1,727,325 research outputs found
Search for the rare decays and
No full textA search for the decays and in a data sample of 1.0 fb collected with the LHCb detector in 2011 is discussed. In the SM, the non-resonant branching fraction is expected to be . One signal candidate is observed in the channel, and no signal candidates are observed in the channel. These observed events are consistent with the expected backgrounds and upper limits on the branching fractions are set at and at 95 % CL
LHCb: Search for the rare decays and at LHCb
No full textA search for the decays and in a data sample of 1.0 inverse femtobarns collected with the LHCb detector in 2011 is discussed. In the SM, the non-resonant branching fraction is expected to be < 10. One signal candidate is observed in the channel, and no signal candidates are observed in the channel. These observed events are consistent with the expected backgrounds and upper limits on the branching fractions are set at and at 95 % CL
Search for Rare B-(s)(0) -> mu(+)mu(-)mu(+)mu(-) Decays
No full textA search for the decays B-s(0) -> mu(+)mu(-)mu(+)mu(-) and B-0 -> mu(+)mu(-)mu(+)mu(-) is performed using data, corresponding to an integrated luminosity of 1.0 fb(-1), collected with the LHCb detector in 2011. The number of candidates observed is consistent with the expected background and, assuming phase-space models of the decays, limits on the branching fractions are set: B(B-s(0) -> mu(+)mu(-)mu(+)mu(-)) mu(+)mu(-)mu(+)mu(-)) SP) SP) <6.3(5.1) x 10(-9) at 95% (90%) confidence level
Search for decays at LHCb
Full text linkA search for decays is performed using proton-proton collision data collected by the LHCb experiment at a centre-of-mass energy of 13 TeV, corresponding to an integrated luminosity of 5.1 . No evidence for signal is found. The 90 % confidence level upper limits are the first set for both decays and are K_{\textrm{S(L)}}^0\rightarrow\mu^{+}\mu^{-}\mu^{+}\mu^{-}fb^{-1}B(K_{\textrm{S}}^0\rightarrow\mu^{+}\mu^{-}\mu^{+}\mu^{-}) < 5.1\times 10^{-12}B(K_{\textrm{L}}^0\rightarrow\mu^{+}\mu^{-}\mu^{+}\mu^{-}) < 2.3\times 10^{-9}$
Search for Rare B-(s)(0) -> mu(+)mu(-)mu(+)mu(-) Decays
No full textA search for the decays B-s(0) -> mu(+)mu(-)mu(+)mu(-) and B-0 -> mu(+)mu(-)mu(+)mu(-) is performed using data, corresponding to an integrated luminosity of 1.0 fb(-1), collected with the LHCb detector in 2011. The number of candidates observed is consistent with the expected background and, assuming phase-space models of the decays, limits on the branching fractions are set: B(B-s(0) -> mu(+)mu(-)mu(+)mu(-)) <1.6(1.2) x 10(-8) and B(B-0 -> mu(+)mu(-)mu(+)mu(-)) <6.6(5.3) x 10(-9) at 95% (90%) confidence level. In addition, limits are set in the context of a supersymmetric model which allows for the B-(s)(0) meson to decay into a scalar ( S) and pseudoscalar particle (P), where S and P have masses of 2.5 GeV/c and 214.3 MeV/c, respectively, both resonances decay into mu(+)mu(-). The branching fraction limits for these decays are B(B-s(0) -> SP) <1.6(1.2) x 10(-8) and B(B-0 -> SP) <6.3(5.1) x 10(-9) at 95% (90%) confidence level
Search for decays at LHCb
Full text linkA search for
decays is performed using proton-proton collision data collected by the LHCb
experiment at a centre-of-mass energy of 13 TeV, corresponding to an integrated
luminosity of 5.1 . No evidence for signal is found. The 90\%
confidence level upper limits are the first set for both decays and are
and .Comment: All figures and tables, along with any supplementary material and
additional information, are available at
https://cern.ch/lhcbproject/Publications/p/LHCb-PAPER-2022-035.html (LHCb
public pages
Study of the rare decay
No full textInternational audienceThe rare electromagnetic decay is observed with a significance greatly exceeding the discovery threshold, using proton-proton collision data collected by the LHCb experiment during 2016-2018 at a center-of-mass energy of 13 TeV, corresponding to an integrated luminosity of . The rate of this decay is measured relative to that of the mode. Using the QED model for the four-muon decay in the efficiency estimation, its branching fraction is determined to be \begin{equation*} {\mathcal{B}}(J/\psi \to \mu^+\mu^-\mu^+\mu^-) = (1.13\pm0.10\pm0.05\pm0.01)\times 10^{-6}, \end{equation*} where the uncertainties are statistical, systematic and due to the uncertainty on the branching fraction of the decay
Observation of the rare decay
No full textThe rare electromagnetic decay is observed with significance greatly exceeding the discovery threshold, using the proton-proton collision data collected by the LHCb experiment in 2016-2018 at a center-of-mass energy of 13 , corresponding to an integrated luminosity of 5.4 . The rate of this decay is measured relative to that of mode. Its branching fraction is determined to be \begin{equation*} \mathcal{B}(J\mskip -3mu/\mskip -2mu\psi \to \mu^+\mu^-\mu^+\mu^-) = (1.13\pm0.10\pm0.05\pm0.01)\times 10^{-6}, \end{equation*} where the uncertainties are statistical, systematic, and that due to the uncertainty on the branching fraction of the decay
Bs to mu mu gamma from Bs to mu mu
No full textInternational audienceThe Bs to mu mu gamma decay offers sensitivity to a wider set of effectiveoperators than its non-radiative counterpart Bs to mu mu, and a set that isinteresting in the light of present-day discrepancies in flavour data. On theother hand, the direct measurement of the Bs to mu mu gamma decay poseschallenges with respect to the Bs to mu mu one. We present a novel strategy tosearch for Bs to mu mu gamma decays in the very event sample selected for Bs tomu mu searches. The method consists in extracting the Bs to mu mu gammaspectrum as a "contamination" to the Bs to mu mu one, as the signal window forthe latter is extended downward with respect to the peak region. We providearguments for the actual practicability of the method already on Run-2 data ofthe LHC
Search for at the LHCb experiment
No full textThese proceedings discuss the search for decays, performed using proton-proton collision data collected by the LHCb experiment at a centre-of-mass energy of 13TeV, corresponding to an integrated luminosity of 5.1 fb . Upper limits are computed to be, at 90% C.L., .These proceedings discuss the search for decays, performed using proton-proton collision data collected by the LHCb experiment at a centre-of-mass energy of 13 TeV, corresponding to an integrated luminosity of 5.1 fb. Upper limits are computed to be, at 90% C.L., < 5.1 10 (2.310
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