arXiv subjects
Publications and source records attributed to Keith A. Ulmer.
This talk presents results from the CMS and ATLAS Collaborations from searches for physics beyond the Standard Model motivated by supersymmetry from Run 1 of the LHC. Representative searches are described to illustrate the diverse nature of the search program in both background estimation techniques and final state topologies. The status of preparation for Run 2 searches at 13 TeV is also presented.
Recent results from CMS are reviewed for searches for supersymmetry in final states with multiple bottom quark jets. Results are based on the full 2012 CMS dataset consisting of 19.5 fb-1 collected at a center-of-mass energy of sqrt(s) = 8 TeV. In particular, searches for final states with multiple b-jets and one or two leptons are presented. These final states are of special interest in the context of the search for third generation squarks in gluino or sbottom cascade decays, as predicted by natural supersymmetry.
The sensitivity for CMS searches for supersymmetry is evaluated in the context of an upgraded LHC at a center-of-mass energy of 14 TeV and an integrated luminosity of 300 fb-1. Results for several key searches for supersymmetry are presented including direct and gluino-mediated stop and sbottom production and electroweak production of supersymmetric particles.
Measurements of heavy flavor production in pp collisions at sqrt(s) = 7.0 TeV recorded at the CMS experiment are presented. Double differential cross sections with respect to transverse momentum and rapidity are shown for J/Psi and Upsilon(1S), Upsilon(2S), and Upsilon(3S). The inclusive open beauty rate is measured with two different techniques, including a study of the angular correlations between b jets in events with two identified b jets. Lastly, the B+, B0, and B0s production rates are measured from the reconstruction of exclusive final states.
Measurements of hadron production in pp collisions at sqrt(s) = 0.9, 2.36 and 7 TeV recorded with the CMS detector are reported. Transverse momentum, pseudorapidity and multiplicity distributions of charged hadrons are presented. For non-single-diffractive collisions, the average charged-hadron transverse momentum and pseudorapidity density reveal an increase in production rate not well matched by theory and models. Measured spectra of identified strange particles, K0S, Lambda, anti-Lambda, Xi- and Xi+, reconstructed based on their decay topology, are also presented. The production rates for strange particles are observed to be in excess of those predicted by Monte Carlo models by up to a factor of three.
The 2009 run provided the first proton-proton collisions from the Large Hadron Collider (LHC) at center of mass energies of 900 GeV and 2.36 TeV. The Compact Muon Solenoid (CMS) experiment has recorded a large sample of minimum bias events from these collisions. We present results from the all silicon tracking detectors from this run. The performance of the tracker and track reconstruction algorithms are considered including signal-to-noise, efficiencies and comparisons to simulation for track parameter and resonance reconstruction performance.
We present recent results of hadronic B meson decays related to the CKM angle beta. The data used were collected by the BABAR detector at the pepII asymmetric-energy e+e- collider operating at the Upsilon(4S) resonance located at the Stanford Linear Accelerator Center.