62,688 research outputs found
Heavy quark production at HERA in k_t factorization supplemented with CCFM evolution
The application of k_t - factorization, supplemented with the CCFM small-x
evolution equation, to heavy quark production is discussed. Differential cross
sections of b-b_bar production and also inelastic J/psi production as measured
at HERA are compared to the hadron level CCFM Monte Carlo generator CASCADE,
using the unintegrated gluon density obtained within the CCFM evolution
approach from a fit to HERA F_2 data.Comment: to appear in: Proceedings of Photon2001, Ascona, Switzerlan
Treating jet correlations in high pile-up at hadron colliders
Experiments in the high-luminosity runs at the Large Hadron Collider face the
challenges of very large pile-up. Primary techniques to deal with this are
based on precise vertex and track reconstruction. Outside tracker acceptances,
however, lie regions of interest for many aspects of the LHC physics program.
We explore complementary approaches to pile-up treatment and propose a
data-driven jet-mixing method which can be used outside tracker acceptances
without depending on Monte Carlo generators. The method can be applied to treat
correlation observables and take into account, besides the jet transverse
momentum pedestal, effects of hard jets from pile-up.Comment: Latex. 8 pages, 5 figure
Angular correlations in multi-jet final states from kt-dependent parton showers
We investigate parton-branching methods based on transverse-momentum
dependent (TMD) parton distributions and matrix elements for the Monte Carlo
simulation of multi-particle final states at high-energy colliders. We observe
that recently measured angular correlations in ep final states with multiple
hadronic jets probe QCD coherence effects in the space-like branching,
associated with finite-angle gluon radiation from partons carrying small
longitudinal momenta, and not included in standard shower generators. We
present Monte Carlo calculations for azimuthal two-jet and three-jet
distributions, for jet multiplicities and for correlations in the
transverse-momentum imbalance between the leading jets. We discuss comparisons
with current experimental multi-jet data, and implications of corrections to
collinear-ordered showers for LHC final states.Comment: 25 pages. Discussion and references expanded; results unchanged.
Additional calculations include
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