skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Inclusive {lambda}{sub c}{sup +} production in e{sup +}e{sup -} annihilations at {radical}(s)=10.54 GeV and in {upsilon}(4S) decays

Abstract

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}cc 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 qq}=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.

Authors:
; ; ; ; ; ; ; ;  [1];  [2];  [3]; ; ; ; ;  [4]; ; ;  [5];  [6]
  1. Laboratoire de Physique des Particules, IN2P3/CNRS et Universite de Savoie, F-74941 Annecy-Le-Vieux (France)
  2. Universitat de Barcelona, Facultat de Fisica, Departament ECM, E-08028 Barcelona (Spain)
  3. Universita di Bari, Dipartimento di Fisica and INFN, I-70126 Bari (Italy)
  4. Institute of High Energy Physics, Beijing 100039 (China)
  5. University of Bergen, Institute of Physics, N-5007 Bergen (Norway)
  6. Lawrence Berkeley National Laboratory and University of California, Berkeley, California 94720 (United States) (and others)
Publication Date:
OSTI Identifier:
20933196
Resource Type:
Journal Article
Resource Relation:
Journal Name: Physical Review. D, Particles Fields; Journal Volume: 75; Journal Issue: 1; Other Information: DOI: 10.1103/PhysRevD.75.012003; (c) 2007 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS; ANNIHILATION; BRANCHING RATIO; C QUARKS; CHARMED MESONS; ELECTRON-POSITRON INTERACTIONS; ELECTRONS; ERRORS; GEV RANGE 10-100; LAMBDA C PLUS BARYONS; LEADING PARTICLES; PARTICLE DECAY; PARTICLE PRODUCTION; PIONS PLUS; POSITRONS

Citation Formats

Aubert, B., Bona, M., Boutigny, D., Couderc, F., Karyotakis, Y., Lees, J. P., Poireau, V., Tisserand, V., Zghiche, A., Grauges, E., Palano, A., Chen, J. C., Qi, N. D., Rong, G., Wang, P., Zhu, Y. S., Eigen, G., Ofte, I., Stugu, B., and Abrams, G. S. Inclusive {lambda}{sub c}{sup +} production in e{sup +}e{sup -} annihilations at {radical}(s)=10.54 GeV and in {upsilon}(4S) decays. United States: N. p., 2007. Web. doi:10.1103/PHYSREVD.75.012003.
Aubert, B., Bona, M., Boutigny, D., Couderc, F., Karyotakis, Y., Lees, J. P., Poireau, V., Tisserand, V., Zghiche, A., Grauges, E., Palano, A., Chen, J. C., Qi, N. D., Rong, G., Wang, P., Zhu, Y. S., Eigen, G., Ofte, I., Stugu, B., & Abrams, G. S. Inclusive {lambda}{sub c}{sup +} production in e{sup +}e{sup -} annihilations at {radical}(s)=10.54 GeV and in {upsilon}(4S) decays. United States. doi:10.1103/PHYSREVD.75.012003.
Aubert, B., Bona, M., Boutigny, D., Couderc, F., Karyotakis, Y., Lees, J. P., Poireau, V., Tisserand, V., Zghiche, A., Grauges, E., Palano, A., Chen, J. C., Qi, N. D., Rong, G., Wang, P., Zhu, Y. S., Eigen, G., Ofte, I., Stugu, B., and Abrams, G. S. Mon . "Inclusive {lambda}{sub c}{sup +} production in e{sup +}e{sup -} annihilations at {radical}(s)=10.54 GeV and in {upsilon}(4S) decays". United States. doi:10.1103/PHYSREVD.75.012003.
@article{osti_20933196,
title = {Inclusive {lambda}{sub c}{sup +} production in e{sup +}e{sup -} annihilations at {radical}(s)=10.54 GeV and in {upsilon}(4S) decays},
author = {Aubert, B. and Bona, M. and Boutigny, D. and Couderc, F. and Karyotakis, Y. and Lees, J. P. and Poireau, V. and Tisserand, V. and Zghiche, A. and Grauges, E. and Palano, A. and Chen, J. C. and Qi, N. D. and Rong, G. and Wang, P. and Zhu, Y. S. and Eigen, G. and Ofte, I. and Stugu, B. and Abrams, G. S.},
abstractNote = {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}cc 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 qq}=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.},
doi = {10.1103/PHYSREVD.75.012003},
journal = {Physical Review. D, Particles Fields},
number = 1,
volume = 75,
place = {United States},
year = {Mon Jan 01 00:00:00 EST 2007},
month = {Mon Jan 01 00:00:00 EST 2007}
}
  • No abstract prepared.
  • 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 anmore » 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.« less
  • The authors present a preliminary inclusive search for strange pentaquark production in e{sup +}e{sup -} interactions at a center-of-mass energy of 10.58 GeV using 123 fb{sup -1} of data collected with the BABAR detector. They look for the states that have been reported previously: the {Theta}{sup +}(1540), interpreted as a udud{bar s} state; and the {Xi}{sup --}(1860) and {Xi}{sup 0}(1860), candidate dsds{bar u} and uss(u{bar u} + d{bar d}) states, respectively. In addition they search for other members of the antidecuplet and corresponding octet to which these states are thought to belong. They find no evidence for the production ofmore » such states and set preliminary limits on their production cross sections as functions of c.m. momentum. The corresponding limits on the {Theta}{sup +}(1540) and {Xi}{sup --}(1860) rates per e{sup +}e{sup -} --> q{bar q} event are well below the rates measured for ordinary baryons of similar mass.« less
  • We measure the production cross sections for e{sup +}e{sup -}{yields}{Upsilon}(1S){pi}{sup +}{pi}{sup -}, {Upsilon}(2S){pi}{sup +}{pi}{sup -}, and {Upsilon}(3S){pi}{sup +}{pi}{sup -} as a function of {radical}(s) between 10.83 GeV and 11.02 GeV. The data consist of 8.1 fb{sup -1} collected with the Belle detector at the KEKB e{sup +}e{sup -} collider. We observe enhanced production in all three final states that does not agree well with the conventional {Upsilon}(10860) line shape. A fit using a Breit-Wigner resonance shape yields a peak mass of [10 888.4{sub -2.6}{sup +2.7}(stat){+-}1.2(syst)] MeV/c{sup 2} and a width of [30.7{sub -7.0}{sup +8.3}(stat){+-}3.1(syst)] MeV/c{sup 2}.
  • Experimental data on the inclusive production of strange particles in the K/sup +/p ..-->.. K/sup 0//sub s/ +..lambda..+X, K/sup +/p ..-->.. K/sup 0//sub s/ +Lambda-bar+X, and K/sup +/p ..-->.. ..lambda..+Lambda-bar+X reactions at 32 GeV/c are presented, the principal reaction mechanisms and the contributions to them from various resonances are analyzed, and the data are compared with the predictions of the Lund quark-fragmentation model.