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Title: Unitary coupled channel study of the {lambda}(1520) resonance

Abstract

We study the {lambda}(1520) resonance in a coupled channel approach involving the {pi}{sigma}(1385), K{xi}(1530), K-barN and {pi}{sigma} channels. Implementing unitarity in coupled channels, we make an analysis of the relative importance of the different mechanisms which contribute to the dynamical structure of this resonance. From experimental information on some partial wave amplitudes and constraints imposed by unitarity, we get a comprehensive description of the amplitudes and hence the couplings to the different channels. We test these amplitudes in different reactions like K-p {yields} {lambda}{pi}{pi}, {gamma}p {yields} K+K-p, {gamma}p {yields} K+{pi}0{pi}0{lambda} and {pi}-p {yields} K0K-p and find a fair agreement with the experimental data.

Authors:
; ; ;  [1];  [2]
  1. Departamento de Fisica Teorica, Institutos de Investigacion de Paterna, Aptdo. 22085, 46071 Valencia (Spain)
  2. (Spain)
Publication Date:
OSTI Identifier:
20798077
Resource Type:
Journal Article
Resource Relation:
Journal Name: AIP Conference Proceedings; Journal Volume: 814; Journal Issue: 1; Conference: 11. international conference on hadron spectroscopy, Rio de Janeiro (Brazil), 21-26 Aug 2005; Other Information: DOI: 10.1063/1.2176490; (c) 2006 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS; AMPLITUDES; COUPLED CHANNEL THEORY; KAON-HYPERON INTERACTIONS; KAONS; LAMBDA-1520 BARYONS; NUCLEONS; PARTIAL WAVES; PARTICLE PROPERTIES; PION-HYPERON INTERACTIONS; RESONANCE PARTICLES; SIGMA BARYONS; UNITARITY; XI BARYONS

Citation Formats

Roca, L., Magas, V. K., Oset, E., Sarkar, Sourav, and IFIC, Centro Mixto Universidad de Valencia-CSIC, Institutos de Investigacion de Paterna, Aptdo. 22085, 46071 Valencia. Unitary coupled channel study of the {lambda}(1520) resonance. United States: N. p., 2006. Web. doi:10.1063/1.2176490.
Roca, L., Magas, V. K., Oset, E., Sarkar, Sourav, & IFIC, Centro Mixto Universidad de Valencia-CSIC, Institutos de Investigacion de Paterna, Aptdo. 22085, 46071 Valencia. Unitary coupled channel study of the {lambda}(1520) resonance. United States. doi:10.1063/1.2176490.
Roca, L., Magas, V. K., Oset, E., Sarkar, Sourav, and IFIC, Centro Mixto Universidad de Valencia-CSIC, Institutos de Investigacion de Paterna, Aptdo. 22085, 46071 Valencia. Sat . "Unitary coupled channel study of the {lambda}(1520) resonance". United States. doi:10.1063/1.2176490.
@article{osti_20798077,
title = {Unitary coupled channel study of the {lambda}(1520) resonance},
author = {Roca, L. and Magas, V. K. and Oset, E. and Sarkar, Sourav and IFIC, Centro Mixto Universidad de Valencia-CSIC, Institutos de Investigacion de Paterna, Aptdo. 22085, 46071 Valencia},
abstractNote = {We study the {lambda}(1520) resonance in a coupled channel approach involving the {pi}{sigma}(1385), K{xi}(1530), K-barN and {pi}{sigma} channels. Implementing unitarity in coupled channels, we make an analysis of the relative importance of the different mechanisms which contribute to the dynamical structure of this resonance. From experimental information on some partial wave amplitudes and constraints imposed by unitarity, we get a comprehensive description of the amplitudes and hence the couplings to the different channels. We test these amplitudes in different reactions like K-p {yields} {lambda}{pi}{pi}, {gamma}p {yields} K+K-p, {gamma}p {yields} K+{pi}0{pi}0{lambda} and {pi}-p {yields} K0K-p and find a fair agreement with the experimental data.},
doi = {10.1063/1.2176490},
journal = {AIP Conference Proceedings},
number = 1,
volume = 814,
place = {United States},
year = {Sat Feb 11 00:00:00 EST 2006},
month = {Sat Feb 11 00:00:00 EST 2006}
}
  • We study the {lambda}(1520) resonance in a coupled-channel approach involving the {pi}{sigma}(1385),K{xi}(1530),KN, and {pi}{sigma} channels. Implementing unitarity in coupled channels, we make an analysis of the relative importance of the different mechanisms that contribute to the dynamical structure of this resonance. From experimental information on some partial wave amplitudes and constraints imposed by unitarity, we get a comprehensive description of the amplitudes and hence the couplings to the different channels. We test these amplitudes in different reactions like K{sup -}p{yields}{lambda}{pi}{pi},{gamma}p{yields}K{sup +}K{sup -}p,{gamma}p{yields}K{sup +}{pi}{sup 0}{pi}{sup 0}{lambda}, and {pi}{sup -}p{yields}K{sup 0}K{sup -}p and find a fair agreement with the experimental data.
  • We study the {lambda}(1520)D{sub 03} in a chiral coupled channel approach. This resonance appears to be dynamically generated from the interaction of the decuplet of baryons and the octet of mesons in s wave, and its treatment is improved here with the phenomenological inclusion of the KN and {pi}{sigma} channels in d wave. Since the most important building block in {lambda}(1520) is the {pi}{sigma}{sup *}(1385)P{sub 13} channel, we study the K{sup -}p{yields}{pi}{sigma}{sup *}(1385)({pi}{sup 0}{lambda}) reaction in the region of {lambda}(1520) and above, and compare the results with recent experimental data. With the coupling of {lambda}(1520) to the {pi}{sigma}{sup *} channelmore » predicted by the theory, we find a cross section in good agreement with the data. There is also agreement for the invariant mass distributions which show a neat peak for {sigma}{sup *}(1385) in the ({pi}{sup 0}{lambda}) spectrum. Predictions are made of a strong {lambda}(1520) resonant peak of the cross section, as a function of the K{sup -} momentum, in the region below the measured data, which, if confirmed experimentally, would give stronger support to the idea of {lambda}(1520) as a dynamically generated resonance.« less
  • We investigate photoproduction of {phi} mesons off protons within a coupled-channel effective-Lagrangian method which is based on the K-matrix approach. Since the threshold energy of the K{lambda}(1520) channel is close to that of {phi}N, the contribution of this channel to {phi} photoproduction near the threshold energy region may give rise to some unexpected structures. In the transition amplitude K{lambda}(1520){yields}{phi}N, the kinematics allows an intermediate kaon to be on-shell. This happens in the energy region where a peak structure has been observed in {phi} photoproduction. In our calculations, the on-shell kaon effect indeed reproduces a peak structure, though with a magnitudemore » that is far too small to explain the observed effect. As a following step, we introduce a nucleon resonance in our model. The coupling of the resonance to the K{lambda}(1520) and {phi}N channels is not suppressed by the Okubo-Zweig-Iizuka (OZI) rule if the resonance contains a dominant hidden strangeness component. We find that the resonance can reproduce a peak structure of the correct magnitude at the right energy. We also investigate the effects of coupled channels and the resonance on the angular distribution and the spin-density matrices for {phi} photoproduction.« less
  • No abstract prepared.