Lambda beta-decay in-medium

Abstract

Under the working hypothesis that the structure of a bound hadron is modified by its interactions with other hadrons, one may expect to see changes in carefully chosen observables. In the light of a recent proposal to measure the axial charge in the strangeness changing beta-decay of a bound Lambda hyperon, we examine the size of the change expected within the quark-meson coupling model. It is predicted to be significant

Quark–Meson-Coupling (QMC) model for finite nuclei, nuclear matter and beyond

“…Recently Guichon and Thomas [92] explored another aspect of β-decay, namely the variation of the rate of semi-leptonic decay of the Λ-hyperon in a hypernucleus, resulting from the change in the wave function of the non-strange quark in the final nucleon. Both the strangeness changing vector and axial weak charges were shown to be reduced by up to 10% at nuclear matter density.…”

Magnetic moments of the octet, decuplet, low-lying charm, and low-lying bottom baryons in a nuclear medium

“…Namely, a naive integration over the common bag radius leads to a violation of the Ademoll-Gatto theorem [55] as discussed in Ref. [56]. Some discussions on this issue will be given later.…”

Feasibility study for measurement of beta-decay rates of Λ hypernuclei

“…/𝑔 # value of a Λ in the free space was measured to be 𝑔 ! /𝑔 # = −0.718 ± 0.015 [3]. However, there is no experimental data on beta decay of Λ in a nucleus and the in-medium 𝑔 !…”

“…Such reduction is ascribed to quenching of the effective 𝑔 ! value in nuclei [3]. To measure the change of 𝑔 !…”