Search results for "Collider"
showing 10 items of 1690 documents
Search for dark matter produced in association with a Higgs boson decaying to two bottom quarks inppcollisions ats=8 TeVwith the ATLAS detector
2016
This article reports on a search for dark matter pair production in association with a Higgs boson decaying to a pair of bottom quarks, using data from 20.3 fb(-1) of pp collisions at a center-of-m ...
Determination of the Strange-Quark Density of the Proton from ATLAS Measurements of theW→ℓνandZ→ℓℓCross Sections
2012
AQCD analysis is reported of ATLAS data on inclusive W-+/- and Z boson production in pp collisions at the LHC, jointly with ep deep-inelastic scattering data from HERA. The ATLAS data exhibit sensitivity to the light quark sea composition and magnitude at Bjorken x similar to 0:01. Specifically, the data support the hypothesis of a symmetric composition of the light quark sea at low x. The ratio of the strange-to-down sea quark distributions is determined to be 1:00(-0:28)(+0.25) at absolute four-momentum transfer squared Q(2) = 1: 9 GeV2 and x = 0: 023.
Measurement of the high-mass Drell–Yan differential cross-section in pp collisions at s=7 TeV with the ATLAS detector
2013
This Letter reports a measurement of the high-mass Drell–Yan differential cross-section in proton–proton collisions at a centre-of-mass energy of 7 TeV at the LHC. Based on an integrated luminosity ...
Measurement of electrons from semileptonic heavy-flavor hadron decays inppcollisions ats=2.76 TeV
2015
The pT-differential production cross section of electrons from semileptonic decays of heavy-flavor hadrons has been measured at midrapidity in proton-proton collisions at s=2.76TeV in the transverse momentum range 0.5<pT<12GeV/c with the ALICE detector at the LHC. The analysis was performed using minimum bias events and events triggered by the electromagnetic calorimeter. Predictions from perturbative QCD calculations agree with the data within the theoretical and experimental uncertainties.
The top quark right coupling in the tbW-vertex
2015
The most general parametrization of the $tbW$ vertex includes a right coupling $V_R$ that is zero at tree level in the standard model. This quantity may be measured at the Large Hadron Collider where the physics of the top decay is currently investigated. This coupling is present in new physics models at tree level and/or through radiative corrections, so its measurement can be sensitive to non standard physics. In this paper we compute the leading electroweak and QCD contributions to the top $V_R$ coupling in the standard model. This value is the starting point in order to separate the standard model effects and, then, search for new physics. We also propose observables that can be address…
Properties of jet fragmentation using charged particles measured with the ATLAS detector in pp collisions at s=13 TeV
2019
This paper presents a measurement of quantities related to the formation of jets from high-energy quarks and gluons (fragmentation). Jets with transverse momentum 100 GeV 500 MeV and vertical bar ...
Measurement ofγ+b+Xandγ+c+XProduction Cross Sections inpp¯Collisions ats=1.96 TeV
2009
First measurements of the differential cross sections for the inclusive production of a photon in association with a heavy quark (c, b) jet are presented, covering photon transverse momenta 30-150 GeV, photon rapidities | y_gamma| 15 GeV. The results are based on an integrated luminosity of 1 fb^-1 in ppbar collisions at sqrt(s)=1.96 TeV recorded with the D0 detector at the Fermilab Tevatron Collider. The results are compared with next-to-leading order perturbative QCD predictions.
Measurement of the chi(b) (3 P) mass and of the relative rate of chi(b1) (1 P) and chi(b2) (1 P) production
2014
The production of $\chi_b$ mesons in proton-proton collisions is studied using a data sample collected by the LHCb detector, at centre-of-mass energies of $\sqrt{s}=7$ and $8$ TeV and corresponding to an integrated luminosity of 3.0 fb$^{-1}$. The $\chi_b$ mesons are identified through their decays to $\Upsilon(1S)\gamma$ and $\Upsilon(2S)\gamma$ using photons that converted to $e^+e^-$ pairs in the detector. The $\chi_b(3P)$ meson mass, and the relative prompt production rate of $\chi_{b1}(1P)$ and $\chi_{b2}(1P)$ mesons as a function of the $\Upsilon(1S)$ transverse momentum in the $\chi_b$ rapidity range 2.0< $y$<4.5, are measured. Assuming a mass splitting between the $\chi_{b1}(3P)$ an…
Measurement of the cross section for hard exclusive π0 muoproduction on the proton
2020
Physics letters / B B805, 135454 (2020). doi:10.1016/j.physletb.2020.135454
Looking for magnetic monopoles at LHC with diphoton events
2012
Magnetic monopoles have been a subject of interest since Dirac established the relation between the existence of monopoles and charge quantization. The intense experimental search carried thus far has not met with success. The Large Hadron Collider is reaching energies never achieved before allowing the search for exotic particles in the TeV mass range. In a continuing effort to discover these rare particles we propose here other ways to detect them. We study the observability of monopoles and monopolium, a monopole-antimonopole bound state, at the Large Hadron Collider in the $\gamma \gamma$ channel for monopole masses in the range 500-1000 GeV. We conclude that LHC is an ideal machine to …