Search for a new bottomonium state decaying to Upsilon(1S) pi+ pi- in pp collisions at sqrt(s) = 8 TeV

TL;DR

This paper reports a search for a new bottomonium state Xb decaying to Upsilon(1S) pi+ pi- in 8 TeV proton-proton collisions, setting the first upper limits on its production at a hadron collider.

Contribution

It presents the first upper limits on Xb production in hadron collisions, based on CMS data at 8 TeV, for masses between 10 and 11 GeV.

Findings

No evidence for Xb signal was observed.

Upper limits on production ratios range from 0.9% to 5.4%.

First constraints on Xb production at a hadron collider.

Abstract

The results of a search for the bottomonium counterpart, denoted as Xb, of the exotic charmonium state X(3872) is presented. The analysis is based on a sample of pp collisions at sqrt(s) = 8 TeV collected by the CMS experiment at the LHC, corresponding to an integrated luminosity of 20.7 inverse femtobarns. The search looks for the exclusive decay channel Xb to Upsilon(1S) pi+ pi- followed by Upsilon(1S) to mu+ mu-. No evidence for an Xb signal is observed. Upper limits are set at the 95% confidence level on the ratio of the inclusive production cross sections times the branching fractions to Upsilon(1S) pi+ pi- of the Xb and the Upsilon(2S). The upper limits on the ratio are in the range 0.9-5.4% for Xb masses between 10 and 11 GeV. These are the first upper limits on the production of a possible Xb at a hadron collider.