A signature-based search for delayed photons in exclusive photon plus missing transverse energy events from $p \bar{p}$ collisions with $\sqrt{s} = 1.96$ TeV
ArXiv 1307.0474 (2013)
Abstract:
We present the first signature-based search for delayed photons using an exclusive photon plus missing transverse energy final state. Events are reconstructed in a data sample from the CDF II detector corresponding to $6.3 \text{fb}^{-1}$ of integrated luminosity from $\sqrt{s}=1.96$ TeV proton-antiproton collisions. Candidate events are selected if they contain a photon with an arrival time in the detector larger than expected from a promptly-produced photon. The mean number of events from standard model sources predicted by the data-driven background model based on the photon timing distribution is $286 \pm 24$. A total of 322 events are observed. A $p$-value of 12% is obtained, showing consistency of the data with standard model predictions.Measurement of the Differential Cross Section d{\sigma}/d(cos {\theta}t) for Top-Quark Pair Production in p-pbar Collisions at sqrt{s} = 1.96 TeV
(2013)
Measurement of the Differential Cross Section dσ/d(cos θt) for Top-Quark Pair Production in p-pbar Collisions at sqrt{s} = 1.96 TeV
ArXiv 1306.2357 (2013)
Abstract:
We report a measurement of the differential cross section, d{\sigma}/d(cos {\theta}t), for top-quark-pair production as a function of the top-quark production angle in proton-antiproton collisions at sqrt{s} = 1.96 TeV. This measurement is performed using data collected with the CDF II detector at the Tevatron, corresponding to an integrated luminosity of 9.4/fb. We employ the Legendre polynomials to characterize the shape of the differential cross section at the parton level. The observed Legendre coefficients are in good agreement with the prediction of the next-to-leading-order standard-model calculation, with the exception of an excess linear-term coefficient, a1 = 0.40 +- 0.12, compared to the standard-model prediction of a1 = 0.15^{+0.07}_{-0.03}.Search for a light charged Higgs boson in the decay channel H +→cs in tt events using pp collisions at √s =7 TeV with the ATLAS detector
European Physical Journal C 73:6 (2013)
Abstract:
A search for a charged Higgs boson (H+) in tt decays is presented, where one of the top quarks decays via t →H + b, followed by H + → two jets (cs). The other top quark decays to Wb, where the W boson then decays into a lepton (e/μ) and a neutrino. The data were recorded in pp collisions at √ s = 7 TeV by the ATLAS detector at the LHC in 2011, and correspond to an integrated luminosity of 4.7 fb−1. With no observation of a signal, 95 % confidence level (CL) upper limits are set on the decay branching ratio of top quarks to charged Higgs bosons varying between 5 % and 1 % for H + masses between 90 GeV and 150 GeV, assuming B(H +→cs) = 100 %.Measurements of Wγ and Zγ production in pp collisions at √s=7 TeV with the ATLAS detector at the LHC
Physical Review D - Particles, Fields, Gravitation and Cosmology 87:11 (2013)