First measurement of the angular coefficients of drell-yan e +e- Pairs in the Z mass region from pp̄ collisions at √s=1.96TeV
Physical Review Letters 106:24 (2011)
Abstract:
We report on the first measurement of the angular distributions of final state electrons in pp̄→γ*/Z→e +e-+X events produced in the Z boson mass region at √s=1.96TeV. The data sample collected by the CDF II detector for this result corresponds to 2.1fb-1 of integrated luminosity. The angular distributions are studied as a function of the transverse momentum of the electron-positron pair and show good agreement with the Lam-Tung relation, consistent with a spin-1 description of the gluon, and demonstrate that, at high values of the transverse momentum, Z bosons are produced via quark-antiquark annihilation and quark-gluon Compton processes. © 2011 American Physical Society.Indication of Electron Neutrino Appearance from an Accelerator-produced Off-axis Muon Neutrino Beam
(2011)
Indication of Electron Neutrino Appearance from an Accelerator-produced Off-axis Muon Neutrino Beam
ArXiv 1106.2822 (2011)
Abstract:
The T2K experiment observes indications of $\nu_\mu\rightarrow \nu_e$ appearance in data accumulated with $1.43\times10^{20}$ protons on target. Six events pass all selection criteria at the far detector. In a three-flavor neutrino oscillation scenario with $|\Delta m_{23}^2|=2.4\times10^{-3}$ eV$^2$, $\sin^2 2\theta_{23}=1$ and $\sin^2 2\theta_{13}=0$, the expected number of such events is 1.5$\pm$0.3(syst.). Under this hypothesis, the probability to observe six or more candidate events is 7$\times10^{-3}$, equivalent to 2.5$\sigma$ significance. At 90% C.L., the data are consistent with 0.03(0.04)$<\sin^2 2\theta_{13}<$ 0.28(0.34) for $\delta_{\rm CP}=0$ and a normal (inverted) hierarchy.Search for high mass dilepton resonances in pp collisions at √s=7 TeV with the ATLAS experiment
Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics 700:3-4 (2011) 163-180
Abstract:
This Letter presents a search for high mass e+e- or μ+μ- resonances in pp collisions at √s=7 TeV at the LHC. The data were recorded by the ATLAS experiment during 2010 and correspond to a total integrated luminosity of ~40 pb-1. No statistically significant excess above the Standard Model expectation is observed in the search region of dilepton invariant mass above 110 GeV. Upper limits at the 95% confidence level are set on the cross section times branching ratio of Z' resonances decaying to dielectrons and dimuons as a function of the resonance mass. A lower mass limit of 1.048 TeV on the Sequential Standard Model Z' boson is derived, as well as mass limits on Z* and E6-motivated Z' models. © 2011 CERN.Evidence for a mass dependent forward-backward asymmetry in top quark pair production
Physical Review D - Particles, Fields, Gravitation and Cosmology 83:11 (2011)