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Title: Radiative decay of the {lambda}*(1520)

Abstract

A recently developed nonperturbative chiral approach to dynamically generate the 3/2{sup -} baryon resonances has been extended to investigate the radiative decays {lambda}*(1520){yields}{gamma}{lambda}(1116) and {lambda}*(1520){yields}{gamma}{sigma}{sup 0}(1193). We show that the {lambda}*(1520) decay into {gamma}{lambda} is an ideal test for the need of extra components of the resonance beyond those provided by the chiral approach since the largest meson-baryon components give no contribution to this decay. The case is different for {gamma}{sigma} decay, where the theory agrees with experiment, though the large uncertainties of these data call for more precise measurements. Some estimates of the weight of the needed genuine resonance component are made.

Authors:
;  [1];  [1];  [2]
  1. Departamento de Fisica Teorica and IFIC, Centro Mixto Universidad de Valencia-CSIC, Institutos de Investigacion de Paterna, Aptd. 22085, E-46071 Valencia (Spain)
  2. (India)
Publication Date:
OSTI Identifier:
20864238
Resource Type:
Journal Article
Resource Relation:
Journal Name: Physical Review. C, Nuclear Physics; Journal Volume: 74; Journal Issue: 6; Other Information: DOI: 10.1103/PhysRevC.74.065204; (c) 2006 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
73 NUCLEAR PHYSICS AND RADIATION PHYSICS; CHIRALITY; LAMBDA BARYONS; MESONS; PHOTONS; RADIATIVE DECAY; RESONANCE PARTICLES; SIGMA BARYONS

Citation Formats

Doering, M., Oset, E., Sarkar, Sourav, and Variable Energy Cyclotron Centre, 1/AF Bidhannagar, Kolkata 700064. Radiative decay of the {lambda}*(1520). United States: N. p., 2006. Web. doi:10.1103/PHYSREVC.74.065204.
Doering, M., Oset, E., Sarkar, Sourav, & Variable Energy Cyclotron Centre, 1/AF Bidhannagar, Kolkata 700064. Radiative decay of the {lambda}*(1520). United States. doi:10.1103/PHYSREVC.74.065204.
Doering, M., Oset, E., Sarkar, Sourav, and Variable Energy Cyclotron Centre, 1/AF Bidhannagar, Kolkata 700064. Fri . "Radiative decay of the {lambda}*(1520)". United States. doi:10.1103/PHYSREVC.74.065204.
@article{osti_20864238,
title = {Radiative decay of the {lambda}*(1520)},
author = {Doering, M. and Oset, E. and Sarkar, Sourav and Variable Energy Cyclotron Centre, 1/AF Bidhannagar, Kolkata 700064},
abstractNote = {A recently developed nonperturbative chiral approach to dynamically generate the 3/2{sup -} baryon resonances has been extended to investigate the radiative decays {lambda}*(1520){yields}{gamma}{lambda}(1116) and {lambda}*(1520){yields}{gamma}{sigma}{sup 0}(1193). We show that the {lambda}*(1520) decay into {gamma}{lambda} is an ideal test for the need of extra components of the resonance beyond those provided by the chiral approach since the largest meson-baryon components give no contribution to this decay. The case is different for {gamma}{sigma} decay, where the theory agrees with experiment, though the large uncertainties of these data call for more precise measurements. Some estimates of the weight of the needed genuine resonance component are made.},
doi = {10.1103/PHYSREVC.74.065204},
journal = {Physical Review. C, Nuclear Physics},
number = 6,
volume = 74,
place = {United States},
year = {Fri Dec 15 00:00:00 EST 2006},
month = {Fri Dec 15 00:00:00 EST 2006}
}
  • 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%)
  • The chiral quark model gives a reasonably good description of many low-energy observables by incorporating the effective degrees carried by the constituent quarks and Goldstone bosons. We calculate the decuplet to octet transition magnetic moments and the decay widths of several excited hyperons using this model. The various radiative decay widths from the chiral quark roughly agree with experimental data including recent JLAB measurement.
  • 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.
  • 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 Large Acceptance Spectrometer 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.
  • No abstract prepared.