The small axial charge of the N(1535) resonance

TL;DR

This paper explains the very small axial charge of the N(1535) resonance through a cancellation effect between different quark components, aligning with recent lattice calculations and setting limits on pentaquark probabilities.

Contribution

It reveals a natural cancellation mechanism in the axial charge of N(1535) due to qqq and qqqqar q components, highlighting the role of these configurations.

Findings

The axial charge of N(1535) is very small or zero.

Cancellation occurs between qqq and qqqqar q contributions.

Provides an upper limit on pentaquark component probability.

Abstract

There is a natural cancellation between the contributions of the $qqq$ and $qqqq\bar q$ components to the axial charge of the N(1535) resonance. While the probability of the former is larger than that of the latter, its coefficient in the axial charge expression is exceptionally small. The magnitude of two of the corresponding coefficients of the $qqqq\bar q$ components are in contrast large and have the opposite sign. This result provides a phenomenological illustration of the recent unquenched lattice calculation result that the axial charge of the N(1535) resonance is very small, if not vanishing \cite{takah}. The result sets an upper limit on the magnitude of the probability of $qqqq\bar q$ components as well.