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Title: Chiral SU(3) dynamics and {lambda} hyperons in the nuclear medium{sup 1}

Abstract

We present a novel approach to the density-dependent mean field and the spin-orbit interaction of a {lambda} hyperon in a nuclear many-body system, based on flavor-SU(3) in-medium chiral perturbation theory. The leading long-range {lambda}N interaction arises from kaon exchange and from two-pion exchange with a {sigma} hyperon in the intermediate state. The empirical {lambda}-nucleus potential depth of about -28 MeV is well reproduced with a single cutoff scale, {lambda}=0.7 GeV, effectively representing all short-distance (high-momentum) dynamics not resolved at scales characteristic of the nuclear Fermi momentum. This value of {lambda} is remarkably consistent with the one required to reproduce the empirical saturation point of isospin-symmetric nuclear matter in the same framework. The smallness of the {lambda}-nuclear spin-orbit interaction finds a natural (yet novel) explanation in terms of an almost complete cancellation between short-range contributions (properly rescaled from the known nucleonic spin-orbit coupling strength) and long-range terms generated by iterated one pion exchange with intermediate {sigma} hyperons. The small {sigma}{lambda}-mass difference figures prominently in this context.

Authors:
;  [1]
  1. Physik-Department, Technische Universitaet Muenchen, D-85747 Garching (Germany)
Publication Date:
OSTI Identifier:
20695902
Resource Type:
Journal Article
Journal Name:
Physical Review. C, Nuclear Physics
Additional Journal Information:
Journal Volume: 71; Journal Issue: 1; Other Information: DOI: 10.1103/PhysRevC.71.015203; (c) 2005 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA); Journal ID: ISSN 0556-2813
Country of Publication:
United States
Language:
English
Subject:
73 NUCLEAR PHYSICS AND RADIATION PHYSICS; CHIRALITY; GEV RANGE; INTERMEDIATE STATE; ISOSPIN; KAONS; L-S COUPLING; LAMBDA BARYONS; MANY-BODY PROBLEM; MASS DIFFERENCE; MEAN-FIELD THEORY; MEV RANGE; NUCLEAR MATTER; NUCLEAR POTENTIAL; PERTURBATION THEORY; PIONS; SIGMA BARYONS; SU-3 GROUPS

Citation Formats

Kaiser, N, and Weise, W. Chiral SU(3) dynamics and {lambda} hyperons in the nuclear medium{sup 1}. United States: N. p., 2005. Web. doi:10.1103/PhysRevC.71.015203.
Kaiser, N, & Weise, W. Chiral SU(3) dynamics and {lambda} hyperons in the nuclear medium{sup 1}. United States. https://doi.org/10.1103/PhysRevC.71.015203
Kaiser, N, and Weise, W. Sat . "Chiral SU(3) dynamics and {lambda} hyperons in the nuclear medium{sup 1}". United States. https://doi.org/10.1103/PhysRevC.71.015203.
@article{osti_20695902,
title = {Chiral SU(3) dynamics and {lambda} hyperons in the nuclear medium{sup 1}},
author = {Kaiser, N and Weise, W},
abstractNote = {We present a novel approach to the density-dependent mean field and the spin-orbit interaction of a {lambda} hyperon in a nuclear many-body system, based on flavor-SU(3) in-medium chiral perturbation theory. The leading long-range {lambda}N interaction arises from kaon exchange and from two-pion exchange with a {sigma} hyperon in the intermediate state. The empirical {lambda}-nucleus potential depth of about -28 MeV is well reproduced with a single cutoff scale, {lambda}=0.7 GeV, effectively representing all short-distance (high-momentum) dynamics not resolved at scales characteristic of the nuclear Fermi momentum. This value of {lambda} is remarkably consistent with the one required to reproduce the empirical saturation point of isospin-symmetric nuclear matter in the same framework. The smallness of the {lambda}-nuclear spin-orbit interaction finds a natural (yet novel) explanation in terms of an almost complete cancellation between short-range contributions (properly rescaled from the known nucleonic spin-orbit coupling strength) and long-range terms generated by iterated one pion exchange with intermediate {sigma} hyperons. The small {sigma}{lambda}-mass difference figures prominently in this context.},
doi = {10.1103/PhysRevC.71.015203},
url = {https://www.osti.gov/biblio/20695902}, journal = {Physical Review. C, Nuclear Physics},
issn = {0556-2813},
number = 1,
volume = 71,
place = {United States},
year = {2005},
month = {1}
}