11,635 research outputs found
The NLO Jet Vertex for Mueller-Navelet and Forward Jets: the Gluon Part
In this paper we complete our calculation of the NLO jet vertex which is part
of the cross section formulae for the production of Mueller Navelet jets at
hadron hadron colliders and of forward jets in deep inelastic electron proton
scattering.Comment: 16 pages, latex, epj style, 6 eps figure
The NLO Jet Vertex for Mueller-Navelet and Forward Jets: the Quark Part
We calculate the next-to-leading corrections to the jet vertex which is
relevant for the Mueller-Navelet-jets production in p-pbar collisions and for
the forward jet cross section in e-p collisions. In this first part we present
the results of the vertex for an incoming quark. Particular emphasis is given
to the separation of the collinear divergent part and the central region of the
produced gluon.Comment: 28 pages, 8 eps figure
Bayesian Model Comparison and Analysis of the Galactic Disk Population of Gamma-Ray Millisecond Pulsars
Pulsed emission from almost one hundred millisecond pulsars (MSPs) has been
detected in -rays by the Fermi Large-Area Telescope. The global
properties of this population remain relatively unconstrained despite many
attempts to model their spatial and luminosity distributions. We perform here a
self-consistent Bayesian analysis of both the spatial distribution and
luminosity function simultaneously. Distance uncertainties, arising from errors
in the parallax measurement or Galactic electron-density model, are
marginalized over. We provide a public Python package for calculating distance
uncertainties to pulsars derived using the dispersion measure by accounting for
the uncertainties in Galactic electron-density model YMW16. Finally, we use
multiple parameterizations for the MSP population and perform Bayesian model
comparison, finding that a broken power law luminosity function with Lorimer
spatial profile are preferred over multiple other parameterizations used in the
past. The best-fit spatial distribution and number of -ray MSPs is
consistent with results for the radio population of MSPs.Comment: 13 pages, 8 figures, 3 tables + Appendix. Public code and source list
available from http://github.com/tedwards2412/MSPDis
Smooth optimal control with Floquet theory
This paper describes an approach to construct temporally shaped control
pulses that drive a quantum system towards desired properties. A
parametrization in terms of periodic functions with pre-defined frequencies
permits to realize a smooth, typically simple shape of the pulses; their
optimization can be performed based on a variational analysis with Floquet
theory. As we show with selected specific examples, this approach permits to
control the dynamics of interacting spins, such that gate operations and
entanglement dynamics can be implemented with very high accuracy
Frictional coupling between sliding and spinning motion
We show that the friction force and torque, acting at a dry contact of two
objects moving and rotating relative to each other, are inherently coupled. As
a simple test system, a sliding and spinning disk on a horizontal flat surface
is considered. We calculate, and also measure, how the disk is slowing down,
and find that it always stops its sliding and spinning motion at the same
moment. We discuss the impact of this coupling between friction force and
torque on the physics of granular materials.Comment: 4 pages, 5 figures; submitte
QCD evolution and skewedness effects in color dipole description of DVCS
We show the role played by QCD evolution and skewedness effects in the DVCS
cross section at large within the color dipole description of the process
at photon level. The dipole cross section is given by the saturation model,
which can be improved by DGLAP evolution at high photon virtualities. We
investigate both possibilities as well as the off-forward effect through a
simple phenomenological parametrisation. The results are compared to the recent
ZEUS DVCS data.Comment: LaTeX, 6 pages, 5 Figs. Vers 2: Minor modifications. Accepted by EPJ
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