Search for dark matter produced in association with a Higgs boson decaying to a pair of bottom quarks in proton-proton collisions at root s=13TeV

A search for dark matter produced in association with a Higgs boson decaying to a pair of bottom quarks is performed in proton-proton collisions at a center-of-mass energy of 13 TeV collected with the CMS detector at the LHC. The analyzed data sample corresponds to an integrated luminosity of 35.9 fb(-1). The signal is characterized by a large missing transverse momentum recoiling against a bottom quark-antiquark system that has a large Lorentz boost. The number of events observed in the data is consistent with the standard model background prediction. Results are interpreted in terms of limits both on parameters of the type-2 two-Higgs doublet model extended by an additional light pseudoscalar boson a (2HDM+a) and on parameters of a baryonic Z simplified model. The 2HDM+a model is tested experimentally for the first time. For the baryonic Z model, the presented results constitute the most stringent constraints to date.Peer reviewe

Genome-wide methylation is modified by caloric restriction in<i> Daphnia magna</i>

Background The degradation of epigenetic control with age is associated with progressive diseases of ageing, including cancers, immunodeficiency and diabetes. Reduced caloric intake slows the effects of ageing and age-related disease in vertebrates and invertebrates, a process potentially mediated by the impact of caloric restriction on epigenetic factors such as DNA methylation. We used whole genome bisulphite sequencing to study how DNA methylation patterns change with diet in a small invertebrate, the crustacean Daphnia magna. Daphnia show the classic response of longer life under caloric restriction (CR), and they reproduce clonally, which permits the study of epigenetic changes in the absence of genetic variation. Results Global cytosine followed by guanine (CpG) methylation was 0.7–0.9%, and there was no difference in overall methylation levels between normal and calorie restricted replicates. However, 333 differentially methylated regions (DMRs) were evident between the normally fed and CR replicates post-filtering. Of these 65% were hypomethylated in the CR group, and 35% were hypermethylated in the CR group. Conclusions Our results demonstrate an effect of CR on the genome-wide methylation profile. This adds to a growing body of research in Daphnia magna that demonstrate an epigenomic response to environmental stimuli. Specifically, gene Ontology (GO) term enrichment of genes associated with hyper and hypo-methylated DMRs showed significant enrichment for methylation and acyl-CoA dehydrogenase activity, which are linked to current understanding of their roles in CR in invertebrate model organisms

Observation of triple J/ψ meson production in proton-proton collisions

Data availability: Tabulated results are provided in the HEPData record for this analysis71. Release and preservation of data used by the CMS Collaboration as the basis for publications is guided by the CMS policy as stated in CMS data preservation, re-use and open access policy.Code availability: The CMS core software is publically available at https://github.com/cms-sw/cmssw.Copyright . Protons consist of three valence quarks, two up-quarks and one down-quark, held together by gluons and a sea of quark-antiquark pairs. Collectively, quarks and gluons are referred to as partons. In a proton-proton collision, typically only one parton of each proton undergoes a hard scattering – referred to as single-parton scattering – leaving the remainder of each proton only slightly disturbed. Here, we report the study of double- and triple-parton scatterings through the simultaneous production of three J/ψ mesons, which consist of a charm quark-antiquark pair, in proton-proton collisions recorded with the CMS experiment at the Large Hadron Collider. We observed this process – reconstructed through the decays of J/ψ mesons into pairs of oppositely charged muons – with a statistical significance above five standard deviations. We measured the inclusive fiducial cross-section to be 272+141−104(stat)±17(syst)fb, and compared it to theoretical expectations for triple-J/ψ meson production in single-, double- and triple-parton scattering scenarios. Assuming factorization of multiple hard-scattering probabilities in terms of single-parton scattering cross-sections, double- and triple-parton scattering are the dominant contributions for the measured process.SCOAP3.Change history: 27 February 2023A Correction to this paper has been published: https://doi.org/10.1038/s41567-023-01992-

Precision measurement of the W boson decay branching fractions in proton-proton collisions at √s=13 TeV

The leptonic and inclusive hadronic decay branching fractions of the W boson are measured using proton-proton collision data collected at ffiffi s p ¼ 13 TeV by the CMS experiment at the CERN LHC, corresponding to an integrated luminosity of 35.9 fb−1. Events characterized by the production of one or two W bosons are selected and categorized based on the multiplicity and flavor of reconstructed leptons, the number of jets, and the number of jets identified as originating from the hadronization of b quarks. A binned maximum likelihood estimate of the W boson branching fractions is performed simultaneously in each event category. The measured branching fractions of the W boson decaying into electron, muon, and tau lepton final states are ð10.83 0.10Þ%, ð10.94 0.08Þ%, and ð10.77 0.21Þ%, respectively, consistent with lepton flavor universality for the weak interaction. The average leptonic and inclusive hadronic decay branching fractions are estimated to be ð10.89 0.08Þ% and ð67.32 0.23Þ%, respec tively. Based on the hadronic branching fraction, three standard model quantities are subsequently derived: the sum of squared elements in the first two rows of the Cabibbo–Kobayashi–Maskawa (CKM) matrix P ij jVijj 2 ¼ 1.984 0.021, the CKM element jVcsj ¼ 0.967 0.011, and the strong coupling constant at the W boson mass scale, αSðm2 WÞ ¼ 0.095 0.033

Search for low-mass dilepton resonances in Higgs boson decays to four-lepton final states in proton–proton collisions at √s=13TeV

Data Availability: This manuscript has no associated data or the data will not be deposited. [Authors’ comment: For CMS Release and preservation of data used by the CMS Collaboration as the basis for publications is guided by the CMS policy as stated in “CMS data preservation, re-use and open access policy” (https://cms-docdb.cern.ch/cgi-bin/PublicDocDB/RetrieveFile?docid=6032&filename=CMSDataPolicyV1.2.pdf&version=2).]Copyright © CERN for the benefit of the CMS collaboration 2022. A search for low-mass dilepton resonances in Higgs boson decays is conducted in the four-lepton final state. The decay is assumed to proceed via a pair of beyond the standard model particles, or one such particle and a Z boson. The search uses proton–proton collision data collected with the CMS detector at the CERN LHC, corresponding to an integrated luminosity of 137fb−1, at a center-of-mass energy s√=13TeV. No significant deviation from the standard model expectation is observed. Upper limits at 95% confidence level are set on model-independent Higgs boson decay branching fractions. Additionally, limits on dark photon and axion-like particle production, based on two specific models, are reported.SCOAP3

Search for light Higgs bosons from supersymmetric cascade decays in pp collisions at √s=13TeV

A search is reported for pairs of light Higgs bosons (H1) produced in supersymmetric cascade decays in f inal states with small missing transverse momentum. A data set of LHC pp collisions collected with the CMS detector at √s = 13TeV and corresponding to an integrated lumi nosity of 138fb−1 is used. The search targets events where both H1 bosons decay into b¯b pairs that are reconstructed as large-radius jets using substructure techniques. No evi dence is found for an excess of events beyond the back ground expectations of the standard model (SM). Results from the search are interpreted in the next-to-minimal super symmetric extension of the SM, where a “singlino” of small mass leads to squark and gluino cascade decays that can pre dominantly end in a highly Lorentz-boosted singlet-like H1 andasinglino-likeneutralinoofsmalltransversemomentum. Upperlimitsaresetontheproductofthesquarkorgluinopair production cross section and the square of the b¯b branching fraction of the H1 in a benchmark model containing almost mass-degenerategluinosandlight-flavoursquarks.Underthe assumption of an SM-like H1 → b¯b branching fraction, H1 bosonswithmassesintherange40–120GeVarisingfromthe decays of squarks or gluinos with a mass of 1200–2500GeV are excluded at 95% confidence level.SCOA

Search for long-lived particles decaying to leptons with large impact parameter in proton-proton collisions at root s=13 TeV

Copyright © CERN for the benefit of the CMS collaboration 2022. A search for new long-lived particles decaying to leptons using proton–proton collision data produced by the CERN LHC at s√=13TeV 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 10cm 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)fb−1 in the ee channel (eμ and μμ channels). The search is designed to be sensitive to a wide range of models with displaced eμ, ee, and μμ 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.SCOAP3