Measurement of the fraction of \Y1S originating from \chib1P decays in $pp$ collisions at $\sqrt{s} = 7\tev$

TL;DR

This paper measures the proportion of \\Y1S mesons originating from \\chib1P decays in proton-proton collisions at 7 TeV, providing insights into bottomonium production mechanisms using LHCb data.

Contribution

It presents the first measurement of the fraction of \\Y1S from \\chib1P decays at 7 TeV, including polarization uncertainties, using a novel reconstruction method.

Findings

Fraction of \\Y1S from \\chib1P decays is approximately 20.7%.

Measurement includes statistical, systematic, and polarization-related uncertainties.

Results help understand bottomonium production in high-energy collisions.

Abstract

The production of \chib1P mesons in $pp$ collisions at a centre-of-mass energy of $7\tev$ is studied using $32\invpb$ of data collected with the \lhcb detector. The $\chib1P$ mesons are reconstructed in the decay mode $\chib1P \to \Y1S\g \to \mumu\g$. The fraction of \Y1S originating from \chib1P decays in the \Y1S transverse momentum range $6 < \pt^{\Y1S} < 15\gevc$ and rapidity range $2.0 < y^{\Y1S} < 4.5$ is measured to be $(20.7\pm 5.7\pm 2.1^{+2.7}_{-5.4})%$, where the first uncertainty is statistical, the second is systematic and the last gives the range of the result due to the unknown \Y1S and \chib1P polarizations.