$\Lambda (1520)$ and $\Sigma (1385)$ in the nuclear medium

Abstract

Recent studies of the $\Lambda (1520)$ resonance within chiral unitary theory with coupled channels find the resonance as a dynamically generated state from the interaction of the decuplet of baryons and the octet of mesons, essentially a quasibound state of $\pi {\Sigma }^{\ast }(1385)$ in this case, although the coupling of the $\Lambda (1520)$ to the $\bar{K}N$ and $\pi \Sigma$ makes this picture only approximate. The $\pi {\Sigma }^{\ast }(1385)$ decay channel of the $\Lambda (1520)$ is forbidden in free space for the nominal mass of the ${\Sigma }^{\ast }(1385)$, but the coupling of the $\pi$ to $ph$ components in the nuclear medium opens new decay channels of the $\Lambda (1520)$ in the nucleus and produces a much larger width. Together with medium modifications of the $\bar{K}N$ and $\pi \Sigma$ decay channels, the final width of the $\Lambda (1520)$ at nuclear matter density is more than five times bigger than the free one. We perform the calculations by dressing simultaneously the $\Lambda (1520)$ and the ${\Sigma }^{\ast }(1385)$ resonances, finding moderate changes in the mass but substantial ones in the width of both resonances.

20 pages, 6 figures; comparison made to data, new references and new (small) decay channel included

References in corpus (10)

• Baryonic Resonances from Baryon Decuplet-Meson Octet Interaction
• phi photo-production from Li, C, Al, and Cu nuclei at Egamma=1.5 - 2.4 GeV
• Cutoff schemes in chiral perturbation theory and the quark mass expansion of the nucleon mass
• Lambda(1520,3/2^-) photoproduction reaction via gamma N -> K Lambda(1520)
• Baryon masses, chiral extrapolations, and all that
• Gauge invariance in two-particle scattering
• Coherent Theta^+ and Lambda(1520) photoproduction off the deuteron
• Chiral coupled channel dynamics of the Lambda(1520) and the K-P -> pi0 pi0 Lambda reaction
• An Experimental Review of the ${\Theta }^{+}$ Pentaquark
• Two pion mediated scalar isoscalar NN interaction in the nuclear medium

Cited by in corpus (17)

• Strange baryon resonance production in $\sqrt{s_{NN}}=200$ GeV $p+p$ and $Au+Au$ collisions
• Chiral approach to antikaon s- and p-wave interactions in dense nuclear matter
• Antikaons and hyperons in nuclear matter with saturation
• Baryonic resonances close to the Kbar-N threshold: the case of Sigma(1385)^+ in pp collisions
• Charm and hidden charm scalar mesons in the nuclear medium
• Anti-strange meson-baryon interaction in hot and dense nuclear matter
• ${\bar{K}}^{\ast }$ meson in dense matter
• $A$ dependence of the $\gamma$- and $p$-induced production of the $\Lambda (1520)$ from nuclei
• ${\Xi }^0(1530)$ Production in Heavy-Ion Collisions \linebreak and its Implications for $\Delta t_{therm-chem}$
• Medium effects in $\Lambda K^{+}$ pair production by 2.83 GeV protons on nuclei
• $\Lambda (1520)$ at finite density
• Near-threshold $K^{\ast }(892{)}^{+}$ meson production in the interaction of ${\pi }^{-}$ mesons with nuclei
• Testing the Lambda(1520) hyperon in-medium width in near-threshold proton-nucleus reactions
• Medium effects in antikaon-induced ${\Xi }^{-}$ hyperon production on nuclei near threshold
• Pion-induced production of $\Lambda (1520)$ hyperons on nuclei near threshold
• Recent developments in chiral dynamics of hadrons and hadrons in a nuclear medium
• Selected topics on Hadrons in Nuclei