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

Journal Article · Mon Jan 01 04:00:00 EST 2007 · Physical Review. D, Particles Fields

DOI:https://doi.org/10.1103/PHYSREVD.75.012003· OSTI ID:20933196

Aubert, B; Bona, M; Boutigny, D; Couderc, F; Karyotakis, Y; Lees, J P; Poireau, V; Tisserand, V; Zghiche, A ^[1]; Grauges, E ^[2]; Palano, A ^[3]; Chen, J C; Qi, N D; Rong, G; Wang, P; Zhu, Y S ^[4]; Eigen, G; Ofte, I; Stugu, B ^[5]; Abrams, G S ^[6]

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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)

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.

• OSTI ID: 20933196
• Journal Information: Physical Review. D, Particles Fields, Journal Name: Physical Review. D, Particles Fields Journal Issue: 1 Vol. 75; ISSN PRVDAQ; ISSN 0556-2821
• Country of Publication: United States
• Language: English

Related Subjects

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