A search for a standard-model-like Higgs boson in the H→WW and H→ZZ decay channels is reported, for Higgs boson masses in the range 145<
m
H
<1000 GeV. The search is based upon proton–proton ...collision data samples corresponding to an integrated luminosity of up to 5.1 fb
−1
at
and up to 5.3 fb
−1
at
, recorded by the CMS experiment at the LHC. The combined upper limits at 95 % confidence level on products of the cross section and branching fractions exclude a standard-model-like Higgs boson in the range 145<
m
H
<710 GeV, thus extending the mass region excluded by CMS from 127–600 GeV up to 710 GeV.
A
bstract
A search for a heavy W′ resonance decaying to one B or T vector-like quark and a top or bottom quark, respectively, is presented. The search uses proton-proton collision data collected in ...2016 with the CMS detector at the LHC, corresponding to an integrated luminosity of 35.9 fb
−1
at
s
=
13
TeV. Both decay channels result in a final state with a top quark, a Higgs boson, and a b quark, each produced with significant energy. The all-hadronic decays of both the Higgs boson and the top quark are considered. The final-state jets, some of which correspond to merged decay products of a boosted top quark and a Higgs boson, are selected using jet substructure techniques, which help to suppress standard model backgrounds. A W′ boson signal would appear as a narrow peak in the invariant mass distribution of these jets. No significant deviation in data with respect to the standard model background predictions is observed. Cross section upper limits on W′ boson production in the top quark, Higgs boson, and b quark decay mode are set as a function of the W′ mass, for several vector-like quark mass hypotheses. These are the first limits for W′ boson production in this decay channel, and cover a range of 0.01 to 0.43 pb in the W′ mass range between 1.5 and 4.0 TeV.
The first measurement of the dependence of γγ → μ+μ− production on the multiplicity of neutrons emitted very close to the beam direction in ultraperipheral heavy ion collisions is reported. Data for ...lead-lead interactions at sNN=5.02 TeV , with an integrated luminosity of approximately 1.5 nb-1 , are collected using the CMS detector at the LHC. The azimuthal correlations between the two muons in the invariant mass region 8<mμμ<60 GeV are extracted for events including 0, 1, or at least 2 neutrons detected in the forward pseudorapidity range | η | >8.3 . The back-to-back correlation structure from leading-order photon-photon scattering is found to be significantly broader for events with a larger number of emitted neutrons from each nucleus, corresponding to interactions with a smaller impact parameter. This observation provides a data-driven demonstration that the average transverse momentum of photons emitted from relativistic heavy ions has an impact parameter dependence. These results provide new constraints on models of photon-induced interactions in ultraperipheral collisions. They also provide a baseline to search for possible final-state effects on lepton pairs caused by traversing a quark-gluon plasma produced in hadronic heavy ion collisions.
A search for new physics is performed in events with two same-sign isolated leptons, hadronic jets, and missing transverse energy in the final state. The analysis is based on a data sample ...corresponding to an integrated luminosity of 4.98 fb(-1) produced in pp collisions at a center-of-mass energy of 7 TeV collected by the CMS experiment at the LHC. This constitutes a factor of 140 increase in integrated luminosity over previously published results. The observed yields agree with the standard model predictions and thus no evidence for new physics is found. The observations are used to set upper limits on possible new physics contributions and to constrain supersymmetric models. To facilitate the interpretation of the data in a broader range of new physics scenarios, information on the event selection, detector response, and efficiencies is provided.
A
bstract
The first observation of the Z boson decaying to four leptons in proton-proton collisions is presented. The analyzed data set corresponds to an integrated luminosity of 5.02 fb
−1
at
TeV ...collected by the CMS detector at the Large Hadron Collider. A pronounced resonance peak, with a statistical significance of 9.7
σ
, is observed in the distribution of the invariant mass of four leptons (electrons and/or muons) with mass and width consistent with expectations for Z boson decays. The branching fraction and cross section reported here are defined by phase space restrictions on the leptons, namely, 80 <
m
4ℓ
< 100 GeV, where
m
4ℓ
is the invariant mass of the four leptons, and
m
ℓℓ
> 4 GeV for all pairs of leptons, where
m
ℓℓ
is the two-lepton invariant mass. The measured branching fraction is
and agrees with the standard model prediction of 4.45 × 10
−6
. The measured cross section times branching fraction is
fb, also consistent with the standard model prediction of 120 fb. The four-lepton mass peak arising from
Z
→ 4
ℓ
decays provides a calibration channel for the Higgs boson search in the
H
→
ZZ
→ 4
ℓ
decay mode.
The energy loss of fast partons traversing the strongly interacting matter produced in high energy nuclear collisions is one of the most interesting observables to probe the nature of the produced ...medium. The collisional and radiative energy loss of the partons will modify the fragmentation functions depending on the path length in the medium. Pb + Pb collisions at
GeV at the LHC will allow detailed measurements of the in-medium modifications of fragmentation functions of parton initiated jets, using the
γ
-jet channel. Since the photon does not strongly interact with the medium, the initial transverse energy of the fragmenting parton can be related to the photon transverse energy. This in turn allows for precision studies of the fragmentation function underlying these jets.
Although physical activity and sedentary behavior are moderately heritable, little is known about the mechanisms that influence these traits. Combining data for up to 703,901 individuals from 51 ...studies in a multi-ancestry meta-analysis of genome-wide association studies yields 99 loci that associate with self-reported moderate-to-vigorous intensity physical activity during leisure time (MVPA), leisure screen time (LST) and/or sedentary behavior at work. Loci associated with LST are enriched for genes whose expression in skeletal muscle is altered by resistance training. A missense variant in ACTN3 makes the alpha-actinin-3 filaments more flexible, resulting in lower maximal force in isolated type II
muscle fibers, and possibly protection from exercise-induced muscle damage. Finally, Mendelian randomization analyses show that beneficial effects of lower LST and higher MVPA on several risk factors and diseases are mediated or confounded by body mass index (BMI). Our results provide insights into physical activity mechanisms and its role in disease prevention.
A
bstract
A search for the standard model Higgs boson produced in association with a top-quark pair is presented using data samples corresponding to an integrated luminosity of 5.0 fb
−1
(5.1 fb
−1
) ...collected in pp collisions at the center-of-mass energy of 7 TeV (8 TeV). Events are considered where the top-quark pair decays to either one lepton+jets
or dileptons
,
ℓ
being an electron or a muon. The search is optimized for the decay mode
. The largest background to the
signal is top-quark pair production with additional jets. Artificial neural networks are used to discriminate between signal and background events. Combining the results from the 7 TeV and 8 TeV samples, the observed (expected) limit on the cross section for Higgs boson production in association with top-quark pairs for a Higgs boson mass of 125 GeV is 5.8 (5.2) times the standard model expectation.
Results are reported from a search for new particles that decay into a photon and two gluons, in events with jets. Novel jet substructure techniques are developed that allow photons to be identified ...in an environment densely populated with hadrons. The analyzed proton-proton collision data were collected by the CMS experiment at the LHC, in 2016 at sqrts=13 TeV, and correspond to an integrated luminosity of 35.9 fb^{-1}. The spectra of total transverse hadronic energy of candidate events are examined for deviations from the standard model predictions. No statistically significant excess is observed over the expected background. The first cross section limits on new physics processes resulting in such events are set. The results are interpreted as upper limits on the rate of gluino pair production, utilizing a simplified stealth supersymmetry model. The excluded gluino masses extend up to 1.7 TeV, for a neutralino mass of 200 GeV and exceed previous mass constraints set by analyses targeting events with isolated photons.
Physical activity (PA) may modify the genetic effects that give rise to increased risk of obesity. To identify adiposity loci whose effects are modified by PA, we performed genome-wide interaction ...meta-analyses of BMI and BMI-adjusted waist circumference and waist-hip ratio from up to 200,452 adults of European (n = 180,423) or other ancestry (n = 20,029). We standardized PA by categorizing it into a dichotomous variable where, on average, 23% of participants were categorized as inactive and 77% as physically active. While we replicate the interaction with PA for the strongest known obesity-risk locus in the FTO gene, of which the effect is attenuated by ~30% in physically active individuals compared to inactive individuals, we do not identify additional loci that are sensitive to PA. In additional genome-wide meta-analyses adjusting for PA and interaction with PA, we identify 11 novel adiposity loci, suggesting that accounting for PA or other environmental factors that contribute to variation in adiposity may facilitate gene discovery.
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