B. Rahbaran

Searches for third-generation squark production in fully hadronic final states in proton-proton collisions at √s=8 TeV

A bstractSearches for third-generation squarks in fully hadronic final states are presented using data samples corresponding to integrated luminosities of 19.4 or 19.7 fb−1, collected at a centre-of-mass energy of 8 TeV with the CMS detector at the LHC. Three mutually exclusive searches are presented, each optimized for a different decay topology. They include a multijet search requiring one fully reconstructed top quark, a dijet search requiring one or two jets originating from b quarks, and a monojet search. No excesses above the standard model expectations are seen, and limits are set on top and bottom squark production in the context of simplified models of supersymmetry. Searches for third-generation squarks in fully hadronic final states are presented using data samples corresponding to integrated luminosities of 19.4 or 19.7 fb-1, collected at a centre-of-mass energy of 8 CMS.TeV with the CMS detector at the LHC. Three mutually exclusive searches are presented, each optimized for a different decay topology. They include a multijet search requiring one fully reconstructed top quark, a dijet search requiring one or two jets originating from b quarks, and a monojet search. No excesses above the standard model expectations are seen, and limits are set on top and bottom squark production in the context of simplified models of supersymmetry.

Search for supersymmetry in the multijet and missing transverse momentum final state in pp collisions at 13 TeV

A search for new physics is performed based on all-hadronic events with large missing transverse momentum produced in proton-proton collisions at √ s = 13 TeV. The data sample, corresponding to an integrated luminosity of 2.3 fb−1, was collected with the CMS detector at the CERN LHC in 2015. The data are examined in search regions of jet multiplicity, tagged bottom quark jet multiplicity, missing transverse momentum, and the scalar sum of jet transverse momenta. The observed numbers of events in all search regions are found to be consistent with the expectations from standard model processes. Exclusion limits are presented for simplified supersymmetric models of gluino pair production. Depending on the assumed gluino decay mechanism, and for a massless, weakly interacting, lightest neutralino, lower limits on the gluino mass from 1440 to 1600 GeV are obtained, significantly extending previous limits. Published in Physics Letters B as doi:10.1016/j.physletb.2016.05.002. c

Search for the production of dark matter in association with top-quark pairs in the single-lepton final state in proton-proton collisions at sqrt(s) = 8 TeV

A bstractA search is presented for particle dark matter produced in association with a pair of top quarks in pp collisions at a centre-of-mass energy of s=8

Measurement of the hadronic activity in events with a Z and two jets and extraction of the cross section for the electroweak production of a Z with two jets in pp collisions at s√ = 7 TeV

\sqrt{s}=8

Measurement of the transverse momentum spectra of weak vector bosons produced in proton-proton collisions at √s=8 TeV

TeV. The data were collected with the CMS detector at the LHC and correspond to an integrated luminosity of 19.7 fb−1. This search requires the presence of one lepton, multiple jets, and large missing transverse energy. No excess of events is found above the SM expectation, and upper limits are derived on the production cross section. Interpreting the findings in the context of a scalar contact interaction between fermionic dark matter particles and top quarks, lower limits on the interaction scale are set. These limits are also interpreted in terms of the dark matter-nucleon scattering cross sections for the spin-independent scalar operator and they complement direct searches for dark matter particles in the low mass region.

Search for top quark decays via Higgs-boson-mediated flavor-changing neutral currents in pp collisions at ?s=8 TeV

The spectra of charged particles produced within the pseudorapidity window |η| < 1 at √ sNN = 5.02 TeV are measured using 404 μb−1 of PbPb and 27.4 pb−1 of pp data collected by the CMS detector at the LHC in 2015. The spectra are presented over the transverse momentum ranges spanning 0.5 < pT < 400 GeV in pp and 0.7 < pT < 400 GeV in PbPb collisions. The corresponding nuclear modification factor, RAA, is measured in bins of collision centrality. The RAA in the 5% most central collisions shows a maximal suppression by a factor of 7–8 in the pT region of 6–9 GeV. This dip is followed by an increase, which continues up to the highest pT measured, and approaches unity in the vicinity of pT = 200 GeV. The RAA is compared to theoretical predictions and earlier experimental results at lower collision energies. The newly measured pp spectrum is combined with the pPb spectrum previously published by the CMS Collaboration to construct the pPb nuclear modification factor, RpA, up to 120 GeV. For pT > 20 GeV, RpA exhibits weak momentum dependence and shows a moderate enhancement above unity. Published in the Journal of High Energy Physics as doi:10.1007/JHEP04(2017)039. c

Search for heavy resonances decaying to tau lepton pairs in proton-proton collisions at ?s=13 TeV

A bstractThe first measurement of the electroweak production cross section of a Z boson with two jets (Zjj) in pp collisions at

Measurement of the differential cross section for top quark pair production in pp collisions at ?s=8 TeV

\sqrt{s}=7