3,142 research outputs found

    B(s)0→μ+μ−B^0_{(s)} \rightarrow \mu^+\mu^- at CMS

    Full text link
    The search for the rare \BMuMu and \BsMuMu decays in pp collisions at s=7\sqrt s = 7~GeV and s=8\sqrt s = 8~GeV, collected at the LHC in 2011 and 2012, is briefly reviewed. The data analyzed by CMS correspond to a total integrated luminosity of 5 and 20 fb−1\rm fb^{-1}, respectively. The time-integrated average branching fraction <B(Bs0→μ+μ−)>\left<{\mathcal B }( { B^{0}_{s}\rightarrow \mu^+\mu^-} )\right> has been measured to be (3.0−0.9+1.0)×10−9(3.0 ^{+1.0}_{-0.9})\times 10^{-9} in accordance with the Standard Model predictions, while an upper limit <B(B0→μ+μ−)><1.1×10−9)\left<{ \mathcal B }( B^{0}\rightarrow \mu^+\mu^-)\right> < 1.1\times 10^{-9}) has been placed on the other investigated decay at 95% CL. A preliminary combination with the results from LHCb is also presented for both channels, and prospects for the future are briefly discussed.Comment: 6 pages, 7 figures, proceedings of LHCP2014 conference, N

    Search for the standard model Higgs boson decaying into two photons in pp collisions at 1as=7TeV

    Get PDF
    A search for a Higgs boson decaying into two photons is described. The analysis is performed using a dataset recorded by the CMS experiment at the LHC from pp collisions at a center-of-mass energy of 7 TeV, which corresponds to an integrated luminosity of 4.8 fb -1. Limits are set on the cross section of the standard model Higgs boson decaying to two photons. The expected exclusion limit at 95% confidence level is between 1.4 and 2.4 times the standard model cross section in the mass range between 110 and 150 GeV. The analysis of the data excludes, at 95% confidence level, the standard model Higgs boson decaying into two photons in the mass range 128 to 132 GeV. The largest excess of events above the expected standard model background is observed for a Higgs boson mass hypothesis of 124 GeV with a local significance of 3.1\u3c3. The global significance of observing an excess with a local significance 653.1\u3c3 anywhere in the search range 110-150 GeV is estimated to be 1.8\u3c3. More data are required to ascertain the origin of this excess

    Study of high-pT charged particle suppression in PbPb compared to pp collisions at sqrt(sNN) = 2.76 TeV

    Get PDF
    The transverse momentum spectra of charged particles have been measured in pp and PbPb collisions at sqrt(sNN) = 2.76 TeV by the CMS experiment at the LHC. In the transverse momentum range pt = 5-10 GeV/c, the charged particle yield in the most central PbPb collisions is suppressed by up to a factor of 5 compared to the pp yield scaled by the number of incoherent nucleon-nucleon collisions. At higher pt, this suppression is significantly reduced, approaching roughly a factor of 2 for particles with pt in the range pt=40-100 GeV/c
    • …
    corecore