arXiv subjects

Y. Hirabayashi

Publications and source records attributed to Y. Hirabayashi.

20 records · Page 2Linked to original sources

arXiv2008

Feasibility of extracting a $Σ^-$ admixture probability in the neutron-rich $^{10}_Λ$Li hypernucleus

We examine theoretically production of the neutron-rich $^{10}_Λ$Li hypernucleus by a double-charge exchange ($π^-$, $K^+$) reaction on a $^{10}$B target with distorted-wave impulse approximation calculations. The result shows that the magnitude and shape of the calculated spectrum at 1.20 GeV/c by a one-step mechanism $π^-p \to K^+ Σ^-$ via $Σ^-$ doorways caused by a $Σ^-p \leftrightarrow Λn$ coupling can explain the recent experimental data, and the $Σ^-$ admixture probability in $^{10}_Λ$Li is found to be the order of 10$^{-1}$ %. The ($π^-$, $K^+$) reaction provides a capability of extracting properties of wave functions with $Λ$-$Σ$ coupling effects in neutron-rich nuclei, together with the reaction mechanism.

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arXiv2004

Optimal Fermi-averaging t-matrix for ($π^+$,$K^+$) reactions in $Λ$ quasi-free region

We propose an optimal Fermi-averaging for an elementary $π^+$+$n$$\to$$K^+$+$Λ$ t-matrix under the on-energy-shell condition, in order to describe ($π^+$,$K^+$) reactions on a nuclear target in the framework of a distorted-wave impulse approximation. We apply it to calculate $Λ$ quasi-free spectra from $^{12}$C($π^+$,$K^+$) reactions at $p_π$= 1.20 GeV/c and 1.05 GeV/c, and compare them with experimental data. The results show that the calculated spectra are in excellent agreement with the data, because the energy-dependence originates from the nature of the optimal Fermi-averaging t-matrix.

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