[Show abstract][Hide abstract] ABSTRACT: A joint measurement is presented of the branching fractions
$B^0_s\to\mu^+\mu^-$ and $B^0\to\mu^+\mu^-$ in proton-proton collisions at the
LHC by the CMS and LHCb experiments. The data samples were collected in 2011 at
a centre-of-mass energy of 7 TeV, and in 2012 at 8 TeV. The combined analysis
produces the first observation of the $B^0_s\to\mu^+\mu^-$ decay, with a
statistical significance exceeding six standard deviations, and the best
measurement of its branching fraction so far, and three standard deviation
evidence for the $B^0\to\mu^+\mu^-$ decay. The measurements are statistically
compatible with SM predictions and impose stringent constraints on several
theories beyond the SM.
[Show abstract][Hide abstract] ABSTRACT: Results are presented of a search for a "natural" supersymmetry scenario with gauge mediated symmetry breaking. It is assumed that only the supersymmetric partners of the top quark (the top squark) and the Higgs boson (Higgsino) are accessible. Events are examined in which there are two photons forming a Higgs boson candidate, and at least two b-quark jets. In 19.7 fb-1 of proton-proton collision data at s=8 TeV, recorded in the CMS experiment, no evidence of a signal is found and lower limits at the 95% confidence level are set, excluding the top squark mass below 360 to 410 GeV, depending on the Higgsino mass.
[Show abstract][Hide abstract] ABSTRACT: Results are presented from a search for the production of a heavy gauge boson
W' decaying into a top and a bottom quark, using a data set collected by the
CMS experiment at sqrt(s)=8 TeV and corresponding to an integrated luminosity
of 19.5 inverse femtobarns. Various models of W'-boson production are studied
by allowing for an arbitrary combination of left- and right-handed couplings.
The analysis is based on the detection of events with a lepton (e, mu), jets,
and missing transverse energy in the final state. No evidence for W'-boson
production is found and 95% confidence level upper limits on the production
cross section times branching fraction are obtained. For W' bosons with purely
right-handed couplings, and for those with left-handed couplings assuming no
interference effects, the observed 95% confidence level limit is M(W')>2.05
TeV. For W' bosons with purely left-handed couplings, including interference
effects, the observed 95% confidence level limit is M(W')>1.84 TeV. The results
presented in this paper are the most stringent limits published to date.