5,827 research outputs found
Comments on "Observation of Long-Range, Near-Side Angular Correlations in proton-proton Collisions at the LHC" by CMS Collaboration. arXiv:1009.4122[hep-ex]
We present comments on the paper "Observation of Long-Range, Near-Side
Angular Correlations in proton-proton Collisions at the LHC"
An Ad-Hoc Facility for Forward Angle Neutron Time-of-Flight Experiments: The 12-C(p,n)12-N Reaction
This work was supported by National Science Foundation Grant PHY 75-00289 and Indiana Universit
Effect of hard processes on momentum correlations in and collisions
The HBT radii extracted in p-pbar and pp collisions at SPS and Tevatron show
a clear correlation with the charged particle rapidity density. We propose to
explain the correlation using a simple model where the distance from the
initial hard parton-parton scattering to the hadronization point depends on the
energy of the partons emitted. Since the particle multiplicity is correlated
with the mean energy of the partons produced we can explain the experimental
observations without invoking scenarios that assume a thermal fireball. The
model has been applied with success to the existing experimental data both in
the magnitude and the intensity of the correlation. As well, the model has been
extended to pp collisions at the LHC energy of 14 TeV. The possibilities of a
better insight into the string spatial development using 3D HBT analysis is
discussed.Comment: 12 pages, 6 figure
Vacancy defects in epitaxial thin film CuGaSe2 and CuInSe2
Epitaxial thin film CuGaSe2 and CuInSe2 samples grown on GaAs substrates with varying [Cu]/[Ga,In] ratios were studied using positron annihilation Doppler-broadening spectroscopy and were compared to bulk crystals. We find both Cu monovacancies and Cu-Se divacancies in CuInSe2, whereas, in CuGaSe2, the only observed vacancy defect is the Cu-Se divacancy.Peer reviewe
Forward Neutron Production at the Fermilab Main Injector
We have measured cross sections for forward neutron production from a variety
of targets using proton beams from the Fermilab Main Injector. Measurements
were performed for proton beam momenta of 58 GeV/c, 84 GeV/c, and 120 GeV/c.
The cross section dependence on the atomic weight (A) of the targets was found
to vary as where is for a beam momentum of
58 GeV/c and 0.540.05 for 120 GeV/c. The cross sections show reasonable
agreement with FLUKA and DPMJET Monte Carlos. Comparisons have also been made
with the LAQGSM Monte Carlo.Comment: Accepted for publication in Physical Review D. This version
incorporates small changes suggested by referee and small corrections in the
neutron production cross sections predicted by FLUK
Search for Branons at LEP
We search, in the context of extra-dimension scenarios, for the possible
existence of brane fluctuations, called branons. Events with a single photon or
a single Z-boson and missing energy and momentum collected with the L3 detector
in e^+ e^- collisions at centre-of-mass energies sqrt{s}=189-209$ GeV are
analysed. No excess over the Standard Model expectations is found and a lower
limit at 95% confidence level of 103 GeV is derived for the mass of branons,
for a scenario with small brane tensions. Alternatively, under the assumption
of a light branon, brane tensions below 180 GeV are excluded
Study of Spin and Decay-Plane Correlations of W Bosons in the e+e- -> W+W- Process at LEP
Data collected at LEP at centre-of-mass energies \sqrt(s) = 189 - 209 GeV are
used to study correlations of the spin of W bosons using e+e- -> W+W- -> lnqq~
events. Spin correlations are favoured by data, and found to agree with the
Standard Model predictions. In addition, correlations between the W-boson decay
planes are studied in e+e- -> W+W- -> lnqq~ and e+e- -> W+W- -> qq~qq~ events.
Decay-plane correlations, consistent with zero and with the Standard Model
predictions, are measured
Measurement of Exclusive rho^0 rho^0 Production in Two-Photon Collisions at High Q^2 at LEP
Exclusive rho rho production in two-photon collisions involving a single
highly virtual photon is studied with data collected at LEP at centre-of-mass
energies 89GeV < \sqrt{s} < 209GeV with a total integrated luminosity of
854.7pb^-1 The cross section of the process gamma gamma^* -> rho rho is
determined as a function of the photon virtuality, Q^2 and the two-photon
centre-of-mass energy, Wgg, in the kinematic region: 1.2GeV^2 < Q^2 < 30GeV^2
and 1.1GeV < Wgg < 3GeV
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