Constraints from $\Lambda$ hypernuclei on the $\Lambda NN$ content of the $\Lambda$-nucleus potential
| Autor: | Friedman, E., Gal, A. |
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| Rok vydání: | 2022 |
| Předmět: | |
| Zdroj: | Physics Letters B 837 (2023) 137669 |
| Druh dokumentu: | Working Paper |
| DOI: | 10.1016/j.physletb.2023.137669 |
| Popis: | A depth of $D_{\Lambda}\approx -28$ MeV for the $\Lambda$-nucleus potential was confirmed in 1988 by studying $\Lambda$ binding energies deduced from $(\pi^+,K^+)$ spectra measured across the periodic table. Modern two-body hyperon-nucleon interaction models require additional interaction terms, most likely $\Lambda NN$ three-body terms, to reproduce $D_{\Lambda}$. In this work we apply a suitably constructed $\Lambda$-nucleus density dependent optical potential to binding energy calculations of observed $1s_{\Lambda}$ and $1p_{\Lambda}$ states in the mass range $12\leq A\leq 208$. The resulting $\Lambda NN$ contribution to $D_{\Lambda}$, about 14 MeV repulsion at symmetric nuclear matter density $\rho_0=0.17$ fm$^{-3}$, makes $D_{\Lambda}$ increasingly repulsive at $\rho\gtrsim 3\rho_0$, leading possibly to little or no $\Lambda$ hyperon content of neutron-star matter. This suggests in some models a stiff equation of state that may support two solar-mass neutron stars. Comment: v1: 5 pages, 3 figures, 1 table; v2: slightly corrected v1, submitted for publication; v3: 14 pages, 3 figures, 1 table, submitted elsewhere; v4: very minor stylistic changes, matches published version |
| Databáze: | arXiv |
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