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M. Kaskulov

Publications and source records attributed to M. Kaskulov.

20 records · Page 2Linked to original sources

$Λ(1520)$ and $Σ(1385)$ in the nuclear medium

Recent studies of the $Λ(1520)$ 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 $πΣ^*(1385)$ in this case, although the coupling of the $Λ(1520)$ to the $\bar{K}N$ and $πΣ$ makes this picture only approximate. The $πΣ^*(1385)$ decay channel of the $Λ(1520)$ is forbidden in free space for the nominal mass of the $Σ^*(1385)$, but the coupling of the $π$ to $ph$ components in the nuclear medium opens new decay channels of the $Λ(1520)$ in the nucleus and produces a much larger width. Together with medium modifications of the $\bar{K}N$ and $πΣ$ decay channels, the final width of the $Λ(1520)$ at nuclear matter density is more than five times bigger than the free one. We perform the calculations by dressing simultaneously the $Λ(1520)$ and the $Σ^*(1385)$ resonances, finding moderate changes in the mass but substantial ones in the width of both resonances.

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The properties of the three-nucleon system with the dressed-bag model for nn interaction. I: New scalar three-body force

A multi-component formalism is developed to describe three-body systems with nonstatic pairwise interactions and non-nucleonic degrees of freedom. The dressed-bag model for $NN$ interaction based on the formation of an intermediate six-quark bag dressed by a $σ$-field is applied to the $3N$ system, where it results in a new three-body force between the six-quark bag and a third nucleon. Concise variational calculations of $3N$ bound states are carried out in the dressed-bag model including the new three-body force. It is shown that this three-body force gives at least half the $3N$ total binding energy, while the weight of non-nucleonic components in the $^3$H and $^3$He wavefunctions can exceed 10%. The new force model provides a very good description of $3N$ bound states with a reasonable magnitude of the $σNN$ coupling constant. The model can serve as a natural bridge between dynamical description of few-nucleon systems and the very successful Walecka approach to heavy nuclei and nuclear matter.

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