199,188 research outputs found
Search for light long-lived particles decaying to displaced jets in proton–proton collisions at s = 13.6 TeV
No full textA search for light long-lived particles (LLPs) decaying to displaced jets is presented, using a data sample of proton-proton collisions at a center-of-mass energy of 13.6 TeV, corresponding to an integrated luminosity of 34.7 fb(-1), collected with the CMS detector at the CERN LHC in 2022. Novel trigger, reconstruction, and machine-learning techniques were developed for and employed in this search. After all selections, the observations are consistent with the background predictions. Limits are presented on the branching fraction of the Higgs boson to LLPs that subsequently decay to quark pairs or tau lepton pairs. An improvement by up to a factor of 10 is achieved over previous limits for models with LLP masses smaller than 60 GeV and proper decay lengths smaller than 1 m. The first constraints are placed on the fraternal twin Higgs (FTH) and folded supersymmetry (FSUSY) models, where the lower bounds on the top quark partner mass reach up to 350 GeV for the FTH model and 250 GeV for the FSUSY model
Stairway to discovery: A report on the CMS programme of cross section measurements from millibarns to femtobarns
No full textThe Large Hadron Collider at CERN, delivering proton–proton collisions at much higher energies and far higher luminosities than previous machines, has enabled a comprehensive programme of measurements of the standard model (SM) processes by the CMS experiment. These unprecedented capabilities facilitate precise measurements of the properties of a wide array of processes, the most fundamental being cross sections. The discovery of the Higgs boson and the measurement of its mass became the keystone of the SM. Knowledge of the mass of the Higgs boson allows precision comparisons of the predictions of the SM with the corresponding measurements. These measurements span the range from one of the most copious SM processes, the total inelastic cross section for proton–proton interactions, to the rarest ones, such as Higgs boson pair production. They cover the production of Higgs bosons, top quarks, single and multibosons, and hadronic jets. Associated parameters, such as coupling constants, are also measured. These cross section measurements can be pictured as a descending stairway, on which the lowest steps represent the rarest processes allowed by the SM, some never seen before
Classificazioni, protocolli, linee guida
No full textLa presentazione espone le problematiche relative al trattamento dei casi di abuso sessuale, con particolare riferimento alla significatività delle lesioni anogenitali in base alle moderne classificazioni ed ai protocolli nazionali ed internazionali attualmente esistenti
OVARIAN SECRETION OF OPIOID-PEPTIDES - EVIDENCE OF A CORRELATION WITH THE OVARIAN-FUNCTION
No full textOVARIAN SECRETION OF OPIOID-PEPTIDES - EVIDENCE OF A CORRELATION WITH THE OVARIAN-FUNCTIO
Search for heavy pseudoscalar and scalar bosons decaying to a top quark pair in proton-proton collisions ats=13TeV
No full textA search for pseudoscalar or scalar bosons decaying to a top quark pair (tt ̄) in final states with one or two charged leptons is presented. The analyzed proton-proton collision data was recorded ats=13TeVby the CMS experiment at the CERN LHC and corresponds to an integrated luminosity of 138 fb-1. The invariant massmtt ̄of the reconstructedtt ̄system and variables sensitive to its spin and parity are used to discriminate against the standard modeltt ̄background. Interference between pseudoscalar or scalar boson production and the standard modeltt ̄continuum is included, leading to peak-dip structures in themtt ̄distribution. An excess of the data above the background prediction, based on perturbative quantum chromodynamics (QCD) calculations, is observed near the kinematictt ̄production threshold, while good agreement is found for highmtt ̄. The data are consistent with the background prediction if the contribution from a simplified model of a color-singlet1S0[1]tt ̄quasi-bound stateηt, inspired by nonrelativistic QCD, is added. Upper limits at 95% confidence level are set on the coupling between the pseudoscalar or scalar bosons and the top quark for boson masses in the range 365-1000 GeV, relative widths between 0.5% and 25%, and two background scenarios with or withoutηtcontribution
Model-agnostic search for dijet resonances with anomalous jet substructure in proton–proton collisions at s = 13 TeV
No full text: This paper presents a model-agnostic search for narrow resonances in the dijet final state in the mass range 1.8-6 TeV. The signal is assumed to produce jets with substructure atypical of jets initiated by light quarks or gluons, with minimal additional assumptions. Search regions are obtained by utilizing multivariate machine-learning methods to select jets with anomalous substructure. A collection of complementary anomaly detection methods-based on unsupervised, weakly supervised, and semisupervised algorithms-are used in order to maximize the sensitivity to unknown new physics signatures. These algorithms are applied to data corresponding to an integrated luminosity of 138 fb-1, recorded by the CMS experiment at the LHC, at a center-of-mass energy of 13 TeV. No significant excesses above background expectations are seen. Exclusion limits are derived on the production cross section of benchmark signal models varying in resonance mass, jet mass, and jet substructure. Many of these signatures have not been previously sought, making several of the limits reported on the corresponding benchmark models the first ever. When compared to benchmark inclusive and substructure-based search strategies, the anomaly detection methods are found to significantly enhance the sensitivity to a variety of models
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