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Title: Strong decays of charmed baryons

Abstract

There has been important experimental progress in the sector of heavy baryons in the past several years. We study the strong decays of the S-wave, P-wave, D-wave, and radially excited charmed baryons using the {sup 3}P{sub 0} model. After comparing the calculated decay pattern and total width with the available data, we discuss the possible internal structure and quantum numbers of those charmed baryons observed recently.

Authors:
; ; ; ;  [1]
  1. Department of physics, Peking University, Beijing, 100871 (China)
Publication Date:
OSTI Identifier:
21020489
Resource Type:
Journal Article
Resource Relation:
Journal Name: Physical Review. D, Particles Fields; Journal Volume: 75; Journal Issue: 9; Other Information: DOI: 10.1103/PhysRevD.75.094017; (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; CHARMED BARYONS; D WAVES; HADRONIC PARTICLE DECAY; P WAVES; PARTICLE STRUCTURE; PARTICLE WIDTHS; QUANTUM NUMBERS; S WAVES

Citation Formats

Chen Chong, Chen Xiaolin, Liu Xiang, Deng Weizhen, and Zhu Shilin. Strong decays of charmed baryons. United States: N. p., 2007. Web. doi:10.1103/PHYSREVD.75.094017.
Chen Chong, Chen Xiaolin, Liu Xiang, Deng Weizhen, & Zhu Shilin. Strong decays of charmed baryons. United States. doi:10.1103/PHYSREVD.75.094017.
Chen Chong, Chen Xiaolin, Liu Xiang, Deng Weizhen, and Zhu Shilin. Tue . "Strong decays of charmed baryons". United States. doi:10.1103/PHYSREVD.75.094017.
@article{osti_21020489,
title = {Strong decays of charmed baryons},
author = {Chen Chong and Chen Xiaolin and Liu Xiang and Deng Weizhen and Zhu Shilin},
abstractNote = {There has been important experimental progress in the sector of heavy baryons in the past several years. We study the strong decays of the S-wave, P-wave, D-wave, and radially excited charmed baryons using the {sup 3}P{sub 0} model. After comparing the calculated decay pattern and total width with the available data, we discuss the possible internal structure and quantum numbers of those charmed baryons observed recently.},
doi = {10.1103/PHYSREVD.75.094017},
journal = {Physical Review. D, Particles Fields},
number = 9,
volume = 75,
place = {United States},
year = {Tue May 01 00:00:00 EDT 2007},
month = {Tue May 01 00:00:00 EDT 2007}
}
  • Strong decays of charmed baryons are analyzed in the framework of heavy hadron chiral perturbation theory (HHChPT) in which heavy quark symmetry and chiral symmetry are synthesized. HHChPT works excellently for describing the strong decays of s-wave charmed baryons. For L=1 orbitally excited states, two of the unknown couplings, namely, h{sub 2} and h{sub 10}, are determined from the resonant {lambda}{sub c}{sup +}{pi}{pi} mode produced in the {lambda}{sub c}(2593) decay and the width of {sigma}{sub c}(2800), respectively. Predictions for the strong decays of the p-wave charmed baryon states {lambda}{sub c}(2625), {xi}{sub c}(2790) and {xi}{sub c}(2815) are presented. Since the decaymore » {lambda}{sub c}(2593){sup +}{yields}{lambda}{sub c}{sup +}{pi}{pi} receives nonresonant contributions, our value for h{sub 2} is smaller than the previous estimates. We also discuss the first positive-parity excited charmed baryons. We conjecture that the charmed baryon {lambda}{sub c}(2880) with is an admixture of with an ; both are L=2 orbitally excited states. The potential model suggests or for {lambda}{sub c}(2940){sup +}. Measurements of the ratio of {sigma}{sub c}*{pi}/{sigma}{sub c}{pi} will enable us to discriminate the J{sup P} assignments for {lambda}{sub c}(2940). We advocate that the J{sup P} quantum numbers of {xi}{sub c}(2980) and {xi}{sub c}(3077) are and , respectively. Under this J{sup P} assignment, it is easy to understand why {xi}{sub c}(2980) is broader than {xi}{sub c}(3077)« less
  • We evaluate the widths for the strong decays {sigma}{sub c} {yields} {lambda}{sub c} {pi}, {sigma}{sub c}* {yields} {lambda}{sub c} {pi} and {xi}{sub c}* {yields} {xi}{sub c} {pi}. The calculations have been done within a nonrelativistic constituent quark model with wave functions that take advantage of the constraints imposed by heavy quark symmetry. Partial conservation of axial current hypothesis allows us to determine the strong vertices from an analysis of the weak axial current matrix elements. Our results are in good agreement with experimental data.
  • Experimental data are presented on the associative photoproduction of the charmed ..lambda../sup +//sub c/ baryon and D-bar meson at tagged photon energies from 20 to 70 GeV. Results are obtained on the photoproduction mechanism, decay modes, and the lifetime of the ..lambda../sup +//sub c/ baryon.
  • Cabibbo-allowed nonleptonic weak decays of charmed baryons [Lambda][sub [ital c]][sup +], [Xi][sub [ital c]][sup 0[ital A]], [Xi][sub [ital c]][sup +[ital A]], and [Omega][sub [ital c]][sup 0] into an octet baryon and a pseudoscalar meson are analyzed. The nonfactorizable contributions are evaluated under the pole approximation, and it turns out that the [ital s]-wave amplitudes are dominated by the low-lying 1/2[sup [minus]] resonances, while [ital p]-wave ones are governed by the ground state 1/2[sup +] poles. The MIT bag model is employed to calculate the coupling constants, form factors, and baryon matrix elements. Our conclusions are the following: (i) [ital s]more » waves are no longer dominated by commutator terms; the current-algebra method is not applicable to parity-violating amplitudes. (ii) Nonfactorizable [ital W]-exchange effects are generally important; they can be comparable to and sometimes even dominate over factorizable contributions, depending on the decay modes under consideration. (iii) The large-[ital N][sub [ital c]] approximation for factorizable amplitudes also works in the heavy baryon sector and it accounts for the color nonsuppression of [Lambda][sub [ital c]][sup +][r arrow][ital p[bar K]][sup 0] relative to [Lambda][sub [ital c]][sup +][r arrow][Lambda][pi][sup +]. (iv) A measurement of the decay rate and the sign of the [alpha] asymmetry parameter of certain proposed decay modes will help discern various models. (v) [ital p] waves are the dominant contributions to the decays [Lambda][sub [ital c]][sup +][r arrow][Xi][sup 0][ital K+] and [Xi][sub [ital c]][sup 0[ital A]][r arrow][Sigma][sup +][ital K[minus]], but they are subject to a large cancellation; this renders present theoretical predictions on these two channels unreliable.« less