3,450 research outputs found
Future prospects of Higgs Physics at CMS
The Higgs boson physics reach of the CMS detector with 300(0) fb-1 of
proton-proton collisions at sqrt{s} = 14 TeV is presented. Precision
measurements of the Higgs boson properties, Higgs boson pair production and
self-coupling, rare Higgs boson decays, and the potential for additional Higgs
bosons are discussed
MoMEMta, a modular toolkit for the Matrix Element Method at the LHC
The Matrix Element Method has proven to be a powerful method to optimally
exploit the information available in detector data. Its widespread use is
nevertheless impeded by its complexity and the associated computing time.
MoMEMta, a C++ software package to compute the integrals at the core of the
method, provides a versatile implementation of the Matrix Element Method to
both the theory and experiment communities. Its modular structure covers the
needs of experimental analysis workflows at the LHC without compromising ease
of use on simpler and smaller simulated samples used for phenomenological
studies. With respect to existing tools, MoMEMta improves on usability and
flexibility. In this paper, we present version 1.0 of MoMEMta, together with
examples illustrating the wide range of applications at the LHC accessible for
the first time with a single tool.Comment: 18 pages, 3 figures; post peer revie
Study of the B +â J / Ď Î ÂŻ p decay in proton-proton collisions at âs = 8 TeV
A study of the B +â J / Ď Î ÂŻ p decay using proton-proton collision data collected at s = 8 TeV by the CMS experiment at the LHC, corresponding to an integrated luminosity of 19.6 fbâ1, is presented. The ratio of branching fractions B(B+âJ/ĎÎÂŻp)/B(B+âJ/ĎKâ(892)+) is measured to be (1.054 Âą 0.057(stat) Âą 0.035(syst) Âą 0.011(B))%, where the last uncertainty reflects the uncertainties in the world-average branching fractions of Î ÂŻ and K*(892) + decays to reconstructed final states. The invariant mass distributions of the J / Ď Î ÂŻ , J/Ďp, and Î ÂŻ p systems produced in the B +â J / Ď ÎÂŻ p decay are investigated and found to be inconsistent with the pure phase space hypothesis. The analysis is extended by using a model-independent angular amplitude analysis, which shows that the observed invariant mass distributions are consistent with the contributions from excited kaons decaying to the Î ÂŻ p system. [Figure not available: see fulltext.
Search for new neutral Higgs bosons through the H â ZAâ â+ââb b ÂŻ process in pp collisions at âs = 13 TeV
This paper reports on a search for an extension to the scalar sector of the standard model, where a new CP-even (odd) boson decays to a Z boson and a lighter CP-odd (even) boson, and the latter further decays to a b quark pair. The Z boson is reconstructed via its decays to electron or muon pairs. The analysed data were recorded in proton-proton collisions at a center-of-mass energy s = 13 TeV, collected by the CMS experiment at the LHC during 2016, corresponding to an integrated luminosity of 35.9 fbâ1. Data and predictions from the standard model are in agreement within the uncertainties. Upper limits at 95% confidence level are set on the production cross section times branching fraction, with masses of the new bosons up to 1000 GeV. The results are interpreted in the context of the two-Higgs-doublet model. [Figure not available: see fulltext.]
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Measurement of the top quark Yukawa coupling from t t kinematic distributions in the lepton+jets final state in proton-proton collisions at s =13 TeV MEASUREMENT of the TOP QUARK YUKAWA COUPLING from ... SIRUNYAN et al.
Results are presented for an extraction of the top quark Yukawa coupling from top quark-antiquark (tt) kinematic distributions in the lepton plus jets final state in proton-proton collisions, based on data collected by the CMS experiment at the LHC at s=13 TeV, corresponding to an integrated luminosity of 35.8 fb-1. Corrections from weak boson exchange, including Higgs bosons, between the top quarks can produce large distortions of differential distributions near the energy threshold of tt production. Therefore, precise measurements of these distributions are sensitive to the Yukawa coupling. Top quark events are reconstructed with at least three jets in the final state, and a novel technique is introduced to reconstruct the tt system for events with one missing jet. This technique enhances the experimental sensitivity in the low invariant mass region, Mtt. The data yields in Mtt, the rapidity difference |yt-yt|, and the number of reconstructed jets are compared with distributions representing different Yukawa couplings. These comparisons are used to measure the ratio of the top quark Yukawa coupling to its standard model predicted value to be 1.07-0.43+0.34 with an upper limit of 1.67 at the 95% confidence level
Search for a heavy Higgs boson decaying to a pair of W bosons in proton-proton collisions at âs = 13 TeV
A search for a heavy Higgs boson in the mass range from 0.2 to 3.0 TeV, decaying to a pair of W bosons, is presented. The analysis is based on proton-proton collisions at s = 13 TeV recorded by the CMS experiment at the LHC in 2016, corresponding to an integrated luminosity of 35.9 fbâ1. The W boson pair decays are reconstructed in the 2â2ν and âν2q final states (with â = e or Îź). Both gluon fusion and vector boson fusion production of the signal are considered. Interference effects between the signal and background are also taken into account. The observed data are consistent with the standard model (SM) expectation. Combined upper limits at 95% confidence level on the product of the cross section and branching fraction exclude a heavy Higgs boson with SM-like couplings and decays up to 1870 GeV. Exclusion limits are also set in the context of a number of two-Higgs-doublet model formulations, further reducing the allowed parameter space for SM extensions. [Figure not available: see fulltext.
Performance of CMS muon reconstruction in pp collision events at sqrt(s) = 7 TeV
The performance of muon reconstruction, identification, and triggering in CMS
has been studied using 40 inverse picobarns of data collected in pp collisions
at sqrt(s) = 7 TeV at the LHC in 2010. A few benchmark sets of selection
criteria covering a wide range of physics analysis needs have been examined.
For all considered selections, the efficiency to reconstruct and identify a
muon with a transverse momentum pT larger than a few GeV is above 95% over the
whole region of pseudorapidity covered by the CMS muon system, abs(eta) < 2.4,
while the probability to misidentify a hadron as a muon is well below 1%. The
efficiency to trigger on single muons with pT above a few GeV is higher than
90% over the full eta range, and typically substantially better. The overall
momentum scale is measured to a precision of 0.2% with muons from Z decays. The
transverse momentum resolution varies from 1% to 6% depending on pseudorapidity
for muons with pT below 100 GeV and, using cosmic rays, it is shown to be
better than 10% in the central region up to pT = 1 TeV. Observed distributions
of all quantities are well reproduced by the Monte Carlo simulation.Comment: Replaced with published version. Added journal reference and DO
Search for the standard model Higgs boson in the H to ZZ to 2l 2nu channel in pp collisions at sqrt(s) = 7 TeV
A search for the standard model Higgs boson in the H to ZZ to 2l 2nu decay
channel, where l = e or mu, in pp collisions at a center-of-mass energy of 7
TeV is presented. The data were collected at the LHC, with the CMS detector,
and correspond to an integrated luminosity of 4.6 inverse femtobarns. No
significant excess is observed above the background expectation, and upper
limits are set on the Higgs boson production cross section. The presence of the
standard model Higgs boson with a mass in the 270-440 GeV range is excluded at
95% confidence level.Comment: Submitted to JHE
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