The Precision Proton Spectrometer (PPS) of the CMS and TOTEM experiments collected 107.7 fb-1 in proton-proton (pp) collisions at the LHC at 13 TeV (Run 2). This paper describes the key features of the PPS alignment and optics calibrations, the proton reconstruction procedure, as well as the detector efficiency and the performance of the PPS simulation. The reconstruction and simulation are validated using a sample of (semi)exclusive dilepton events. The performance of PPS has proven the feasibility of continuously operating a near-beam proton spectrometer at a high luminosity hadron collider.
The first measurement of the top quark pair ($$ \textrm{t}\overline{\textrm{t}} $$ t t ¯ ) production cross section in proton-proton collisions at $$ \sqrt{s} $$ s = 13.6 TeV is presented. Data recorded with the CMS detector at the CERN LHC in Summer 2022, corresponding to an integrated luminosity of 1.21 fb−1, are analyzed. Events are selected with one or two charged leptons (electrons or muons) and additional jets. A maximum likelihood fit is performed in event categories defined by the number and flavors of the leptons, the number of jets, and the number of jets identified as originating from b quarks. An inclusive $$ \textrm{t}\overline{\textrm{t}} $$ t t ¯ production cross section of 881 ± 23 (stat + syst) ± 20 (lumi) pb is measured, in agreement with the standard model prediction of $$ {924}_{-40}^{+32} $$ 924 − 40 + 32 pb.
A measurement of the top quark pole mass $$ {m}_{\textrm{t}}^{\textrm{pole}} $$ m t pole in events where a top quark-antiquark pair ($$ \textrm{t}\overline{\textrm{t}} $$ t t ¯ ) is produced in association with at least one additional jet ($$ \textrm{t}\overline{\textrm{t}} $$ t t ¯ +jet) is presented. This analysis is performed using proton-proton collision data at $$ \sqrt{s} $$ s = 13 TeV collected by the CMS experiment at the CERN LHC, corresponding to a total integrated luminosity of 36.3 fb−1. Events with two opposite-sign leptons in the final state (e+e−, μ+μ−, e±μ∓) are analyzed. The reconstruction of the main observable and the event classification are optimized using multivariate analysis techniques based on machine learning. The production cross section is measured as a function of the inverse of the invariant mass of the $$ \textrm{t}\overline{\textrm{t}} $$ t t ¯ +jet system at the parton level using a maximum likelihood unfolding. Given a reference parton distribution function (PDF), the top quark pole mass is extracted using the theoretical predictions at next-to-leading order. For the ABMP16NLO PDF, this results in $$ {m}_{\textrm{t}}^{\textrm{pole}} $$ m t pole = 172.93 ± 1.36 GeV.
Three searches are presented for signatures of physics beyond the standard model (SM) in ττ final states in proton-proton collisions at the LHC, using a data sample collected with the CMS detector at $$ \sqrt{s} $$ s = 13 TeV, corresponding to an integrated luminosity of 138 fb−1. Upper limits at 95% confidence level (CL) are set on the products of the branching fraction for the decay into τ leptons and the cross sections for the production of a new boson ϕ, in addition to the H(125) boson, via gluon fusion (ggϕ) or in association with b quarks, ranging from $$ \mathcal{O} $$ O (10 pb) for a mass of 60 GeV to 0.3 fb for a mass of 3.5 TeV each. The data reveal two excesses for ggϕ production with local p-values equivalent to about three standard deviations at mϕ = 0.1 and 1.2 TeV. In a search for t-channel exchange of a vector leptoquark U1, 95% CL upper limits are set on the dimensionless U1 leptoquark coupling to quarks and τ leptons ranging from 1 for a mass of 1 TeV to 6 for a mass of 5 TeV, depending on the scenario. In the interpretations of the $$ {M}_{\textrm{h}}^{125} $$ M h 125 and $$ {M}_{\textrm{h},\textrm{EFT}}^{125} $$ M h , EFT 125 minimal supersymmetric SM benchmark scenarios, additional Higgs bosons with masses below 350 GeV are excluded at 95% CL.
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$$\,\text {Te\hspace{-.08em}V}$$ Te V . 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$$\,\text {fb}^{-1}$$ fb - 1 . The signal strength modifier $$\mu $$ μ , defined as the ratio of the observed production rate in a given decay channel to the standard model expectation, is measured to be $$\mu = 0.95^{+0.10}_{-0.09}$$ μ = 0 . 95 - 0.09 + 0.10 . All results are found to be compatible with the standard model within the uncertainties.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
customersupport@researchsolutions.com
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.