1,332 research outputs found
Geometric scaling in diffractive deep inelastic scattering
The geometric scaling property observed in the HERA data at small x, that the
deep inelastic scattering (DIS) total cross-section is a function of only the
variable Q^2*x^\lambda, has been argued to be a manifestation of the saturation
regime of QCD and of the saturation scale Q^2_s(x) x^{-\lambda}. We show that
this implies a similar scaling in the context of diffractive DIS and we
observe, for several diffractive observables, that the experimental data from
HERA confirm the expectations of this scaling.Comment: 9 pages, 3 figures, references added, version to appear in PL
Gluon production and diffraction in the dipole picture
Using the eikonal approximation, we show that inclusive gluon production is
related to the scattering of a gluon-gluon dipole while diffractive gluon
production in DIS is related to a two- dipole scattering amplitude.
Hence diffractive photon dissociation cross-sections are observables that
provide potential information on dipole correlations, which represent an open
issue in high-energy QCD.Comment: 4 pages, 2 figures, Proceedings of the 10th International Baryons
Conference (Baryons04), Ecole Polytechnique, Palaiseau, France, October 25-29
200
Gaps between jets in double-Pomeron-exchange processes at the LHC
The possibility to measure jet-gap-jet final states in
double-Pomeron-exchange events at the LHC is presented. In the context of the
ATLAS experiment with additional forward physics detectors, cross sections for
different experimental settings and gap definitions are estimated. This is done
in the framework of the Forward Physics Monte Carlo interfaced with a
perturbative QCD model that successfully reproduces standard jet-gap-jet cross
sections at the Tevatron. The extrapolation to LHC energies follows from the
Balitsky-Fadin-Kuraev-Lipatov dynamics, implemented in the model at
next-to-leading logarithmic accuracy.Comment: 8 pages, 5 figures, version to appear in PR
Buoyant Venus station mission feasibility study for 1972 and 1973 launch opportunities. Volume 2 - Trajectory analysis for 1972 and 1973 missions Final report
Trajectory analysis for 1972 and 1973 buoyant Venus station missio
Energy loss and thermalization of heavy quarks in a strongly-coupled plasma
Using the AdS/CFT correspondence, we compute the medium-induced energy loss
of a decelerating heavy quark moving through a strongly-coupled supersymmetric
Yang Mills plasma. In the regime where the deceleration is small, a
perturbative calculation is possible and we obtain the first two corrections to
the energy-loss rate of a heavy quark with constant velocity. The
thermalization of the heavy quark is also discussed.Comment: 4 pages, no figures, Proceedings of the 21st International Conference
on Ultra-Relativistic Nucleus Nucleus Collisions (QM09), Knoxville, USA,
March 30-April 4 200
Next-leading BFKL effects in forward-jet production at HERA
We show that next-leading logarithmic (NLL) Balitsky-Fadin-Kuraev-Lipatov
(BFKL) effects can be tested by the forward-jet cross sections recently
measured at HERA. For d\sigma/dx, the NLL corrections are small which confirms
the stability of the BFKL description. The triple differential cross section
d\sigma/dxdk_T^2dQ^2 is sensitive to NLL effects and opens the way for an
experimental test of the full BFKL theoretical framework at NLL accuracy.Comment: 5 pages, 4 figures, NLL-BFKL saddle-point approximation now compared
with exact integration, version to appear in PL
Dihadron momentum imbalance and correlations in d+Au collisions
We calculate in perturbative QCD the transverse momentum imbalance of dijet
and dihadron production in high energy p+A (d+A) collisions. We evaluate the
effect of both initial- and final-state multiple scattering, which determines
the strength of this transverse momentum imbalance. Combining this new result
with the suppression of the cross section in d+Au collisions, which arises from
cold nuclear matter energy loss and coherent power corrections, we are able to
describe the dihadron correlations measured by both PHENIX and STAR
collaborations at RHIC, including mid-mid, mid-forward, and forward-forward
rapidity hadron pairs.Comment: 12 pages, 6 figure
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