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

• Main Author: CMS collaboration (2224 authors)
• Publication Date: 2013
• Other Authors: Hollar, Jonathan, Nayak, Aruna, Calpas, Betty, Almeida, Nuno, Bargassa, Pedrame, Beirão Da Cruz E Silva, Cristóvão, Faccioli, Pietro, Ferreira Parracho, Pedro Guilherme, Gallinaro, Michele, Nguyen, Federico, Rodrigues Antunes, Joao, Seixas, Joao, Varela, Joao, Vischia, Pietro, Lloret Iglesias, Lara, David Tinoco Mendes, Andre, Musella, Pasquale, Silva, Pedro, Pela, Joao, Leonardo, Nuno
• Format: Article
• Language: eng
• Source: Repositórios Científicos de Acesso Aberto de Portugal (RCAAP)
• Download full: http://dx.doi.org/10.1016/j.physletb.2013.10.016; http://hdl.handle.net/10400.26/26472

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.