Neutron beta-decay and the quark-mixing CKM-matrix

TL;DR

This paper discusses recent neutron decay measurements revealing a deviation from the Standard Model's unitarity condition of the CKM matrix, suggesting potential new physics beyond current theories.

Contribution

It reports new experimental results on neutron decay that indicate a possible violation of CKM matrix unitarity, challenging existing Standard Model predictions.

Findings

Measured deviation from unitarity: Delta = 0.0083(28)

Neutron decay provides insights into quark-mixing

Potential evidence for physics beyond the Standard Model

Abstract

Neutrons study a number of hot topics from the field of particle physics and cosmology: Recent measurements of various mixed American-British-French-German-Hungarian-Japan-Russian groups of researchers determine the strength of the weak interaction of the neutron, which gives us unique information on quark-mixing and the question of unitarity. Much to our surprise, with neutron-decay we find a deviation Delta = 0.0083(28) from the unitarity condition, an effect that cannot be explained by the current Standard Model of particle physics.