In-medium Λ isospin impurity from charge symmetry breaking in the Λ4H−Λ4He mirror hypernuclei
Year: 2022
Type: article
Abstract: Charge-symmetry breaking, or CSB, is a fundamental concept in nuclear physics. Adding a $\mathrm{\ensuremath{\Lambda}}$ hyperon, a sibling of the nucleon with a strange quark, to light nuclei promises new insights as its isospin impurity must impact CSB in mirror hypernuclei, where the only good data available are for $A=4$. The authors use an ansatz that relates the charge-symmetry-breaking $\mathrm{\ensuremath{\Lambda}}\phantom{\rule{0}{0ex}}N$ interaction to the $\mathrm{\ensuremath{\Lambda}}\phantom{\rule{0}{0ex}}N\ensuremath{\leftrightarrow}\mathrm{\ensuremath{\Sigma}}\phantom{\rule{0}{0ex}}N$ strong-interaction coupling via the small isospin-one admixture the $\mathrm{\ensuremath{\Lambda}}$ obtains from the ${\mathrm{\ensuremath{\Sigma}}}^{0}$, as both are members of an SU(3) baryon octet and have an $u$-$d$-$s$ quark structure. Once the large CSB observed in mirror hypernuclei ${}_{\mathrm{\ensuremath{\Lambda}}}^{4}$H and ${}_{\mathrm{\ensuremath{\Lambda}}}^{4}$He is reproduced, the deduced isospin-one admixture of the $\mathrm{\ensuremath{\Lambda}}$ when inside these hypernuclei matches that in free space, provided SU(3) symmetry is partially conserved for these baryons. This approach can be tested in heavier hypernuclei when precise data for CSB become available.
Source: Physical Review C
Authors: M. Schäfer, N. Barnea, A. Gal
Institution: Hebrew University of Jerusalem
Language: Latvian
Subfield: Nuclear and High Energy Physics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: green
Awards: G2652204519, G7233877507
OpenAlex ID: W4221151904