# Unquenched quark model for baryons: magnetic moments, spins and orbital angular momenta

## TL;DR

This paper introduces an unquenched quark model for baryons that explicitly includes quark-antiquark pairs, revealing their significant impact on orbital angular momentum contributions to baryon spins, especially in the proton and Lambda hyperon.

## Contribution

The model explicitly incorporates quark-antiquark pairs in baryons, allowing detailed study of their effects on magnetic moments and angular momentum contributions.

## Key findings

- Quark-antiquark pairs do not alter baryon magnetic moments.
- Orbital angular momentum significantly contributes to the proton and Lambda hyperon spins.
- The approach is applicable to any initial baryon and quark flavor.

## Abstract

We present an unquenched quark model for baryons in which the effects of the quark-antiquark pairs (up, down and strange) are taken into account in an explicit form via a microscopic, QCD-inspired, quark-antiquark creation mechanism. In the present approach, the contribution of the quark-antiquark pairs can be studied for any inital baryon and for any flavor of the pairs. It is shown that, while the inclusion of quark-antiquark pairs does not affect the baryon magnetic moments, it leads to a sizeable contribution of the orbital angular momentum to the spin of the proton and the Lambda hyperon.