeV at Fermilab's Tevatron collider. Using 1070 {+-} 60pb{sup -1} of data collected by the Collider Detector at Fermilab (CDF), a clean sample of about 3,000 fully-reconstructed {Lambda}{sub b}{sup 0} {yields} {Lambda}{sub c}{sup +}{pi}{sup -} decays (with {Lambda}{sub c}{sup +} subsequently decaying via {Lambda}{sub c}{sup +} {yields} p{sup +} K{sup -} {pi}{sup +}) is used to extract the lifetime of the {Lambda}{sub b}{sup 0} baryon, which is found to be c{tau}({Lambda}{sub b}{sup 0}) = 422.8 {+-} 13.8(stat) {+-} 8.8(syst){micro}m. This is the most precise measurement of its kind, and is even better than the current world average. It also settles the recent controversy regarding the apparent inconsistency between CDF's other measurement and the rest of the world.

  18. A Study of Bbar to Xi_c Lambda_c^- and Bbar to Lambda_c^+ Lambda_c^- Kbar Decays at \\babar

    SciTech Connect

    Aubert, B.

    2007-11-07

    We report measurements of B-meson decays into two- and three-body final states containing two charmed baryons using a sample of 230 million {Upsilon}(4S) {yields} B{bar B} decays. We find significant signals in two modes, measuring branching fractions {beta}(B{sup -} {yields} {Lambda}{sub c}{sup +}{Lambda}{sub c}{sup -}K{sup -}) = (1.14 {+-} 0.15 {+-} 0.17 {+-} 0.60) x 10{sup -3} and {beta}(B{sup -}{yields} {Xi}{sup 0}{sub c}{bar {Lambda}}{sub c}{sup -}) x {beta}({Xi}{sup 0}{sub c} {yields} {Xi}{sup -}{pi}{sup +}) = (2.08 {+-} 0.65 {+-} 0.29 {+-} 0.54) x 10{sup -5}, where the uncertainties are statistical, systematic, and from the branching fraction {beta}({Lambda}{sup +}{sub c} {yields} pK{sup -}{pi}{sup +}), respectively. We also set upper limits at the 90% confidence level on two other modes: {beta}({bar {beta}}{sup 0} {yields} {Xi}{sup +}{sub c}{bar {Lambda}}{sup -}{sub c}) x {beta}({Xi}{sup +}{sub c} {yields} {Xi}{sup -}{pi}{sup +}{pi}{sup +}) < 5.6 x 10{sup -5} and {beta}({bar B}{sup 0} {yields} {Lambda}{sup +}{sub c}{bar {Lambda}}{sup -}{sub c}{bar K}{sup 0}) < 1.5 x 10{sup -3}. We observe structure centered at an invariant mass of 2.93 GeV/c{sup 2} in the {Lambda}{sup +}{sub c}K{sup -} mass distribution of the decay B{sup -} {yields} {Lambda}{sup +}{sub c}{bar {Lambda}}{sup -}{sub c}K{sup -}.

  19. On the local behaviour of the multidimensional {Lambda}-variation

    SciTech Connect

    Bakhvalov, Alexandr N

    2011-01-14

    Let two classes ({Lambda}{sup 1},...,{Lambda}{sup m})BV and (M{sup 1},...,M{sup m})BV on an interval {Delta} be given. In the paper, we find necessary and sufficient conditions for the {Lambda}-variation of any function in the M-class, over a neighbourhood of every regular point, to tend to zero as the neighbourhood decreases. Bibliography: 10 titles.

  20. First measurement of the ratio of branching fractions BR(Lambda(b) to Lambda(c) mu nu)/BR(Lambda(b) to Lambda(c) pi) at CDF II

    SciTech Connect

    Yu, Shin-shan

    2005-01-01

    In this dissertation, we measure the properties of the lowest-mass beauty baryon, {Lambda}{sub b}. Baryons are the bound states of three quarks. Protons and neutrons, constituents of atomic nuclei, are the most common baryons. Other types of baryons can be produced and studied in the high-energy collider environment. Three-body dynamics makes baryons composed of low mass quarks difficult to study. On the other hand, baryons with one heavy quark simplify the theoretical treatment of baryon structure, since the heavy quark can be treated the same way as the nucleus in the atom. The {Lambda}{sub b} is composed of u, d, and b quarks, where the b quark is much heavier than the other two. Although, it is accessible, little is known about {Lambda}{sub b}. In 1991, UA1 [1] reconstructed 9 {+-} 1 {Lambda}{sub b} {yields} J/{Psi}{Lambda} candidates. In 1996, ALEPH and DELPHI reconstructed the decay {Lambda}{sub b} {yields} {Lambda}{sub c}{sup +}{pi}{sup -} and found only 3-4 candidates [2, 3]. ALEPH measured a {Lambda}{sub b} mass of 5614 {+-} 21 MeV/c{sup 2}, while DELPHI measured 5668 {+-} 18 MeV/c{sup 2}, about 2 {sigma} higher. Subsequently, CDF-I observed 20 {Lambda}{sub b} {yields} J/{Psi}{Lambda} events [4], confirmed the existence of {Lambda}{sub b} unambiguously and made a more precise measurement of {Lambda}{sub b} mass, 5621 {+-} 5 MeV/c{sup 2}. A recent CDF-II measurement by Korn [5] yields 5619.7 {+-} 1.7 MeV/c{sup 2}, which will significantly improve the current world average, 5624 {+-} 9 MeV/c{sup 2}, and resolve the discrepancy of ALEPH and DELPHI.

  1. The fluxonium as a lambda system

    NASA Astrophysics Data System (ADS)

    Vool, U.; Kou, A.; Smith, W. C.; Serniak, K.; Shankar, S.; Girvin, S. M.; Devoret, M. H.

    A lambda system is a 3-level system in which two low-energy states can transition to a third higher-energy state by a coherent drive but not to each other. Lambda systems are commonly implemented in systems relying on atomic transitions. In the field of superconducting quantum circuits, the fluxonium qubit, an artificial atom consisting of a Josephson junction shunted by a super-inductance, is a unique artificial atom with highly non-linear energy levels. At half-flux quantum it has two low-energy states with a long energy lifetime, but it is difficult to perform fast quantum gates in this manifold. Employing the higher 2nd excited state as an intermediate level would be much more efficient. However, selection rules in the fluxonium qubit prohibit transitions between low-energy states and higher-energy states of the same parity. In this talk, we will introduce a way to create formerly forbidden transitions between levels of the fluxonium qubit - thus creating a more interesting artificial atom and a useful tool for future superconducting quantum circuits. Work supported by ARO, ONR, AFOSR and YINQE.

  2. The LAMBDA photon-counting pixel detector

    NASA Astrophysics Data System (ADS)

    Pennicard, D.; Lange, S.; Smoljanin, S.; Hirsemann, H.; Graafsma, H.; Epple, M.; Zuvic, M.; Lampert, M.-O.; Fritzsch, T.; Rothermund, M.

    2013-03-01

    The Medipix3 photon-counting detector chip has a number of novel features that are attractive for synchrotron experiments, such as a high frame rate with zero dead time and high spatial resolution. DESY are developing a large-area Medipix3-based detector array (LAMBDA). A single LAMBDA module consists of 2 by 6 Medipix3 chips on a ceramic carrier board, bonded to either a single large silicon sensor or two smaller high-Z sensors. The readout system fits behind the carrier board to allow module tiling, and uses a large on-board RAM and multiple 10 Gigabit Ethernet links to permit high-speed readout. Currently, the first large silicon modules have been constructed and read out at low speed, and the firmware for highspeed readout is being developed. In addition to these silicon sensors, we are developing a germanium hybrid pixel detector in collaboration with Canberra for higher-energy beamlines. Canberra have produced a set of 256-by-256-pixel planar germanium sensors with 55μm pitch, and these are currently being bonded to Medipix3 readout chips by Fraunhofer IZM (Berlin).

  3. ON THE BINDING ENERGY PARAMETER {lambda} OF COMMON ENVELOPE EVOLUTION

    SciTech Connect

    Xu Xiaojie; Li Xiangdong

    2010-06-10

    The binding energy parameter {lambda} plays an important role in common envelope evolution. Previous works have already pointed out that {lambda} varies throughout the stellar evolution, though it has been adopted as a constant in most of the population synthesis calculations. We have systematically calculated the binding energy parameter {lambda} for both Population I and Population II stars of masses 1-20 M {sub sun}, taking into account the contribution from the internal energy of stellar matter. We present fitting formulae for {lambda} that can be incorporated into future population synthesis investigations. We also briefly discuss the possible applications of the results in binary evolutions.

  4. Rare {Lambda}{sub b} decays in a quark model

    SciTech Connect

    Mott, L.; Roberts, W.

    2010-08-05

    Hadronic form factors for the rare weak transitions {Lambda}{sub b{yields}{Lambda}}{sup (*)} are calculated using a nonrelativistic quark model. The form factors obtained in this way are found to satisfy the relationships expecetd from the heavy quark effective theory. Differential decay rates and branching ratios are calculated for the dileptonic decays {Lambda}{sub b{yields}{Lambda}}{sup (*)}l{sup +}l{sup -}, for both ground state and excited daughter baryons. Inclusion of the long distance contributions from charmonium resonances significantly enhances the decay rates. Future work is outlined.

  5. Charge-symmetry breaking {Lambda}-nucleon interaction

    SciTech Connect

    Bodmer, A.R.; Murali, M.; Usmani, Q.N.

    1995-08-01

    Some time ago we showed that the charge-symmetry-breaking interaction, as obtained from the mass four hypernuclei ({sub {Lambda}}{sup 4}H, {sub {Lambda}}{sup 4}He), was spin-independent; a result which cannot be understood with the conventional meson-exchange models. The calculations of ({sub {Lambda}}{sup 4}H, {sub {Lambda}}{sup 4}He) are currently being extended to include noncentral nuclear and hypernuclear forces which could modify this result. At a more fundamental level we intend to study quark-structure contributions to the charge-symmetry-breaking interaction.

  6. Remarks on the generalized Tukey's lambda family of distributions

    SciTech Connect

    Lam, H.; Bowman, K.O.; Shenton, L.R.

    1980-01-01

    The family of curves generated by the mapping of the uniform density F/sup -1/(lambda) = ..cap alpha.. + ..beta..(lambda/sup ..gamma..delta/ - (1-lambda)/sup ..gamma../)/..gamma.., 0 < lambda < 1, is considered. Primary interest is the application of the above density to approximating theoretical distribution functions of test statistics such as S.D., skewness, and kurtosis under non-normality. Moments are straight forward to evaluate in terms of gamma functions, or polygamma functions in special cases. 1 figure, 8 tables. (RWR)

  7. Analysis of the {Lambda}{sub b{yields}{Lambda}}l{sup +}l{sup -} decay in QCD

    SciTech Connect

    Aliev, T. M.; Savci, M.; Azizi, K.

    2010-03-01

    Taking into account the {Lambda} baryon distribution amplitudes and the most general form of the interpolating current of the {Lambda}{sub b}, the semileptonic {Lambda}{sub b{yields}{Lambda}}l{sup +}l{sup -} transition is investigated in the framework of the light cone QCD sum rules. Sum rules for all 12 form factors responsible for the {Lambda}{sub b{yields}{Lambda}}l{sup +}l{sup -} decay are constructed. The obtained results for the form factors are used to compute the branching fraction. A comparison of the obtained results with the existing predictions of the heavy quark effective theory is presented. The results of the branching ratio shows the detectability of this channel at the Large Hadron Collider beauty in the near future is quite high.

  8. {lambda}N space-exchange correlation effects in the {sub {lambda}}{sup 5}He hypernucleus

    SciTech Connect

    Usmani, A.A.

    2006-01-15

    A complete realistic study of the {sub {lambda}}{sup 5}He hypernucleus is presented using a realistic Hamiltonian and a fully correlated wave function that takes into account all relevant dynamical correlations and {lambda}N space-exchange correlation (SEC). Results are sensitive to SEC, which significantly affects energy breakdown, {lambda}-separation energy, nuclear core polarization, point proton radius, and density profiles.

  9. QCD factorization for {Lambda}{sub b}{sup 0}{yields}{Lambda}{sub c}{sup +}{pi}{sup -}

    SciTech Connect

    Zhang Zhenhua; Guo Xinheng; Lue Gang

    2011-02-01

    We prove that in the limit m{sub b},m{sub c}{yields}{infinity}, with m{sub c}/m{sub b} fixed, factorization holds at order {alpha}{sub s} for the decay {Lambda}{sub b}{sup 0}{yields}{Lambda}{sub c}{sup +}{pi}{sup -}. This proof is done in the infinite-momentum frame in which the momenta of {pi}, {Lambda}{sub c}, and {Lambda}{sub b} go to infinity. Our result is renormalization-scale- and scheme-independent at O({alpha}{sub s}). This is the same as the QCD factorization for B{yields}D{pi}.

  10. Environmental chemistry, ecotoxicity, and fate of lambda-cyhalothrin.

    PubMed

    He, Li-Ming; Troiano, John; Wang, Albert; Goh, Kean

    2008-01-01

    Lambda-cyhalothrin is a pyrethroid insecticide used for controlling pest insects in agriculture, public health, and in construction and households. Lambda-cyhalothrin is characterized by low vapor pressure and a low Henry's law constant but by a high octanol-water partition coefficient (K(ow)) and high water-solid-organic carbon partition coefficient (K(oc)) values. Lambda-cyhalothrin is quite stable in water at pH < 8, whereas it hydrolyzes to form HCN and aldehyde under alkaline conditions. Although lambda-cyhalothrin is relatively photostable under natural irradiation, with a half-life > 3 wk, its photolysis process is fast under UV irradiation, with a half-life < 10 min. The fate of lambda-cyhalothrin in aquatic ecosystems depends on the nature of system components such as suspended solids (mineral and organic particulates) and aquatic organisms (algae, macrophytes, or aquatic animals). Lambda-cyhalothrin residues dissolved in water decrease rapidly if suspended solids and/or aquatic organisms are present because lambda-cyhalothrin molecules are strongly adsorbed by particulates and plants. Adsorbed lambda-cyhalothrin molecules show decreased degradation rates because they are less accessible to breakdown than free molecules in the water column. On the other hand, lambda-cyhalothrin adsorbed to suspended solids or bottom sediments may provide a mechanism to mitigate its acute toxicity to aquatic organisms by reducing their short-term bioavailability in the water column. The widespread use of lambda-cyhalothrin has resulted in residues in sediment, which have been found to be toxic to aquatic organisms including fish and amphipods. Mitigation measures have been used to reduce the adverse impact of lambda-cyhalothrin contributed from agricultural or urban runoff. Mitigation may be achieved by reducing the quantity of runoff and suspended solid content in runoff through wetlands, detention ponds, or vegetated ditches. PMID:18418954

  11. The A dependence of K{sup 0} and {lambda} Neutrino production on nuclei

    SciTech Connect

    Agababyan, N. M.; Ammosov, V. V.; Atayan, M.; Grigoryan, N.; Gulkanyan, H.; Ivanilov, A. A. Karamyan, Zh.; Korotkov, V. A.

    2007-10-15

    The A dependence of the production of K{sup 0} and {lambda} is investigated for the first time in neutrino-nuclear reactions using the data obtained with the SKAT bubble chamber. An exponential parametrization ({approx}A{sup {beta}}) of the particle yields results in {sigma}({beta}{sub V}{sup 0}) {sigma} = 0.20 {+-} 0.05 for V{sup 0} particles (K{sup 0} and {lambda}), while for {pi}{sup -} mesons the A dependence is much weaker ({sigma}({beta}{sub {pi}}{sup -}) {sigma} = 0.068 {+-} 0.007). A nuclear enhancement of the ratio K{sup 0}/{pi}{sup -} is found; this ratio increases from 0.055 {+-} 0.013 for vN interactions up to 0.070 {+-} 0.011 at A {approx} 21 and 0.099 {+-} 0.011 at A {approx} 45. It is observed that the multiplicity rise of V{sup 0} occurs predominantly in the backward hemisphere of the hadronic system. It is shown that the A dependence of the {lambda}{sup 0} and {pi}{sup -} yields can be reproduced in the framework of a model incorporating the secondary intranuclear interactions of pions originating from the primary vN interactions.

  12. The motion of a single molecule, the lambda-receptor, in the bacterial outer membrane.

    PubMed Central

    Oddershede, Lene; Dreyer, Jakob Kisbye; Grego, Sonia; Brown, Stanley; Berg-Sørensen, Kirstine

    2002-01-01

    Using optical tweezers and single particle tracking, we have revealed the motion of a single protein, the lambda-receptor, in the outer membrane of living Escherichia coli bacteria. We genetically modified the lambda-receptor placing a biotin on an extracellular site of the receptor in vivo. The efficiency of this in vivo biotinylation is very low, thus enabling the attachment of a streptavidin-coated bead binding specifically to a single biotinylated lambda-receptor. The bead was used as a handle for the optical tweezers and as a marker for the single particle tracking routine. We propose a model that allows extraction of the motion of the protein from measurements of the mobility of the bead-molecule complex; these results are equally applicable to analyze bead-protein complexes in other membrane systems. Within a domain of radius approximately 25 nm, the receptor diffuses with a diffusion constant of (1.5 +/- 1.0) x 10(-9) cm(2)/s and sits in a harmonic potential as if it were tethered by an elastic spring of spring constant of ~1.0 x 10(-2) pN/nm to the bacterial membrane. The purpose of the protein motion might be to facilitate transport of maltodextrins through the outer bacterial membrane. PMID:12496085

  13. Lambda/2 fringe-spacing interferometer.

    PubMed

    de Chatellus, H Guillet; Pique, J-P

    2009-03-15

    The precision of interferometry is directly linked to the fringe spacing of the recorded interferogram. Whereas all interferometric devices show a fringe spacing equal to a wavelength of the laser light we present a novel scheme of a two-beam interferometer exhibiting a fringe spacing reduced by a factor of 2; the direct detection of the beat signal is replaced with the monitoring of the fluorescence of a twofold degenerate atomic system resonant with the laser. The lambda/2 fringe spacing in the fluorescence signal is demonstrated with a hot sodium vapor excited by a broadband laser tuned to the D1 line. In the saturation regime, the dark fringes are expected to be extremely narrow, leading to the possibility of nanoscale displacement measurements or atom localization. PMID:19282922

  14. A Measurement of the Lifetime of the Lambda_b Baryon with the CDF Detector at the Tevatron Run II

    SciTech Connect

    Unverhau, Tatjana Alberta Hanna; /Glasgow U.

    2004-12-01

    In March 2001 the Tevatron accelerator entered its Run II phase, providing colliding proton and anti-proton beams with an unprecedented center-of-mass energy of 1.96 TeV. The Tevatron is currently the only accelerator to produce {Lambda}{sub b} baryons, which provides a unique opportunity to measure the properties of these particles. This thesis presents a measurement of the mean lifetime of the {Lambda}{sub b} baryon in the semileptonic channel {Lambda}{sub b}{sup 0} {yields} {Lambda}{sub c}{sup +} {mu}{sup -} {bar {nu}}{sub {mu}}. In total 186 pb{sup -1} of data were used for this analysis, collected with the CDF detector between February 2002 and September 2003. To select the long-lived events from b-decays, the secondary vertex trigger was utilized. This significant addition to the trigger for Run II allows, for the first time, the selection of events with tracks displaced from the primary interaction vertex at the second trigger level. After the application of selection cuts this trigger sample contains approximately 991 {Lambda}{sub b} candidates. To extract the mean lifetime of {Lambda}{sub b} baryons from this sample, they transverse decay length of the candidates is fitted with an unbinned maximum likelihood fit under the consideration of the missing neutrino momentum and the bias introduced by the secondary vertex trigger. The mean lifetime of the {Lambda}{sub b} is measured to be {tau} = 1.29 {+-} 0.11(stat.) {+-} 0.07(syst.) ps equivalent to a mean decay length of c{tau} = 387 {+-} 33(stat.) {+-} 21 (syst.) {micro}m.

  15. Moderate-resolution spectral standards from lambda 5600 to lambda 9000

    NASA Technical Reports Server (NTRS)

    Allen, Lori E.; Strom, Karen M.

    1995-01-01

    We present a grid of stellar classification spectra of moderate resolution (R approximately 1500) in the range lambda lambda 5600-9000 A, compiled from high signal-to noise spectra of 275 stars, most in the open clusters Praesepe and M67. The grid covers dwarfs from types B8 through M5, giants from G8 through M7, and subgiants from F5 through K0. We catalog atomic and molecular absorption features useful for stellar classification, and demonstrate the use of luminosity-sensitive features to distinguish between late-type dwarf and giant stars. The entire database is made available in digital format on anonymous ftp and through the World Wide Web.

  16. K{sup 0} and {lambda} production in Ni+Ni collisions near threshold

    SciTech Connect

    Merschmeyer, M.; Herrmann, N.; Benabderrahmane, M. L.; Cordier, E.; Mangiarotti, A.; Pelte, D.; Xiao, Z. G.; Lopez, X.; Andronic, A.; Hartmann, O. N.; Hildenbrand, K. D.; Koczon, P.; Leifels, Y.; Reisdorf, W.; Schuettauf, A.; Bastid, N.; Crochet, P.; Barret, V.; Dupieux, P.

    2007-08-15

    New results concerning the production of neutral strange particles, K{sup 0} and {lambda} in Ni+Ni collisions at 1.93A GeV, measured with the FOPI detector at GSI Darmstadt, are presented. Rapidity density distributions and Boltzmann slope parameter distributions are measured in nearly the full phase space of the reaction. The observables are compared to existing K{sup +} and proton data. While the K{sup 0} data agree with previously reported K{sup +} measurements, the {lambda} distributions show a different behavior relative to that of protons. The strangeness balance and the production yield per participating nucleon as a function of the centrality of the reaction are discussed, for the first time at GSI Schwerionen Synchrotron (SIS) energies.

  17. Experimental Investigation of Weak Non-Mesonic Decay of 10Be(Lambda)Hypernuclei at CEBAF

    SciTech Connect

    S. Majewski; L. Majling; A. Margaryan; L. Tang

    2005-08-05

    Hypernuclei are convenient laboratory to study the baryon-baryon weak interaction and associated effective Hamiltonian. The strangeness changing process, in which a Lambda hyperon converts to a neutron with a release up to 176 MeV, provides a clear signal for a conversion of an s-quark to a d-quark. We propose to perform a non-mesonic weak decay study of 10Be(Lambda)hypernuclei using the (e,eK) reaction. These investigations will fully utilize the unique parameters of the CEBAF CW electron beam and RF system and are enabled by (1) the use of new detector for alpha particles based on the recently developed RF timing technique with picosecond resolution and (2) the small angle and large acceptance kaon spectrometer-HKS in Hall C.

  18. Properties of the Lambda(1405) Measured at CLAS

    SciTech Connect

    Kei Moriya, Reinhard Schumacher

    2012-04-01

    The nature of the {Lambda}(1405), and its place in the baryon spectrum has remained uncertain for decades. Theoretical studies have shown that it may possess strong dynamical components which are not seen in other well-known baryons. Using the CLAS detector system in Hall B at Jefferson Lab, we have measured the photoproduction reaction {gamma} + p {yields} K{sup +} {Lambda}(1405) with high statistics and over different {Sigma}{pi} decay channels. The reconstructed invariant mass distribution (lineshape) has been measured, as well as the differential cross sections for the {Lambda}(1405), {Sigma}(1385), and {Lambda}(1520). Our analysis method is discussed and our near-final results for the {Lambda}(1405) lineshape and differential cross section are presented.

  19. Lineshape of the Lambda(1405) measured at CLAS

    SciTech Connect

    Kei Moriya, Reinhard Schumacher, CLAS Collaboration

    2012-04-01

    The {Lambda}(1405) has been a subject of controversy for decades, and its nature as a hyperon resonance has yet to be established firmly. Its peculiar lineshape, i.e., its {Sigma}{pi} invariant mass spectrum has lead to various theoretical studies, and some of these show that it may possess strong dynamical components which are not seen in other well-known baryons. With the CLAS detector system in Hall B at Jefferson Lab, we have measured the photoproduction reaction {gamma} + p {yields} K{sup +} {Lambda}(1405) with high statistics over different {Sigma}{pi} decay channels. The reconstructed invariant mass distribution has been measured, as well as the differential cross sections for the nearby {Lambda}(1405), {Sigma}(1385), and {Lambda}(1520). Our analysis method is discussed and our near-final results for the {Lambda}(1405) lineshape is presented.

  20. Simple model for lambda-doublet propensities in bimolecular reactions

    NASA Technical Reports Server (NTRS)

    Bronikowski, Michael J.; Zare, Richard N.

    1990-01-01

    A simple geometric model is presented to account for lambda-doublet propensities in bimolecular reactions A + BC - AB + C. It applies to reactions in which AB is formed in a pi state, and in which the unpaired molecular orbital responsible for lambda-doubling arises from breaking the B-C bond. The lambda-doublet population ratio is predicted to be 2:1 provided that: (1) the motion of A in the transition state determines the plane of rotation of AB; (2) the unpaired pi orbital lying initially along the B-C bond may be resolved into a projection onto the AB plane of rotation and a projection perpendicular to this plane; (3) there is no preferred geometry for dissociation of ABC. The 2:1 lambda-doublet ratio is the 'unconstrained dynamics prior' lambda-doublet distribution for such reactions.

  1. High Resolution Spectroscopy of 16N_Lambda by Electroproduction

    SciTech Connect

    Cusanno, Francesco; Urciuoli, Guido; Acha Quimper, Armando; Ambrozewicz, Pawel; Aniol, Konrad; Baturin, Pavlo; Bertin, Pierre; Benaoum, Hachemi; Blomqvist, Ingvar; Boeglin, Werner; Breuer, Herbert; Brindza, Paul; Bydzovsky, Petr; Camsonne, Alexandre; Chang, C.; Chang, C.C.; Chang, C.; Chang, C.C.; Chang, C.; Chang, C.C.; Chang, C.; Chang, C.C.; Chen, Jian-Ping; Choi, Seonho; Chudakov, Eugene; Cisbani, Evaristo; Colilli, Stefano; Coman, Luminita; Craver, Brandon; de Cataldo, Giacinto; De Jager, Cornelis; De Leo, Raffaele; Deur, Alexandre; Ferdi, Catherine; Feuerbach, Robert; Folts, Edward; Frullani, Salvatore; Garibaldi, Franco; Gayou, Olivier; Giuliani, Fausto; Gomez, Javier; Gricia, Massimo; Hansen, Jens-Ole; Hayes, David; Higinbotham, Douglas; Holmstrom, Timothy; Hyde, Charles; Ibrahim, Hassan; Iodice, Mauro; Jiang, Xiaodong; Kaufman, Lisa; Kino, Kouichi; Kross, Brian; Lagamba, Luigi; LeRose, John; Lindgren, Richard; Lucentini, Maurizio; Margaziotis, Demetrius; Markowitz, Pete; Marrone, Stefano; Meziani, Zein-Eddine; McCormick, Kathy; Michaels, Robert; Millener, D.; Miyoshi, Toshinobu; Moffit, Bryan; Monaghan, Peter; Moteabbed, Maryam; Munoz Camacho, Carlos; Nanda, Sirish; Nappi, E.; Nelyubin, Vladimir; Norum, Blaine; Okasyasu, Y.; Paschke, Kent; Perdrisat, Charles; Piasetzky, Eliazer; Punjabi, Vina; Qiang, Yi; Raue, Brian; Reimer, Paul; Reinhold, Joerg; Reitz, Bodo; Roche, Rikki; Rodriguez, Victor; Saha, Arunava; Santavenere, Fabio; Sarty, Adam; Segal, John; Shahinyan, Albert; Singh, Jaideep; Sirca, Simon; Snyder, Ryan; Solvignon, Patricia; Sotona, M.; Sotona, Miloslav; Sotona, M.; Sotona, Miloslav; Sotona, M.; Sotona, Miloslav; Sotona, M.; Sotona, Miloslav; Subedi, Ramesh; Sulkosky, Vince; Sulkosky, Vincent; Sulkosky, Vince; Sulkosky, Vincent; Suzuki, Tomokazu; Ueno, Hiroaki; Ulmer, Paul; Veneroni, P.P.; Voutier, Eric; Wojtsekhowski, Bogdan; Zeng, X.; Zorn, Carl

    2009-01-01

    An experimental study of the 16O(e, e'K+)16N_Lambda reaction has been performed at Jefferson Lab. A thin film of falling water was used as a target. This permitted a simultaneous measurement of the p(e, e'K+)Lambda,Sigma_0 exclusive reactions and a precise calibration of the energy scale. A ground-state binding energy of 13.76 ± 0.16 MeV was obtained for 16N_Lambda with better precision than previous measurements on the mirror hypernucleus 16O_Lambda. Precise energies have been determined for peaks arising from a Lambda in s and p orbits coupled to the p1/2 and p3/2 hole states of the 15N core nucleus.

  2. Is there a {pi}{lambda}N bound state?

    SciTech Connect

    Gal, A.; Garcilazo, H.

    2008-07-01

    We have searched for bound states in the {pi}{lambda}N system by solving the nonrelativistic Faddeev equations, as well as a relativistic version, with input separable {pi}N, {pi}{lambda}, and {lambda}N interactions. A bound-state solution, driven by the {delta}(1232) and the {sigma}(1385) p-wave meson-baryon resonances, was found in the channel (I,J{sup P})=((3/2),2{sup +}), provided the {lambda} laboratory momentum at which the {lambda}N {sup 3}S{sub 1} phase shift becomes negative is larger than p{sub lab}{approx}750-800 MeV/c. Other strange and charmed {pi}BB{sup '} systems that might have bound states of a similar nature are listed.

  3. Comments on \\Lambda and other repelling equations of state

    NASA Astrophysics Data System (ADS)

    Schulz, Hartmut

    DeSitter's (1917) cosmology of a universe devoid of matter but expanding due to a positive cosmological constant \\Lambda is commonly considered as a valid counterexample against a Machian interpretation of General Relativity. This view is conceptually questionable because of the mathematical equivalence of \\Lambda with a constant (`vacuum') energy density \\rho_{\\Lambda} (as e.g.\\ inflationists use it) implying an equation of state P=-\\rho_{\\Lambda} that leads to a `repelling force' in a standard universe. We discuss the reasons for this apparent antigravity extracted from the structure of the theory. Antigravitational effects can be produced by other equations of state as well, notably by proposed dark matter constituents. Such components plus matter and radiation lead to world models (we show examples) beyond the classical classification schemes for which we propose extensions in terms of `critical equations of state' rather than `critical \\Lambda'.

  4. Phillips' Lambda function: Data summary and physical model

    NASA Astrophysics Data System (ADS)

    Irisov, V.; Plant, W.

    2016-03-01

    Measurements of Phillips' Lambda function describing the average length of breakers on the ocean per unit area at speed cb are summarized. An expression is developed that fits these data within reasonable bounds. A physical model for the Lambda function is derived based on the assumption that breaking occurs when the surface steepness exceeds a threshold value. The energy contained in the breaking region is related to the fifth power of the breaker speed, as Phillips showed, and from this the probability of finding a breaker with a speed cb may be determined from a simulation of the long-wave surface based on a linear superposition of Fourier components. This probability is directly related to the Lambda function so that a form for this function can be determined. The Lambda function so determined agrees in both shape and intensity with the fit to the measured Lambda functions.

  5. High-resolution spectroscopy of Lambda16N by electroproduction.

    PubMed

    Cusanno, F; Urciuoli, G M; Acha, A; Ambrozewicz, P; Aniol, K A; Baturin, P; Bertin, P Y; Benaoum, H; Blomqvist, K I; Boeglin, W U; Breuer, H; Brindza, P; Bydzovský, P; Camsonne, A; Chang, C C; Chen, J-P; Choi, Seonho; Chudakov, E A; Cisbani, E; Colilli, S; Coman, L; Craver, B J; De Cataldo, G; de Jager, C W; De Leo, R; Deur, A P; Ferdi, C; Feuerbach, R J; Folts, E; Fratoni, R; Frullani, S; Garibaldi, F; Gayou, O; Giuliani, F; Gomez, J; Gricia, M; Hansen, J O; Hayes, D; Higinbotham, D W; Holmstrom, T K; Hyde, C E; Ibrahim, H F; Iodice, M; Jiang, X; Kaufman, L J; Kino, K; Kross, B; Lagamba, L; LeRose, J J; Lindgren, R A; Lucentini, M; Margaziotis, D J; Markowitz, P; Marrone, S; Meziani, Z E; McCormick, K; Michaels, R W; Millener, D J; Miyoshi, T; Moffit, B; Monaghan, P A; Moteabbed, M; Muñoz Camacho, C; Nanda, S; Nappi, E; Nelyubin, V V; Norum, B E; Okasyasu, Y; Paschke, K D; Perdrisat, C F; Piasetzky, E; Punjabi, V A; Qiang, Y; Raue, B; Reimer, P E; Reinhold, J; Reitz, B; Roche, R E; Rodriguez, V M; Saha, A; Santavenere, F; Sarty, A J; Segal, J; Shahinyan, A; Singh, J; Sirca, S; Snyder, R; Solvignon, P H; Sotona, M; Subedi, R; Sulkosky, V A; Suzuki, T; Ueno, H; Ulmer, P E; Veneroni, P; Voutier, E; Wojtsekhowski, B B; Zheng, X; Zorn, C

    2009-11-13

    An experimental study of the (16)O(e,e'K(+))(Lambda)(16)N reaction has been performed at Jefferson Lab. A thin film of falling water was used as a target. This permitted a simultaneous measurement of the p(e,e'K(+))Lambda, Sigma(0) exclusive reactions and a precise calibration of the energy scale. A ground-state binding energy of 13.76+/-0.16 MeV was obtained for (Lambda)(16)N with better precision than previous measurements on the mirror hypernucleus (Lambda)(16)O. Precise energies have been determined for peaks arising from a Lambda in s and p orbits coupled to the p(1/2) and p(3/2) hole states of the (15)N core nucleus. PMID:20365979

  6. Tertiary structure of human {Lambda}6 light chains.

    SciTech Connect

    Pokkuluri, P. R.; Solomon, A.; Weiss, D. T.; Stevens, F. J.; Schiffer, M.; Center for Mechanistic Biology and Biotechnology; Univ. of Tennessee Medical Center /Graduate School of Medicine

    1999-01-01

    AL amyloidosis is a disease process characterized by the pathologic deposition of monoclonal light chains in tissue. To date, only limited information has been obtained on the molecular features that render such light chains amyloidogenic. Although protein products of the major human V kappa and V lambda gene families have been identified in AL deposits, one particular subgroup--lambda 6--has been found to be preferentially associated with this disease. Notably, the variable region of lambda 6 proteins (V lambda 6) has distinctive primary structural features including the presence in the third framework region (FR3) of two additional amino acid residues that distinguish members of this subgroup from other types of light chains. However, the structural consequences of these alterations have not been elucidated. To determine if lambda 6 proteins possess unique tertiary structural features, as compared to light chains of other V lambda subgroups, we have obtained x-ray diffraction data on crystals prepared from two recombinant V lambda 6 molecules. These components, isolated from a bacterial expression system, were generated from lambda 6-related cDNAs cloned from bone marrow-derived plasma cells from a patient (Wil) who had documented AL amyloidosis and another (Jto) with multiple myeloma and tubular cast nephropathy, but no evident fibrillar deposits. The x-ray crystallographic analyses revealed that the two-residue insertion located between positions 68 and 69 (not between 66 and 67 as previously surmised) extended an existing loop region that effectively increased the surface area adjacent to the first complementarity determining region (CDR1). Further, an unusual interaction between the Arg 25 and Phe 2 residues commonly found in lambda 6 molecules was noted. However, the structures of V lambda 6 Wil and Jto also differed from each other, as evidenced by the presence in the latter of certain ionic and hydrophobic interactions that we posit increased protein

  7. Measurement of the production fraction times branching fraction $\\boldsymbol{ f(b\\to\\Lambda_{b})\\cdot \\mathcal{B}(\\Lambda_{b}\\to J/\\psi \\Lambda)}$

    SciTech Connect

    Abazov, Victor Mukhamedovich; Abbott, Braden Keim; Acharya, Bannanje Sripath; Adams, Mark Raymond; Adams, Todd; Alexeev, Guennadi D.; Alkhazov, Georgiy D.; Alton, Andrew K.; Alverson, George O.; Alves, Gilvan Augusto; Ancu, Lucian Stefan; /Nijmegen U. /Fermilab

    2011-05-01

    The {Lambda}{sub b}(udb) baryon is observed in the decay {Lambda}{sub b} {yields} J/{psi}{Lambda} using 6.1 fb{sup -1} of p{bar p} collisions collected with the D0 detector at {radical}s = 1.96 TeV. The production fraction multiplied by the branching fraction for this decay relative to that for the decay B{sup 0} {yields} J/{psi}K{sub s}{sup 0} is measured to be 0.345 {+-} 0.034 (stat.) {+-} 0.033 (syst.) {+-} 0.003 (PDG). Using the world average value of f(b {yields} B{sup 0}) {center_dot} {Beta}(B{sup 0} {yields} J/{psi}K{sub s}{sup 0}) = (1.74 {+-} 0.08) x 10{sup -5}, they obtain f(b {yields} {Lambda}{sub b}) {center_dot} {Beta}({Lambda}{sub b} {yields} J/{psi}{Lambda}) = (6.01 {+-} 0.60 (stat.) {+-} 0.58 (syst.) {+-} 0.28 (PDG)) x 10{sup -5}. This measurement represents an improvement in precision by about a factor of three with respect to the current world average.

  8. Doublet-spacing enhancement caused by {Lambda}N-{Sigma}N coupling in {sub {Lambda}L}i hypernuclear isotopes

    SciTech Connect

    Umeya, Atsushi; Harada, Toru

    2011-03-15

    We theoretically investigate energy spacings of doublets in {sub {Lambda}L}i hypernuclear isotopes with A=7-10 in shell-model calculations with a {Lambda}N-{Sigma}N coupling effect. The calculated results show that the energy shifts are {Delta}{epsilon}=0.09-0.28 MeV and the {Sigma}-mixing probabilities are P{sub {Sigma}}=0.10%-0.34% in {Lambda} ground states for the isotopes because of the {Lambda}N-{Sigma}N coupling in the first-order perturbation. It is found that the energy spacing of the doublet is enhanced as a neutron number N increases; the contribution of the {Lambda}N-{Sigma}N coupling interaction is comparable to that of the {Lambda}N interaction in the neutron-rich {Lambda} hypernuclei. The coherent mechanism of this doublet-spacing enhancement is also discussed in terms of Fermi-type and Gamow-Teller-type {Lambda}N-{Sigma}N couplings.

  9. Hepatopancreatic intoxication of lambda cyhalothrin insecticide on albino rats

    PubMed Central

    Elhalwagy, Manal EA; Abd-Alrahman, Sherif H; Nahas, AA; Ziada, Reem M; Mohamady, Aziza H

    2015-01-01

    Background: Despite the known adverse effects of lambda cyhalothrin insecticide, little is known about its hepatopancreatic intoxication effects. The present study was carried out to elucidate sub-chronic effect of Karat 2.5% EC formulation of lambda cyhalothrin on male albino rats. Methods: To explore the effects of exposure to lambda cyhalothrin on rats and its mechanism, low (1/40 of LD50, 5 mg/kg/day) and high dose (1/4 of LD50, 50 mg/kg/day) lambda cyhalothrin were applied to rats via drinking water for 3 months. Blood samples were collected monthly, and the animals were dissected for liver and pancreas’s examination at the end of the experiment. Lambda cyhalothrin administration was associated with the elevation in lipid peroxidation marker, malondialdehyde (MDA), reduction in SH-protein a major marker for antioxidant, as well as basel paraoxonase (PON) in both treated groups throughout the experimental periods. Results: In addition, significant elevations in liver enzymes alanin amino transferase, (ALT), and aspartate amino transferase (AST), as well as plasma acetylcholinesterase (AChE) and glucose level. While, significant reduction in insulin level through the experimental periods. Results of histopathological and histochemical studies showed that lambda cyhalothrin exposure induces liver and pancreatic tissues damage and depletion in glycogen content was pronounced in liver of both treated groups. Conclusions: In conclusion subchronic intoxication with lambda cyhalothrin formulation induced remarkable changes in the examined parameters. PMID:26221269

  10. Lambda Probe Measurements of Laboratory Spheromaks

    NASA Astrophysics Data System (ADS)

    Jorne, E.; Bellan, P. M.; Hsu, S. C.; Moynihan, C.

    2003-10-01

    A combined current and magnetic probe (lambda probe) has been constructed and is being tested for the purpose of investigating the behavior of spheromaks formed by the Caltech planar spheromak gun. The probe consists of a 1.5cm diameter, 52 turn Rogowski coil and a single loop magnetic coil, housed in a ceramic shell attached to a 95cm long hollow, steel shaft. A high voltage power supply was used to test the probe's ability to measure pulsed currents with submicrosecond rise times. A calibrated current pulse was provided by a 1μF capacitor discharged by a krytron switch to a low inductance circuit. Magnetic calibration was obtained by using the capacitor bank to power a 16cm diameter Helmholtz coil. Both magnetic and current calibration were in good agreement with estimates based on geometry. An existing steel shaft will be replaced by a ceramic shaft in order to minimize undesired effects on the plasma by a conductor. Once sealed with epoxy, the probe will be ready for insertion into the vacuum chamber and used to measure the magnetic field and parallel current during spheromak formation.

  11. Energy of the ground and 2{sup +} excited states of {sub {lambda}}{sub {lambda}}{sup 10}Be: A partial ten-body model

    SciTech Connect

    Shoeb, Mohammad; Sonika

    2009-08-15

    The energies of the ground and excited 2{sup +} states of {sub {lambda}}{sub {lambda}}{sup 10}Be have been calculated variationally in the Monte Carlo framework. The hypernucleus is treated as a partial ten-body problem in the {lambda}{lambda}+{alpha}{alpha} model where nucleonic degrees of freedom of {alpha}'s are taken into consideration ignoring the antisymmetrization between two {alpha}'s. The central two-body {lambda}N and {lambda}{lambda} and the three-body dispersive and two-pion exchange {lambda}NN forces, constrained by the {lambda}p scattering data and the observed ground state energies of {sub {lambda}}{sup 5}He and {sub {lambda}}{sub {lambda}}{sup 6}He, are employed. The product-type trial wave function predicts binding energy for the ground state considerably less than for the event reported by Danysz et al.; however, it is consistent with the value deduced assuming a {gamma} ray of 3.04 MeV must have escaped undetected in the decay of the product {sub {lambda}}{sup 9}Be* {yields} {sub {lambda}}{sup 9}Be+{gamma} of the emulsion event {sub {lambda}}{sub {lambda}}{sup 10}Be{yields} {pi}{sup -}+p+{sub {lambda}}{sup 9}Be* and for the excited 2{sup +} state closer to the value measured in the Demachi-Yanagi event. The hypernucleus {sub {lambda}}{sub {lambda}}{sup 10}Be has an oblate shape in the excited state. These results are consistent with the earlier four-body {alpha} cluster model approach where {alpha}'s are assumed to be structureless entities.

  12. Acoustics of the Lambda Transition in Superfluid Helium

    NASA Astrophysics Data System (ADS)

    Megson, Peter; Meichle, David; Lathrop, Daniel

    2014-11-01

    Liquid Helium undergoes a phase transition and becomes a quantum superfluid when cooled below the Lambda transition temperature of 2.17 Kelvin. The superfluid, which is a partial Bose Einstein Condensate, exhibits unique macroscopic properties such as flow without viscosity and ballistic temperature propagation. We have recorded striking audio-frequency sounds using a micro electromechanical microphone (MEMS) present as the Helium goes through the Lambda transition. Characterization of this sound, as well as its relevance to theories of the Lambda transition will be presented.

  13. High resolution spectroscopy of (lambda)(12)B by electroproduction.

    PubMed

    Iodice, M; Cusanno, F; Acha, A; Ambrozewicz, P; Aniol, K A; Baturin, P; Bertin, P Y; Benaoum, H; Blomqvist, K I; Boeglin, W U; Breuer, H; Brindza, P; Bydzovský, P; Camsonne, A; Chang, C C; Chen, J-P; Choi, Seonho; Chudakov, E A; Cisbani, E; Colilli, S; Coman, L; Craver, B J; De Cataldo, G; de Jager, C W; De Leo, R; Deur, A P; Ferdi, C; Feuerbach, R J; Folts, E; Fratoni, R; Frullani, S; Garibaldi, F; Gayou, O; Giulani, F; Gomez, J; Gricia, M; Hansen, J O; Hayes, D; Higinbotham, D W; Holmstrom, T K; Hyde, C E; Ibrahim, H F; Jiang, X; Kaufman, L J; Kino, K; Kross, B; Lagamba, L; LeRose, J J; Lindgren, R A; Lucentini, M; Margaziotis, D J; Markowitz, P; Marrone, S; Meziani, Z E; McCormick, K; Michaels, R W; Millener, D J; Miyoshi, T; Moffit, B; Monaghan, P A; Moteabbed, M; Muñoz Camacho, C; Nanda, S; Nappi, E; Nelyubin, V V; Norum, B E; Okasyasu, Y; Paschke, K D; Perdrisat, C F; Piasetzky, E; Punjabi, V A; Qiang, Y; Raue, B; Reimer, P E; Reinhold, J; Reitz, B; Roche, R E; Rodriguez, V M; Saha, A; Santavenere, F; Sarty, A J; Segal, J; Shahinyan, A; Singh, J; Sirca, S; Snyder, R; Solvignon, P H; Sotona, M; Subedi, R; Sulkosky, V A; Suzuki, T; Ueno, H; Ulmer, P E; Urciuoli, G M; Veneroni, P; Voutier, E; Wojtsekhowski, B B; Ye, Y; Zheng, X; Zhou, S; Zorn, C

    2007-08-01

    An experiment measuring electroproduction of hypernuclei has been performed in hall A at Jefferson Lab on a 12C target. In order to increase counting rates and provide unambiguous kaon identification two superconducting septum magnets and a ring imaging Cherenkov detector were added to the hall A standard equipment. An unprecedented energy resolution of less than 700 keV FWHM has been achieved. Thus, the observed (Lambda)(12)B spectrum shows for the first time identifiable strength in the core-excited region between the ground-state s-wave Lambda peak and the 11 MeV p-wave Lambda peak. PMID:17930747

  14. Hierarchy of N-point functions in the {Lambda}CDM and ReBEL cosmologies

    SciTech Connect

    Hellwing, Wojciech A.; Juszkiewicz, Roman; Weygaert, Rien van de

    2010-11-15

    In this work we investigate higher-order statistics for the {Lambda}CDM and ReBEL scalar-interacting dark matter models by analyzing 180h{sup -1} Mpc dark matter N-body simulation ensembles. The N-point correlation functions and the related hierarchical amplitudes, such as skewness and kurtosis, are computed using the counts-in-cells method. Our studies demonstrate that the hierarchical amplitudes S{sub n} of the scalar-interacting dark matter model significantly deviate from the values in the {Lambda}CDM cosmology on scales comparable and smaller than the screening length r{sub s} of a given scalar-interacting model. The corresponding additional forces that enhance the total attractive force exerted on dark matter particles at galaxy scales lower the values of the hierarchical amplitudes S{sub n}. We conclude that hypothetical additional exotic interactions in the dark matter sector should leave detectable markers in the higher-order correlation statistics of the density field. We focused in detail on the redshift evolution of the dark matter field's skewness and kurtosis. From this investigation we find that the deviations from the canonical {Lambda}CDM model introduced by the presence of the 'fifth' force attain a maximum value at redshifts 0.5

  15. Observation of the Baryonic B decay B0bar to Lambda_c^+ anti-Lambda K-

    SciTech Connect

    Lees, J.P.; Poireau, V.; Tisserand, V.; Garra Tico, J.; Grauges, E.; Martinelli, M.; Milanes, D.A.; Palano, A.; Pappagallo, M.; Eigen, G.; Stugu, B.; Sun, L.; Brown, D.N.; Kerth, L.T.; Kolomensky, Yu.G.; Lynch, G.; Koch, H.; Schroeder, T.; Asgeirsson, D.J.; Hearty, C.; Mattison, T.S.; /British Columbia U. /Brunel U. /Novosibirsk, IYF /UC, Irvine /UC, Riverside /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 /INFN, Ferrara /INFN, Ferrara /Ferrara U. /INFN, Ferrara /Ferrara U. /INFN, Ferrara /Ferrara U. /INFN, Ferrara /Ferrara U. /INFN, Ferrara /Ferrara U. /INFN, Ferrara /Ferrara U. /INFN, Ferrara /Ferrara U. /INFN, Ferrara /Frascati /INFN, Genoa /Genoa U. /INFN, Genoa /Genoa U. /INFN, Genoa /Genoa U. /INFN, Genoa /Genoa U. /INFN, Genoa /INFN, Genoa /Genoa U. /INFN, Genoa /Indian Inst. Tech., Guwahati /Harvard U. /Harvey Mudd Coll. /Heidelberg U. /Humboldt U., Berlin /Imperial Coll., London /Iowa State 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., Comp. Sci. Dept. /Maryland U. /Massachusetts U., Amherst /MIT /McGill U. /INFN, Milan /Milan U. /INFN, Milan /Milan U. /INFN, Milan /INFN, Milan /Milan U. /INFN, Milan /Milan U. /INFN, Milan /Milan U. /Mississippi U. /Montreal U. /INFN, Naples /Naples U. /INFN, Naples /Naples U. /INFN, Naples /Naples U. /INFN, Naples /Naples U. /NIKHEF, Amsterdam /Notre Dame U. /Ohio State U. /Oregon U. /INFN, Padua /Padua U. /INFN, Padua /Padua U. /INFN, Padua /Padua U. /INFN, Padua /INFN, Padua /INFN, Padua /INFN, Padua /Padua U. /INFN, Padua /Padua U. /Paris U., VI-VII /INFN, Perugia /Perugia U. /INFN, Perugia /Perugia U. /INFN, Perugia /Perugia U. /INFN, Perugia /Perugia U. /INFN, Pisa /Pisa U. /INFN, Pisa /Pisa U. /INFN, Pisa /Pisa U. /INFN, Pisa /Pisa U. /Sassari U. /INFN, Pisa /Pisa U. /INFN, Pisa /Pisa U. /INFN, Pisa /Pisa U. /INFN, Pisa /Pisa U. /INFN, Pisa /Pisa, Scuola Normale Superiore /INFN, Pisa /Pisa U. /INFN, Pisa /Pisa U. /INFN, Pisa /INFN, Pisa /Pisa U. /INFN, Pisa /Princeton U. /INFN, Rome /INFN, Rome /INFN, Rome /Rome U. /INFN, Rome /INFN, Rome /Rome U. /INFN, Rome /Rome U. /INFN, Rome /INFN, Rome /INFN, Rome /Rostock U. /Rutherford /DAPNIA, Saclay /SLAC /South Carolina U. /Southern Methodist U. /Stanford U., Phys. Dept. /SUNY, Albany /Tel Aviv U. /Tennessee U. /Texas U. /Texas U., Dallas /INFN, Turin /Turin U. /INFN, Turin /Turin U. /INFN, Trieste /Trieste U. /INFN, Trieste /Trieste U. /Valencia U., IFIC /Victoria U. /Warwick U. /Wisconsin U., Madison

    2011-11-08

    The authors report the observation of the baryonic B decay {bar B}{sup 0} {yields} {Lambda}{sub c}{sup +} {bar {Lambda}}K{sup -} with a significance larger than 7 standard deviations based on 471 x 10{sup 6} B{bar B} pairs collected with the BABAR detector at the PEP-II storage ring at SLAC. They measure the branching fraction for the decay {bar B}{sup 0} {yields} {Lambda}{sub c}{sup +} {bar {Lambda}}K{sup -} to be (3.8 {+-} 0.8{sub stat} {+-} 0.2{sub sys} {+-} 1.0 {sub {Lambda}{sub c}{sup +}}) x 10{sup -5}. The uncertainties are statistical, systematic, and due to the uncertainty in the {Lambda}{sub c}{sup +} branching fraction. They find that the {Lambda}{sub c}{sup +} K{sup -} invariant mass distribution shows an enhancement above 3.5 GeV/c{sup 2}.

  16. The chemical composition of the Lambda Bootis stars

    NASA Technical Reports Server (NTRS)

    Baschek, B.; Slettebak, A.

    1988-01-01

    Measurements of the equivalent widths of 24 ultraviolet lines from IUE spectra of 10 Lambda Bootis or suspected Lambda Bootis stars and 19 normal standard stars of spectral types B8-A7 have been compared with line strengths determined using model atmospheres. Abundance differences are estimated via a differential analysis technique. It is found that the ratio of C, N, and O to the heavier elements Mg to Ni is significantly larger than that for solar composition stars.

  17. A high statistics measurement of the Lambda(+)(c) lifetime.

    PubMed

    Link, J M; Reyes, M; Yager, P M; Anjos, J C; Bediaga, I; Göbel, C; Magnin, J; Massafferi, A; de Miranda, J M; Pepe, I M; dos Reis, A C; Carrillo, S; Casimiro, E; Cuautle, E; Sánchez-Hernández, A; Uribe, C; Vazquez, F; Agostino, L; Cinquini, L; Cumalat, J P; O'Reilly, B; Ramirez, J E; Segoni, I; Butler, J N; Cheung, H W K; Gaines, I; Garbincius, P H; Garren, L A; Gottschalk, E; Kasper, P H; Kreymer, A E; Kutschke, R; Bianco, S; Fabbri, F L; Zallo, A; Cawlfield, C; Kim, D Y; Rahimi, A; Wiss, J; Gardner, R; Kryemadhi, A; Chung, Y S; Kang, J S; Ko, B R; Kwak, J W; Lee, K B; Park, H; Alimonti, G; Boschini, M; D'Angelo, P; DiCorato, M; Dini, P; Giammarchi, M; Inzani, P; Leveraro, F; Malvezzi, S; Menasce, D; Mezzadri, M; Milazzo, L; Moroni, L; Pedrini, D; Pontoglio, C; Prelz, F; Rovere, M; Sala, S; Davenport, T F; Arena, V; Boca, G; Bonomi, G; Gianini, G; Liguori, G; Merlo, M M; Pantea, D; Ratti, S P; Riccardi, C; Vitulo, P; Hernandez, H; Lopez, A M; Luiggi, E; Mendez, H; Mendez, L; Mirles, A; Montiel, E; Olaya, D; Paris, A; Quinones, J; Rivera, C; Xiong, W; Zhang, Y; Wilson, J R; Cho, K; Handler, T; Mitchell, R; Engh, D; Hosack, M; Johns, W E; Nehring, M; Sheldon, P D; Stenson, K; Vaandering, E W; Webster, M; Sheaff, M

    2002-04-22

    A high statistics measurement of the Lambda(+)(c) lifetime from the Fermilab fixed-target FOCUS photoproduction experiment is presented. We describe the analysis technique with particular attention to the determination of the systematic uncertainty. The measured value of 204.6 +/- 3.4 (stat) +/- 2.5 (syst) fs from 8034 +/- 122 Lambda(+)(c)-->pK(-)pi(+) decays represents a significant improvement over the present world average. PMID:11955226

  18. Absorption of {Lambda}(1520) hyperons in photon-nucleus collisions

    SciTech Connect

    Paryev, E. Ya.

    2012-12-15

    In the framework of the nuclear spectral function approach for incoherent primary photon-nucleon and secondary pion-nucleon production processes we study the inclusive {Lambda}(1520)-hyperon production in the interaction of 2-GeV photons with nuclei. In particular, the A and momentum dependences of the absolute and relative {Lambda}(1520)-hyperon yields are investigated in two scenarios for its in-medium width. Our model calculations show that the pion-nucleon production channel contributes appreciably to the {Lambda}(1520) creation at intermediate momenta both in light and heavy nuclei in the chosen kinematics and, hence, has to be taken into consideration on close examination of the dependences of the {Lambda}(1520)-hyperon yields on the target mass number with the aim to get information on its width in the medium. They also demonstrate that the A and momentum dependences of the absolute and relative {Lambda}(1520)-hyperon production cross sections at incident energy of interest are markedly sensitive to the {Lambda}(1520) in-medium width, which means that these observables may be an important tool to determine the above width.

  19. {lambda}-Polarization Measurement in {pi}-p{yields}K0{lambda} in the Framework of 'EPECUR' Experiment Proposal

    SciTech Connect

    Alekseev, I. G.; Budkovsky, P. E.; Kanavets, V. P.; Kats, M. M.; Koroleva, L. I.; Kulikov, V. V.; Morozov, B. V.; Nesterov, V. M.; Ryltsov, V. V.; Sakharov, V. A.; Sulimov, A. D.; Svirida, D. N.; Filimonov, E. A.; Golubev, V. V.; Kovalev, A. I.; Kozlenko, N. G.; Kozlov, V. S.; Krivshich, A. G.; Novinsky, D. V.; Sumachev, V. V.

    2007-06-13

    The idea of 'EPECUR' was inspired by the recent splash of the activity around the pentaquark matters. The goal of the experiment is the search for narrow resonant states in the reactions {pi}-p {yields} {pi}-p and {pi}-p {yields} K0{lambda} based on the very precise cross section measurements in fine energy steps of 0.5 MeV in terms of the invariant mass. As a valuable byproduct of the second stage of the experiment, {lambda}-polarization in {pi}-p {yields} K0{lambda} can be measured, based on the well-known weak {lambda}-decay asymmetry. The expected statistical significance of the measurement overrides the best existing data from 'NIMROD' detector by an order of magnitude. The experimental setup is under construction at the ITEP proton synchrotron in collaboration with PNPI and ACU.

  20. Proton energy spectra in the nonmesonic weak decay of 12lambdaC and 28lambdaSi hypernuclei.

    PubMed

    Hashimoto, O; Ajimura, S; Aoki, K; Bhang, H; Hasegawa, T; Hotchi, H; Kim, Y D; Kishimoto, T; Maeda, K; Noumi, H; Ohta, Y; Omata, K; Outa, H; Park, H; Sato, Y; Sekimoto, M; Shibata, T; Takahashi, T; Youn, M

    2002-01-28

    Numbers of protons per Gamma hypernuclear weak decay were measured as a function of proton energy above 40 MeV, explicitly identifying production of Gamma hypernuclei by the (pi+,K+) reaction. The ratios between the neutron-stimulated to proton-stimulated nonmesonic decay widths, Gamma((Lambda)n-->nn)/Gamma((Lambda)p-->np) ( = Gamma(n)/Gamma(p)) were extracted by fitting the proton energy spectra. The present result claims that the proton yields are suppressed and the Gamma(n)/Gamma(p) ratios are close to 1 both for 12LambdaC and 28LambdaSi in contradiction to theoretical expectations based on meson exchange models. PMID:11801115

  1. Improved Measurement of the Form Factors in the Decay {lambda}{sub c}{sup +}{yields}{lambda}e{sup +}{nu}{sub e}

    SciTech Connect

    Hinson, J.W.; Huang, G.S.; Lee, J.; Miller, D.H.; Pavlunin, V.; Rangarajan, R.; Sanghi, B.; Shibata, E.I.; Shipsey, I.P.J.; Cronin-Hennessy, D.; Park, C.S.; Park, W.; Thayer, J.B.; Thorndike, E.H.; Coan, T.E.; Gao, Y.S.; Liu, F.; Stroynowski, R.; Artuso, M.; Boulahouache, C.

    2005-05-20

    Using the CLEO detector at the Cornell Electron Storage Ring, we have studied the distribution of kinematic variables in the decay {lambda}{sub c}{sup +}{yields}{lambda}e{sup +}{nu}{sub e}. By performing a four-dimensional maximum likelihood fit, we determine the form factor ratio, R=f{sub 2}/f{sub 1}=-0.31{+-}0.05(stat){+-}0.04(syst), the pole mass, M{sub pole}=[2.21{+-}0.08(stat){+-}0.14(syst)] GeV/c{sup 2}, and the decay asymmetry parameter of the {lambda}{sub c}{sup +}, {alpha}{sub {lambda}}{sub {sub c}}=-0.86{+-}0.03(stat){+-}0.02(syst), for =0.67 (GeV/c{sup 2}){sup 2}. We compare the angular distributions of the {lambda}{sub c}{sup +} and {lambda}{sub c}{sup -} and find no evidence for CP violation: A{sub {lambda}}{sub {sub c}}=(({alpha}{sub {lambda}}{sub {sub c}}+{alpha}{sub {lambda}}{sub {sub c}})/({alpha}{sub {lambda}}{sub {sub c}}-= {alpha}{sub {lambda}}{sub {sub c}}))=0.00{+-}0.03(stat){+-}0.01(syst){+-}0.02, where the third error is from the uncertainty in the world average of the CP-violating parameter, A{sub {lambda}}, for {lambda}{yields}p{pi}{sup -}.

  2. The First Generation of Stars in Lambda-CDM Cosmology

    SciTech Connect

    Gao, Liang; Abel, T.; Frenk, C.S.; Jenkins, A.; Springel, V.; Yoshida, N.; /Nagoya U.

    2006-10-10

    We have performed a large set of high-resolution cosmological simulations using smoothed particle hydrodynamics (SPH) to study the formation of the first luminous objects in the {Lambda}CDM cosmology. We follow the collapse of primordial gas clouds in eight early structures and document the scatter in the properties of the first star-forming clouds. Our first objects span formation redshifts from z {approx} 10 to z {approx} 50 and cover an order of magnitude in halo mass. We find that the physical properties of the central star-forming clouds are very similar in all of the simulated objects despite significant differences in formation redshift and environment. This suggests that the formation path of the first stars is largely independent of the collapse redshift; the physical properties of the clouds have little correlation with spin, mass, or assembly history of the host halo. The collapse of proto-stellar objects at higher redshifts progresses much more rapidly due to the higher densities, which accelerates the formation of molecular hydrogen, enhances initial cooling and shortens the dynamical timescales. The mass of the star-forming clouds cover a broad range, from a few hundred to a few thousand solar masses, and exhibit various morphologies: some have disk-like structures which are nearly rotational supported; others form flattened spheroids; still others form bars. All of them develop a single protostellar ''seed'' which does not fragment into multiple objects up to the moment that the central gas becomes optically thick to H{sub 2} cooling lines. At this time, the instantaneous mass accretion rate onto the centre varies significantly from object to object, with disk-like structures having the smallest mass accretion rates. The formation epoch and properties of the star-forming clouds are sensitive to the values of cosmological parameters.

  3. Non-LTE radiative transfer with lambda-acceleration - Convergence properties using exact full and diagonal lambda-operators

    NASA Technical Reports Server (NTRS)

    Macfarlane, J. J.

    1992-01-01

    We investigate the convergence properties of Lambda-acceleration methods for non-LTE radiative transfer problems in planar and spherical geometry. Matrix elements of the 'exact' A-operator are used to accelerate convergence to a solution in which both the radiative transfer and atomic rate equations are simultaneously satisfied. Convergence properties of two-level and multilevel atomic systems are investigated for methods using: (1) the complete Lambda-operator, and (2) the diagonal of the Lambda-operator. We find that the convergence properties for the method utilizing the complete Lambda-operator are significantly better than those of the diagonal Lambda-operator method, often reducing the number of iterations needed for convergence by a factor of between two and seven. However, the overall computational time required for large scale calculations - that is, those with many atomic levels and spatial zones - is typically a factor of a few larger for the complete Lambda-operator method, suggesting that the approach should be best applied to problems in which convergence is especially difficult.

  4. Measurement of the asymmetry parameter for the decay {Lambda}{yields}p{pi}{sup +}

    SciTech Connect

    Ablikim, M.; Bai, J. Z.; Bai, Y.; Cai, X.; Chen, H. S.; Chen, H. X.; Chen, J. C.; Chen, Jin; Chen, Y. B.; Chu, Y. P.; Deng, Z. Y.; Du, S. X.; Fang, J.; Fu, C. D.; Gao, C. S.; Gu, S. D.; Guo, Y. N.; He, K. L.; Heng, Y. K.; Hu, H. M.

    2010-01-01

    Based on a sample of 58x10{sup 6}J/{psi} decays collected with the BESII detector at the BEPC, the {Lambda} decay parameter {alpha}{sub {Lambda}}for {Lambda}{yields}p{pi}{sup +} is measured using about 9000 J/{psi}{yields}{Lambda}{Lambda}{yields}pp{pi}{sup +{pi}-} decays. A fit to the joint angular distributions yields {alpha}{sub {Lambda}({Lambda}{yields}p{pi}{sup +})}=-0.755{+-}0.083{+-}0.063, where the first error is statistical, and the second systematic.

  5. The multiplicity and the spectra of secondaries correlated with the leading particle energy

    NASA Technical Reports Server (NTRS)

    Kruglov, N. A.; Proskuryakov, A. S.; Sarycheva, L. I.; Smirnova, L. N.

    1985-01-01

    The spectra of leading particles of different nature in pp-collisions at E sub 0 = 33 GeV are obtained. The multiplicities and the spectra of secondaries, mesons, gamma-quanta, lambda and lambda-hyperons and protons for different leading particle energy ranges are determined.

  6. Ultraviolet Synthetic Spectra for Three Lambda Bootis Stars

    NASA Astrophysics Data System (ADS)

    Cheng, Kwang-Ping; Neff, James E.; Gray, Richard O.; Corbally, Christopher J.; Johnson, Dustin; Tarbell, Erik

    2015-01-01

    Lambda Boo-type stars are a group of late B to early F-type Population I dwarfs that show mild to extreme deficiencies of iron-peak elements (up to 2 dex), but their C, N, O, and S abundances are near solar. We show that the International Ultraviolet Explorer (IUE) spectra (1280-3200 A) of Lambda Bootis, 29 Cygni (a "confirmed" Lambda Boo star), and Vega (a "mild" Lambda Boo star) can be fit remarkably well by single-temperature synthetic spectra. We computed the full resolution synthetic ultraviolet (UV) spectrum covering the IUE wavelength range using Gray's Stellar Spectral Synthesis Program SPECTRUM. To improve the synthetic spectra, we generated a grid of LTE atmosphere models with the appropriate stellar parameters using ATLAS9 and the existing Castelli and Kurucz 2004 models. One of the improvements of their opacity distribution functions (ODFs) is the addition to the line blanketing near 1400 A and 1600 A by the quasi-molecular absorptions of atomic hydrogen undergoing collisions with protons and other neutral hydrogen atoms. New-ODF fluxes reproduce the ultraviolet observations of Lambda Boo stars in a more realistic way than previous computations. We also constructed our own UV line list for the relevant set of absorption features. Modeling the UV line spectra of Lambda Boo stars allows us to confirm their published surface abundances, including CNO and the iron group elements. It also provides further insight into their photospheric conditions (e.g., Teff, log g, [M/H], micro turbulent velocity, etc.). About 40 percent of the published Lambda Boo candidates have existing IUE spectra. We plan to follow this pilot study and perform UV spectral synthesis for all of them.

  7. Measurement of the branching fraction ${\\mathcal{B}}(\\Lambda^0_b\\rightarrow \\Lambda^+_c\\pi^-\\pi^+\\pi^-)$ at CDF

    SciTech Connect

    Aaltonen, T.; Alvarez Gonzalez, B.; Amerio, S.; Amidei, D.; Anastassov, A.; Annovi, A.; Antos, J.; Apollinari, G.; Appel, J.A.; Arisawa, T.; Artikov, A.; /Dubna, JINR /Texas A-M

    2011-12-01

    We report an analysis of the {Lambda}{sub b}{sup 0} {yields} {Lambda}{sub c}{sup +}{pi}{sup -}{pi}{sup +}{pi}{sup -} decay in a data sample collected by the CDF II detector at the Fermilab Tevatron corresponding to 2.4 fb{sup -1} of integrated luminosity. We reconstruct the currently largest samples of the decay modes {Lambda}{sub b}{sup 0} {yields} {Lambda}{sub c}(2595){sup +}{pi}{sup -} (with {Lambda}{sub c}(2595){sup +} {yields} {Lambda}{sub c}{sup +}{pi}{sup +}{pi}{sup -}), {Lambda}{sub b}{sup 0} {yields} {Lambda}{sub c}(2625){sup +}{pi}{sup -} (with {Lambda}{sub c}(2625){sup +} {yields} {Lambda}{sub c}{sup +}{pi}{sup +}{pi}{sup -}), {Lambda}{sub b}{sup 0} {yields} {Sigma}{sub c}(2455){sup ++}{pi}{sup -}{pi}{sup -} (with {Sigma}{sub c}(2455){sup ++} {yields} {Lambda}{sub c}{sup +}{pi}{sup +}), and {Lambda}{sub b}{sup 0} {yields} {Sigma}{sub c}(2455)0{pi}{sup +}{pi}{sup -} (with {Sigma}{sub c}(2455)0 {yields} {Lambda}{sub c}{sup +}{pi}{sup -}) and measure the branching fractions relative to the {Lambda}{sub b}{sup 0} {yields} {Lambda}{sub c}{sup +}{pi}{sup -} branching fraction. We measure the ratio {Beta}({Lambda}{sub b}{sup 0} {yields} {Lambda}{sub c}{sup +}{pi}{sup -}{pi}{sup +}{pi}{sup -})/ {Beta}({Lambda}{sub b}{sup 0} {yields} {Lambda}{sub c}{sup +}{pi}{sup -})=3.04 {+-} 0.33(stat){sub -0.55}{sup +0.70}(syst) which is used to derive {Beta}({Lambda}{sub b}{sup 0} {yields} {Lambda}{sub c}{sup +}{pi}{sup -}{pi}{sup +}{pi}{sup -})=(26.8{sub -11.2}{sup +11.9}) x 10{sup -3}.

  8. Integrative genomic analyses on interferon-lambdas and their roles in cancer prediction.

    PubMed

    Yang, Liming; Wei, Jifu; He, Shaoheng

    2010-02-01

    Interferon (IFN)-lambdas, including IFN-lambda1, IFN-lambda2, and IFN-lambda3, are a newly described group of cytokines distantly related to the type I IFNs and IL-10 family members. Besides the antiviral activity, IFN-lambdas were reported to inhibit various tumor growths in vitro and in vivo. Herein, we identified IFN-lambda genes from the genome sequences of the human, chimpanzee, macaque, orangutan, mouse, rat and dog, and found that the locations and copy of a specific IFN-lambda varied in different genomes, not just the copy of IFN-lambdas. We found human IFN-lambdas were expressed in fetal retina, fetal brain and T cells by ESTs search. Moreover, IFN-lambdas were also found to express in bladder cancer, blood cancer, breast cancer, glioma, head and neck cancer and lung cancer tissues. Three tumor-related transcriptional factors (steroidogenic factor-1, Wilms tumor 1 and P53) binding sites were identified within the 1.0-kb regions upstream of the transcriptional start site of human IFN-lambdas. Meta-analysis of the prognostic value of IFN-lambda genes in various cancers showed that the expression of IFN-lambdas are indeed related to the cancer prognosis in certain types of cancer. It can be predicted that IFN-lambdas take part in the cancer development by the regulation of expression of IFN-lambdas related to the SF-1, P53 and WT-1. PMID:20043142

  9. First observation and measurement of the resonant structure of the lambda_b->lambda_c pi-pi+pi- decay mode

    SciTech Connect

    Azzurri, P.; Barria, P.; Ciocci, M.A.; Donati, S.; Vataga, E.

    2009-12-01

    The authors present the first observation of the {Lambda}{sub b}{sup 0} {yields} {Lambda}{sub c}{sup +}{pi}{sup -}{pi}{sup +}{pi}{sup -} decay using data from an integrated luminosity of approximately 2.4 fb{sup -1} of p{bar p} collisions at {radical}s = 1.96 TeV, collected with the CDF II detector at the Fermilab Tevatron. They also present the first observation of the resonant decays {Lambda}{sub b}{sup 0} {yields} {Sigma}{sub c}(2455){sup 0} {pi}{sup +}{pi}{sup -} {yields} {Lambda}{sub c}{sup +}{pi}{sup -}{pi}{sup +}{pi}{sup -}, {Lambda}{sub b}{sup 0} {yields} {Sigma}{sub c}(2455){sup ++}{pi}{sup -}{pi}{sup -} {yields} {Lambda}{sub c}{sup +}{pi}{sup -}{pi}{sup +}{pi}{sup -}, {Lambda}{sub b}{sup 0} {yields} {Lambda}{sub c}(2595){sup +}{pi}{sup -} {yields} {Lambda}{sub c}{sup +}{pi}{sup -}{pi}{sup +}{pi}{sup -} and {Lambda}{sub b}{sup 0} {yields} {Lambda}{sub c}(2625){sup +}{pi}{sup -} {yields} {Lambda}{sub c}{sup +}{pi}{sup -}{pi}{sup +}{pi}{sup -}, and measure their relative branching ratios.

  10. A Measurement of the Recoil Polarization of Electroproduced {Lambda}(1116)

    SciTech Connect

    Simeon McAleer

    2002-01-01

    The CEBAF Large Acceptance Spectrometer at the Thomas Jefferson National Laboratory was used to study the reaction e + p {yields} e{prime} + K{sup +} + {Lambda}(1116) for events where {Lambda}(1116) subsequently decayed via the channel {Lambda}(1116) {yields} p + {pi}{sup -}. Data were taken at incident electron beam energies of 2.5, 4.0, and 4.2 GeV during the 1999 E1C run period. They hyperon production spectra span the Q{sup 2} range from 0.5 to 2.8 GeV{sup 2} and nearly the entire range in the center of mass angles. The proton angular distribution in the {Lambda}(1116) rest frame is used to deduce the recoil polarization of the hyperon, and the W and cos {theta}{sub cm}{sup K+} dependence of the recoil polarization will be presented. The data show sizeable negative polarizations for the {Lambda}(1116) as a function of both cos {theta}{sub cm}{sup K+} and W.

  11. Inclusive Rates and Spectra of the Lambda, Cascade, and Omega Hyperons atBaBar

    SciTech Connect

    Chien, Andrew L.; /SLAC /UCLA

    2008-05-19

    We employ Runs 1-4 off-peak data sample (about 21.5 fb{sup -1}) to produce the current world-best spectra and production rates measurements for three strangely-flavored baryons: the {Lambda} hyperon, the cascade hyperon, and the {Omega} hyperon. These improved measurements shall enable theoretical and phenomelogical workers to generate more realistic models for the hadronization process, currently one of the unresolved problem areas in the standard model of particle physics. This analysis was conducted using codes from release 16 series. We report the production rate at 10.54 GeV for the {Lambda} as 0.0900 {+-} 0.0006(stat.) {+-} 0.0039(sys.) per hadronic event. Our measured production rate at the same energy for the cascade hyperon is 0.00562 {+-} 0.00013(stat.) {+-} 0.00045(sys.) per hadronic event, while that for the {Omega} hyperon is 0.00027 {+-} 0.00004(stat.) {+-} 0.0008(sys.) per hadronic event. The spectral measurements for the respective particles also constitute current world-best measurements.

  12. Short range correlations in the weak decay of {Lambda} hypernuclei

    SciTech Connect

    Parreno, A.; Ramos, A.; Oset, E.

    1995-05-01

    The differences found in the relativistic and nonrelativistic methods used in the literature to account for short range nuclear correlations in the decay of {Lambda} hypernuclei are analyzed. By means of a schematic microscopic model for the origin of correlations, the appropriate method to include them in nuclear processes is derived and is found to be the same one used in the nonrelativistic approach. The differences do not stem from relativistic effects but from the improper implementation of the correlations in the relativistic approach, which leads to several pathologies as shown in the paper. General formulas are given to evaluate the nonmesonic decay width of finite hypernuclei and results are obtained for {sub {Lambda}}{sup 5}He and {sub {Lambda}}{sup 12}C.

  13. Determination of the Lambda parameter from full lattice QCD

    SciTech Connect

    Goeckeler, M.; Horsley, R.; Irving, A.C.; Rakow, P.E.L.; Pleiter, D.; Schierholz, G.; Stueben, H.

    2006-01-01

    We present a determination of the QCD parameter {lambda} in the quenched approximation (n{sub f}=0) and for two flavors (n{sub f}=2) of light dynamical quarks. The calculations are performed on the lattice using O(a) improved Wilson fermions and include taking the continuum limit. We find {lambda}{sub n{sub f}=0}{sup MS}=259(1)(19) MeV and {lambda}{sub n{sub f}=2}{sup MS}=261(17)(26) MeV, using r{sub 0}=0.467 fm to set the scale. Extrapolating our results to five flavors, we obtain for the running coupling constant at the mass of the Z boson {alpha}{sub s}{sup MS}(m{sub Z})=0.112(1)(2)

  14. Prediction of narrow N* and {Lambda}* with hidden charm

    SciTech Connect

    Wu Jiajun; Molina, R.; Oset, E.; Zou, B. S.

    2011-10-24

    The interaction between various charmed mesons and charmed baryons, such as D-bar{Sigma}{sub c}-D-bar{Lambda}{sub c}, D-bar*{Sigma}{sub c}-D-bar*{Lambda}{sub c}, and related strangeness channels, are studied within the framework of the coupled channel unitary approach with the local hidden gauge formalism. Six narrow N* and {Lambda}* resonances are dynamically generated with mass above 4 GeV and width smaller than 100 MeV. These predicted new resonances definitely cannot be accommodated by quark models with three constituent quarks. We make estimates of production cross sections of these predicted resonances in p-barp collisions for PANDA at the forthcoming FAIR facility.

  15. Persistence behaviour of thiamethoxam and lambda cyhalothrin in transplanted paddy.

    PubMed

    Barik, Suhrid Ranjan; Ganguly, Pritam; Kunda, Samir Kumar; Kole, Ramen Kumar; Bhattacharyya, Anjan

    2010-10-01

    A field study was conducted in Pre-Kharif season 2007 on paddy to determine the persistence of thiamethoxam (12.6%) and lambda cyhalothrin (9.4%) [in a 'Readymix' formulation Alika 247 ZC], following the application of 33 g. a.i. ha⁻¹ (T₁) and 66 g. a.i. ha⁻¹ (T₂). Spraying of insecticide was done during milking stage of the crop (63 days after transplantation). Thiamethoxam and lambda cyhalothrin residues were estimated by HPLC and GLC respectively. The half-life values were 5.2-5.8 and 4.8 days for thiamethoxam and lambda cyhalothrin respectively. No residue was detected in the harvested paddy, straw, grain, and soil samples. PMID:20703448

  16. LOCAL MEASUREMENT OF {Lambda} USING PULSAR TIMING ARRAYS

    SciTech Connect

    Espriu, Domenec; Puigdomenech, Daniel

    2013-02-20

    We consider the propagation of gravitational waves (GWs) in de Sitter spacetime and how a non-zero value of the cosmological constant might affect their detection in pulsar timing arrays (PTAs). If {Lambda} {ne} 0, the waves are anharmonic in Friedmann-Robertson-Walker coordinates, and although this effect is very small it gives rise to noticeable consequences for GWs originating in extragalactic sources such as spiraling black hole binaries. The results indicate that the timing residuals induced by GWs from such sources in PTAs will show a peculiar angular dependence with a marked enhancement around a particular value of the angle subtended by the source and the pulsars, depending mainly on the actual value of the cosmological constant and the distance to the source. The position of the peak could represent a gauge of the value of {Lambda}. The enhancement that the new effect brings about could facilitate the first direct detection of GWs while representing a local measurement of {Lambda}.

  17. Spectroscopic Research of Lambda Hypdernuclei at JLab Hall C

    SciTech Connect

    Gogami, Toshiyuki; et. al.,

    2014-03-01

    A Lambda hyperon which has a strangeness can be bound in deep inside of a nucleus since a Λ does not suffer from the Pauli exclusion principle from nucleons. Thus, a Λ could be a useful tool to investigate inside of a nucleus. Since 2000, Lambda hypernuclear spectroscopic experiments by the (e,e'k) reaction have been performed at the experimental hall C in Thomas Jefferson National Accelerator Facility (JLab Hall C). An experiment, JLab E05-115 was carried out to investigate Lambda hypernuclei with a wide mass range (the mass number, A = 7, 9, 10, 12, 52). The latest analysis status of JLab E05-115 experiment is discussed in the present article.

  18. Characterization of a lymphoblastoid line deleted for lambda immunoglobulin genes

    SciTech Connect

    Hough, C.A., White, B.N., Holden, J.A.

    1995-04-01

    While characterizing the cat eye syndrome (CES) supernumerary chromosome for the presence of {lambda} immunoglobulin gene region sequences, a lymphoblastoid cell line from one CES patient was identified in which there was selection of cells deleted from some IGLC and IGLV genes. Two distinct deletions, one on each chromosome 22, were identified, presumably arising from independent somatic recombination events occurring during B-lymphocyte differentiation. The extent of the deleted regions was determined using probes from the various IGLV subgroups and they each covered at least 82 kilobases. The precise definition of the deletions was not possible because of conservation of some restriction sites in the IGLV region. The cell line was used to map putative IGLV genes within the recombinant phage {lambda}V{lambda}135 to the distal part of the IGLV gene region. 35 refs., 4 figs.

  19. He II lambda 1640/lambda 4686 and Ly-alpha/H-beta ratios in the extraordinary Seyfert galaxy Markarian 359

    NASA Technical Reports Server (NTRS)

    Macalpine, G. M.; Davidson, K.; Gull, T. R.; Wu, C.-C.

    1985-01-01

    The exceptionally narrow-lined Seyfert 1 galaxy Mrk 359 is ideally suited for determining reddening via the He II lambda 1640/lambda 4686 emission-line ratio. Here the validity of He II lines as a reddening indicator for quasars and Seyfert galaxies is reexamined and confirmed in the context of the most complete photoionization models available. In addition, lambda 1640 equivalent width measurements are shown to support previous contentions of substantial differences between observed and intrinsic quasar far-ultraviolet continua. Then IUE satellite and ground-based spectral data are presented, with the surprising result that both the lambda 1640/lambda 4686 and Ly-alpha/H-beta ratios do not differ greatly from case B recombination values in Mrk 359. This object is only slightly reddened, and it shows no evidence for extended, high-optical-depth H(+)/H(0) transition regions in the line-emitting gas. The very narrow lines and lack of deep transition regions and/or reddening may be related. In addition, Mrk 359 has low luminosity compared with most other Seyfert 1 galaxies, measured emission lines suggest an unusually high ionization parameter, and there is a hint of low nitrogen abundance. Further work is needed to examine possible relationships among all these peculiar properties.

  20. Observation of parity violation in the Omega- ---> Lambda K- decay

    SciTech Connect

    Lu, L.C.; Burnstein, R.A.; Chakravorty, A.; Chen, Y.C.; Choong, W.-S.; Clark, K.; Dukes, E.C.; Durandet, C.; Felix, J.; Fu, Y.; Gidal, G.; Gustafson, H.R.; Holmstrom, T.; Huang, M.; James, C.; Jenkins, C.M.; Jones, T.D.; Kaplan, D.M.; Longo, M.J.; Luebke, W.; Luk, K.-B.; /Taiwan, Inst. Phys. /UC, Berkeley /Fermilab /Guanajuato U. /IIT, Chicago /Lausanne U. /LBL, Berkeley /Michigan U. /South Alabama U. /Virginia U.

    2005-05-01

    The {alpha} decay parameter in the process {Omega}{sup -} {yields} {Lambda}K{sup -} has been measured from a sample of 4.50 million unpolarized {Omega}{sup -} decays recorded by the HyperCP (E871) experiment at Fermilab and found to be [1.78 {+-} 0.19(stat) {+-} 0.16(syst)] x 10{sup -2}. This is the first unambiguous evidence for a nonzero {alpha} decay parameter, and hence parity violation, in the {Omega}{sup -} {Lambda}K{sup -} decay.

  1. Technical challenges involved in supporting the Lambda Point Experiment

    NASA Technical Reports Server (NTRS)

    Petrac, D.; Israelsson, U.; Otth, D.; Simmons, L.; Staats, J.; Thompson, A.

    1990-01-01

    The Lambda Point Experiment (LPE) is one of the instruments included in the U.S. Microgravity Payload Mission 1 planned for one of the Space Shuttle flights in 1992. The objective of the experiment is to measure the heat capacity of liquid helium within a narrow interval around the transition between superfluid and normal helium (the lambda point) with an unprecedented temperature resolution of about 10 to the -10th. Multiple technical challenges are presented in the areas of structural support, safety analysis, and modal frequency tests. This paper describes the technical challenges of JPL's multidisciplinary involvement in support of these experiments in microgravity.

  2. Accurate LTE abundances for some lambda Boo stars

    NASA Astrophysics Data System (ADS)

    Andrievsky, S. M.; Chernyshova, I. V.; Klochkova, V. G.; Panchuk, V. E.

    1998-04-01

    High-resolution and high S/N CCD spectra were analyzed to determine accurate LTE abundances in four lambda Boo stars: pi1 Ori, 29 Cyg, HR 8203 and 15 And. In general, 14 chemical elements were investigated. The main results are the following: all stars have a strong deficiency of the majority of investigated metals. Oxygen exhibits a moderate deficiency. The carbon abundance is close to the solar one. The results obtained support an accretion/diffusion model, which is currently adopted for the explanation of the lambda Boo phenomenon.

  3. High Resolution Spectroscopy of 12B_Lambda by Electroproduction

    SciTech Connect

    M. Iodice; F. Cusanno; A. Acha; P. Ambrozewicz; K.A. Aniol; P. Baturin; P.Y. Bertin; H. Benaoum; K.I. Blomqvist; W.U. Boeglin; H. Breuer; P. Brindza; P. Bydˇzovsk´y; A. Camsonne; C.C. Chang; J.-P. Chen; Seonho Choi; E.A. Chudakov; E. Cisbani; S. Colilli; L. Coman; B.J. Craver; G. De Cataldo; C.W. de Jager; R. De Leo; A.P. Deur; C. Ferdi; R.J. Feuerbach; E. Folts; R. Fratoni; S. Frullani; F. Garibaldi; O. Gayou; F. Giulani; J. Gomez; M. Gricia; J.O. Hansen; D. Hayes; D.W. Higinbotham; T.K. Holmstrom; C.E. Hyde; H.F. Ibrahim; X. Jiang; L.J. Kaufman; K. Kino; B. Kross; L. Lagamba; J.J. LeRose; R.A. Lindgren; M. Lucentini; D.J. Margaziotis; P. Markowitz; S. Marrone; Z.E. Meziani; K. McCormick; R.W. Michaels; D.J. Millener; T. Miyoshi; B. Moffit; P.A. Monaghan; M. Moteabbed; C. Munoz Camacho; S. Nanda; E. Nappi; V.V. Nelyubin; B.E. Norum; Y. Okasyasu; K.D. Paschke; C.F. Perdrisat; E. Piasetzky; V.A. Punjabi; Y. Qiang; B. Raue; P.E. Reimer; J. Reinhold; B. Reitz; R.E. Roche; V.M. Rodriguez; A. Saha; F. Santavenere; A.J. Sarty; J. Segal; A. Shahinyan; J. Singh; S. ˇ Sirca; R. Snyder; P.H. Solvignon; M. Sotona; R. Subedi; V.A. Sulkosky; T. Suzuki; H. Ueno; P.E. Ulmer; G.M. Urciuoli; P. Veneroni; E. Voutier; B.B. Wojtsekhowski; X. Zheng; and C. Zorn

    2007-07-01

    An experiment measuring electroproduction of hypernuclei has been performed in Hall A at Jefferson Lab on a $^{12}$C target. In order to increase counting rates and provide unambiguous kaon identification two superconducting septum magnets and a Ring Imaging CHerenkov detector (RICH) were added to the Hall A standard equipment. An unprecedented energy resolution of less than 700 keV FWHM has been achieved. Thus, the observed \\lam{12}{B} spectrum shows for the first time identifiable strength in the core-excited region between the ground-state {\\it s}-wave $\\Lambda$ peak and the 11 MeV {\\it p}-wave $\\Lambda$ peak.

  4. Experimental transport studies of yttrium barium copper oxide and lambda-DNA

    NASA Astrophysics Data System (ADS)

    Zhang, Yuexing

    This dissertation consists of two parts. In Part I, we focus on the quasi-particle transport properties in the high temperature superconductor YBa2Cu3O7-delta (YBCO), probed by the thermal Hall conductivity (kappa xy). The thermal Hall conductivity selectively reflects the transport behaviors of the charge carriers. By measuring kappaxy in the normal state YBCO, we established a new method to determine the Wiedemann-Franz (WF) ratio in cuprates. We determined the Hall-channel WF ratio kappa xy/sigmaxyT in Cu and YBCO. In the latter, we uncovered a T-linear dependence and suppression of the Hallchannel WF ratio. The suppression of the Hall-channel WF ratio in systems with predominant electron-electron scattering will be discussed. Thermal transport behaviors of the quasi-particles in the mixed state were studied by measuring kappaxx and kappa xy in a high-purity YBCO crystal. From the field-dependence of the thermal conductivity kappaxx, we separated the quasi particle contribution (kappae) from the phonon background. In the Hall channel, we observed that the (weak-field) kappa xy increased 103-fold between T c (90 K) and 30 K, implying a 100-fold enhancement of the quasi-particle lifetime. We found that kappaxy exhibited a specific scaling behavior below ˜30 K. The implication of the scaling behavior will be discussed. In Part II, we describe an experiment on determining the electrical conductivity of the bacteriophage lambda-DNA, an issue currently under intense debate. We covalently bonded the DNA to Au electrodes by incorporating thiol modified dTTP into the 'sticky' ends of the lambda-DNA. Two-probe measurements on such molecules provided a lower bound for the resistivity rho > 10 6 mum at bias potentials up to 20 V, in conflict with recent claims of moderate to high conductivity. We stress the importance of eliminating salt residues in these measurements.

  5. Observation of the baryonic B decay B{sup 0}{yields}{Lambda}{sub c}{sup +}{Lambda}K{sup -}

    SciTech Connect

    Lees, J. P.; Poireau, V.; Tisserand, V.; Martinelli, M.; Palano, A.; Pappagallo, M.; Milanes, D. A.; Eigen, G.; Stugu, B.; Sun, L.; Brown, D. N.; Kerth, L. T.; Kolomensky, Yu. G.; Lynch, G.; Koch, H.; Schroeder, T.; Asgeirsson, D. J.; Hearty, C.

    2011-10-01

    We report the observation of the baryonic B decay B{sup 0}{yields}{Lambda}{sub c}{sup +}{Lambda}K{sup -} with a significance larger than 7 standard deviations based on 471x10{sup 6} BB pairs collected with the BABAR detector at the PEP-II storage ring at SLAC. We measure the branching fraction for the decay B{sup 0}{yields}{Lambda}{sub c}{sup +}{Lambda}K{sup -} to be (3.8{+-}0.8{sub stat}{+-}0.2{sub sys}{+-}1.0{sub {Lambda}}{sub c}{sup +})x10{sup -5}. The uncertainties are statistical, systematic, and due to the uncertainty in the {Lambda}{sub c}{sup +} branching fraction. We find that the {Lambda}{sub c}{sup +}K{sup -} invariant-mass distribution shows an enhancement above 3.5 GeV/c{sup 2}.

  6. Observation of. lambda. -hypernuclei in the reaction /sup 12/C(. pi. /sup +/,K/sup +/)/sub. lambda. //sup 12/C

    SciTech Connect

    Milner, E.C.

    1985-12-01

    The observation of ..lambda..-hypernuclear levels in /sub ..lambda..//sup 12/C by associated production through the (..pi../sup +/,K/sup +/) reaction is reported. Spectrometers used in the measurements are discussed. The /sub ..lambda..//sup 12/C excitation energy spectra were recorded at laboratory scattering angles of 5.6/sup 0/, 10.3/sup 0/, and 15.2/sup 0/. The spectra show two major peaks - one attributed to the ground state, and one about 11 MeV higher in excitation. The peak near 11 MeV excitation energy is believed to be almost entirely composed of a multiplet of three J/sup ..pi../ = 2/sup +/ states. Relativistic DWBA calculations imply support for the expectation that higher spin states are preferentially populated in the (..pi../sup +/,K/sup +/) reaction, compared to the (K/sup -/,..pi../sup -/) reaction in which lower spin states are excited. 29 refs., 40 figs.

  7. LAMBDA Polarization with a Transversely Polarized Proton Target at the COMPASS Experiment

    SciTech Connect

    Negrini, Teresa

    2009-08-04

    The transverse polarization of LAMBDA and LAMBDA-bar hyperons is investigated at the COMPASS experiment at CERN. In 2007 a 160 GeV/c longitudinally polarized muon beam and a transversely polarized NH{sub 3} target were employed to study events in semi-inclusive deep-inelastic scattering. Preliminary results for the LAMBDA and LAMBDA-bar polarizations extracted from this new data set are presented as a function of x{sub Bj} and z. The polarizations of LAMBDA and LAMBDA-bar are compatible with zero within their error bars and no dependence on x{sub Bj} or z is observed.

  8. Bacteriophage lambda stabilization by auxiliary protein gpD: timing, location, and mechanism of attachment determined by cryoEM

    PubMed Central

    Lander, Gabriel C.; Evilevitch, Alex; Jeembaeva, Meerim; Potter, Clinton S.; Carragher, Bridget; Johnson, John E.

    2008-01-01

    Summary We report the cryoEM structure of bacteriophage lambda and the mechanism for stabilizing the 20Å thick capsid containing the dsDNA genome. The crystal structure of the HK97 bacteriophage capsid fits most of the T=7 lambda particle density with only minor adjustment. A prominent surface feature at the 3-fold axes corresponds to the cementing protein gpD, necessary for stabilization of the capsid shell. Its position coincides with the location of the covalent cross-link formed in the docked HK97 crystal structure, suggesting an evolutionary replacement of this gene product in lambda by autocatalytic chemistry in HK97. The crystal structure of the trimeric gpD, in which the fourteen N-terminal residues required for capsid binding are disordered, fits precisely into the corresponding EM density. The N-terminal residues of gpD are well ordered in the cryoEM density adding a strand to a beta-sheet formed by the capsid proteins and explaining the mechanism of particle stabilization. PMID:18786402

  9. X-Ray Flare Characteristics in lambda Eridani

    NASA Technical Reports Server (NTRS)

    Smith, Myron A.

    1997-01-01

    This proposal was for a joint X-ray/ultraviolet/ground-based study of the abnormal Be star lambda Eri, which has previously shown evidence of X-ray flaring from ROSAT observations in 1991. The X-ray component consisted of observations from both the ASCA and ROSAT satellites.

  10. X-Ray Flare Characteristics in Lambda Eridani

    NASA Technical Reports Server (NTRS)

    Smith, Myron A.

    1997-01-01

    This proposal was for a joint X-ray/ultraviolet/ground-based study of the abnormal Be star lambda Eri, which has previously shown evidence of X-ray flaring from ROSAT observations in 1991. The X-ray component consisted of observations from both the ASCA and ROSAT satellites.

  11. GRAVITATIONAL LENSING CORRECTIONS IN FLAT {Lambda}CDM COSMOLOGY

    SciTech Connect

    Kantowski, Ronald; Chen Bin; Dai Xinyu E-mail: Bin.Chen-1@ou.ed

    2010-08-01

    We compute the deflection angle to order (m/r {sub 0}){sup 2} and m/r{sub 0} x {Lambda}r {sup 2}{sub 0} for a light ray traveling in a flat {Lambda}CDM cosmology that encounters a completely condensed mass region. We use a Swiss cheese model for the inhomogeneities and find that the most significant correction to the Einstein angle occurs not because of the nonlinear terms but instead occurs because the condensed mass is embedded in a background cosmology. The Swiss cheese model predicts a decrease in the deflection angle of {approx}2% for weakly lensed galaxies behind the rich cluster A1689 and that the reduction can be as large as {approx}5% for similar rich clusters at z {approx} 1. Weak-lensing deflection angles caused by galaxies can likewise be reduced by as much as {approx}4%. We show that the lowest order correction in which {Lambda} appears is proportional to m/r{sub 0} x {radical}({Lambda}r{sub 0}{sup 2}) and could cause as much as a {approx}0.02% increase in the deflection angle for light that passes through a rich cluster. The lowest order nonlinear correction in the mass is proportional to m/r{sub 0}x{radical}(m/r{sub 0}) and can increase the deflection angle by {approx}0.005% for weak lensing by galaxies.

  12. Spin-orbit splitting of {sub {lambda}}{sup 9}Be excited states studied with the SU{sub 6} quark-model baryon-baryon interactions

    SciTech Connect

    Fujiwara, Y.; Kohno, M.; Miyagawa, K.; Suzuki, Y.

    2004-10-01

    The previous Faddeev calculation of the two-alpha plus {lambda} system for {sub {lambda}}{sup 9}Be is extended to incorporate the spin-orbit components of the SU{sub 6} quark-model (QM) baryon-baryon interactions. We employ the Born kernel of the QM {lambda}N LS interaction and generate the spin-orbit component of the {lambda}{alpha} potential by {alpha}-cluster folding. The Faddeev calculation in the jj-coupling scheme implies that the direct use of the QM Born kernel for the {lambda}N LS component is not good enough to reproduce the small experimental value {delta}E{sub ls}{sup expt}=43{+-}5 keV for the 5/2{sup +}-3/2{sup +} splitting. This procedure predicts 3-5 times larger values in the models FSS and fss2. The spin-orbit contribution from the effective meson-exchange potentials in fss2 is argued to be unfavorable to the small ls splitting, through the analysis of the Scheerbaum factors for the single-particle spin-orbit potentials calculated in the G-matrix formalism.

  13. Heat capacity and thermal relaxation of bulk helium very near the lambda point

    NASA Technical Reports Server (NTRS)

    Lipa, John A.; Swanson, D. R.; Nissen, J. A.; Chui, T. C. P.

    1994-01-01

    In October 1992 a low temperature experiment was flown on the Space Shuttle in low Earth orbit. The objective of the mission was to measure the heat capacity and thermal conductivity of helium very close to the lambda point with the smearing effect of gravity removed. We report preliminary results from the experiment, and compare them with related measurements performed on the ground. The sample was s sphere of helium 3.5 cm in diameter contained within a copper calorimeter of vey high thermal conductivity. The calorimeter was attached to a pair of high resolution paramagnetic salt thermometers with noise levels in the 10(exp -10) K range and suspended from a high stability thermal isolation system. During the mission we found that the resolution of the thermometers was degraded somewhat due to the impact of charged particles. This effect limited the useful resolution of the measurements to about two nanokelvins from the lambda point. The results reported here are limited to about ten nanokelvins from the transition.

  14. Differential equations whose solution of the Cauchy problem displays nonclassical behaviour with respect to the parameter {lambda}

    SciTech Connect

    Yakubov, Vladimir Ya

    2009-10-31

    The behaviour of solutions of the equation y''+{lambda}{rho}(x,{lambda})y=0 with respect to the spectral parameter {lambda} is investigated under the assumption that the function {rho}(x,{lambda}) does not satisfy the classical conditions. Two types of equations are considered: the Sturm-Liouville equation y''+{lambda}{rho}(x)y=0, whose solutions grow like c({rho}){lambda}{sup m} in the norm of C[0,l] (where m>0 is arbitrary), and equations of the form y''+{lambda}{rho}(x,{lambda})y=0, lim {sub {lambda}}{sub {yields}}{sub +{infinity}}{rho}(x,{lambda})=1, whose solutions can grow like c{lambda}{sup m} in the norm of C[0,l] (where m>0 is arbitrary) and even like exp{l_brace}m{lambda}{sup 1-{gamma}}{r_brace} where 0<{gamma}<1. Bibliography: 3 titles.

  15. Approaches for the direct estimation of lambda, and demographic contributions to lambda, using capture-recapture data

    USGS Publications Warehouse

    Nichols, J.D.; Hines, J.E.

    2002-01-01

    We first consider the estimation of the finite rate of population increase or population growth rate, lambda sub i, using capture-recapture data from open populations. We review estimation and modelling of lambda sub i under three main approaches to modelling open-population data: the classic approach of Jolly (1965) and Seber (1965), the superpopulation approach of Crosbie & Manly (1985) and Schwarz & Arnason (1996), and the temporal symmetry approach of Pradel (1996). Next, we consider the contributions of different demographic components to lambda sub i using a probabilistic approach based on the composition of the population at time i + 1 (Nichols et al., 2000b). The parameters of interest are identical to the seniority parameters, gamma sub i, of Pradel (1996). We review estimation of gamma sub i under the classic, superpopulation, and temporal symmetry approaches. We then compare these direct estimation approaches for lambda sub i and gamma sub i with analogues computed using projection matrix asymptotics. We also discuss various extensions of the estimation approaches to multistate applications and to joint likelihoods involving multiple data types.

  16. Bacteriophage lambda repressor mediates the formation of a complex enhancer-like structure

    PubMed Central

    Cui, Lun; Murchland, Iain; Dodd, Ian B; Shearwin, Keith E

    2013-01-01

    For the past 40 years, bacteriophage lambda has been crucial in revealing fundamental principles underlying control of transcription by elements positioned close to promoters. With the discovery that lambda CI repressors bound to distant sites can interact efficiently, lambda also provides a model for long range gene regulation, including the action of enhancer elements. PMID:23989664

  17. A spectroscopic survey for lambda Bootis stars. III. Final results

    NASA Astrophysics Data System (ADS)

    Paunzen, E.

    2001-07-01

    In the third paper of a series dedicated to the spectroscopic survey for new lambda Bootis stars, we present all new and confirmed members of the group as well as a detailed analysis of the observed sample. The nature of this small group of chemically peculiar stars of the upper main sequence still challenges our understanding of processes like diffusion, mass-loss and accretion. The typical abundances pattern (nearly solar values for C, N, O and S whereas the Fe-peak elements are moderate to strong underabundant) can still not be explained by any proposed theory. Hence, the significant increase of new members gives the opportunity to investigate the group properties in more detail. We report the discovery of 26 new members of the group and the confirmation of 18 candidates from the literature. This almost triples the number of known lambda Bootis stars. The existence of one member in the young open cluster NGC 2264 and four members in the Orion OB1 association proves that the lambda Bootis phenomenon already works at very early stages of stellar evolution. Recent results from the Hipparcos mission have shown that the well established lambda Bootis stars of the Galactic field comprise the whole area from the Zero Age Main Sequence to the Terminal Age Main Sequence (~ 109 yr for an A-type star). There is a continuous transition between very young and rather evolved evolutionary stages. We find that the overall percentage of lambda Bootis type among all normal type stars in the spectral range from B8 to F4 is 2% in the Galactic field as well as in open clusters. Furthermore, 44 metal-weak objects are listed which might be connected with the lambda Bootis phenomenon. Our biased sample (chosen by photometric boxes) is not distinguished from all A-type stars in the corresponding spectral region by the rotational velocity distribution. Only for the luminosity classes IV and III (especially for the cooler program stars) the determined mean v sin i values are very high

  18. K0(s) and Lambda0 production studies in p anti-p collisions at s**(1/2) = 1800 and 630-GeV

    SciTech Connect

    Acosta, D.; Affolder, Anthony A.; Albrow, M.G.; Ambrose, D.; Amidei, D.; Anikeev, K.; Antos, J.; Apollinari, G.; Arisawa, T.; Artikov, A.; Ashmanskas, W.; Azfar, F.; Azzi-Bacchetta, P.; Bacchetta, N.; Bachacou, H.; Badgett, W.; Barbaro-Galtieri, A.; Barnes, V.E.; Barnett, B.A.; Baroiant, S.; Barone, M.; /Taiwan, Inst. Phys. /Argonne /INFN, Bologna /Bologna U. /Brandeis U. /UC, Davis /UCLA /UC, Santa Barbara /Cantabria Inst. of Phys. /Carnegie Mellon U. /Chicago U., EFI /Dubna, JINR /Duke U. /Fermilab /Florida U. /Frascati /Geneva U. /Glasgow U. /Harvard U. /Hiroshima U. /Johns Hopkins U.

    2005-04-01

    The authors present a study of the production of K{sub s}{sup 0} and {Lambda}{sup 0} in inelastic p{bar p} collisions at {radical}s = 1800 and 630 GeV using data collected by the CDF experiment at the Fermilab Tevatron. Analyses of K{sub s}{sup 0} and {Lambda}{sup 0} multiplicity and transverse momentum distributions, as well as of the dependencies of the average number and (p{sub T}) of K{sub s}{sup 0} and {Lambda}{sup 0} on charged particle multiplicity are reported. Systematic comparisons are performed for the full sample of inelastic collisions, and for the low and high momentum transfer subsamples, at the two energies. The p{sub T} distributions extend above 8 GeV/c, showing a (p{sub T}) higher than previous measurements. The dependence of the mean K{sub s}{sup 0}({Lambda}{sup 0}) p{sub T} on the charged particle multiplicity for the three samples shows a behavior analogous to that of charged primary tracks.

  19. Mathematical modeling of the lambda switch: a fuzzy logic approach.

    PubMed

    Laschov, Dmitriy; Margaliot, Michael

    2009-10-21

    Gene regulation plays a central role in the development and functioning of living organisms. Gaining a deeper qualitative and quantitative understanding of gene regulation is an important scientific challenge. The Lambda switch is commonly used as a paradigm of gene regulation. Verbal descriptions of the structure and functioning of the switch have appeared in biological textbooks. We apply fuzzy modeling to transform one such verbal description into a well-defined mathematical model. The resulting model is a piecewise-quadratic second-order differential equation. It demonstrates functional fidelity with known results while being simple enough to allow a rather detailed analysis. Properties such as the number, location, and domain of attraction of equilibrium points can be studied analytically. Furthermore, the model provides a rigorous explanation for the so-called stability puzzle of the Lambda switch. PMID:19589343

  20. Fourth generation effect on {Lambda}{sub b} decays

    SciTech Connect

    Mohanta, R.; Giri, A. K.

    2010-11-01

    The rare decays of the {Lambda}{sub b} baryon governed by the quark level transitions b{yields}s are investigated in the fourth quark generation model popularly known as SM4. Recently it has been shown that SM4, which is a very simple extension of the standard model, can successfully explain several anomalies observed in the CP violation parameters of B and B{sub s} mesons. We find that in this model due to the additional contributions coming from the heavy t{sup '} quark in the loop, the branching ratios and other observables in rare {Lambda}{sub b} decays deviate significantly from their standard model values. Some of these modes are within the reach of the LHCb experiment and search for such channels is strongly argued.

  1. LAMBDA — Large Area Medipix3-Based Detector Array

    NASA Astrophysics Data System (ADS)

    Pennicard, D.; Lange, S.; Smoljanin, S.; Hirsemann, H.; Graafsma, H.

    2012-11-01

    Medipix3 is a photon-counting readout chip for X-ray detection. It has a small pixel size (55 μm) and a high frame rate with zero dead time, which makes it attractive for experiments at synchrotrons. Using Medipix3, DESY are developing the LAMBDA (Large Area Medipix3-Based Detector Array) system. A single LAMBDA module carries either a single large silicon sensor of 1536 by 512 pixels, or two smaller high-Z sensors. The sensor is bonded to 12 Medipix3 chips, and mounted on a ceramic carrier board. The readout system for the module then provides a fast FPGA, a large RAM and four 10 Gigabit Ethernet links to allow operation at high frame rates. Multiple modules may then be tiled together a larger area. Currently, the first large silicon modules have been constructed and tested at low speed, and the firmware for fast readout is being developed.

  2. On the role of Cro in lambda prophage induction.

    PubMed

    Svenningsen, Sine L; Costantino, Nina; Court, Donald L; Adhya, Sankar

    2005-03-22

    The lysogenic state of bacteriophage lambda is exceptionally stable yet the prophage is readily induced in response to DNA damage. This delicate epigenetic switch is believed to be regulated by two proteins; the lysogenic maintenance promoting protein CI and the early lytic protein Cro. First, we confirm, in the native configuration, the previous observation that the DNA loop mediated by oligomerization of CI bound to two distinct operator regions (O(L) and O(R)), increases repression of the early lytic promoters and is important for stable maintenance of lysogeny. Second, we show that the presence of the cro gene might be unimportant for the lysogenic to lytic switch during induction of the lambda prophage. We revisit the idea that Cro's primary role in induction is instead to mediate weak repression of the early lytic promoters. PMID:15728734

  3. Measurement of sigma Lambda b0/sigma B0 x B(Lambda b0-->Lambda c+pi-)/B(B0-->D+pi-) in pp collisions at square root s=1.96 TeV.

    PubMed

    Abulencia, A; Adelman, J; Affolder, T; Akimoto, T; Albrow, M G; Ambrose, D; Amerio, S; Amidei, D; Anastassov, A; Anikeev, K; Annovi, A; Antos, J; Aoki, M; Apollinari, G; Arguin, J-F; Arisawa, T; Artikov, A; Ashmanskas, W; Attal, A; Azfar, F; Azzi-Bacchetta, P; Azzurri, P; Bacchetta, N; Badgett, W; Barbaro-Galtieri, A; Barnes, V E; Barnett, B A; Baroiant, S; Bartsch, V; Bauer, G; Bedeschi, F; Behari, S; Belforte, S; Bellettini, G; Bellinger, J; Belloni, A; Benjamin, D; Beretvas, A; Beringer, J; Berry, T; Bhatti, A; Binkley, M; Bisello, D; Blair, R E; Blocker, C; Blumenfeld, B; Bocci, A; Bodek, A; Boisvert, V; Bolla, G; Bolshov, A; Bortoletto, D; Boudreau, J; Boveia, A; Brau, B; Brigliadori, L; Bromberg, C; Brubaker, E; Budagov, J; Budd, H S; Budd, S; Budroni, S; Burkett, K; Busetto, G; Bussey, P; Byrum, K L; Cabrera, S; Campanelli, M; Campbell, M; Canelli, F; Canepa, A; Carillo, S; Carlsmith, D; Carosi, R; Casarsa, M; Castro, A; Catastini, P; Cauz, D; Cavalli-Sforza, M; Cerri, A; Cerrito, L; Chang, S H; Chen, Y C; Chertok, M; Chiarelli, G; Chlachidze, G; Chlebana, F; Cho, I; Cho, K; Chokheli, D; Chou, J P; Choudalakis, G; Chuang, S H; Chung, K; Chung, W H; Chung, Y S; Ciljak, M; Ciobanu, C I; Ciocci, M A; Clark, A; Clark, D; Coca, M; Compostella, G; Convery, M E; Conway, J; Cooper, B; Copic, K; Cordelli, M; Cortiana, G; Crescioli, F; Cuenca Almenar, C; Cuevas, J; Culbertson, R; Cully, J C; Cyr, D; DaRonco, S; D'Auria, S; Davies, T; D'Onofrio, M; Dagenhart, D; de Barbaro, P; De Cecco, S; Deisher, A; De Lentdecker, G; Dell'Orso, M; Delli Paoli, F; Demortier, L; Deng, J; Deninno, M; De Pedis, D; Derwent, P F; Di Giovanni, G P; Dionisi, C; Di Ruzza, B; Dittmann, J R; DiTuro, P; Dörr, C; Donati, S; Donega, M; Dong, P; Donini, J; Dorigo, T; Dube, S; Efron, J; Erbacher, R; Errede, D; Errede, S; Eusebi, R; Fang, H C; Farrington, S; Fedorko, I; Fedorko, W T; Feild, R G; Feindt, M; Fernandez, J P; Field, R; Flanagan, G; Foland, A; Forrester, S; Foster, G W; Franklin, M; Freeman, J C; Furic, I; Gallinaro, M; Galyardt, J; Garcia, J E; Garberson, F; Garfinkel, A F; Gay, C; Gerberich, H; Gerdes, D; Giagu, S; Giannetti, P; Gibson, A; Gibson, K; Gimmell, J L; Ginsburg, C; Giokaris, N; Giordani, M; Giromini, P; Giunta, M; Giurgiu, G; Glagolev, V; Glenzinski, D; Gold, M; Goldschmidt, N; Goldstein, J; Gomez, G; Gomez-Ceballos, G; Goncharov, M; González, O; Gorelov, I; Goshaw, A T; Goulianos, K; Gresele, A; Griffiths, M; Grinstein, S; Grosso-Pilcher, C; Group, R C; Grundler, U; Guimaraes da Costa, J; Gunay-Unalan, Z; Haber, C; Hahn, K; Hahn, S R; Halkiadakis, E; Hamilton, A; Han, B-Y; Han, J Y; Handler, R; Happacher, F; Hara, K; Hare, M; Harper, S; Harr, R F; Harris, R M; Hartz, M; Hatakeyama, K; Hauser, J; Heijboer, A; Heinemann, B; Heinrich, J; Henderson, C; Herndon, M; Heuser, J; Hidas, D; Hill, C S; Hirschbuehl, D; Hocker, A; Holloway, A; Hou, S; Houlden, M; Hsu, S-C; Huffman, B T; Hughes, R E; Husemann, U; Huston, J; Incandela, J; Introzzi, G; Iori, M; Ishizawa, Y; Ivanov, A; Iyutin, B; James, E; Jang, D; Jayatilaka, B; Jeans, D; Jensen, H; Jeon, E J; Jindariani, S; Jones, M; Joo, K K; Jun, S Y; Jung, J E; Junk, T R; Kamon, T; Karchin, P E; Kato, Y; Kemp, Y; Kephart, R; Kerzel, U; Khotilovich, V; Kilminster, B; Kim, D H; Kim, H S; Kim, J E; Kim, M J; Kim, S B; Kim, S H; Kim, Y K; Kimura, N; Kirsch, L; Klimenko, S; Klute, M; Knuteson, B; Ko, B R; Kondo, K; Kong, D J; Konigsberg, J; Korytov, A; Kotwal, A V; Kovalev, A; Kraan, A C; Kraus, J; Kravchenko, I; Kreps, M; Kroll, J; Krumnack, N; Kruse, M; Krutelyov, V; Kubo, T; Kuhlmann, S E; Kuhr, T; Kusakabe, Y; Kwang, S; Laasanen, A T; Lai, S; Lami, S; Lammel, S; Lancaster, M; Lander, R L; Lannon, K; Lath, A; Latino, G; Lazzizzera, I; Le, Y; LeCompte, T; Lee, J; Lee, J; Lee, Y J; Lee, S W; Lefèvre, R; Leonardo, N; Leone, S; Levy, S; Lewis, J D; Lin, C; Lin, C S; Lindgren, M; Lipeles, E; Lister, A; Litvintsev, D O; Liu, T; Lockyer, N S; Loginov, A; Loreti, M; Loverre, P; Lu, R-S; Lucchesi, D; Lujan, P; Lukens, P; Lungu, G; Lyons, L; Lys, J; Lysak, R; Lytken, E; Mack, P; MacQueen, D; Madrak, R; Maeshima, K; Makhoul, K; Maki, T; Maksimovic, P; Malde, S; Manca, G; Margaroli, F; Marginean, R; Marino, C; Marino, C P; Martin, A; Martin, M; Martin, V; Martínez, M; Maruyama, T; Mastrandrea, P; Masubuchi, T; Matsunaga, H; Mattson, M E; Mazini, R; Mazzanti, P; McFarland, K S; McIntyre, P; McNulty, R; Mehta, A; Mehtala, P; Menzemer, S; Menzione, A; Merkel, P; Mesropian, C; Messina, A; Miao, T; Miladinovic, N; Miles, J; Miller, R; Mills, C; Milnik, M; Mitra, A; Mitselmakher, G; Miyamoto, A; Moed, S; Moggi, N; Mohr, B; Moore, R; Morello, M; Movilla Fernandez, P; Mülmenstädt, J; Mukherjee, A; Muller, Th; Mumford, R; Murat, P; Nachtman, J; Nagano, A; Naganoma, J; Nakano, I; Napier, A; Necula, V; Neu, C; Neubauer, M S; Nielsen, J; Nigmanov, T; Nodulman, L; Norniella, O; Nurse, E; Oh, S H; Oh, Y D; Oksuzian, I; Okusawa, T; Oldeman, R; Orava, R; Osterberg, K; Pagliarone, C; Palencia, E; Papadimitriou, V; Paramonov, A A; Parks, B; Pashapour, S; Patrick, J; Pauletta, G; Paulini, M; Paus, C; Pellett, D E; Penzo, A; Phillips, T J; Piacentino, G; Piedra, J; Pinera, L; Pitts, K; Plager, C; Pondrom, L; Portell, X; Poukhov, O; Pounder, N; Prakoshyn, F; Pronko, A; Proudfoot, J; Ptohos, F; Punzi, G; Pursley, J; Rademacker, J; Rahaman, A; Ranjan, N; Rappoccio, S; Reisert, B; Rekovic, V; Renton, P; Rescigno, M; Richter, S; Rimondi, F; Ristori, L; Robson, A; Rodrigo, T; Rogers, E; Rolli, S; Roser, R; Rossi, M; Rossin, R; Ruiz, A; Russ, J; Rusu, V; Saarikko, H; Sabik, S; Safonov, A; Sakumoto, W K; Salamanna, G; Saltó, O; Saltzberg, D; Sánchez, C; Santi, L; Sarkar, S; Sartori, L; Sato, K; Savard, P; Savoy-Navarro, A; Scheidle, T; Schlabach, P; Schmidt, E E; Schmidt, M P; Schmitt, M; Schwarz, T; Scodellaro, L; Scott, A L; Scribano, A; Scuri, F; Sedov, A; Seidel, S; Seiya, Y; Semenov, A; Sexton-Kennedy, L; Sfyrla, A; Shapiro, M D; Shears, T; Shepard, P F; Sherman, D; Shimojima, M; Shochet, M; Shon, Y; Shreyber, I; Sidoti, A; Sinervo, P; Sisakyan, A; Sjolin, J; Slaughter, A J; Slaunwhite, J; Sliwa, K; Smith, J R; Snider, F D; Snihur, R; Soderberg, M; Soha, A; Somalwar, S; Sorin, V; Spalding, J; Spinella, F; Spreitzer, T; Squillacioti, P; Stanitzki, M; Staveris-Polykalas, A; St Denis, R; Stelzer, B; Stelzer-Chilton, O; Stentz, D; Strologas, J; Stuart, D; Suh, J S; Sukhanov, A; Sun, H; Suzuki, T; Taffard, A; Takashima, R; Takeuchi, Y; Takikawa, K; Tanaka, M; Tanaka, R; Tecchio, M; Teng, P K; Terashi, K; Thom, J; Thompson, A S; Thomson, E; Tipton, P; Tiwari, V; Tkaczyk, S; Toback, D; Tokar, S; Tollefson, K; Tomura, T; Tonelli, D; Torre, S; Torretta, D; Tourneur, S; Trischuk, W; Tseng, J; Tsuchiya, R; Tsuno, S; Turini, N; Ukegawa, F; Unverhau, T; Uozumi, S; Usynin, D; Vallecorsa, S; van Remortel, N; Varganov, A; Vataga, E; Vázquez, F; Velev, G; Veramendi, G; Veszpremi, V; Vidal, R; Vila, I; Vilar, R; Vine, T; Vollrath, I; Volobouev, I; Volpi, G; Würthwein, F; Wagner, P; Wagner, R G; Wagner, R L; Wagner, J; Wagner, W; Wallny, R; Wang, S M; Warburton, A; Waschke, S; Waters, D; Wester, W C; Whitehouse, B; Whiteson, D; Wicklund, A B; Wicklund, E; Williams, G; Williams, H H; Wilson, P; Winer, B L; Wittich, P; Wolbers, S; Wolfe, C; Wright, T; Wu, X; Wynne, S M; Yagil, A; Yamamoto, K; Yamaoka, J; Yamashita, T; Yang, C; Yang, U K; Yang, Y C; Yao, W M; Yeh, G P; Yoh, J; Yorita, K; Yoshida, T; Yu, G B; Yu, I; Yu, S S; Yun, J C; Zanello, L; Zanetti, A; Zaw, I; Zhang, X; Zhou, J; Zucchelli, S

    2007-03-23

    We present the first observation of the baryon decay Lambda b0-->Lambda c+pi- followed by Lambda c+-->pK-pi+ in 106 pb-1 pp collisions at square root s=1.96 TeV in the CDF experiment. In order to reduce systematic error, the measured rate for Lambda b0 decay is normalized to the kinematically similar meson decay B0-->D+pi- followed by D+-->pi+K-pi+. We report the ratio of production cross sections (sigma) times the ratio of branching fractions (B) for the momentum region integrated above pT>6 GeV/c and pseudorapidity range |eta|<1.3: sigma(pp-->Lambda b0X)/sigma(pp-->B0X)xB(Lambda b0-->Lambda c+pi-)/B(B0-->D+pi-)=0.82+/-0.08(stat)+/-0.11(syst)+/-0.22[B(Lambda c+-->pK-pi+)]. PMID:17501113

  4. Cholestasis and liver failure with lambda-AL amyloidosis.

    PubMed Central

    Konikoff, F; Mor, C; Stern, S; Shaklai, M; Halevy, J; Theodor, E

    1987-01-01

    Clinically significant liver involvement in systemic amyloidosis, especially with cholestasis, is rare. We report a case of primary amyloidosis with severe intrahepatic cholestasis leading to terminal liver failure. The present case is the first of its kind reported involving Lambda light chains only as the associated paraprotein. Conventional treatment and a therapeutic trial with dimethyl sulphoxide were unsuccessful. Images Fig. 1 Fig. 2 PMID:3115870

  5. Lambda modes of the neutron diffusion equation in hexagonal geometry

    SciTech Connect

    Barrachina, T.; Ginestar, D.; Verdu, G.

    2006-07-01

    A nodal collocation method is proposed to compute the dominant Lambda modes of nuclear reactor core with a hexagonal geometry. This method is based on a triangular mesh and assumes that the neutronic flux can be approximated as a finite expansion in terms of Dubiner's polynomials. The method transforms the initial differential eigenvalue problem into a generalized algebraic one, from which the dominant modes of the reactor can be computed. The performance of the method is tested with two benchmark problems. (authors)

  6. ({lambda}, p) Spectrum Analysis in p+A Interactions at 10 GeV/c

    SciTech Connect

    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(lambda}{lambda})) and heavy H0,+. New event, detected on the photographs of the propane bubble chamber was interpreted as heavy H+(2488) dibaryon by two weak decay channels of K-pp or {sigma}+p{pi}-.

  7. Anti p and anti Lambda production in Si + Au collisions at the AGS

    NASA Technical Reports Server (NTRS)

    Wu, Yue-Dong

    1996-01-01

    (anti (ital p)) and (anti (Lambda)) production in central Si + Au collisions has been measured by E589 at the BNL-AGS. Preliminary (ital m)(sub (perpendicular)) spectra are presented for (anti (ital p))'s and (anti (Lambda))'s. The (ital dn/dy) distribution for (anti (ital p))'s is also presented. Based on the (anti (ital p)) and (anti (Lambda)) measurements, (anti (Lambda))/(anti (ital p)) ratios are calculated in the rapidity range of 1.1-1.5.

  8. MLAMBDA: a modified LAMBDA method for integer least-squares estimation

    NASA Astrophysics Data System (ADS)

    Chang, X.-W.; Yang, X.; Zhou, T.

    2005-12-01

    The least-squares ambiguity Decorrelation (LAMBDA) method has been widely used in GNSS for fixing integer ambiguities. It can also solve any integer least squares (ILS) problem arising from other applications. For real time applications with high dimensions, the computational speed is crucial. A modified LAMBDA (MLAMBDA) method is presented. Several strategies are proposed to reduce the computational complexity of the LAMBDA method. Numerical simulations show that MLAMBDA is (much) faster than LAMBDA. The relations between the LAMBDA method and some relevant methods in the information theory literature are pointed out when we introduce its main procedures.

  9. Minimal gene regulatory circuits that can count like bacteriophage lambda.

    PubMed

    Avlund, M; Dodd, Ian B; Sneppen, K; Krishna, S

    2009-12-11

    The behavior of living systems is dependent on large dynamical gene regulatory networks (GRNs). However, the functioning of even the smallest GRNs is difficult to predict. The bistable GRN of bacteriophage lambda is able to count to make a decision between lysis and lysogeny on the basis of the number of phages infecting the cell, even though replication of the phage genome eliminates this initial difference. By simulating the behavior of a large number of random transcriptional GRNs, we show that a surprising variety of GRNs can carry out this complex task, including simple CI-Cro-like mutual repression networks. Thus, our study extends the repertoire of simple GRNs. Counterintuitively, the major effect of the addition of CII-like regulation, generally thought to be needed for counting by lambda, was to improve the ability of the networks to complete a simulated prophage induction. Our study suggests that additional regulatory mechanisms to decouple Cro and CII levels may exist in lambda and that infection counting could be widespread among temperate bacteriophages, many of which contain CI-Cro-like circuits. PMID:19796646

  10. Measurement of the Lambda(0)(b) lifetime in the exclusive decay Lambda(0)(b) -> J/psi Lambda(0) in p(p)over-bar collisions at root s=1.96 TeV

    SciTech Connect

    Abazov V. M.; Abbott, B.; Acharya, B. S.; Adams, M.; Adams, T.; Alexeev, G. D.; Alkhazov, G.; Alton, A.; Alverson, G.; Aoki, M.; Askew, A.; Atkins, S.; Augsten, K.; Avila, C.; Badaud, F.; Bagby, L.; Baldin, B.; Bandurin, D. V.; Banerjee, S.; Barberis, E.; Baringer, P.; Barreto, J.; Bartlett, J. F.; Bassler, U.; Bazterra, V.; Bean, A.; Begalli, M.; Bellantoni, L.; Beri, S. B.; Bernardi, G.; Bernhard, R.; Bertram, I.; et al.

    2012-06-07

    We measure the {Lambda}{sub b}{sup 0} lifetime in the fully reconstructed decay {Lambda}{sub b}{sup 0} {yields} J/{psi}{Lambda}{sup 0} using 10.4 fb{sup -1} of p{bar p} collisions collected with the D0 detector at {radical}s = 1.96 TeV. The lifetime of the topologically similar decay channel B{sup 0} {yields} J/{psi}K{sub S}{sup 0} is also measured. We obtain {tau}({Lambda}{sub b}{sup 0}) = 1.303 {+-} 0.075(stat) {+-} 0.035(syst) ps and {tau}(B{sup 0}) = 1.508 {+-} 0.025(stat) {+-} 0.043(syst) ps. Using these measurements, we determine the lifetime ratio of {tau}({Lambda}{sub b}{sup 0})/{tau}(B{sup 0}) = 0.864 {+-} 0.052(stat) {+-} 0.033(syst).

  11. Measurement of the Lambda0(b) Lifetime in Lambda0(b) ---> J/psi Lambda0 in p anti-p Collisions at s**(1/2) = 1.96-TeV

    SciTech Connect

    Abulencia, A.; Adelman, J.; Affolder, T.; Akimoto, T.; Albrow, M.G.; Ambrose, D.; Amerio, S.; Amidei, D.; Anastassov, A.; Anikeev, K.; Annovi, A.; /Taiwan, Inst. Phys. /Argonne /Barcelona, IFAE /Baylor U. /INFN, Bologna /Bologna U. /Brandeis U. /UC, Davis /UCLA /UC, San Diego /UC, Santa Barbara

    2006-09-01

    The authors report a measurement of the {Lambda}{sub b}{sup 0} lifetime in the exclusive decay {Lambda}{sub b}{sup 0} {yields} J/{psi}{Lambda}{sup 0} in p{bar p} collisions at {radical}s = 1.96 TeV using an integrated luminosity of 1.0 fb{sup -1} of data collected by the CDF II detector at the Fermilab Tevatron. Using fully reconstructed decays, they measure {tau}({Lambda}{sub b}{sup 0}) = 1.593{sub -0.078}{sup +0.083}(stat.) {+-} 0.033(syst.) ps. This is the single most precise measurement of {tau}({Lambda}{sub b}{sup 0}) and is 3.2 {sigma} higher than the current world average.

  12. Stable carbon isotope fractionation during the biodegradation of lambda-cyhalothrin.

    PubMed

    Shen, Xiaoli; Xu, Zemin; Zhang, Xichang; Yang, Fangxing

    2015-11-01

    In this study, the microbial degradation of lambda-cyhalothrin in soil was investigated using compound-specific stable isotope analysis. The results revealed that lambda-cyhalothrin was biodegraded in soil under laboratory conditions. The half-lives of lambda-cyhalothrin were determined to be 49 and 161 days in non-sterile and sterile soils spiked with 2mg/kg lambda-cyhalothrin and 84 and 154 days in non-sterile and sterile soils spiked with 10mg/kg lambda-cyhalothrin, respectively. The biodegradation of lambda-cyhalothrin resulted in carbon isotope fractionation, which shifted from -29.0‰ to -26.5‰ in soil spiked with 2mg/kg lambda-cyhalothrin, and to -27.5‰ with 10mg/kg lambda-cyhalothrin. A relationship was established between the stable carbon isotope fraction and the residual concentrations of lambda-cyhalothrin by the Rayleigh equation in which the carbon isotope enrichment factor ε of the microbial degradation of lambda-cyhalothrin in the soil was calculated as -2.53‰. This study provides an approach to quantitatively evaluate the biodegradation of lambda-cyhalothrin in soil in field studies. PMID:26092290

  13. Search for CP violation in charged-Xi and Lambda hyperon decays

    SciTech Connect

    Holmstrom, T.; Leros, N.; Burnstein, R.A.; Chakravorty, A.; Chan, A.; Chen, Y.C.; Choong, W.S.; Clark, K.; Dukes, E.C.; Durandet, C.; Felix, J.; Fu, Y.; Gidal, G.; Gu, P.; Gustafson, H.R.; Ho, C.; Huang, M.; James, C.; Jenkins, C.M.; Jones, T.; Kaplan, D.M.; /Virginia U. /Lausanne U. /Taiwan, Inst. Phys. /UC, Berkeley /Fermilab /Guanajuato U. /IIT, Chicago /Lausanne U. /LBL, Berkeley /Michigan U. /South Alabama U. /Virginia U.

    2004-12-01

    The authors have compared the p and {bar p} angular distributions in 117 million {Xi}{sup -} {yields} {Lambda}{pi}{sup -} {yields} p{pi}{sup -}{pi}{sup -} and 41 million {Xi}{sup +} {yields} {bar {Lambda}}{pi}{sup +} {yields} {bar p}{pi}{sup +}{pi}{sup +} decays using a subset of the data from the HyperCP experiment (ES71) at Fermilab. They find no evidence of CP violation, with the direct-CP-violating parameter A{sub {Xi}{Lambda}} {triple_bond} (a{sub {Xi}}a{sub {Lambda}} - {bar a}{sub {Xi}}{bar a}{sub {Lambda}})/(a{sub {Xi}}a{sub {Lambda}} + {bar a}{sub {Xi}}{bar a}{sub {Lambda}}) = [0.0 {+-} 5.1(stat) {+-} 4.4(syst)] x 10{sup -4}.

  14. Inclusive Lambda_c Production in e+e- Annihilations at sqrt{s}=10.54 GeV and in Upsilon(4S) Decays

    SciTech Connect

    Aubert, B.

    2006-09-07

    We present measurements of the total production rates and momentum distributions of the charmed baryon {Lambda}{sub c}{sup +} in e{sup +}e{sup -} {yields} hadrons at a center-of-mass energy of 10.54 GeV and in {Upsilon}(4S) decays. In hadronic events at 10.54 GeV, charmed hadrons are almost exclusively leading particles in e{sup +}e{sup -} {yields} c{bar c} events, allowing direct studies of c-quark fragmentation. We measure a momentum distribution for {Lambda}{sub c}{sup +} baryons that differs significantly from those measured previously for charmed mesons. Comparing with a number of models, we find none that can describe the distribution completely. We measure an average scaled momentum of (x{sub p}) = 0.574 {+-} 0.009 and a total rate of N{sub {Lambda}{sub c}}{sup q{bar q}} = 0.057 {+-} 0.002(exp.) {+-} 0.015(BF) {Lambda}{sub c}{sup +} per hadronic event, where the experimental error is much smaller than that due to the branching fraction into the reconstructed decay mode, pK{sup -} {pi}{sup +}. In {Upsilon}(4S) decays we measure a total rate of N{sub {Lambda}{sub c}}{sup {Upsilon}} = 0.091 {+-} 0.006(exp.) {+-} 0.024(BF) per {Upsilon}(4S) decay, and find a much softer momentum distribution than expected from B decays into a {Lambda}{sub c}{sup +} plus an antinucleon and one to three pions.

  15. The origin of N III lambda 990 and C III lambda 977 emission in AGN narrow-line region gas

    NASA Technical Reports Server (NTRS)

    Ferguson, J. W.; Ferland, G. J.; Pradhan, A. K.

    1995-01-01

    We discuss implications of Hopkins Ultraviolet Telescope (HUT) detections of C III lambda 977 and N III lambda 990 emission from the narrow-line region of the Seyfert 2 galaxy NGC 1068. In their discovery paper Kriss et al. showed that the unexpectedly great strength of these lines implies that the emitting gas must be shock-heated if the lines are collisionally excited. Here we investigate other processes which excite these lines in photoionization equilibrium. Recombination, mainly dielectronic, and continuum fluorescence are strong contributors to the line. The resulting intensities are sensitive to the velocity field of the emitting gas and require that the turbulence be of the same order of magnitude as the observed line width. We propose optical observations that will decide whether the gas is collisionally or radiatively heated.

  16. A study of K{sub s} {Lambda} and {bar {Lambda}} production in hadronic Z{sup 0} decays

    SciTech Connect

    Baird, K.G.; SLD Collaboration

    1994-08-01

    We present a preliminary measurement of the inclusive production rates of K{sub s}, A and X hadrons produced in e{sup +}e{sup {minus}} annihilation at the Z{sup 0} pole. The analysis is based upon approximately 50K Z{sup 0} decays collected in the SLD experiment at SLAC in 1993. The observed rates of (K{sub s}) = 1.02 {plus_minus} 0.02 {plus_minus} 0.09 and ({Lambda}) + ({bar {Lambda}}) = 0.38 {plus_minus} 0.01 {plus_minus} 0.04 are consistent with previous measurements. Our differential cross section peak-position results are shown to be consistent with QCD predictions based on the modified leading logarithm approximation and local parton-hadron duality.

  17. Inactivation of lambda phage infectivity and lambda deoxyribonucleic acid transfection by N-methyl-isatin beta-thiosemicarbazone-copper complexes.

    PubMed

    Levinson, W; Helling, R

    1976-01-01

    The infectivity of intact lambda phage and transfection by lambda deoxyribonucleic acid were inactivated by exposure to the copper complexes of N-methyl-isatin beta-thiosemicarbazone, thiosemicarbazide, and semicarbazide, but not methyl-isatin. No inactivation was observed when these compounds were used in the absence of copper sulfate. This confirms our previous observation that the activity of N-methyl-isatin beta-thiosemicarbazone is mediated by its thiosemicarbazone moiety and that the presence of copper is required for action. This represents the first time, to our knowledge, that semicarbazide has been found to possess antiviral activity. It is clear that these compounds act directly on deoxyribonucleic acid; whether the compounds also act on proteins has not been determined. PMID:769669

  18. Utilizing Synthetic Spectra to Refine Lambda Boo Stars' UV Classification Criteria

    NASA Astrophysics Data System (ADS)

    Cheng, Kwang-Ping; Neff, James E.; Johnson, Dustin; Tarbell, Erik; Romo, Christopher; Steele, Patricia; Gray, Richard O.; Corbally, Christopher J.

    2016-01-01

    Lambda Boo-type stars are a group of late B to early F-type Population I dwarfs that show deficiencies of iron-peak elements (up to 2 dex), but their C, N, O, and S abundances are near solar. This stellar class has recently regained the spotlight because of the directly-imaged planets around a confirmed Lambda Boo star, HR 8799, and a suggested Lambda Boo star Beta Pictoris. The discovery of a giant asteroid belt around Vega, another possible Lambda Boo star, also suggests hidden planets. This possible link between Lambda Boo stars and planet-bearing stars motivates us to study Lambda Boo stars systematically. Since the peculiar nature of the prototype Lambda Bootis was first noticed in 1943, Lambda Boo candidates published in the literature have been selected using widely different criteria. The Lambda Boo label has been applied to almost any peculiar A-type stars that do not fit elsewhere. In order to determine the origin of Lambda Boo stars' unique abundance pattern and to better discriminate between theories explaining the Lambda Boo phenomenon, a consistent working definition of Lambda Boo stars is needed. We have re-evaluated all published Lambda Boo candidates and their available ultraviolet and visible spectra. Using observed and synthetic spectra, we explored the classification of Lambda Boo stars and developed quantitative criteria that discriminate metal-poor stars from bona fide Lambda Boo stars. With model spectra, we demonstrated that the (C I 1657 Angstrom)/ (Al II 1671 Angstrom) line ratio is the best single criterion to distinguish between Lambda Boo stars and metal weak stars, and that one cannot use a single C I/Al II cut-off value as a Lambda Boo classification criterion. The C I/Al II cut-off value is a function of a star's effective temperature and metallicity. Using these stricter Lambda Boo classification criteria, we concluded that neither Beta Pictoris nor Vega should be classified as Lambda Boo stars.

  19. Dynamic processes in Be star atmospheres. I - 'Dimple' formation in the He I lambda 6678 line of lambda Eridani

    NASA Technical Reports Server (NTRS)

    Smith, Myron A.; Polidan, Ronald S.

    1993-01-01

    Several examples of weakenings of the C IV and N V resonance lines are found to coincide with the appearance of lambda 6678 dimples. The absence of variations in other UV lines and in the UV continuum at the same time or nearly the same time argues against dimples being caused by thermal variations from the underlying star. It is instead suggested that the resonance line weakenings are caused by non-LTE effects associated with the condensation of high density structures at some elevation over the star. A simple model of an opaque, essentially stationary slab which backscatters lambda 6678 line radiation into a surrounding 'penumbral' region is presented. Lambda 6678 photons are scattered a second time in this region back into the observer's line of sight and in the process acquire the local projected Doppler shift from rotation. Slabs would probably produce too little emission to be easily detected in the H alpha profile. Their detection in strong He I lines seems the best strategy among early Be stars.

  20. Dynamic processes in Be star atmospheres. I - 'Dimple' formation in the He I lambda 6678 line of lambda Eridani

    NASA Astrophysics Data System (ADS)

    Smith, Myron A.; Polidan, Ronald S.

    1993-05-01

    Several examples of weakenings of the C IV and N V resonance lines are found to coincide with the appearance of lambda 6678 dimples. The absence of variations in other UV lines and in the UV continuum at the same time or nearly the same time argues against dimples being caused by thermal variations from the underlying star. It is instead suggested that the resonance line weakenings are caused by non-LTE effects associated with the condensation of high density structures at some elevation over the star. A simple model of an opaque, essentially stationary slab which backscatters lambda 6678 line radiation into a surrounding 'penumbral' region is presented. Lambda 6678 photons are scattered a second time in this region back into the observer's line of sight and in the process acquire the local projected Doppler shift from rotation. Slabs would probably produce too little emission to be easily detected in the H alpha profile. Their detection in strong He I lines seems the best strategy among early Be stars.

  1. Utilizing Synthetic UV Spectra to Explore the Physical Basis for the Classification of Lambda Boötis Stars

    NASA Astrophysics Data System (ADS)

    Cheng, Kwang-Ping; Neff, James E.; Johnson, Dustin M.; Tarbell, Erik S.; Romo, Christopher A.; Prabhaker, Arvind; Steele, Patricia A.; Gray, Richard O.; Corbally, Christopher J.

    2016-04-01

    Lambda Boo-type stars are a group of late B to early F-type Population I dwarfs that show mild to extreme deficiencies of iron-peak elements (up to 2 dex), but their C, N, O, and S abundances are near solar. This intriguing stellar class has recently regained the spotlight because of the directly imaged planets around a confirmed Lambda Boo star, HR 8799, and a suggested Lambda Boo star, Beta Pictoris. The discovery of a giant asteroid belt around Vega, another possible Lambda Boo star, also suggests hidden planets. The possible link between Lambda Boo stars and planet-bearing stars motivates us to study Lambda Boo stars systematically. Since the peculiar nature of the prototype Lambda Boötis was first noticed in 1943, Lambda Boo candidates published in the literature have been selected using widely different criteria. In order to determine the origin of Lambda Boo stars’ unique abundance pattern and to better discriminate between theories explaining the Lambda Boo phenomenon, a consistent working definition of Lambda Boo stars is needed. We have re-evaluated all published Lambda Boo candidates and their available ultraviolet and visible spectra. In this paper, using observed and synthetic spectra, we explore the physical basis for the classification of Lambda Boo stars, and develop quantitative criteria that discriminate metal-poor stars from bona fide Lambda Boo stars. Based on these stricter Lambda Boo classification criteria, we conclude that neither Beta Pictoris nor Vega should be classified as Lambda Boo stars.

  2. Role of five-quark components in radiative and strong decays of the LAMBDA(1405) resonance

    SciTech Connect

    An, C. S.; Saghai, B.

    2010-04-15

    Within an extended chiral constituent quark model, the three- and five-quark structure of the S{sub 01} resonance LAMBDA(1405) is investigated. Helicity amplitudes for electromagnetic decays [LAMBDA(1405)->LAMBDA(1116)gamma, SIGMA(1194)gamma] and transition amplitudes for strong decays [LAMBDA(1405)->SIGMA(1194)pi, K{sup -}p] are derived, as well as the relevant decay widths. The experimental value for the strong decay width, GAMMA{sub LAMBDA}{sub (1405)-}>{sub (SIGMA{sub pi})}{sup o} =50+-2 MeV, is well reproduced with about 50% of a five-quark admixture in the LAMBDA(1405). Important effects owing to the configuration mixing among LAMBDA{sub 1}{sup 2}P{sub A}, LAMBDA{sub 8}{sup 2}P{sub M}, and LAMBDA{sub 8}{sup 4}P{sub M} are found. In addition, transitions between the three- and the five-quark components in the baryons turn out to be significant in both radiative and strong decays of the LAMBDA(1405) resonance.

  3. Inhibitory effect of tocotrienol on eukaryotic DNA polymerase {lambda} and angiogenesis

    SciTech Connect

    Mizushina, Yoshiyuki . E-mail: mizushin@nutr.kobegakuin.ac.jp; Nakagawa, Kiyotaka; Shibata, Akira; Awata, Yasutoshi; Kuriyama, Isoko; Shimazaki, Noriko; Koiwai, Osamu; Uchiyama, Yukinobu; Sakaguchi, Kengo; Miyazawa, Teruo; Yoshida, Hiromi

    2006-01-20

    Tocotrienols, vitamin E compounds that have an unsaturated side chain with three double bonds, selectively inhibited the activity of mammalian DNA polymerase {lambda} (pol {lambda}) in vitro. These compounds did not influence the activities of replicative pols such as {alpha}, {delta}, and {epsilon}, or even the activity of pol {beta} which is thought to have a very similar three-dimensional structure to the pol {beta}-like region of pol {lambda}. Since {delta}-tocotrienol had the strongest inhibitory effect among the four ({alpha}- to {delta}-) tocotrienols, the isomer's structure might be an important factor in the inhibition of pol {lambda}. The inhibitory effect of {delta}-tocotrienol on both intact pol {lambda} (residues 1-575) and a truncated pol {lambda} lacking the N-terminal BRCA1 C-terminus (BRCT) domain (residues 133-575, del-1 pol {lambda}) was dose-dependent, with 50% inhibition observed at a concentration of 18.4 and 90.1 {mu}M, respectively. However, del-2 pol {lambda} (residues 245-575) containing the C-terminal pol {beta}-like region was unaffected. Tocotrienols also inhibited the proliferation of and formation of tubes by bovine aortic endothelial cells, with {delta}-tocotrienol having the greatest effect. These results indicated that tocotrienols targeted both pol {lambda} and angiogenesis as anti-cancer agents. The relationship between the inhibition of pol {lambda} and anti-angiogenesis by {delta}-tocotrienol was discussed.

  4. The Viral DNA Packaging Motor of Bacteriophage Lambda

    NASA Astrophysics Data System (ADS)

    Catalano, Carlos E.

    2007-03-01

    Terminase enzymes are common to both eukaryotic and prokaryotic double-stranded DNA viruses. These enzymes, which serve as molecular motors that selectively ``package'' viral DNA into a pre-formed procapsid structure, are among the most powerful biological motors characterized to date. Bacteriophage lambda terminase is a heteroligomer composed of gpA and gpNu1 subunits. The smaller gpNu1 subunit is required for specific recognition of viral DNA, a process that is modulated by ATP. The gpA subunit possesses site-specific nuclease and helicase activities that ``mature'' the viral genome prior to packaging. The subunit further possesses a DNA translocase activity that is central to the packaging motor complex. Discrete ATPase sites in gpA modulate the DNA maturation reactions and fuel the DNA packaging reaction. Kinetic characterization of lambda terminase indicates significant interaction between the multiple catalytic sites of the enzyme and has led to a minimal kinetic model describing the assembly of a catalytically-competent packaging motor complex. Biophysical studies demonstrate that purified lambda terminase forms a homogenous, heterotrimeric structure consisting of one gpA subunit in association with two gpNu1 proteins. Four heterotrimers further assemble into a ring-like structure of sufficient size to encircle duplex DNA. The ensemble of data suggests that the ring tetramer represents the biologically relevant, catalytically-competent motor complex responsible for genome processing and packaging reactions. We present a model for the functional DNA packaging motor complex that finds general utility in our global understanding of the enzymology of virus assembly.

  5. An improved lambda-scheme for one-dimensional flows

    NASA Technical Reports Server (NTRS)

    Moretti, G.; Dipiano, M. T.

    1983-01-01

    A code for the calculation of one-dimensional flows is presented, which combines a simple and efficient version of the lambda-scheme with tracking of discontinuities. The latter is needed to identify points where minor departures from the basic integration scheme are applied to prevent infiltration of numerical errors. Such a tracking is obtained via a systematic application of Boolean algebra. It is, therefore, very efficient. Fifteen examples are presented and discussed in detail. The results are exceptionally good. All discontinuites are captured within one mesh interval.

  6. Modeling Uncertainties in Power System by Generalized Lambda Distribution

    NASA Astrophysics Data System (ADS)

    Xiao, Qing

    2014-06-01

    This paper employs the generalized lambda distribution (GLD) to model random variables with various probability distributions in power system. In the context of the probability weighted moment (PWM), an optimization-free method is developed to assess the parameters of GLD. By equating the first four PWMs of GLD with those of the target random variable, a polynomial equation with one unknown is derived to solve for the parameters of GLD. When employing GLD to model correlated multivariate random variables, a method of accommodating the dependency is put forward. Finally, three examples are worked to demonstrate the proposed method.

  7. Origin of the {lambda} Transition in Liquid Sulfur

    SciTech Connect

    Scopigno, T.; Yannopoulos, S. N.; Andrikopoulos, K. S.; Fioretto, D.; Ruocco, G.

    2007-07-13

    Developing a novel experimental technique, we applied photon correlation spectroscopy using infrared radiation in liquid sulfur around T{sub {lambda}}, i.e., in the temperature range where an abrupt increase in viscosity by 4 orders of magnitude is observed upon heating within few degrees. This allowed us--overcoming photoinduced and absorption effects at visible wavelengths--to reveal a chain relaxation process with characteristic time in the millisecond range. These results do rehabilitate the validity of the Maxwell relation in sulfur from an apparent failure, allowing rationalizing of the mechanical and thermodynamic behavior of this system within a viscoelastic scenario.

  8. Bacteriophage lambda cro mutations: effects on activity and intracellular degradation.

    PubMed Central

    Pakula, A A; Young, V B; Sauer, R T

    1986-01-01

    Following random mutagenesis of the bacteriophage lambda cro gene, we have isolated missense mutations that affect approximately half of the 66 residue positions of Cro. About two-thirds of the mutations change residues involved in the maintenance of Cro structure and stability. The corresponding mutant proteins are severely degraded in the cell but often have specific activities near that of wild-type Cro. The remaining mutations affect residues involved in DNA binding. These mutant proteins are present at moderately reduced intracellular levels, but their specific activities are much lower than that of wild type. Images PMID:2947238

  9. GAS CLUMPING IN THE OUTSKIRTS OF {Lambda}CDM CLUSTERS

    SciTech Connect

    Nagai, Daisuke; Lau, Erwin T.

    2011-04-10

    Recent Suzaku X-ray observations revealed that the observed entropy profile of the intracluster medium (ICM) deviates significantly from the prediction of hydrodynamical simulations of galaxy clusters. In this work, we show that gas clumping introduces significant biases in X-ray measurements of the ICM profiles in the outskirts of galaxy clusters. Using hydrodynamical simulations of galaxy cluster formation in a concordance {Lambda}CDM model, we demonstrate that gas clumping leads to an overestimate of the observed gas density and causes flattening of the entropy profile. Our results suggest that gas clumping must be taken into account when interpreting X-ray measurements of cluster outskirts.

  10. Container structure of alpha-alpha-Lambda clusters in 9-Lambda-Beryrium

    NASA Astrophysics Data System (ADS)

    Funaki, Yasuro; Yamada, Taiichi; Hiyama, Emiko; Zhou, Bo; Ikeda, Kiyomi

    2014-11-01

    A new concept of clustering is discussed in Λ hypernuclei using a new-type microscopic cluster model wave function, which has a structure in which constituent clusters are confined in a container, whose size is a variational parameter and which we refer to as a hyper-Tohsaki-Horiuchi-Schuck-Röpke (hyper-THSR) wave function. By using the hyper-THSR wave function, the 2α + Λ-cluster structure in {{^9_Λ}{Be}} is investigated. We show that full microscopic solutions in the 2α + Λ-cluster system, which are given as 2α + Λ Brink-GCM (generator coordinate method) wave functions, are almost perfectly reproduced by the single configurations of the hyper-THSR wave function. The squared overlaps between both wave functions are calculated to be 99.5%, 99.4%, and 97.7% for J^π =0^+ , 2^+ , and 4^+ states, respectively. We also simulate the structural change by adding the Λ particle, by varying the Λ N interaction artificially. With the increase of the Λ N interaction, the Λ particle gets to move more deeply inside the core and strongly invokes the spatial core shrinkage. Accordingly, distinct localized 2α clusters appear in the nucleonic intrinsic density, though, in the {^8Be} nucleus, a gaslike 2α-cluster structure is shown. The origin of the localization is associated with the strong effect of the Pauli principle. We conclude that the container picture of the 2α and Λ clusters is essential in understanding the cluster structure in {^9_ΛBe}, in which the very compact spatial localization of clusters is shown in the density distribution.

  11. Radiative decays of the Sigma0(1385) and Lambda(1520) hyperons

    SciTech Connect

    Simon Taylor; Gordon Mutchler; CLAS Collaboration

    2005-03-01

    The electromagnetic decays of the {Sigma}{sup 0}(1385) and {Lambda}(1520) hyperons were studied in photon-induced reactions {gamma} p {yields} K{sup +} {Lambda}(1116){gamma} in the CLAS detector at the Thomas Jefferson National Accelerator Facility. We report the first observation of the radiative decay of the {Sigma}{sup 0}(1385) and a measurement of the {Lambda}(1520) radiative decay width. For the {Sigma}{sup 0}(1385) {yields} {Lambda}(1116){gamma} transition, we measured a partial width of 479 {+-} 120(stat){sub -100}{sup +81}(sys) keV, larger than all of the existing model predictions. For the {Lambda}(1520) {yields} {Lambda}(1116){gamma} transition, we obtained a partial width of 167 {+-} 43(stat){sub -12}{sup +26}(sys) keV.

  12. Mesonic and nonmesonic absorption of kaon in nuclear matter and {Lambda}(1405) doorway process

    SciTech Connect

    Sekihara, T.; Yamagata-Sekihara, J.; Jido, D.; Kanada-En'yo, Y.

    2010-12-28

    The mesonic and nonmesonic absorptions of kaon into nuclear systems are investigated from a viewpoint of {Lambda}(1405) doorway process. Using a one-meson exchange model in the calculation of the nonmesonic {Lambda}(1405)N{yields}YN transition and using the chiral unitary approach for the description of the {Lambda}(1405), we obtain the nonmesonic transition ratio {Gamma}{sub {Lambda}N}/{Gamma}{sub {Sigma}}{sup 0}{sub N{approx_equal}}1.2 which is almost independent of the nucleon density, and find the total nonmesonic decay width of the {Lambda}(1405) in uniform nuclear matter to be 22 MeV at the normal density. We also calculate the absorption for stopped K{sup -} in nuclear matter, and find that the ''formation rate'' of {Lambda}(1405) is important for the density dependence and the absolute value of the absorption potential of kaon in nuclear matter.

  13. Fully covariant radiation force on a polarizable particle

    NASA Astrophysics Data System (ADS)

    Pieplow, Gregor; Henkel, Carsten

    2013-02-01

    The electromagnetic force on a polarizable particle is calculated in a covariant framework. Local equilibrium temperatures for the electromagnetic field and the particle's dipole moment are assumed, using a relativistic formulation of the fluctuation-dissipation theorem. Two examples illustrate radiative friction forces: a particle moving through a homogeneous radiation background and above a planar interface. Previous results for arbitrary relative velocities are recovered in a compact way. The authors acknowledge the use of the Legacy Archive for Microwave Background Data Analysis (LAMBDA) in the video abstract. Support for LAMBDA is provided by the NASA Office of Space Science.

  14. Spectroscopic study of the Lambda hypernuclei by the (e,e'K+) reaction

    SciTech Connect

    Toshinobu Miyoshi

    2003-03-31

    Hypernuclear spectroscopy study via the (e,e'K+) reaction has been carried out for the first time, establishing a new technique to study Lambda hypernuclei. The high quality electron beam at Jefferson Lab made it possible to measure Lambda hypernuclear spectra with an energy resolution better than 1 MeV (FWHM). The present experiment was designed to make full use of the virtual photon flux, which peaks at very forward angles, by detecting scattered electrons at 0 degrees. Scattered positive kaons were also detected near 0 degrees, where the cross section of the kaon photo-production is maximized. This unique kinematical configuration was realized with the HyperNuclear Spectrometer System (HNSS), which consisted of the Short-Orbit Spectrometer, the Enge Split-Pole Spectrometer, and the splitter magnet. The Lambda12B mass spectrum was measured in the 12C(e,e'K+)Lambda12B reaction with 0.9 MeV (FWHM) energy resolution. The averaged binding energy of the Lambda12B ground state doublet was obtained to be 11.7 ± 0.1 (statistical) ± 0.3 (systematic) MeV, which is consistent with emulsion data. The general spectral structure of the 12C(e,e'K+) Lambda12B reaction was found to be similar to that of the 12C(Lambda+,K+)Lambda12C reaction, showing characteristic peaks corresponding to sLambda and pLambda orbits, as well as a few core-excited states. The cross section of the Lambda12B ground state doublet was derived to be 117 ± 13 (statistical) ± 14 (systematic) nb/sr. The theoretical prediction of the cross section was consistent with the present result, validating DWIA calculation for hypernuclear yields. The present study proved the effectiveness of the (e,e'K+) reaction for future Lambda hypernuclear spectroscopy studies.

  15. Detection of single lambda DNA fragments by flow cytometry

    SciTech Connect

    Johnson, M.E.; Goodwin, P.M.; Ambrose, W.P.; Martin, J.C.; Marrone, B.L.; Keller, R.A. )

    1993-01-01

    The authors have demonstrated flow cytometric detection and sizing of single pieces of fluorescently stained lambda DNA (48.5 kb) and individual Kpn I restriction fragments of lambda DNA at 17.05 kb and 29.95 kb. DNA fragments were stained stoichiometrically with an intercalating dye such that the fluorescence from each fragment was directly proportional to fragment length. Laser powers range from 10 to 100 mW and transit times through the focused laser beam were several milliseconds. Measurements were made using time-resolved single photon counting of the detected fluorescence emission from individual stained DNA fragments. Samples were analyzed at rates of about 50 fragments per second. The measured fluorescence intensities are linearly correlated with DNA fragment length over the range measured. Detection sensitivity and resolution needed for analysis of small pieces of DNA are discussed and a comparison of single photon counting measurements of DNA fragments to measurements using more conventional flow cytometers is made. Applications of this methodology to DNA sizing and DNA fingerprinting are discussed.

  16. Absorption Kinetics of Phage Lambda on Its Host Under Shear Flow

    NASA Astrophysics Data System (ADS)

    Yip, C. W.; Wu, X. L.

    2000-03-01

    Classical blender experiment by Hershey and Chase played a seminal role in illustrating the infectious process of bacteriophage to its host, and showed unequivocally that DNA is responsible for the transmission of heredity. Subsequent works by others have established that interaction between phage particles and bacterial cells is a diffusion-limited process in that, statistically speaking, each collision results in an irreversible infection. However, such a result is hard to reconcile with the fact that the infection appears to be independent of the density of phage receptors on the bacterial cell membrane. Thus, quantitative experiments showing how a phage finds its receptor and how long does it take would be valuable to this paradoxical view. Simple calculations based on Brownian motion of the phage particles show that the interaction time between the receptor and the phage is given by tau=b^2/(5D), where b is the length of the phage and D is its diffusion coefficient. Using a shear flow apparatus we study absorption kinetics of lambda phage on E. Coli (strain YMEL) under different flow conditions, and the results are compared with a simple diffusion model taking into account the hydrodynamic convection and the interaction time tau.

  17. Beta-sitosterol-3-O-beta-D-glucopyranoside: a eukaryotic DNA polymerase lambda inhibitor.

    PubMed

    Mizushina, Yoshiyuki; Nakanishi, Rumi; Kuriyama, Isoko; Kamiya, Kohei; Satake, Toshiko; Shimazaki, Noriko; Koiwai, Osamu; Uchiyama, Yukinobu; Yonezawa, Yuko; Takemura, Masaharu; Sakaguchi, Kengo; Yoshida, Hiromi

    2006-05-01

    Beta-sitosterol-3-O-beta-D-glucopyranoside (compound 1), a steroidal glycoside isolated from onion (Allium cepa L.) selectively inhibited the activity of mammalian DNA polymerase lambda (pol lambda) in vitro. The compound did not influence the activities of replicative DNA polymerases such as alpha, delta and epsilon, but also showed no effect even on the activity of pol beta which is thought to have a very similar three-dimensional structure to the pol beta-like region of pol lambda. Since parts of compound 1 such as beta-sitosterol (compound 2) and D-glucose (compound 3) did not influence the activities of any enzymes tested, the converted structure of compounds 2 and 3 might be important for pol lambda inhibition. The inhibitory effect of compound 1 on both intact pol lambda (i.e. residues 1-575) and a truncated pol lambda lacking the N-terminal BRCA1 C-terminus (BRCT) domain (133-575, del-1 pol lambda) was dose-dependent, and 50% inhibition was observed at a concentration of 9.1 and 5.4 microM, respectively. The compound 1-induced inhibition of del-1 pol lambda activity was non-competitive with respect to both the DNA template-primer and the dNTP substrate. On the basis of these results, the pol lambda inhibitory mechanism of compound 1 is discussed. PMID:16621516

  18. Probing internal structure of {Lambda}(1405) in meson-baryon dynamics with chiral symmetry

    SciTech Connect

    Sekihara, Takayasu; Hyodo, Tetsuo; Jido, Daisuke

    2011-10-21

    The internal structure of the resonant {Lambda}(1405) state is investigated based on meson-baryon coupled-channels chiral dynamics, by evaluating density distributions obtained from the form factors of the {Lambda}(1405) state. The form factors are extracted from current-coupled scattering amplitudes in which the current is coupled to the constituent hadrons inside {Lambda}(1405). Using several probe interactions and channel decomposition, we find that the resonant {Lambda}(1405) state is dominantly composed of widely spread K-bar around N, with a small fraction of the escaping {pi}{Sigma} component.

  19. Radiative decay of {Lambda}{sub c}(2940){sup +} in a hadronic molecule picture

    SciTech Connect

    Dong, Yubing; Faessler, Amand; Gutsche, Thomas; Lyubovitskij, Valery E.; Kumano, S.

    2010-08-01

    The {Lambda}{sub c}(2940){sup +} baryon with quantum numbers J{sup P}=(1/2){sup +} is considered as a molecular state composed of a nucleon and D{sup *} meson. We give predictions for the width of the radiative decay process {Lambda}{sub c}(2940){sup +}{yields}{Lambda}{sub c}(2286){sup +}+{gamma} in this interpretation. Based on our results we argue that an experimental determination of the radiative decay width of {Lambda}{sub c}(2940){sup +} is important for the understanding of its intrinsic properties.

  20. Lambda production in electron-positron annihilation at 29 GeV

    SciTech Connect

    Baden, A.R.

    1986-08-01

    The inclusive cross-secton for the production of the singly-strange baryons lambda and anti lambda, along with the differential cross-sections in momentum and energy, are measured by e/sup +/e/sup -/ annihilation at a center-of-mass energy of 29GeV. The charged decay mode lambda ..-->.. p..pi.. is used in a search for polarization. Such a polarization may be used as a check of CP invariance in lambda production. The sample of events with two detected decays is analyzed for correlations in production angle. 43 refs., 44 figs.

  1. High-resolution view of bacteriophage lambda gene expression by ribosome profiling

    PubMed Central

    Liu, Xiaoqiu; Jiang, Huifeng; Gu, Zhenglong; Roberts, Jeffrey W.

    2013-01-01

    Bacteriophage lambda is one of the most extensively studied organisms and has been a primary model for understanding basic modes of genetic regulation. Here, we examine the progress of lambda gene expression during phage development by ribosome profiling and, thereby, provide a very-high-resolution view of lambda gene expression. The known genes are expressed in a predictable fashion, authenticating the analysis. However, many previously unappreciated potential open reading frames become apparent in the expression analysis, revealing an unexpected complexity in the pattern of lambda gene function. PMID:23812753

  2. Measurement of the Lambda_b Lifetime in Lambda_b -> Lambda_c+ pi- Decays in p-pbar Collisions at sqrt(s) = 1.96 TeV

    SciTech Connect

    Aaltonen, T.; Adelman, J.; Alvarez Gonzalez, B.; Amerio, S.; Amidei, D.; Anastassov, A.; Annovi, A.; Antos, J.; Apollinari, G.; Apresyan, A.; Arisawa, T.; /Waseda U. /Dubna, JINR

    2009-12-01

    We report a measurement of the lifetime of the {Lambda}{sub b}{sup 0} baryon in decays to the {Lambda}{sub c}{sup +} {pi}{sup -} final state in a sample corresponding to 1.1 fb{sup -1} collected in p{bar p} collisions at {radical}s = 1.96 TeV by the CDF II detector at the Tevatron collider. Using a sample of about 3000 fully reconstructed {Lambda}{sub b}{sup 0} events we measure {tau}({Lambda}{sub b}{sup 0}) = 1.401 {+-} 0.046 (stat) {+-} 0.035 (syst) ps (corresponding to c{tau}({Lambda}{sub b}{sup 0}) = 420.1 {+-} 13.7 (stat) {+-} 10.6 (syst) {micro}m, where c is the speed of light). The ratio of this result and the world average B{sup 0} lifetime yields {tau}({Lambda}{sub b}{sup 0})/{tau}(B{sup 0}) = 0.918 {+-} 0.038 (stat and syst), in good agreement with recent theoretical predictions.

  3. Irreversible adsorption of particles on heterogeneous surfaces.

    PubMed

    Adamczyk, Zbigniew; Jaszczółt, Katarzyna; Michna, Aneta; Siwek, Barbara; Szyk-Warszyńska, Lilianna; Zembala, Maria

    2005-12-30

    Methods of theoretical and experimental evaluation of irreversible adsorption of particles, e.g., colloids and globular proteins at heterogeneous surfaces were reviewed. The theoretical models were based on the generalized random sequential adsorption (RSA) approach. Within the scope of these models, localized adsorption of particles occurring as a result of short-ranged attractive interactions with discrete adsorption sites was analyzed. Monte-Carlo type simulations performed according to this model enabled one to determine the initial flux, adsorption kinetics, jamming coverage and the structure of the particle monolayer as a function of the site coverage and the particle/site size ratio, denoted by lambda. It was revealed that the initial flux increased significantly with the site coverage theta(s) and the lambda parameter. This behavior was quantitatively interpreted in terms of the scaled particle theory. It also was demonstrated that particle adsorption kinetics and the jamming coverage increased significantly, at fixed site coverage, when the lambda parameter increased. Practically, for alpha = lambda2theta(s) > 1 the jamming coverage at the heterogeneous surfaces attained the value pertinent to continuous surfaces. The results obtained prove unequivocally that spherically shaped sites were more efficient in binding particles in comparison with disk-shaped sites. It also was predicted that for particle size ratio lambda < 4 the site multiplicity effect plays a dominant role, affecting significantly the structure of particle monolayers and the jamming coverage. Experimental results validating main aspects of these theoretical predictions also have been reviewed. These results were derived by using monodisperse latex particles adsorbing on substrates produced by covering uniform surface by adsorption sites of a desired size, coverage and surface charge. Particle deposition occurred under diffusion-controlled transport conditions and their coverage was

  4. Particle-type dependence of azimuthal anisotropy and nuclearmodification of particle production in Au+Au collisions at sNN = 200GeV

    SciTech Connect

    Adams, J.; Adler, C.; Aggarwal, M.M.; Ahammed, Z.; Amonett, J.; Anderson, B.D.; Anderson, M.; Arkhipkin, D.; Averichev, G.S.; Badyal,S.K.; Balewski, J.; Barannikova, O.; Barnby, L.S.; Baudot, J.; Bekele,S.; Belaga, V.V.; Bellwied, R.; Berger, J.; Bezverkhny, B.I.; Bhardwaj,S.; Bhaskar, P.; Bhati, A.K.; Billmeier, A.; Bland, L.C.; Blyth, C.O.; Bonner, B.E.; Botje, M.; Boucham, A.; Brandin, A.; Bravar, A.; Cadman,R.V.; Cai, X.Z.; Caines, H.; Calderon de la Barca Sanchez, M.; Carroll,J.; Castillo, J.; Castro, M.; Cebra, D.; Chaloupka, P.; Chattopadhyay,S.; Chen, H.F.; Chen, Y.; Chernenko, S.P.; Cherney, M.; Chikanian, A.; Choi, B.; Christie, W.; Coffin, J.P.; Cormier, T.M.; Cramer, J.G.; Crawford, H.J.; Das, D.; Das, S.; Derevschikov, A.A.; Didenko, L.; Dietel, T.; Dong, W.J.; Dong, X.; Draper, J.E.; Du, F.; Dubey, A.K.; Dunin, V.B.; Dunlop, J.C.; Dutta Majumdar, M.R.; Eckardt, V.; Efimov,L.G.; Emelianov, V.; Engelage, J.; Eppley, G.; Erazmus, B.; Fachini, P.; Faine, V.; Faivre, J.; Fatemi, R.; Filimonov, K.; Filip, P.; Finch, E.; Fisyak, Y.; Flierl, D.; Foley, K.J.; Fu, J.; Gagliardi, C.A.; Gagunashvili, N.; Gans, J.; Ganti, M.S.; Gutierrez, T.D.; Gaudichet, L.; Germain, M.; Geurts, F.; Ghazikhanian, V.; Ghosh, P.; Gonzalez, J.E.; Grachov, O.; Grigoriev, V.; Gronstal, S.; Drosnick, D.; Guedon, M.; Guertin, S.M.; Gushin, E.; Hallman, T.J.; Hardtke, D.; Harris, J.W.; Heinz, M.; Henry, T.W.; Heppelmann, S.; Herston, T.; Hippolyte, B.; Hirsch, A.; Hjort, E.; Hoffmann, G.W.; Horsley, M.; Huang, H.Z.; Huang,S.L.; Humanic, T.J.; Igo, G.; Ishihara, A.; Jacobs, P.; Jacobs, W.W.; Janik, M.; Johnson, I.; Jones, P.G.; Judd, E.G.; Kabana, S.; Kaneta, M.; Kaplan, M.; Keane, D.; Kiryluk, J.; Kisiel, A.; Klay, J.; Klein, S.R.; Klyachko, A.; Koetke, D.D.; Kollegger, T.; Konstantinov, A.; Kopytine,S.M.; Kotchenda, L.; Kovalenko, A.D.; Kramer, M.; Kravtsov, P.; Krueger,K.; Kuhn, C.; Kulikov, A.I.; Kunde, G.J.; Kunz, C.L.; Kutuev, R.K.; et al.

    2003-06-18

    We present STAR measurements of the azimuthal anisotropy parameter v{sub 2} and the binary-collision scaled centrality ratio R{sub CP} for kaons and lambdas ({Lambda} + {bar {Lambda}}) at mid-rapidity in Au+Au collisions at {radical}s{sub NN} = 200 GeV. In combination, the v{sub 2} and R{sub CP} particle-type dependencies contradict expectations from partonic energy loss followed by standard fragmentation in vacuum. We establish p{sub T} {approx} 5 GeV/c as the value where the centrality dependent baryon enhancement ends. The K{sub S}{sup 0} and {Lambda} + {bar {Lambda}} v{sub 2} values are consistent with expectations of constituent-quark-number scaling from models of hadron formation by parton coalescence or recombination.

  5. BULLET CLUSTER: A CHALLENGE TO {Lambda}CDM COSMOLOGY

    SciTech Connect

    Lee, Jounghun; Komatsu, Eiichiro

    2010-07-20

    To quantify how rare the bullet-cluster-like high-velocity merging systems are in the standard {Lambda} cold dark matter (CDM) cosmology, we use a large-volume (27 h {sup -3} Gpc{sup 3}) cosmological N-body MICE simulation to calculate the distribution of infall velocities of subclusters around massive main clusters. The infall velocity distribution is given at (1-3)R{sub 200} of the main cluster (where R{sub 200} is similar to the virial radius), and thus it gives the distribution of realistic initial velocities of subclusters just before collision. These velocities can be compared with the initial velocities used by the non-cosmological hydrodynamical simulations of 1E0657-56 in the literature. The latest parameter search carried out by Mastropietro and Burkert has shown that an initial velocity of 3000 km s{sup -1} at about 2R{sub 200} is required to explain the observed shock velocity, X-ray brightness ratio of the main and subcluster, X-ray morphology of the main cluster, and displacement of the X-ray peaks from the mass peaks. We show that such a high infall velocity at 2R{sub 200} is incompatible with the prediction of a {Lambda}CDM model: the probability of finding 3000 km s{sup -1} in (2-3)R{sub 200} is between 3.3 x 10{sup -11} and 3.6 x 10{sup -9}. A lower velocity, 2000 km s{sup -1} at 2R{sub 200}, is also rare, and moreover, Mastropietro and Burkert have shown that such a low initial velocity does not reproduce the X-ray brightness ratio of the main and subcluster or morphology of the main cluster. Therefore, we conclude that the existence of 1E0657-56 is incompatible with the prediction of a {Lambda}CDM model, unless a lower infall velocity solution for 1E0657-56 with {approx}<1800 km s{sup -1} at 2R{sub 200} is found.

  6. Longitudinal spin transfer to {lambda} and {lambda} hyperons in polarized proton-proton collisions at {radical}(s)=200 GeV

    SciTech Connect

    Abelev, B. I.; Barannikova, O.; Betts, R. R.; Garcia-Solis, E. J.; Hofman, D. J.; Hollis, R. S.; Iordanova, A.; Kauder, K.; Suarez, M. C.; Aggarwal, M. M.; Bhati, A. K.; Kumar, L.; Pruthi, N. K.; Ahammed, Z.; Chattopadhyay, S.; Dutta Mazumdar, M. R.; Ganti, M. S.; Ghosh, P.; Mohanty, B.; Nayak, T. K.

    2009-12-01

    The longitudinal spin transfer, D{sub LL}, from high energy polarized protons to {lambda} and {lambda} hyperons has been measured for the first time in proton-proton collisions at {radical}(s)=200 GeV with the STAR detector at the Relativistic Heavy Ion Collider. The measurements cover pseudorapidity, {eta}, in the range |{eta}|<1.2 and transverse momenta, p{sub T}, up to 4 GeV/c. The longitudinal spin transfer is found to be D{sub LL}=-0.03{+-}0.13(stat){+-}0.04(syst) for inclusive {lambda} and D{sub LL}=-0.12{+-}0.08(stat){+-}0.03(syst) for inclusive {lambda} hyperons with <{eta}>=0.5 and =3.7 GeV/c. The dependence on {eta} and p{sub T} is presented.

  7. Longitudinal Spin Transfer to Lambda and Lambda bar Hyperons in Polarized Proton-Proton Collisions at sqrt s = 200 GeV

    SciTech Connect

    STAR Collaboration; Abelev, Betty

    2010-07-05

    The longitudinal spin transfer, D{sub LL}, from high energy polarized protons to {Lambda} and {bar {Lambda}} hypersons has been measured for the first time in proton-proton collisions at {radical}s = 200 GeV with the STAR detector at RHIC. The measurements cover pseudorapidity, {eta}, in the range |{eta}| < 1.2 and transverse momenta, p{sub T}, up to 4 GeV/c. The longitudinal spin transfer is found to be D{sub LL} = -0.03{+-}0.13(stat){+-}0.04(syst) for inclusive {Lambda} and D{sub LL} = -0.12{+-}0.08(stat){+-}0.03(syst) for inclusive {bar {Lambda}} hyperons with <{eta}> = 0.5 and = 3.7 GeV/c. The dependence on {eta} and p{sub T} is presented.

  8. Longitudinal Spin Transfer of LAMBDA and LAMBDA-bar Hyperons in Polarized Proton-Proton Collisions at sq root(s) = 200 GeV

    SciTech Connect

    Sichtermann, Ernst

    2009-08-04

    The longitudinal spin transfer D{sub LL} of LAMBDA and LAMBDA-bar hyperons produced with large transverse momenta P{sub T} in polarized proton-proton collisions is sensitive to the helicity distribution functions of strange quarks and anti-quarks, and to polarized fragmentation functions. This contribution reports a measurement of the longitudinal spin transfer D{sub LL} in the inclusive production of LAMBDA and LAMBDA-bar hyperons at central rapidities in polarized proton-proton collisions at a center of mass energy of sq root(s) = 200 GeV. The data were collected with the STAR experiment at RHIC and correspond to a approx =3 pb{sup -1} luminosity and a approx =50% beam polarization.

  9. Longitudinal spin transfer to {Lambda} and {bar Lambda} hyperons in polarized proton-proton collisions at {radical}{ovr s} = 200 GeV.

    SciTech Connect

    Abelev, B. I.; Aggarwal, M. M.; Ahammed, Z.; Alakhverdyants, A. V.; Anderson, B. D.; Bridgeman, A.; Krueger, K.; Spinka, H. M.; Underwood, D. G.; STAR Collaboration

    2009-01-01

    The longitudinal spin transfer, D{sub LL}, from high energy polarized protons to {Lambda} and {bar {Lambda}} hyperons has been measured for the first time in proton-proton collisions at {radical}s = 200 GeV with the STAR detector at the Relativistic Heavy Ion Collider. The measurements cover pseudorapidity, {eta}, in the range |{eta}| < 1.2 and transverse momenta, p{sub T}, up to 4 GeV/c. The longitudinal spin transfer is found to be D{sub LL} = -0.03 {+-} 0.13(stat) {+-} 0.04(syst) for inclusive {Lambda} and D{sub LL} = -0.12 {+-} 0.08(stat) {+-} 0.03(syst) for inclusive {bar {Lambda}} hyperons with {eta} = 0.5 and p{sub T} =3.7 GeV/c. The dependence on {eta} and p{sub T} is presented.

  10. Vortex Loops at the Superfluid Lambda Transition: An Exact Theory?

    NASA Technical Reports Server (NTRS)

    Williams, Gary A.

    2003-01-01

    A vortex-loop theory of the superfluid lambda transition has been developed over the last decade, with many results in agreement with experiments. It is a very simple theory, consisting of just three basic equations. When it was first proposed the main uncertainty in the theory was the use Flory scaling to find the fractal dimension of the random-walking vortex loops. Recent developments in high-resolution Monte Carlo simulations have now made it possible to verify the accuracy of this Flory-scaling assumption. Although the loop theory is not yet rigorously proven to be exact, the Monte Carlo results show at the least that it is an extremely good approximation. Recent loop calculations of the critical Casimir effect in helium films in the superfluid phase T < Tc will be compared with similar perturbative RG calculations in the normal phase T > Tc; the two calculations are found to match very nicely right at Tc.

  11. Arcs and Clumps in the Uranian Lambda Ring

    NASA Technical Reports Server (NTRS)

    Showalter, Mark R.

    1995-01-01

    Careful reprocessing of the Voyager images reveals that the Uranian lambda ring has marked longitudinal variations in brightness comparable in magnitude to those in Saturn's F ring and Neptune's Adams ring. The ring's variations show a dominant five-cycle (72-degree) periodicity, although additional structure down to scales of about 0.5 degree is also present. The ring's shape is defined by a small overall eccentricity plus a six-cycle (60-degree) sinusoidal variation of radial amplitude around 4 kilometers. Both of these properties can be explained by the resonant perturbations of a moon at a semimajor axis of 56,479 kilometers, but no known moon orbits at this location. Unfortunately, the mass required suggests that such a body should have been imaged by Voyager.

  12. Magnetized completion of the {lambda}CDM paradigm

    SciTech Connect

    Giovannini, Massimo; Kunze, Kerstin E.

    2008-03-15

    The standard {lambda}CDM paradigm is complemented with a magnetized contribution whose effects on the anisotropies of the cosmic microwave background are assessed by means of a dedicated numerical approach. The accuracy on the temperature and polarization correlations stems from the inclusion of the large-scale magnetic fields both at the level of the initial conditions and at the level of the Einstein-Boltzmann hierarchy which is consistently embedded in a generalized magnetohydrodynamical framework. Examples of the calculations of the temperature and polarization angular power spectra are illustrated and discussed. The reported results and the described numerical tools set the groundwork for a consistent inclusion of a magnetized contribution in current strategies of cosmological parameter estimation.

  13. High resolution spectroscopic study of Be10Lambda;

    NASA Astrophysics Data System (ADS)

    Gogami, T.; Chen, C.; Kawama, D.; Achenbach, P.; Ahmidouch, A.; Albayrak, I.; Androic, D.; Asaturyan, A.; Asaturyan, R.; Ates, O.; Baturin, P.; Badui, R.; Boeglin, W.; Bono, J.; Brash, E.; Carter, P.; Chiba, A.; Christy, E.; Danagoulian, S.; de Leo, R.; Doi, D.; Elaasar, M.; Ent, R.; Fujii, Y.; Fujita, M.; Furic, M.; Gabrielyan, M.; Gan, L.; Garibaldi, F.; Gaskell, D.; Gasparian, A.; Han, Y.; Hashimoto, O.; Horn, T.; Hu, B.; Hungerford, Ed. V.; Jones, M.; Kanda, H.; Kaneta, M.; Kato, S.; Kawai, M.; Khanal, H.; Kohl, M.; Liyanage, A.; Luo, W.; Maeda, K.; Margaryan, A.; Markowitz, P.; Maruta, T.; Matsumura, A.; Maxwell, V.; Mkrtchyan, A.; Mkrtchyan, H.; Nagao, S.; Nakamura, S. N.; Narayan, A.; Neville, C.; Niculescu, G.; Niculescu, M. I.; Nunez, A.; Nuruzzaman, Okayasu, Y.; Petkovic, T.; Pochodzalla, J.; Qiu, X.; Reinhold, J.; Rodriguez, V. M.; Samanta, C.; Sawatzky, B.; Seva, T.; Shichijo, A.; Tadevosyan, V.; Tang, L.; Taniya, N.; Tsukada, K.; Veilleux, M.; Vulcan, W.; Wesselmann, F. R.; Wood, S. A.; Yamamoto, T.; Ya, L.; Ye, Z.; Yokota, K.; Yuan, L.; Zhamkochyan, S.; Zhu, L.; Hksjlab E05-115 Collaboration

    2016-03-01

    Spectroscopy of a Be10Lambda; hypernucleus was carried out at JLab Hall C using the (e ,e'K+) reaction. A new magnetic spectrometer system (SPL+HES+HKS), specifically designed for high resolution hypernuclear spectroscopy, was used to obtain an energy spectrum with a resolution of ˜0.78 MeV (FWHM). The well-calibrated spectrometer system of the present experiment using p (e ,e'K+)Λ ,Σ0 reactions allowed us to determine the energy levels; and the binding energy of the ground-state peak (mixture of 1- and 2- states) was found to be BΛ=8.55 ±0.07 (stat . ) ±0.11 (sys . ) MeV. The result indicates that the ground-state energy is shallower than that of an emulsion study by about 0.5 MeV which provides valuable experimental information on the charge symmetry breaking effect in the Λ N interaction.

  14. Behavior of Coliphage Lambda in Shigella flexneri 2a

    PubMed Central

    Gemski, P.; Alexeichik, J. A.; Baron, L. S.

    1972-01-01

    The insensitivity of wild-type Shigella flexneri 2a to coliphage λ is a consequence of its native genetic defect in the malA gene cluster. The “smooth” S. flexneri 2a lipopolysaccharide layer affects the efficient adsorption of λ. Derivatives, capable of serving as functional hosts for λ, were obtained by repairing the malA lesion, enabling the expression of the malB-λrcp region of S. flexneri. Introduction of a mutation into S. flexneri causing a “rough” lipopolysaccharide character resulted in more efficient adsorption of λ. Such S. flexneri hosts can be stably lysogenized and upon induction yield gal+-transducing lysates. Lambda propagated on a malA+ rough S. flexneri host was restricted by Escherichia coli K-12 and E. coli B, but not by E. coli C. This S. flexneri host did not restrict λ grown on these E. coli strains. PMID:4563593

  15. A lambda sensor with a plate-type structure

    SciTech Connect

    Byung-Ki Kim; Jong-Heun Lee; Chungho Lee; Hoin Kim

    1996-12-31

    A new lambda sensor was constructed with a plate-type structure using a single YSZ (Yttria Stabilized Zirconia) solid electrolyte plate shared by electrochemical oxygen pumping and sensing cells. A reference electrode with the constant oxygen concentration was used instead of air reference electrode. Oxygen was formed by the electrochemical oxygen pumping from the electrode 1 to the electrode 3 which was covered by a porous layer for gas diffusion barrier. The voltages between the electrode 2 and 3 were used as the sensing signal. A protective layer was established on the electrodes 1 and 2. The sensor was fabricated by co-firing of laminate at 1450{degrees}C, for 2 hrs. The dynamic response characteristics were tested in the exhaust gas of a real engine and the static ones were studied in a controlled test gas containing N{sub 2}, O{sub 2}, CO, and CO{sub 2} gases.

  16. Spectral diagnostics of high energy emission in lambda Eri

    NASA Technical Reports Server (NTRS)

    Smith, Myron

    1995-01-01

    Multi-line observations of the optical spectrum of lambda Eri demonstrates that rapidly varying, low-velocity emissions occur in several He I lines even when H alpha shows no emission. A peculiar aspect of the He I emissions is that the ratio 5876/6678 is = 1. A theory of helium line formation generally admits two common emission mechanisms. The first is recombination/cascades, which is well known to give a ratio of greater than or equal to 3. The second is a non-LTE effect that occurs in hot (O-type) photospheres when resonance He I 584 radiation becomes transparent and drives single lines along into the emission. To accommodate a ratio of 5876/6678 = 1 may require that both processes sometimes operate at the same time, presumably in separate localities near the surface of this star.

  17. Genomic variation in the porcine immunoglobulin lambda variable region.

    PubMed

    Guo, Xi; Schwartz, John C; Murtaugh, Michael P

    2016-04-01

    Production of a vast antibody repertoire is essential for the protection against pathogens. Variable region germline complexity contributes to repertoire diversity and is a standard feature of mammalian immunoglobulin loci, but functional V region genes are limited in swine. For example, the porcine lambda light chain locus is composed of 23 variable (V) genes and 4 joining (J) genes, but only 10 or 11 V and 2 J genes are functional. Allelic variation in V and J may increase overall diversity within a population, yet lead to repertoire holes in individuals lacking key alleles. Previous studies focused on heavy chain genetic variation, thus light chain allelic diversity is not known. We characterized allelic variation of the porcine immunoglobulin lambda variable (IGLV) region genes. All intact IGLV genes in 81 pigs were amplified, sequenced, and analyzed to determine their allelic variation and functionality. We observed mutational variation across the entire length of the IGLV genes, in both framework and complementarity determining regions (CDRs). Three recombination hotspot motifs were also identified suggesting that non-allelic homologous recombination is an evolutionarily alternative mechanism for generating germline antibody diversity. Functional alleles were greatest in the most highly expressed families, IGLV3 and IGLV8. At the population level, allelic variation appears to help maintain the potential for broad antibody repertoire diversity in spite of reduced gene segment choices and limited germline sequence modification. The trade-off may be a reduction in repertoire diversity within individuals that could result in an increased variation in immunity to infectious disease and response to vaccination. PMID:26791019

  18. Search for the Baryon and Lepton Number Violating Decays tau to Lambda h

    SciTech Connect

    Aubert, B.

    2006-11-28

    The authors have searched for the violation of baryon number B and lepton number L in the (B-L)-conserving modes {tau}{sup -} {yields} {bar {Lambda}}{sup 0}{pi}{sup -} and {tau}{sup -} {yields} {bar {Lambda}}{sup 0}K{sup -} as well as the (B-L)-violating modes {tau}{sup -} {yields} {Lambda}{sup 0}{pi}{sup -} and {tau}{sup -} {yields} {Lambda}{sup 0}K{sup -} using 237 fb{sup -1} of data collected with the BABAR detector at the PEP-II asymmetric-energy e{sup +}e{sup -} storage ring. They do not observe any signal and determine preliminary upper limits on the branching fractions {Beta}({tau}{sup -} {yields} {bar {Lambda}}{sup 0}{pi}{sup -}) < 5.9 x 10{sup -8}, {Beta}({tau}{sup -} {yields} {Lambda}{sup 0}{pi}{sup -}) < 5.8 x 10{sup -8}, {Beta}({tau}{sup -} {yields} {bar {Lambda}}{sup 0}K{sup -}) < 7.2 x 10{sup -8}, and {Beta}({tau}{sup -} {yields} {Lambda}{sup 0}K{sup -}) < 15 x 10{sup -8} at 90% confidence level.

  19. Plasmid-Controlled Variation in the Content of Methylated Bases in Bacteriophage Lambda Deoxyribonucleic Acid

    PubMed Central

    Hattman, Stanley

    1972-01-01

    The N6-methyladenine (MeAde) and 5-methylcytosine (MeC) contents in deoxyribonucleic acid (DNA) of bacteriophage lambda has been analyzed as a function of host specificity. The following facts have emerged: (i) lambda grown on strains harboring the P1 prophage contain ca. 70 more MeAde residues/DNA molecule than lambda grown either in the P1-sensitive parent, or in a P1 immune-defective lysogen which does not confer P1 modification; (ii) lambda grown on strains harboring the N-3 drug-resistance factor contain ca. 60 more MeC residues/DNA molecule than lambda grown on the parental strain lacking the factor; (iii) lambda grown in Escherichia coli B strains is devoid of MeC, whereas lambda grown in a B (N-3) host contains a high level of MeC; (iv) the MeAde content in lambda DNA is not affected by the N-3 factor. These results suggest that P1 controls an adenine-specific DNA methylase, and that the N-3 plasmid controls a cytosine-specific DNA methylase. The N-3 factor has been observed previously to direct cytosine-specific methylation of phage P22 DNA and E. coli B DNA in vivo; in vitro studies presented here demonstrate this activity. PMID:4561202

  20. Heavy gauge boson and {Lambda}{sub b} baryon searches at CDF

    SciTech Connect

    Maeshima, K.; The CDF Collaboration

    1992-06-01

    We have searched for new gauge bosons (W{prime}{yields} lv, Z{prime} {yields} ll) and b baryons ({Lambda}{sub b} {yields} {psi}{Lambda}{sup 0}) in p{bar p} collisions at {radical}s = 1.8 TeV from the 1988--1989 run of the Collider Detector at Fermilab (CDF). We present 95% confidence level (C.L.) limits on the W{prime} and Z{prime} production cross section in leptonic decay modes. The nonobservation of these processes leads to limits of M{sub w{prime}} > 520 GeV/c{sub 2} and M{sub z{prime}} > 412 GeV/c{sub 2} (95% C.L.), assuming Standard Model coupling strengths. We see no evidence for the signal ({Lambda}{sub b} {yields} {psi}{Lambda}{sup 0}) in our {psi} sample ({psi} {yields} {mu}{mu}) around the {Lambda}{sub b} mass region of 5600 MeV. We set an upper limit on F({Lambda}{sub b})Br({Lambda}{sub b} {yields} {psi}{Lambda}{sup 0}) of 0.55 {times} 10{sup {minus}3} (90% C.L.), assuming that b baryons and mesons are produced in the fragmentation process in similar ways. The CDF Ai, search is also reported in the QCD session of this conference. This paper summarizes our result briefly; the details can be found in the other talk.

  1. LambdaStation: Exploiting Advance Networks In Data Intensive High Energy Physics Applications

    SciTech Connect

    Harvey B. Newman

    2009-09-11

    Lambda Station software implements selective, dynamic, secure path control between local storage & analysis facilities, and high bandwidth, wide-area networks (WANs). It is intended to facilitate use of desirable, alternate wide area network paths which may only be intermittently available, or subject to policies that restrict usage to specified traffic. Lambda Station clients gain awareness of potential alternate network paths via Clarens-based web services, including path characteristics such as bandwidth and availability. If alternate path setup is requested and granted, Lambda Station will configure the local network infrastructure to properly forward designated data flows via the alternate path. A fully functional implementation of Lambda Station, capable of dynamic alternate WAN path setup and teardown, has been successfully developed. A limited Lambda Station-awareness capability within the Storage Resource Manager (SRM) product has been developed. Lambda Station has been successfully tested in a number of venues, including Super Computing 2008. LambdaStation software, developed by the Fermilab team, enables dynamic allocation of alternate network paths for high impact traffic and to forward designated flows across LAN. It negotiates with reservation and provisioning systems of WAN control planes, be it based on SONET channels, demand tunnels, or dynamic circuit networks. It creates End-To-End circuit between single hosts, computer farms or networks with predictable performance characteristics, preserving QoS if supported in LAN and WAN and tied security policy allowing only specific traffic to be forwarded or received through created path. Lambda Station project also explores Network Awareness capabilities.

  2. Transition magnetic moment of {Lambda}{yields}{Sigma}{sup 0} in QCD sum rules

    SciTech Connect

    Lee, Frank X.; Wang Lai

    2011-05-01

    The {Lambda}{yields}{Sigma}{sup 0} transition magnetic moment is computed in the QCD sum rules approach. Three independent tensor structures are derived in the external-field method using generalized interpolating fields. They are analyzed together with the {Lambda} and {Sigma}{sup 0} mass sum rules using a Monte-Carlo-based analysis, with attention to operator product expansion convergence, ground-state dominance, and the role of the transitions in the intermediate states. Relations between sum rules for magnetic moments of {Lambda} and {Sigma}{sup 0} and sum rules for transition magnetic moment of {Lambda}{yields}{Sigma}{sup 0} are also examined. Our best prediction for the transition magnetic moment is {mu}{sub {Sigma}}{sup 0}{sub {Lambda}=}1.60{+-}0.07{mu}{sub N}. A comparison is made with other calculations in the literature.

  3. Measurement of the Branching Ratio Lambda_c+ -> p pi+ pi-

    SciTech Connect

    Lopez-Hinojosa, Guillermo; /San Luis Potosi U.

    2008-03-01

    The confirmation of the Cabibbo-suppressed charm baryon decay mode {Lambda}{sub c}{sup +} {yields} p{pi}{sup +}{pi}{sup -} is reported. All data analyzed are from SELEX, a fixed target experiment at Fermilab that took data during 1996 and 1997, mainly with a 600 GeV/c {Sigma}{sup -} beam. The branching ratio of the Cabibbo-suppressed decay mode {Lambda}{sub c}{sup +} {yields} p{pi}{sup +}{pi}{sup -} relative to the Cabibbo-favored mode {Lambda}{sub c}{sup +} {yields} pK{sup -}{pi}{sup +} is measured to be: {Gamma}({Lambda}{sub c}{sup +} {yields} p{pi}{sup +}{pi}{sup -})/{Gamma}({Lambda}{sub c}{sup +} {yields} pK{sup -}{pi}{sup +}) = 0.103 {+-} 0.022.

  4. Search for R-parity violating supersymmetry via the LL anti-E couplings lambda(121), lambda(122) or lambda(133) in p anti-p collisions at s**(1/2) = 1.96-TeV

    SciTech Connect

    Abazov, V.M.; Abbott, B.; Abolins, M.; Acharya, B.S.; Adams, M.; Adams, T.; Agelou, M.; Agram, J.-L.; Ahn, S.H.; Ahsan, M.; Alexeev, G.D.; /Buenos Aires U. /Rio de Janeiro, CBPF /Rio de Janeiro State U. /Sao Paulo, IFT /Alberta U. /Simon Fraser U. /York U., Canada /McGill U. /Beijing, Inst. High Energy Phys. /Hefei, CUST /Andes U., Bogota

    2006-05-01

    A search for gaugino pair production with a trilepton signature in the framework of R-parity violating supersymmetry via the couplings {lambda}{sub 121}, {lambda}{sub 122}, or {lambda}{sub 133} is presented. The data, corresponding to an integrated luminosity of L {approx} 360 pb{sup -1}, were collected from April 2002 to August 2004 with the D0 detector at the Fermilab Tevatron Collider, at a center-of-mass energy of {radical}s = 1.96 TeV. This analysis considers final states with three charged leptons with the flavor combinations ee{ell}, {mu}{mu}{ell}, and ee{tau} ({ell} = e or {mu}). No evidence for supersymmetry is found and limits at the 95% confidence level are set on the gaugino pair production cross section and lower bounds on the masses of the lightest neutralino and chargino are derived in two supersymmetric models.

  5. Searches for the baryon- and lepton-number violating decays $B^0\\rightarrow\\Lambda_c^ \\ell^-$, $B^-\\rightarrow\\Lambda\\ell^-$, and $B^-\\rightarrow\\bar{\\Lambda}\\ell^-$

    SciTech Connect

    del Amo Sanchez, P.; Lees, J.P.; Poireau, V.; Prencipe, E.; Tisserand, V.; Garra Tico, J.; Grauges, E.; Martinelli, M.; Milanes, D.A.; Palano, A.; Pappagallo, M.; Eigen, G.; Stugu, B.; Sun, L.; Brown, D.N.; Kerth, L.T.; Kolomensky, Yu.G.; Lynch, G.; Osipenkov, I.L.; Koch, H.; Schroeder, T.; /Ruhr U., Bochum /British Columbia U. /Brunel U. /Novosibirsk, IYF /UC, Irvine /UC, Riverside /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 /Frascati /INFN, Genoa /Genoa U. /INFN, Genoa /INFN, Genoa /Genoa U. /INFN, Genoa /Indian Inst. Tech., Guwahati /Harvard U. /Harvey Mudd Coll. /Heidelberg U. /Humboldt U., Berlin /Imperial Coll., London /Iowa State U. /Iowa State U. /Johns Hopkins U. /Paris U., VI-VII /LLNL, Livermore /Liverpool U. /Queen Mary, U. of London /Royal Holloway, U. of London /Royal Holloway, U. of London /Louisville U. /Mainz U., Inst. Kernphys. /Manchester U. /Maryland U. /Massachusetts U., Amherst /MIT /McGill U. /Milan U. /Milan U. /Milan U. /Milan U. /Milan U. /Mississippi U. /Montreal U. /INFN, Naples /Naples U. /NIKHEF, Amsterdam /NIKHEF, Amsterdam /Notre Dame U. /Ohio State U. /Oregon U. /INFN, Padua /Padua U. /INFN, Padua /INFN, Padua /Padua U. /Paris U., VI-VII /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. /Rostock U. /Rutherford /DAPNIA, Saclay /SLAC /South Carolina U. /Southern Methodist U. /Stanford U., Phys. Dept. /SUNY, Albany /Tel Aviv U. /Tennessee U. /Texas Nuclear Corp., Austin /Texas U., Dallas /INFN, Turin /Turin U. /INFN, Trieste /Trieste U. /Valencia U. /Victoria U. /Warwick U. /Wisconsin U., Madison

    2011-06-22

    Searches for B mesons decaying to final states containing a baryon and a lepton are performed, where the baryon is either {Lambda}{sub c} or {Lambda} and the lepton is a muon or an electron. These decays violate both baryon and lepton number and would be a signature of physics beyond the standard model. No significant signal is observed in any of the decay modes, and upper limits in the range (3.2 - 520) x 10{sup -8} are set on the branching fractions at the 90% confidence level.

  6. Attenuation of {Lambda}(1520) Hyperons in near-threshold pA reactions

    SciTech Connect

    Paryev, E. Ya.

    2010-12-15

    In the framework of the nuclear spectral function approach for incoherent primary proton-nucleon and secondary pion-nucleon production processes we study the inclusive {Lambda}(1520)-hyperon production in the interaction of 2.83-GeV protons with nuclei. In particular, the A and momentum dependences of the absolute and relative {Lambda}(1520)-hyperon yields are investigated within the different scenarios for their in-medium width. Our model calculations show that the pion-nucleon production channel contributes distinctly to the 'low-momentum' {Lambda}(1520) creation both in light and heavy nuclei in the chosen kinematics and, hence, has to be taken into consideration on close examination of the dependences of the {Lambda}(1520)-hyperon yields on the target mass number with the aim to get information on their width in the medium. They also demonstrate that both the A dependence of the relative {Lambda}(1520)-hyperon production cross section and momentum dependence of the absolute {Lambda}(1520)-hyperon yield at incident energy of interest are appreciably sensitive to the {Lambda}(1520) in-medium width, which means that these observables may be an important tool to determine the above width.

  7. Observation of the baryonic B-decay B0bar -> LambdaC antiproton K- pi

    SciTech Connect

    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

    2009-10-20

    The authors report the observation of the baryonic B-decay {bar B}{sup 0} {yields} {Lambda}{sub c}{sup +}{bar p}K{sup -}{pi}{sup +}, excluding contributions from the decay {bar B}{sup 0} {yields} {Lambda}{sub c}{sup +}{bar {Lambda}}K{sup -}. Using a data sample of 467 million B{bar B} pairs collected with the BABAR detector at the PEP-II storage ring at SLAC, the measured branching fraction is (4.33 {+-} 0.82){sub stat} {+-} 0.33{sub syst} {+-} 1.13{sub {Lambda}{sub c}{sup +}} x 10{sup -5}. In addition they find evidence for the resonant decay {bar B}{sup 0} {yields} {Sigma}{sub c}(2455){sup ++}{bar p}K{sup -} and determine its branching fraction to be (1.11 {+-} 0.30{sub stat} {+-} 0.09{sub syst} {+-} 0.29{sub {Lambda}{sub c}{sup +}}) x 10{sup -5}. The errors are statistical, systematic, and due to the uncertainty in the {Lambda}{sub c}{sup +} branching fraction. For the resonant decay {bar B}{sup 0} {yields} {Lambda}{sub c}{sup +}{bar p}{bar K}*{sup 0} we obtain an upper limit of 2.42 x 10{sup -5} at 90% confidence level.

  8. Recombination between bacteriophage lambda and plasmid pBR322 in Escherichia coli.

    PubMed Central

    Pogue-Geile, K L; Dassarma, S; King, S R; Jaskunas, S R

    1980-01-01

    Recombinant lambda phages were isolated that resulted from recombination between the lambda genome and plasmid pBR322 in Escherichia coli, even though these deoxyribonucleic acids (DNAs) did not share extensive regions of homology. The characterization of these recombinant DNAs by heteroduplex analysis and restriction endonucleases is described. All but one of the recombinants appeared to have resulted from reciprocal recombination between a site on lambda DNA and a site on the plasmid. In general, there were two classes of recombinants. One class appeared to have resulted from recombination at the phage attachment site that probably resulted from lambda integration into secondary attachment sites on the plasmid. Seven different secondary attachment sites on pBR322 were found. The other class resulted from plasmid integration at other sites that were widely scattered on the lambda genome. For this second class of recombinants, more than one site on the plasmid could recombine with lambda DNA. Thus, the recombination did not appear to be site specific with respect to lambda or the plasmid. Possible mechanisms for generating these recombinants are discussed. Images PMID:6247334

  9. Interferon Lambda: A New Sword in Cancer Immunotherapy

    PubMed Central

    Lasfar, Ahmed; Abushahba, Walid; Balan, Murugabaskar; Cohen-Solal, Karine A.

    2011-01-01

    The discovery of the interferon-lambda (IFN-λ) family has considerably contributed to our understanding of the role of interferon not only in viral infections but also in cancer. IFN-λ proteins belong to the new type III IFN group. Type III IFN is structurally similar to type II IFN (IFN-γ) but functionally identical to type I IFN (IFN-α/β). However, in contrast to type I or type II IFNs, the response to type III IFN is highly cell-type specific. Only epithelial-like cells and to a lesser extent some immune cells respond to IFN-λ. This particular pattern of response is controlled by the differential expression of the IFN-λ receptor, which, in contrast to IFN-α, should result in limited side effects in patients. Recently, we and other groups have shown in several animal models a potent antitumor role of IFN-λ that will open a new challenging era for the current IFN therapy. PMID:22190970

  10. A WIYN Lithium Survey for Young Stars Near lambda Orionis

    NASA Astrophysics Data System (ADS)

    Mathieu, R. D.; Dolan, C. J.

    1999-09-01

    We have used the WIYN Multi-Object Spectrograph to test 537 stars within 0.5 deg of the lambda Orionis OB association for the presence of lithium 6708{ Angstroms} absorption, a diagnostic of youth. These stars were selected as a complete sample of pre-main-sequence candidates in the region, based on our CCD photometric survey. We find 72 stars which show large lithium equivalent widths and radial velocities consistent with association membership, only two of which were previously discovered by Hα surveys. Comparison with evolutionary models indicate that these stars have an age distribution either younger than (D'Antona & Mazzitelli 1998) or coeval with (Baraffe et al. 1998) the 2-6 Myr OB stars, and that they are roughly 0.3-1.0 M_sun. Kinematic evidence and the shape of the age distributions suggest that an event about a million years ago has strongly affected the star formation history of the region. Estimating our sample completeness at about 80%, we find that the local initial mass function within 7 parsecs of the 11 OB stars is indistinguishable from the IMF of the field. Finally, despite their youth, only four of these stars have T Tauri-like Hα emission, suggesting an absence of accretion disks. This absence may be indicative of photoevaporation of the disks due to close proximity with the OB stars. This work is supported by NSF grant AST 94-1715 and the Wisconsin Space Grant Consortium.