1,543 research outputs found
Jet correlation measurement in heavy-ion collisions: from RHIC to LHC
We attempt to deduce simple options of `jet quenching' phenomena in heavy-ion
collisions at \snn=5.5 \tev at the LHC from the present knowledge of
leading-hadron suppression at RHIC energies. In light of the nuclear
modification factor for leading particles we introduce the nuclear modification
factor for jets, \RAA^{jet}, and for the longitudinal momenta of particles
along the jet axis, \RAA^{p_{\rm L}}.Comment: 9 pages, 7 figures, proceedings, MIT workshop on fluctuations and
correlations in relativistic nuclear collision
Electroweak and QCD corrections to Higgs production via vector-boson fusion at the LHC
The radiative corrections of the strong and electroweak interactions are
calculated at next-to-leading order for Higgs-boson production in the
weak-boson-fusion channel at hadron colliders. Specifically, the calculation
includes all weak-boson fusion and quark--antiquark annihilation diagrams to
Higgs-boson production in association with two hard jets, including all
corresponding interferences. The results on the QCD corrections confirm that
previously made approximations of neglecting s-channel diagrams and
interferences are well suited for predictions of Higgs production with
dedicated vector-boson fusion cuts at the LHC. The electroweak corrections,
which also include real corrections from incoming photons and leading
heavy-Higgs-boson effects at two-loop order, are of the same size as the QCD
corrections, viz. typically at the level of 5-10% for a Higgs-boson mass up to
\sim 700 GeV. In general, both types of corrections do not simply rescale
differential distributions, but induce distortions at the level of 10%. The
discussed corrections have been implemented in a flexible Monte Carlo event
generator.Comment: 33 pages, LaTeX, 24 postscript figure
Vector Boson Pair Production via Vector Boson Fusion at NLO QCD
NLO QCD corrections to Vector Boson Pair Production via Vector Boson Fusion
have recently been calculated and implemented in a parton-level Monte-Carlo
program with full experimental cuts. We briefly sketch the elements of the
calculation and show numerical results for the Large Hadron Collider.Comment: 6 pages, 3 figures, presented by G.Bozzi at IFAE 2007 (Napoli, April
2007) and HEP 2007 (Manchester, July 2007
Dijet Cross Section and Longitudinal Double Spin Asymmetry Measurements in Polarized Proton-proton Collisions at \sqrt{s}=200 GeV at STAR
These proceedings show the preliminary results of the dijet cross sections
and the dijet longitudinal double spin asymmetries A_LL in polarized
proton-proton collisions at \sqrt{s} = 200 GeV at the mid-rapidity |eta| < 0.8.
The integrated luminosity of 5.39 pb^{-1} collected during RHIC Run-6 was used
in the measurements. The preliminary results are presented as functions of the
dijet invariant mass M_jj. The dijet cross sections are in agreement with
next-to-leading-order pQCD predictions. The A_LL is compared with theoretical
predictions based on various parameterizations of polarized parton
distributions of the proton. Projected precision of data analyzed to date from
Run-9 are shown.Comment: 8 pages, 5 figures, Proceedings of the SPIN2010 conference (Juelich,
Germany, 2010
Photon - Jet Correlations and Constraints on Fragmentation Functions
We study the production of a large-pT photon in association with a jet in
proton-proton collisions. We examine the sensitivity of the jet rapidity
distribution to the gluon distribution function in the proton. We then assess
the sensitivity of various photon + jet correlation observables to the photon
fragmentation functions. We argue that RHIC data on photon-jet correlations can
be used to constrain the photon fragmentation functions in a region which was
barely accessible in LEP experiments.Comment: 23 pages, 9 figure
LCDG4 and DigiSim - Simulation activities at NICADD/NIU
We present two software packages developed to support detector R&D studies
for the International Linear Collider. LCDG4 is a full-detector simulator that
provides energy deposits from particles traversing the sensitive volumes of the
detector. It has been extensively used within the American ILC community,
providing data for algorithm development and detector optimization studies.
DigiSim models real-life digitization effects, converting the idealized
response into simulated detector readout. It has many useful features to
improve the realism in modeling detector response. The main characteristics of
these two complementary packages are discussed.Comment: 8 pages, 7 figures, submitted to LCWS05 conference proceedings. Uses
slac_one.rt
Quality Control Studies of Wavelength Shifting Fibers for a Scintillator- based Tail-Catcher Muon-Tracker Linear Collider Prototype Detector
Detailed measurements of the wavelength shifting fiber response to a stable and reliable light source are presented. Details about materials, a double reference method, and measurement technique are included. The fibers studied were several hundred KURARAY, Y-11, multiclad, 1.2mm outer diameter wavelength shifting fibers each cut from a reel to about one meter length. The fibers were polished, mirrored, and the mirrors were UV epoxy protected. Each fiber passed quality control requirements before installation. About 94% of the fibers have a response within 1% of the overall mea
Quality Control Studies of Wavelength Shifting Fibers for a Scintillator- based Tail-Catcher Muon-Tracker Linear Collider Prototype Detector
Detailed measurements of the wavelength shifting fiber response to a stable and reliable light source are presented. Details about materials, a double reference method, and measurement technique are included. The fibers studied were several hundred KURARAY, Y-11, multiclad, 1.2mm outer diameter wavelength shifting fibers each cut from a reel to about one meter length. The fibers were polished, mirrored, and the mirrors were UV epoxy protected. Each fiber passed quality control requirements before installation. About 94% of the fibers have a response within 1% of the overall mea
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