A comparative measurement of $\phi\rightarrow K^+K^-$ and $\phi\rightarrow \mu^+\mu^-$ in In-In collisions at the CERN SPS

TL;DR

This study compares $\,\,\phi$ meson production in In-In collisions at CERN SPS through two decay channels, revealing consistent results and contrasting previous discrepancies observed in Pb-Pb collisions, with implications for understanding meson production.

Contribution

It provides a direct comparison of $\,\,\phi$ meson yields in two decay channels in In-In collisions, highlighting consistency and addressing prior discrepancies in heavy-ion collision measurements.

Findings

Yields and spectra are compatible across decay channels within errors.

Contrasts with previous Pb-Pb collision results showing discrepancies.

Discusses potential physics implications of the findings.

Abstract

The NA60 experiment at the CERN SPS has studied $\phi$ meson production in In-In collisions at 158A GeV via both the $K^+K^-$ and the $\mu^+\mu^-$ decay channels. The yields and inverse slope parameters of the $m_T$ spectra observed in the two channels are compatible within errors, different from the large discrepancies seen in Pb-Pb collisions between the hadronic (NA49) and dimuon (NA50) decay channels. Possible physics implications are discussed.