Observation of the $\Omega$(2012) baryon at the LHC

TL;DR

This paper reports the first observation of the $ ext{Ω}(2012)$ baryon at the LHC, measuring its mass, width, and production characteristics, confirming previous findings and providing new insights into its properties.

Contribution

The paper presents the first LHC measurement of the $ ext{Ω}(2012)$ baryon, including its mass, width, transverse momentum spectrum, and yield, corroborating earlier observations and expanding understanding of excited baryon states.

Findings

Observation of $ ext{Ω}(2012)$ with $15σ$ significance

Measured mass and narrow width of the $ ext{Ω}(2012)$

First transverse-momentum spectrum and yield measurement

Abstract

A signal consistent with the $\Omega$(2012) baryon has been observed with a significance of $15\sigma$ in pp collisions at $\sqrt{s}=13$ TeV at the LHC. In this paper, the analysis technique is described and measurements of the mass and width of the $\Omega$(2012) are reported, along with the first measurement of its transverse-momentum spectrum and yield. This paper corroborates the observation by Belle of this excited $\Omega$ state and the observation that the $\Omega$(2012) has a rather narrow width for a strongly decaying resonance. The yield measurement is combined with a statistical thermal model calculation of strange baryon yield ratios to obtain estimates of the $\Omega{\rm (2012)}^{-} \rightarrow \Xi\overline{\rm K}$ branching ratios. These results will improve our understanding of the internal structure and mass spectrum of excited baryon states and serve as a baseline for searches regarding modifications of these properties in high-temperature media.