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

Title: Study of Decay Mechanisms in B{sup -}{yields}{lambda}{sub c}{sup +}p{pi}{sup -} Decays and Observation of Low-Mass Structure in the {lambda}{sub c}{sup +}p System

Abstract

Using a sample of 152x10{sup 6} BB pairs accumulated with the Belle detector at the KEKB e{sup +}e{sup -} collider, we study the decay mechanism of three-body charmed decay B{sup -}{yields}{lambda}{sub c}{sup +}p{pi}{sup -}. The intermediate two-body decay B{sup -}{yields}{sigma}{sub c}(2455){sup 0}p is observed for the first time with a branching fraction of (3.7{+-}0.7{+-}0.4{+-}1.0)x10{sup -5} and a statistical significance of 8.4{sigma}. We also observe a low-mass enhancement in the ({lambda}{sub c}{sup +}p) system, which can be parametrized as a Breit-Wigner function with a mass of (3.35{sub -0.02}{sup +0.01}{+-}0.02) GeV/c{sup 2} and a width of (0.07{sub -0.03}{sup +0.04}{+-}0.04) GeV/c{sup 2}. We measure its branching fraction to be (3.9{sub -0.7}{sup +0.8}{+-}0.4{+-}1.0)x10{sup -5} with a statistical significance of 6.2{sigma}. The errors are statistical, systematic, and that of the {lambda}{sub c}{sup +}{yields}pK{sup -}{pi}{sup +} decay branching fraction.

Authors:
; ; ; ; ; ; ;  [1]; ; ; ; ; ; ; ; ; ; ; ;  [2]
  1. Budker Institute of Nuclear Physics, Novosibirsk (Russian Federation)
  2. High Energy Accelerator Research Organization (KEK), Tsukuba (Japan) (and others)
Publication Date:
OSTI Identifier:
20861471
Resource Type:
Journal Article
Resource Relation:
Journal Name: Physical Review Letters; Journal Volume: 97; Journal Issue: 24; Other Information: DOI: 10.1103/PhysRevLett.97.242001; (c) 2006 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; B MINUS MESONS; BRANCHING RATIO; BREIT-WIGNER FORMULA; ERRORS; FUNCTIONS; GEV RANGE 01-10; LAMBDA C PLUS BARYONS; MASS; PARTICLE DECAY; PARTICLE PRODUCTION; PARTICLE WIDTHS; PIONS MINUS; PIONS PLUS; PROTONS; THREE-BODY PROBLEM; TWO-BODY PROBLEM

Citation Formats

Gabyshev, N., Aulchenko, V., Bondar, A., Eidelman, S., Krokovny, P., Kuzmin, A., Sidorov, V., Zhilich, V., Abe, K., Adachi, I., Gershon, T., Hazumi, M., Ishikawa, A., Itoh, R., Iwasaki, Y., Katayama, N., Kichimi, H., Nakao, M., Nakazawa, H., and Nishida, S. Study of Decay Mechanisms in B{sup -}{yields}{lambda}{sub c}{sup +}p{pi}{sup -} Decays and Observation of Low-Mass Structure in the {lambda}{sub c}{sup +}p System. United States: N. p., 2006. Web. doi:10.1103/PHYSREVLETT.97.242001.
Gabyshev, N., Aulchenko, V., Bondar, A., Eidelman, S., Krokovny, P., Kuzmin, A., Sidorov, V., Zhilich, V., Abe, K., Adachi, I., Gershon, T., Hazumi, M., Ishikawa, A., Itoh, R., Iwasaki, Y., Katayama, N., Kichimi, H., Nakao, M., Nakazawa, H., & Nishida, S. Study of Decay Mechanisms in B{sup -}{yields}{lambda}{sub c}{sup +}p{pi}{sup -} Decays and Observation of Low-Mass Structure in the {lambda}{sub c}{sup +}p System. United States. doi:10.1103/PHYSREVLETT.97.242001.
Gabyshev, N., Aulchenko, V., Bondar, A., Eidelman, S., Krokovny, P., Kuzmin, A., Sidorov, V., Zhilich, V., Abe, K., Adachi, I., Gershon, T., Hazumi, M., Ishikawa, A., Itoh, R., Iwasaki, Y., Katayama, N., Kichimi, H., Nakao, M., Nakazawa, H., and Nishida, S. Fri . "Study of Decay Mechanisms in B{sup -}{yields}{lambda}{sub c}{sup +}p{pi}{sup -} Decays and Observation of Low-Mass Structure in the {lambda}{sub c}{sup +}p System". United States. doi:10.1103/PHYSREVLETT.97.242001.
@article{osti_20861471,
title = {Study of Decay Mechanisms in B{sup -}{yields}{lambda}{sub c}{sup +}p{pi}{sup -} Decays and Observation of Low-Mass Structure in the {lambda}{sub c}{sup +}p System},
author = {Gabyshev, N. and Aulchenko, V. and Bondar, A. and Eidelman, S. and Krokovny, P. and Kuzmin, A. and Sidorov, V. and Zhilich, V. and Abe, K. and Adachi, I. and Gershon, T. and Hazumi, M. and Ishikawa, A. and Itoh, R. and Iwasaki, Y. and Katayama, N. and Kichimi, H. and Nakao, M. and Nakazawa, H. and Nishida, S.},
abstractNote = {Using a sample of 152x10{sup 6} BB pairs accumulated with the Belle detector at the KEKB e{sup +}e{sup -} collider, we study the decay mechanism of three-body charmed decay B{sup -}{yields}{lambda}{sub c}{sup +}p{pi}{sup -}. The intermediate two-body decay B{sup -}{yields}{sigma}{sub c}(2455){sup 0}p is observed for the first time with a branching fraction of (3.7{+-}0.7{+-}0.4{+-}1.0)x10{sup -5} and a statistical significance of 8.4{sigma}. We also observe a low-mass enhancement in the ({lambda}{sub c}{sup +}p) system, which can be parametrized as a Breit-Wigner function with a mass of (3.35{sub -0.02}{sup +0.01}{+-}0.02) GeV/c{sup 2} and a width of (0.07{sub -0.03}{sup +0.04}{+-}0.04) GeV/c{sup 2}. We measure its branching fraction to be (3.9{sub -0.7}{sup +0.8}{+-}0.4{+-}1.0)x10{sup -5} with a statistical significance of 6.2{sigma}. The errors are statistical, systematic, and that of the {lambda}{sub c}{sup +}{yields}pK{sup -}{pi}{sup +} decay branching fraction.},
doi = {10.1103/PHYSREVLETT.97.242001},
journal = {Physical Review Letters},
number = 24,
volume = 97,
place = {United States},
year = {Fri Dec 15 00:00:00 EST 2006},
month = {Fri Dec 15 00:00:00 EST 2006}
}
  • We report the first measurements of the doubly charmed baryonic B decays B{yields}{lambda}{sub c}{sup +}{lambda}{sub c}{sup -}K. The B{sup +}{yields}{lambda}{sub c}{sup +}{lambda}{sub c}{sup -}K{sup +} decay is observed with a branching fraction of (6.5{sub -0.9}{sup +1.0}{+-}1.1{+-}3.4)x10{sup -4} and a statistical significance of 15.4{sigma}. The B{sup 0}{yields}{lambda}{sub c}{sup +}{lambda}{sub c}{sup -}K{sup 0} decay is observed with a branching fraction of (7.9{sub -2.3}{sup +2.9}{+-}1.2{+-}4.1)x10{sup -4} and a statistical significance of 6.6{sigma}. The branching fraction errors are statistical, systematic, and the error resulting from the uncertainty of the {lambda}{sub c}{sup +}{yields}pK{sup -}{pi}{sup +} decay branching fraction. The analysis is based on 357 fb{supmore » -1} of data accumulated at the {upsilon}(4S) resonance with the Belle detector at the KEKB asymmetric-energy e{sup +}e{sup -} collider.« less
  • We present an investigation of the decays B{sup 0}{yields}{lambda}{sub c}{sup +}p and B{sup -}{yields}{lambda}{sub c}{sup +}p{pi}{sup -} based on 383x10{sup 6} {upsilon}(4S){yields}BB decays recorded with the BABAR detector. We measure the branching fractions of these decays; their ratio is B(B{sup -}{yields}{lambda}{sub c}{sup +}p{pi}{sup -})/B(B{sup 0}{yields}{lambda}{sub c}{sup +}p)=15.4{+-}1.8{+-}0.3. The B{sup -}{yields}{lambda}{sub c}{sup +}p{pi}{sup -} process exhibits an enhancement at the {lambda}{sub c}{sup +}p threshold and is a laboratory for searches for excited charm baryon states. We observe the resonant decays B{sup -}{yields}{sigma}{sub c}(2455){sup 0}p and B{sup -}{yields}{sigma}{sub c}(2800){sup 0}p but see no evidence for B{sup -}{yields}{sigma}{sub c}(2520){sup 0}p. This is themore » first observation of the decay B{sup -}{yields}{sigma}{sub c}(2800){sup 0}p; however, the mass of the observed excited {sigma}{sub c}{sup 0} state is (2846{+-}8{+-}10) MeV/c{sup 2}, which is somewhat inconsistent with previous measurements. Finally, we examine the angular distribution of the B{sup -}{yields}{sigma}{sub c}(2455){sup 0}p decays and measure the spin of the {sigma}{sub c}(2455){sup 0} baryon to be 1/2, as predicted by the quark model.« less
  • In a sample of 467x10{sup 6} BB pairs collected with the BABAR detector at the PEP-II collider at SLAC we have observed the decay B{sup 0}{yields}{Lambda}{sub c}{sup +}p{pi}{sup 0} and measured the branching fraction to be (1.94{+-}0.17{+-}0.14{+-}0.50)x10{sup -4}, where the uncertainties are statistical, systematic, and the uncertainty on the {Lambda}{sub c}{sup +}{yields}pK{sup -}{pi}{sup +} branching fraction, respectively. We determine an upper limit of 1.5x10{sup -6} at 90% C.L. for the product branching fraction B(B{sup 0}{yields}{Sigma}{sub c}{sup +}(2455)p)xB({Lambda}{sub c}{sup +}{yields}pK{sup -}{pi}{sup +}). Furthermore, we observe an enhancement at the threshold of the invariant mass of the baryon-antibaryon pair.
  • We study the three-body charmed baryonic decays B{sup 0}{yields}{sigma}{sub c}{sup ++}p{pi}{sup -} and B{sup 0}{yields}{sigma}{sub c}{sup 0}p{pi}{sup +} in the four-body final state B{sup 0}{yields}{lambda}{sub c}{sup +}p{pi}{sup +}{pi}{sup -}, using a data sample of 357 fb{sup -1} accumulated at the {upsilon}(4S) resonance with the Belle detector at the KEKB asymmetric-energy e{sup +}e{sup -} collider. We measure the branching fractions B(B{sup 0}{yields}{sigma}{sub c}(2455){sup ++}p{pi}{sup -})=(2.1{+-}0.2{+-}0.3{+-}0.5)x10{sup -4}, B(B{sup 0}{yields}{sigma}{sub c}(2455){sup 0}p{pi}{sup +})=(1.4{+-}0.2{+-}0.2{+-}0.4)x10{sup -4} and B(B{sup 0}{yields}{sigma}{sub c}(2520){sup ++}p{pi}{sup -})=(1.2{+-}0.1{+-}0.2{+-}0.3)x10{sup -4} with signal significances of 13.1{sigma}, 9.4{sigma} and 7.1{sigma}, respectively. The errors are statistical, systematic, and due to the uncertainty in B({lambda}{sub c}{supmore » +}{yields}pK{sup -}{pi}{sup +}), respectively. We also set an upper limit B(B{sup 0}{yields}{sigma}{sub c}(2520){sup 0}p{pi}{sup +})<0.38x10{sup -4} at the 90% confidence level. In addition, we obtain a nonresonant branching fraction of (6.4{+-}0.4{+-}0.9{+-}1.7)x10{sup -4}, and a total branching fraction of (11.2{+-}0.5{+-}1.4{+-}2.9)x10{sup -4} for B{sup 0}{yields}{lambda}{sub c}{sup +}p{pi}{sup +}{pi}{sup -}.« less