3 research outputs found

    Effective lifetime measurements in the Bs0→K+K-, B0→K+π-and B0s→π+K-decays

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    Measurements of the effective lifetimes in the Bs0→K+K-,B0→K +π- and Bs0→π+K- decays are presented using 1.0 fb -1 of pp collision data collected at a centre-of-mass energy of 7 TeV by the LHCb experiment. The analysis uses a data-driven approach to correct for the decay time acceptance. The measured effective lifetimes areτBs0→K+K-=1.407±0.016(stat)±0.007(syst) ps,τB0→K+π-=1.524±0.011(stat)±0.004(syst) ps,τBs0→π+K-=1.60±0.06(stat)±0.01(syst) ps. This is the most precise determination to date of the effective lifetime in the Bs0→K+K- decay and provides constraints on contributions from physics beyond the Standard Model to the Bs0 mixing phase and the width difference δΓs. © 2014 The Authors

    Search for heavy ZZ resonances in the l(+) l(-) l(+) l(-) and l(+) l(-) nu(nu)over-bar final states using proton-proton collisions at root s=13 TeV with the ATLAS detector

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    A search for heavy resonances decaying into a pair of ZZ bosons leading to ++\ell^+\ell^-\ell^+\ell^- and +ννˉ\ell^+\ell^-\nu\bar\nu final states, where \ell stands for either an electron or a muon, is presented. The search uses proton proton collision data at a centre-of-mass energy of 13 TeV corresponding to an integrated luminosity of 36.1 fb1^{-1} collected with the ATLAS detector during 2015 and 2016 at the Large Hadron Collider. Different mass ranges for the hypothetical resonances are considered, depending on the final state and model. The different ranges span between 200 GeV and 2000 GeV. The results are interpreted as upper limits on the production cross section of a spin 0 or spin 2 resonance. The upper limits for the spin 0 resonance are translated to exclusion contours in the context of Type I and Type II two-Higgs-doublet models, while those for the spin 2 resonance are used to constrain the Randall Sundrum model with an extra dimension giving rise to spin 2 graviton excitations

    Search for heavy ZZ resonances in the +−+− and +−νν¯ final states using proton–proton collisions at √s = 13 TeV with the ATLAS detector

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    A search for heavy resonances decaying into a pair of Z bosons leading to +−+− and +−νν¯ final states, where stands for either an electron or a muon, is presented. The search uses proton–proton collision data at a centre-of-mass energy of 13 TeV corresponding to an integrated luminosity of 36.1 fb−1 collected with the ATLAS detector during 2015 and 2016 at the Large Hadron Collider. Different mass ranges for the hypothetical resonances are considered, depending on the final state and model. The different ranges span between 200 and 2000 GeV. The results are interpreted as upper limits on the production cross section of a spin-0 or spin-2 resonance. The upper limits for the spin-0 resonance are translated to exclusion contours in the context of Type-I and Type-II two-Higgs-doublet models, while those for the spin-2 resonance are used to constrain the Randall–Sundrum model with an extra dimension giving rise to spin-2 graviton excitations
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