Differential branching fraction and angular analysis of Λ 0 b → Λμ+μ− decays
The differential branching fraction of the rare decay Λ 0 b → Λμ+μ− is measured as a function of q2, the square of the dimuon invariant mass. The analysis is performed using proton-proton collision data, corresponding to an integrated luminosity of 3.0 fb−1, collected by the LHCb experiment. Eviden...
| Authors: | ; ; ; |
|---|---|
| Format: | Article |
| Status: | Published version |
| Publication date: | 2015 |
| Country: | España |
| Institution: | Universitat Ramon Llull (URL) |
| Repository: | DAU Arxiu Digital de la Universitat Ramon Llull |
| OAI Identifier: | oai:dau.url.edu:20.500.14342/3137 |
| Online Access: | http://hdl.handle.net/20.500.14342/3137 https://doi.org/10.1007/JHEP06(2015)115 |
| Access Level: | Open access |
| Keyword: | Gran col·lisionador d'hadrons (França i Suïssa) Partícules (Física nuclear) Col·lisions (Física nuclear) Protons 539 |
| Summary: | The differential branching fraction of the rare decay Λ 0 b → Λμ+μ− is measured as a function of q2, the square of the dimuon invariant mass. The analysis is performed using proton-proton collision data, corresponding to an integrated luminosity of 3.0 fb−1, collected by the LHCb experiment. Evidence of signal is observed in the q2 region below the square of the J/ψ mass. Integrating over 15 < q2 < 20 GeV2/c4 the differential branching fraction is measured as dB(Λ0b→Λμ+μ−)/dq2=(1.18+0.09−0.08±0.03±0.27)×10−7(GeV2/c4)−1, where the uncertainties are statistical, systematic and due to the normalisation mode, Λ 0 b → J/ψΛ, respectively. In the q2 intervals where the signal is observed, angular distributions are studied and the forward-backward asymmetries in the dimuon (A ℓFB ) and hadron (A hFB ) systems are measured for the first time. In the range 15 < q2 < 20 GeV2/c4 they are found to be AℓFB=−0.05±0.09(stat)±0.03(syst)andAhFB=−0.29±0.07(stat)±0.03(syst). |
|---|