3,779 research outputs found
at CMS
The search for the rare \BMuMu and \BsMuMu decays in pp collisions at ~GeV and ~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 , respectively. The time-integrated average
branching fraction has been measured to be in
accordance with the Standard Model predictions, while an upper limit 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
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
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
Validation tests of the CMS TIB/TID structures
Tracker Inner Barrel half-cylinders and Tracker Inner Disks of the CMS tracker have been integrated in three INFN sites. Integrated structures are submitted to an extensive set of tests whose main aim is to validate the functioning of the structures in CMS-like conditions. The tests have furthermore proven to be a great opportunity to study several aspects of the performance in detail. In this note the tests are described in some detail and an overview of the results is presented
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