https://vital.lib.tsu.ru/vital/access/manager/Index en-us 5 Measurement of the nuclear modification factor for muons from charm and bottom hadrons in Pb+Pb collisions at 5.02 TeV with the ATLAS detector https://vital.lib.tsu.ru/vital/access/manager/Repository/koha:001001001 Wed 10 May 2023 10:47:33 KRAT ]]> Using Z boson events to study parton-medium interactions in Pb-Pb collisions https://vital.lib.tsu.ru/vital/access/manager/Repository/koha:001002204 30 GeV/c are analyzed. The Z boson constrains the initial energy and direction of the associated parton. In heavy ion events, azimuthal angular distributions of charged hadrons with respect to the direction of a Z boson are sensitive to modifications of the in-medium parton shower and medium response. compared to reference data from pp interactions, the results for central Pb-Pb collisions indicate a modification of the angular correlations. The measurements of the fragmentation functions and p(T) spectra of charged particles in Z boson events, which are sensitive to medium modifications of the parton shower longitudinal structure, are also reported. Significant modifications in central Pb-Pb events compared to the pp reference data are also found for these observables.]]> Tue 06 Jun 2023 15:22:25 KRAT ]]> Search for heavy resonances decaying to a pair of Lorentz-boosted Higgs bosons in final states with leptons and a bottom quark pair at √s = 13 TeV https://vital.lib.tsu.ru/vital/access/manager/Repository/koha:001001384 b (b) over bar WW* -> b (b) over bar lvq (q) over bar' and the dilepton decay channels HH -> b (b) over bar WW* -> b (b) over bar lvlv and HH -> b (b) over bar tau tau -> b (b) over bar lvvlvv are examined, where l in the final state corresponds to an electron or muon. The signal is extracted using a two-dimensional maximum likelihood fit of the H -> b (b) over bar jet mass and HH invariant mass distributions. No significant excess above the standard model expectation is observed in data. Model-independent exclusion limits are placed on the product of the cross section and branching fraction for narrow spin-0 and spin-2 massive bosons decaying to HH. The results are also interpreted in the context of radion and bulk graviton production in models with a warped extra spatial dimension. The results provide the most stringent limits to date for X -> HH signatures with final-state leptons and at some masses provide the most sensitive limits of all X -> HH searches.]]> Fri 19 May 2023 11:46:02 KRAT ]]> Search for higgsinos decaying to two Higgs bosons and missing transverse momentum in proton-proton collisions at √s = 13 TeV https://vital.lib.tsu.ru/vital/access/manager/Repository/koha:001001383 b (b) over bar, and large missing transverse momentum. The search uses a data sample corresponding to an integrated luminosity of 137fb(-1) collected by the CMS experiment at the CERN LHC. The search is motivated by models of supersymmetry that predict the production of neutralinos, the neutral partners of the electroweak gauge and Higgs bosons. The observed event yields in the signal regions are found to be consistent with the standard model background expectations. The results are interpreted using simplified models of supersymmetry. For the electroweak production of nearly mass-degenerate higgsinos, each of whose decay chains yields a neutralino ((chi) over tilde (0)(1)) that in turn decays to a massless goldstino and a Higgs boson, (chi) over tilde (0)(1) masses in the range 175 to 1025 GeV are excluded at 95% confidence level. For the strong production of gluino pairs decaying via a slightly lighter (chi) over tilde (0)(2) to H and a light (chi) over tilde (0)(1), gluino masses below 2330 GeV are excluded.]]> Fri 19 May 2023 11:46:02 KRAT ]]>