Deep inelastic inclusive and diffractive scattering at Q2 values from 25 to 320 GeV2 with the ZEUS forward plug calorimeter
Nuclear Physics B 800:1-2 (2008) 1-76
Abstract:
Deep inelastic scattering and its diffractive component, e p → e′ γ* p → e′ X N, have been studied at HERA with the ZEUS detector using an integrated luminosity of 52.4 pb-1. The MX method has been used to extract the diffractive contribution. A wide range in the centre-of-mass energy W (37-245 GeV), photon virtuality Q2 (20-450 GeV2) and mass MX (0.28-35 GeV) is covered. The diffractive cross section for 2 < MX < 15 GeV rises strongly with W, the rise becoming steeper as Q2 increases. The data are also presented in terms of the diffractive structure function, F2D (3), of the proton. For fixed Q2 and fixed MX, xP F2D (3) shows a strong rise as xP → 0, where xP is the fraction of the proton momentum carried by the pomeron. For Bjorken-x < 1 × 10-3, xP F2D (3) shows positive log Q2 scaling violations, while for x ≥ 5 × 10-3 negative scaling violations are observed. The diffractive structure function is compatible with being leading twist. The data show that Regge factorisation is broken. © 2008 Elsevier B.V. All rights reserved.First observation of the decay Bs --> Ds K and measurement of the ratio of branching fractions Br(Bs --> DsK)/Br(Bs --> Ds pi)
ArXiv 0809.0080 (2008)
Search for heavy, long-lived neutralinos that decay to photons at CDF II using photon timing
Physical Review D - Particles, Fields, Gravitation and Cosmology 78:3 (2008)
Abstract:
We present the results of the first hadron collider search for heavy, long-lived neutralinos that decay via χ10→γG in gauge-mediated supersymmetry breaking models. Using an integrated luminosity of 570±34pb-1 of pp̄ collisions at s=1.96TeV, we select γ+jet+missing transverse energy candidate events based on the arrival time of a high-energy photon at the electromagnetic calorimeter as measured with a timing system that was recently installed on the CDF II detector. We find 2 events, consistent with the background estimate of 1.3±0.7 events. While our search strategy does not rely on model-specific dynamics, we set cross section limits and place the world-best 95% C.L. lower limit on the χ 10 mass of 101GeV/c2 at τχ 10=5ns. © 2008 The American Physical Society.Erratum: Search for pair production of scalar top quarks decaying to a τ Lepton and a b quark in pp̄ collisions at s=1.96TeV (Physical Review Letters (2008) 101 (071802))
Physical Review Letters 101:8 (2008)
Search for Supersymmetry in ppbar Collisions at sqrt(s)=1.96 TeV Using the Trilepton Signature for Chargino-Neutralino Production
ArXiv 0808.2446 (2008)