Weak $K\to \pi$ generalized form factors and transverse transition quark-spin density from the instanton vacuum

TL;DR

This paper studies the $K o $ transition form factors and transverse quark spin density using a nonlocal chiral quark model from the instanton vacuum, aligning well with lattice QCD data.

Contribution

It introduces a calculation of generalized $K o $ transition form factors and transverse quark spin densities within the instanton vacuum framework, providing new insights into hadronic structure.

Findings

Transition tensor form factor agrees with lattice QCD data.

Transverse quark spin density behavior resembles that of pion and kaon.

Results enhance understanding of $K o $ transition dynamics.

Abstract

We investigate the generalized $K\to \pi$ transition vector and tensor form factors, from which we derive the transverse quark spin density in the course of the $K\to\pi$ transition, based on the nonlocal chiral quark model from the instanton vacuum. The results of the transition tensor form factor are in good agreement with recent data of lattice QCD. The behavior of the transverse quark spin density of the $K\to\pi$ transition turn out to be very similar to those of the pion and the kaon.