A search for exotic decays of the Higgs boson (
) with a mass of 125
to a pair of light pseudoscalars
is performed in final states where one pseudoscalar decays to two
quarks and the other to a pair ...of muons or
leptons. A data sample of proton-proton collisions at
corresponding to an integrated luminosity of 138
recorded with the CMS detector is analyzed. No statistically significant excess is observed over the standard model backgrounds. Upper limits are set at 95% confidence level (
) on the Higgs boson branching fraction to
and to
via a pair of
s. The limits depend on the pseudoscalar mass
and are observed to be in the range (0.17-3.3)
and (1.7-7.7)
in the
and
final states, respectively. In the framework of models with two Higgs doublets and a complex scalar singlet (2HDM+S), the results of the two final states are combined to determine upper limits on the branching fraction
at 95%
, with
being a muon or a
lepton. For different types of 2HDM+S, upper bounds on the branching fraction
are extracted from the combination of the two channels. In most of the Type II 2HDM+S parameter space,
values above 0.23 are excluded at 95%
for
values between 15 and 60
.
The double differential cross sections of the Drell-Yan lepton pair (
, dielectron or dimuon) production are measured as functions of the invariant mass
, transverse momentum
, and
. The
observable, ...derived from angular measurements of the leptons and highly correlated with
, is used to probe the low-
region in a complementary way. Dilepton masses up to 1
are investigated. Additionally, a measurement is performed requiring at least one jet in the final state. To benefit from partial cancellation of the systematic uncertainty, the ratios of the differential cross sections for various
ranges to those in the Z mass peak interval are presented. The collected data correspond to an integrated luminosity of 36.3
of proton-proton collisions recorded with the CMS detector at the LHC at a centre-of-mass energy of 13
. Measurements are compared with predictions based on perturbative quantum chromodynamics, including soft-gluon resummation.
Production cross sections of the standard model Higgs boson decaying to a pair of W bosons are measured in proton-proton collisions at a center-of-mass energy of 13
. The analysis targets Higgs ...bosons produced via gluon fusion, vector boson fusion, and in association with a W or Z boson. Candidate events are required to have at least two charged leptons and moderate missing transverse momentum, targeting events with at least one leptonically decaying W boson originating from the Higgs boson. Results are presented in the form of inclusive and differential cross sections in the simplified template cross section framework, as well as couplings of the Higgs boson to vector bosons and fermions. The data set collected by the CMS detector during 2016-2018 is used, corresponding to an integrated luminosity of 138
. The signal strength modifier
, defined as the ratio of the observed production rate in a given decay channel to the standard model expectation, is measured to be
. All results are found to be compatible with the standard model within the uncertainties.
A search is reported for pairs of light Higgs bosons (
) produced in supersymmetric cascade decays in final states with small missing transverse momentum. A data set of LHC
collisions collected with ...the CMS detector at
and corresponding to an integrated luminosity of 138
is used. The search targets events where both
bosons decay into pairs that are reconstructed as large-radius jets using substructure techniques. No evidence is found for an excess of events beyond the background expectations of the standard model (SM). Results from the search are interpreted in the next-to-minimal supersymmetric extension of the SM, where a "singlino" of small mass leads to squark and gluino cascade decays that can predominantly end in a highly Lorentz-boosted singlet-like
and a singlino-like neutralino of small transverse momentum. Upper limits are set on the product of the squark or gluino pair production cross section and the square of the branching fraction of the
in a benchmark model containing almost mass-degenerate gluinos and light-flavour squarks. Under the assumption of an SM-like branching fraction,
bosons with masses in the range 40-120
arising from the decays of squarks or gluinos with a mass of 1200-2500
are excluded at 95% confidence level.
The production of Z bosons associated with jets is measured in
collisions at
with data recorded with the CMS experiment at the LHC corresponding to an integrated luminosity of 36.3
. The multiplicity ...of jets with transverse momentum
is measured for different regions of the Z boson's
, from lower than 10
to higher than 100
. The azimuthal correlation
between the Z boson and the leading jet, as well as the correlations between the two leading jets are measured in three regions of
. The measurements are compared with several predictions at leading and next-to-leading orders, interfaced with parton showers. Predictions based on transverse-momentum dependent parton distributions and corresponding parton showers give a good description of the measurement in the regions where multiple parton interactions and higher jet multiplicities are not important. The effects of multiple parton interactions are shown to be important to correctly describe the measured spectra in the low
regions.
A search for decays to invisible particles of Higgs bosons produced in association with a top-antitop quark pair or a vector boson, which both decay to a fully hadronic final state, has been ...performed using proton-proton collision data collected at
by the CMS experiment at the LHC, corresponding to an integrated luminosity of 138
. The 95% confidence level upper limit set on the branching fraction of the 125
Higgs boson to invisible particles,
, is 0.54 (0.39 expected), assuming standard model production cross sections. The results of this analysis are combined with previous
searches carried out at
, 8, and 13
in complementary production modes. The combined upper limit at 95% confidence level on
is 0.15 (0.08 expected).
The mass of the top quark is measured in 36.3
of LHC proton-proton collision data collected with the CMS detector at
. The measurement uses a sample of top quark pair candidate events containing one ...isolated electron or muon and at least four jets in the final state. For each event, the mass is reconstructed from a kinematic fit of the decay products to a top quark pair hypothesis. A profile likelihood method is applied using up to four observables per event to extract the top quark mass. The top quark mass is measured to be
. This approach significantly improves the precision over previous measurements.
Using a data sample of
proton-proton collisions collected by the CMS experiment at the LHC in 2017 and 2018 with an integrated luminosity of
, the
and
decays are observed with significances exceeding ...5 standard deviations. The resulting branching fraction ratios, measured for the first time, correspond to
and
, where the last uncertainty in the first ratio is related to the uncertainty in the ratio of production cross sections of
and
mesons,
.
A search for new long-lived particles decaying to leptons using proton-proton collision data produced by the CERN LHC at
is presented. Events are selected with two leptons (an electron and a muon, ...two electrons, or two muons) that both have transverse impact parameter values between 0.01 and 10
and are not required to form a common vertex. Data used for the analysis were collected with the CMS detector in 2016, 2017, and 2018, and correspond to an integrated luminosity of 118 (113)
in the
channel (
and
channels). The search is designed to be sensitive to a wide range of models with displaced
,
, and
final states. The results constrain several well-motivated models involving new long-lived particles that decay to displaced leptons. For some areas of the available phase space, these are the most stringent constraints to date.
Measurements of the associated production of a W boson and a charm (
) quark in proton-proton collisions at a centre-of-mass energy of 8
are reported. The analysis uses a data sample corresponding to ...a total integrated luminosity of 19.7
collected by the CMS detector at the LHC. The W bosons are identified through their leptonic decays to an electron or a muon, and a neutrino. Charm quark jets are selected using distinctive signatures of charm hadron decays. The product of the cross section and branching fraction
, where
or
, and the cross section ratio
are measured in a fiducial volume and differentially as functions of the pseudorapidity and of the transverse momentum of the lepton from the W boson decay. The results are compared with theoretical predictions. The impact of these measurements on the determination of the strange quark distribution is assessed.
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