The observation of the standard model (SM) Higgs boson decay to a pair of bottom quarks is presented. The main contribution to this result is from processes in which Higgs bosons are produced in association with a $W$ or $Z$ boson ($VH$), and are searched for in final states including 0, 1, or 2 charged leptons and two identified bottom quark jets. The results from the measurement of these processes in a data sample recorded by the CMS experiment in 2017, comprising $41.3{\mathrm{fb}}^{-1}$ of proton-proton collisions at $\sqrt{s}=13\mathrm{TeV}$, are described. When combined with previous $VH$ measurements using data collected at $\sqrt{s}=7$, 8, and 13 TeV, an excess of events is observed at $m_H=125\mathrm{GeV}$ with a significance of 4.8 standard deviations, where the expectation for the SM Higgs boson is 4.9. The corresponding measured signal strength is $1.01\pm 0.22$. The combination of this result with searches by the CMS experiment for $H\to b\overline{b}$ in other production processes yields an observed (expected) significance of 5.6 (5.5) standard deviations and a signal strength of $1.04\pm 0.20$.

The observation of Higgs boson production in association with a top quark-antiquark pair is reported, based on a combined analysis of proton-proton collision data at center-of-mass energies of $\sqrt{s}=7$, 8, and 13 TeV, corresponding to integrated luminosities of up to 5.1, 19.7, and $35.9{\mathrm{fb}}^{-1}$, respectively. The data were collected with the CMS detector at the CERN LHC. The results of statistically independent searches for Higgs bosons produced in conjunction with a top quark-antiquark pair and decaying to pairs of $W$ bosons, $Z$ bosons, photons, $\tau$ leptons, or bottom quark jets are combined to maximize sensitivity. An excess of events is observed, with a significance of 5.2 standard deviations, over the expectation from the background-only hypothesis. The corresponding expected significance from the standard model for a Higgs boson mass of 125.09 GeV is 4.2 standard deviations. The combined best fit signal strength normalized to the standard model prediction is ${1.26}_{-0.26}^{+0.31}$.

A measurement of the inelastic proton-proton cross section with the CMS detector at a center-of-mass energy of $$ \sqrt{s}=13 $$s=13 TeV is presented. The analysis is based on events with energy deposits in the forward calorimeters, which cover pseudorapidities of −6.6< η <−3.0 and +3.0< η <+5.2. An inelastic cross section of 68.6 ± 0.5(syst) ± 1.6(lumi) mb is obtained for events withM_X>4.1 GeV and/orM_Y>13 GeV, whereM_XandM_Yare the masses of the diffractive dissociation systems at negative and positive pseudorapidities, respectively. The results are compared with those from other experiments as well as to predictions from high-energy hadron-hadron interaction models.

A search for a heavy neutral lepton $N$ of Majorana nature decaying into a $W$ boson and a charged lepton is performed using the CMS detector at the LHC. The targeted signature consists of three prompt charged leptons in any flavor combination of electrons and muons. The data were collected in proton-proton collisions at a center-of-mass energy of 13 TeV, with an integrated luminosity of $35.9{\mathrm{fb}}^{-1}$. The search is performed in the $N$ mass range between 1 GeV and 1.2 TeV. The data are found to be consistent with the expected standard model background. Upper limits are set on the values of ${|V_{eN}|}^2$ and ${|V_{\mu N}|}^2$, where $V_{\ell N}$ is the matrix element describing the mixing of $N$ with the standard model neutrino of flavor $\ell$. These are the first direct limits for $N$ masses above 500 GeV and the first limits obtained at a hadron collider for $N$ masses below 40 GeV.

The first observation of electroweak production of same-sign $W$ boson pairs in proton-proton collisions is reported. The data sample corresponds to an integrated luminosity of $35.9{\mathrm{fb}}^{-1}$ collected at a center-of-mass energy of 13 TeV with the CMS detector at the LHC. Events are selected by requiring exactly two leptons (electrons or muons) of the same charge, moderate missing transverse momentum, and two jets with a large rapidity separation and a large dijet mass. The observed significance of the signal is 5.5 standard deviations, where a significance of 5.7 standard deviations is expected based on the standard model. The ratio of measured event yields to that expected from the standard model at leading order is $0.90\pm 0.22$. A cross section measurement in a fiducial region is reported. Bounds are given on the structure of quartic vector boson interactions in the framework of dimension-8 effective field theory operators and on the production of doubly charged Higgs bosons.

Searches for resonances decaying into pairs of jets are performed using proton-proton collision data collected at $$ \sqrt{s}=13 $$ s = 13 TeV corresponding to an integrated luminosity of up to 36 fb⁻¹. A low-mass search, for resonances with masses between 0.6 and 1.6 TeV, is performed based on events with dijets reconstructed at the trigger level from calorimeter information. A high-mass search, for resonances with masses above 1.6 TeV, is performed using dijets reconstructed offline with a particle-flow algorithm. The dijet mass spectrum is well described by a smooth parameterization and no evidence for the production of new particles is observed. Upper limits at 95% confidence level are reported on the production cross section for narrow resonances with masses above 0.6 TeV. In the context of specific models, the limits exclude string resonances with masses below 7.7 TeV, scalar diquarks below 7.2 TeV, axigluons and colorons below 6.1 TeV, excited quarks below 6.0 TeV, color-octet scalars below 3.4 TeV, W^′ bosons below 3.3 TeV, Z^′ bosons below 2.7 TeV, Randall-Sundrum gravitons below 1.8 TeV and in the range 1.9 to 2.5 TeV, and dark matter mediators below 2.6 TeV. The limits on both vector and axial-vector mediators, in a simplified model of interactions between quarks and dark matter particles, are presented as functions of dark matter particle mass and coupling to quarks. Searches are also presented for broad resonances, including for the first time spin-1 resonances with intrinsic widths as large as 30% of the resonance mass. The broad resonance search improves and extends the exclusions of a dark matter mediator to larger values of its mass and coupling to quarks.