Nucleon-Nucleon Short-Ranged Correlations, $\beta$ Decay and the Unitarity of the CKM Matrix

TL;DR

This paper investigates how nucleon-nucleon short-range correlations affect nuclear beta decay measurements and the implications for testing the unitarity of the CKM matrix, highlighting the model-dependent nature of these effects.

Contribution

It demonstrates that SRC significantly influence beta decay analyses and discusses their impact on CKM unitarity tests, using $^{46}$V as a case study.

Findings

SRC can cause substantial modifications in beta decay calculations.

The effects of SRC are highly model-dependent.

Implications for CKM unitarity tests are significant.

Abstract

The influence of nucleon-nucleon short-ranged correlations (SRC) on nuclear super-allowed $\beta$ decay is examined. The need for this is driven by the observed depletion of spectroscopic strength obtained in studies of $(e,e')$ and $(d,^3{\rm He})$ reactions on a wide variety of nuclei. We show that the influence of SRC is model-dependent, but may be very substantial. The $^{46}$V nucleus is used as an example. The resulting impact on studies of the unitarity of the Cabibbo-Kobayashi-Maskawa (CKM) matrix element is discussed.