A measurement is presented of electroweak (EW) production of a
boson in association with two jets in proton-proton collisions at
. The data sample was recorded by the CMS Collaboration at the LHC and ...corresponds to an integrated luminosity of 35.9
. The measurement is performed for the
jj final state (with
indicating a lepton-neutrino pair, and j representing the quarks produced in the hard interaction) in a kinematic region defined by invariant mass
and transverse momenta
. The cross section of the process is measured in the electron and muon channels yielding
per channel, in agreement with leading-order standard model predictions. The additional hadronic activity of events in a signal-enriched region is studied, and the measurements are compared with predictions. The final state is also used to perform a search for anomalous trilinear gauge couplings. Limits on anomalous trilinear gauge couplings associated with dimension-six operators are given in the framework of an effective field theory. The corresponding 95% confidence level intervals are
,
, and
. These results are combined with the CMS EW
analysis, yielding the constraint on the
coupling:
.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Abstract
During the operation of the CMS experiment at the
High-Luminosity LHC the silicon sensors of the Phase-2 Outer Tracker
will be exposed to radiation levels that could potentially
deteriorate ...their performance. Previous studies had determined that
planar float zone silicon with n-doped strips on a p-doped substrate
was preferred over p-doped strips on an n-doped substrate. The last
step in evaluating the optimal design for the mass production of
about 200 m
2
of silicon sensors was to compare sensors of
baseline thickness (about 300 μm) to thinned sensors (about
240 μm), which promised several benefits at high radiation
levels because of the higher electric fields at the same bias
voltage. This study provides a direct comparison of these two
thicknesses in terms of sensor characteristics as well as charge
collection and hit efficiency for fluences up to
1.5 × 10
15
n
eq
/cm
2
. The measurement results
demonstrate that sensors with about 300 μm thickness will
ensure excellent tracking performance even at the highest considered
fluence levels expected for the Phase-2 Outer
Tracker.
Measurements are presented of the triple-differential cross section for inclusive isolated-photon+jet events in Formula omitted collisions at Formula omitted TeV as a function of photon transverse ...momentum ( Formula omitted), photon pseudorapidity ( Formula omitted), and jet pseudorapidity ( Formula omitted). The data correspond to an integrated luminosity of Formula omitted that probe a broad range of the available phase space, for Formula omitted and Formula omitted, Formula omitted, Formula omitted Formula omitted, and jet transverse momentum, Formula omitted, > 25 Formula omitted. The measurements are compared to next-to-leading order perturbative quantum chromodynamics calculations, which reproduce the data within uncertainties.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
The average total energy as well as its hadronic and electromagnetic components are measured with the CMS detector at pseudorapidities Formula omitted in proton-proton collisions at a centre-of-mass ...energy Formula omitted. The results are presented as a function of the charged particle multiplicity in the region Formula omitted. This measurement is sensitive to correlations induced by the underlying event structure over a very wide pseudorapidity region. The predictions of Monte Carlo event generators commonly used in collider experiments and ultra-high energy cosmic ray physics are compared to the data. All generators considered overestimate the fraction of energy going into hadrons.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
A search for new physics in top quark production is performed in proton-proton collisions at Formula omitted. The data set corresponds to an integrated luminosity of Formula omitted collected in 2016 ...with the CMS detector. Events with two opposite-sign isolated leptons (electrons or muons), and Formula omitted quark jets in the final state are selected. The search is sensitive to new physics in top quark pair production and in single top quark production in association with a Formula omitted boson. No significant deviation from the standard model expectation is observed. Results are interpreted in the framework of effective field theory and constraints on the relevant effective couplings are set, one at a time, using a dedicated multivariate analysis. This analysis differs from previous searches for new physics in the top quark sector by explicitly separating Formula omitted from Formula omitted events and exploiting the specific sensitivity of the Formula omitted process to new physics.
Celotno besedilo
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
A measurement for inclusive 2- and 3-jet events of the azimuthal correlation between the two jets with the largest transverse momenta, Formula omitted, is presented. The measurement considers events ...where the two leading jets are nearly collinear ("back-to-back") in the transverse plane and is performed for several ranges of the leading jet transverse momentum. Proton-proton collision data collected with the CMS experiment at a center-of-mass energy of Formula omitted and corresponding to an integrated luminosity of Formula omitted are used. Predictions based on calculations using matrix elements at leading-order and next-to-leading-order accuracy in perturbative quantum chromodynamics supplemented with leading-log parton showers and hadronization are generally in agreement with the measurements. Discrepancies between the measurement and theoretical predictions are as large as 15%, mainly in the region Formula omitted. The 2- and 3-jet measurements are not simultaneously described by any of models.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Exclusive \{{{\uprho _{}^{}} _{}^{}}{{\left( {770}\right) }{}_{}^{}}} ^{0}\ photoproduction is measured for the first time in ultraperipheral pPb collisions at \\sqrt{\smash b{s_{_{\mathrm {NN}}} = ...5.02\,\text {Te}\text {V} \ with the CMS detector. The cross section \\sigma ({\upgamma _{}^{}} \mathrm{p}\rightarrow {{{\uprho _{}^{}} _{}^{}}{{\left( {770}\right) }{}_{}^{}}} ^{0}\mathrm{p})\ is \11.0 \pm 1.4\,\text {(stat)} \pm 1.0\,\text {(syst)} \\\mu \b at \\langle W_{{\upgamma _{}^{}} \mathrm{p}}\rangle = 92.6\,\text {Ge}\text {V} \ for photon–proton centre-of-mass energies \W_{{\upgamma _{}^{}} \mathrm{p}}\ between 29 and \213\,\text {Ge}\text {V} \. The differential cross section \\mathrm {d}\sigma /\mathrm {d}|t |\ is measured in the interval \0.025< |t | < 1\,\text {Ge}\text {V} ^{2}\ as a function of \W_{{\upgamma _{}^{}} \mathrm{p}}\, where t is the squared four-momentum transfer at the proton vertex. The results are compared with previous measurements and theoretical predictions. The measured cross section \\sigma ({\upgamma _{}^{}} \mathrm{p}\rightarrow {{{\uprho _{}^{}} _{}^{}}{{\left( {770}\right) }{}_{}^{}}} ^{0}\mathrm{p})\ has a power-law dependence on the photon–proton centre-of-mass, consistent with electron–proton collision measurements performed at HERA. The \W_{{\upgamma _{}^{}} \mathrm{p}}\ dependence of the exponential slope of the differential cross section \\mathrm {d}\sigma /\mathrm {d}|t |\ is also measured.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
A search is presented for a heavy pseudoscalar boson Formula omitted decaying to a Z boson and a Higgs boson with mass of 125 Formula omitted. In the final state considered, the Higgs boson decays to ...a bottom quark and antiquark, and the Z boson decays either into a pair of electrons, muons, or neutrinos. The analysis is performed using a data sample corresponding to an integrated luminosity of 35.9 Formula omitted collected in 2016 by the CMS experiment at the LHC from proton-proton collisions at a center-of-mass energy of 13 Formula omitted. The data are found to be consistent with the background expectations. Exclusion limits are set in the context of two-Higgs-doublet models in the Formula omitted boson mass range between 225 and 1000 Formula omitted.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
A search for supersymmetry is presented based on events with at least one photon, jets, and large missing transverse momentum produced in proton-proton collisions at a center-of-mass energy of 13 ...Formula omitted. The data correspond to an integrated luminosity of 35.9 Formula omitted and were recorded at the LHC with the CMS detector in 2016. The analysis characterizes signal-like events by categorizing the data into various signal regions based on the number of jets, the number of Formula omitted-tagged jets, and the missing transverse momentum. No significant excess of events is observed with respect to the expectations from standard model processes. Limits are placed on the gluino and top squark pair production cross sections using several simplified models of supersymmetric particle production with gauge-mediated supersymmetry breaking. Depending on the model and the mass of the next-to-lightest supersymmetric particle, the production of gluinos with masses as large as 2120 Formula omitted and the production of top squarks with masses as large as 1230 Formula omitted are excluded at 95% confidence level.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Combined measurements of the production and decay rates of the Higgs boson, as well as its couplings to vector bosons and fermions, are presented. The analysis uses the LHC proton-proton collision ...data set recorded with the CMS detector in 2016 at Formula omitted, corresponding to an integrated luminosity of 35.9 Formula omitted. The combination is based on analyses targeting the five main Higgs boson production mechanisms (gluon fusion, vector boson fusion, and associated production with a Formula omitted or Formula omitted boson, or a top quark-antiquark pair) and the following decay modes: Formula omitted, Formula omitted, Formula omitted, Formula omitted, Formula omitted, and Formula omitted. Searches for invisible Higgs boson decays are also considered. The best-fit ratio of the signal yield to the standard model expectation is measured to be Formula omitted, assuming a Higgs boson mass of Formula omitted. Additional results are given for various assumptions on the scaling behavior of the production and decay modes, including generic parametrizations based on ratios of cross sections and branching fractions or couplings. The results are compatible with the standard model predictions in all parametrizations considered. In addition, constraints are placed on various two Higgs doublet models.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
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