Showing papers by "Zack Sullivan published in 2012"
TL;DR: In this paper, a lower bound of 1750-1800 GeV at 7 TeV and 5 fb^-1 depending on the sign of the interference with standard model single-top-quark production was established.
Abstract: The semileptonic decay of single-top-quark production provides a strong probe for W-prime bosons at the CERN Large Hadron Collider We propose an explicit search strategy for pp -> W-prime -> tb -> l nu b j for use at 7 TeV and 8 TeV collider energies, and integrated luminosities ranging from 5 to 20 fb^-1 Based on detector-simulated results, we predict that a lower bound can be placed on the mass of right-handed W-prime_R with standard model-like couplings of m_{W-prime_R} > 1800 GeV at sqrt{S}=7 TeV with 5 fb^-1, and of m_{W-prime_R} > 2000 GeV at 8 TeV with 20 fb^-1 For left-handed W-prime_L bosons we find a lower bound of 1750-1800 GeV at 7 TeV and 5 fb^-1 depending on the sign of the interference with standard model single-top-quark production We present effective coupling g^prime dependent limits for accessible masses, and stress the importance of these limits for comparison with theoretical models
26 citations
TL;DR: In this article, the authors obtained contraints on three Universal Extra Dimensional models utilizing limits from the CMS Collaboration on W' production and decay into a single-top-quark final state.
Abstract: We obtain contraints on three Universal Extra Dimensional models utilizing limits from the CMS Collaboration on W' production and decay into a single-top-quark final state. We find a weak constraint on the Minimal Universal Extra Dimensions model due to small Kaluza-Klein number violating terms. In contrast, the W' search puts a strong limit on the size of the Dirac mass term of the quarks in Split Universal Extra Dimension models. In Non-minimal Universal Extra Dimension models the W' search constrains the splitting between the boundary localized kinetic terms of the gauge bosons and the quarks. Each of these bounds can be translated into constraints on the mass splitting between the Kaluza-Klein excitations of the SU(2) charged quarks and the Klauza-Klein excitations of the W boson.
19 citations
TL;DR: In this article, a top quark forward-backward asymmetry measured at the Fermilab Tevatron collider deviates from the standard model prediction, and it is shown that such a boson would be produced in association with a top-quark at the CERN Large Hadron Collider (LHC), thus inducing additional $t\overline{t}+j$ events.
Abstract: The top quark forward-backward asymmetry measured at the Fermilab Tevatron collider deviates from the standard model prediction. A ${W}^{\ensuremath{'}}$ boson model is described, where the coupling ${W}^{\ensuremath{'}}$-$t$-$d$ is fixed by the $t\overline{t}$ forward-backward asymmetry and total cross section at the Tevatron. We show that such a ${W}^{\ensuremath{'}}$ boson would be produced in association with a top quark at the CERN Large Hadron Collider (LHC), thus inducing additional $t\overline{t}+j$ events. We use measurements of $t\overline{t}+n$-jet production from the LHC to constrain the allowed ${W}^{\ensuremath{'}}$-$t$-$d$ couplings as a function of ${W}^{\ensuremath{'}}$ boson mass. We find that this ${W}^{\ensuremath{'}}$ model is constrained at the $95%$ confidence level using $0.7\text{ }\mathrm{f}{\mathrm{b}}^{1}$ of data from the LHC, and could be fully excluded with $5\text{ }\mathrm{f}{\mathrm{b}}^{1}$ of data.
17 citations
TL;DR: In this paper, the LHC data at 7 TeV with $4.9 standard deviation signal significance was used to distinguish a fermiophobic Higgs boson from a standard model Higgs particle near 125 GeV at about 1.9σ signal significance.
Abstract: Production in association with an electroweak vector boson $V$ is a distinctive mode of production for a Higgs boson $H$ without tree-level couplings to fermions, known as a fermiophobic Higgs boson. We focus on $HV$ associated production with $H$ decay into a pair of photons, and $V$ into a pair of jets, with the goal of distinguishing a fermiophobic Higgs boson from the standard model Higgs boson. Performing a simulation of the signal and pertinent QCD backgrounds, and using the same event selection cuts employed by the LHC ATLAS Collaboration, we argue that existing LHC data at 7 TeV with $4.9\text{ }\text{ }{\mathrm{fb}}^{\ensuremath{-}1}$ of integrated luminosity may distinguish a fermiophobic Higgs boson from a standard model Higgs boson near 125 GeV at about 1.9 standard deviation signal significance ($1.9\ensuremath{\sigma}$) per experiment. At 8 TeV we show that associated production could yield $2.8\ensuremath{\sigma}$ significance per experiment with $10\text{ }\text{ }{\mathrm{fb}}^{\ensuremath{-}1}$ of data.
11 citations