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

CMS [UCL] Basegmez, Suzan [UCL] Beluffi, Camille [UCL] Bruno, Giacomo [UCL] Castello, Roberto [UCL] Caudron, Adrien [UCL] Ceard, Ludivine [UCL] Da Silveira, Gustavo Gil [UCL] Delaere, Christophe [UCL] Du Pree, Tristan [UCL] Favart, Denis [UCL] Forthomme, Laurent [UCL] Giammanco, Andrea [UCL] Hollar, Jonathan [UCL] Jez, Pavel [UCL] Lemaitre, Vincent [UCL] Liao, Junhui [UCL] Militaru, Otilia [UCL] Nuttens, Claude [UCL] Pagano, Davide [UCL] Pin, Arnaud [UCL] Piotrzkowski, Krzysztof [UCL] Popov, Andrey [UCL] Selvaggi, Michele [UCL] Vidal Maroño, Miguel [UCL] Vizan Garcia, Jesús Manuel [UCL] et al.

The results of a search for the bottomonium counterpart, denoted as $X_b$, 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 $X_b \to \Upsilon(1S) \pi^+ \pi^-$ followed by $\Upsilon(1S) \to \mu^+ \mu^-$. No evidence for an $X_b$ 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 $X_b$ and the $\Upsilon$(2S). The upper limits on the ratio are in the range 0.9-5.4% for $X_b$ masses between 10 and 11 GeV. These are the first upper limits on the production of a possible $X_b$ at a hadron collider.