Hadron Mass Effects: Kaons at HERMES vs. COMPASS

TL;DR

This paper investigates how hadron mass effects at leading order and twist can reconcile discrepancies between HERMES and COMPASS measurements of kaon multiplicities, especially for the $K^+/K^-$ ratio.

Contribution

It demonstrates that Hadron Mass Corrections can fully reconcile certain kaon multiplicity data discrepancies between two major experiments.

Findings

Hadron Mass Corrections reconcile $K^+/K^-$ ratio data.

Mass effects reduce discrepancies in $K^+ + K^-$ data.

Residual differences in data shape remain unexplained.

Abstract

Experimental data for integrated kaon multiplicities taken at HERMES and COMPASS measurements look incompatible with each other. In this talk, we investigate the effects of hadron masses calculated at leading-order and leading twist at the kinematics of these two experiments. We present evidence that Hadron Mass Corrections can fully reconcile the data for the $K^+/K^-$ multiplicity ratio, and can also sizeably reduce the apparent large discrepancy in the case of $K^+ + K^-$ data. Residual differences in the shape of the latter one remains to be understood.