1,375 research outputs found
Parton shower contributions to jets from high rapidities at the LHC
We discuss current issues associated with the dependence of jet distributions
at the LHC on the behavior of QCD parton showers for high rapidities.Comment: Contribution at DIS2012, Univ. of Bonn, March 201
Calculation of the Z+jet cross section including transverse momenta of initial partons
We perform calculations of Z+jet cross-section taking into account the
transverse momenta of the initial partons. Transverse Momentum Dependent (TMD)
parton densities obtained with the Parton Branching method are used and higher
order corrections are included via TMD parton showers in the initial state. The
predictions are compared to measurements of forward Z+jet production of the
LHCb collaboration at TeV. We show that the results obtained in
kT-factorization are in good agreement with results obtained from a NLO
calculation matched with traditional parton showers. We also demonstrate that
in the forward rapidity region, kT-factorization and hybrid factorization
predictions agree with each other.Comment: 16 pages, 8 figure
Fluctuating local moments, itinerant electrons and the magnetocaloric effect: the compositional hypersensitivity of FeRh
We describe an ab-initio Disordered Local Moment Theory for materials with
quenched static compositional disorder traversing first order magnetic phase
transitions. It accounts quantitatively for metamagnetic changes and the
magnetocaloric effect. For perfect stoichiometric B2-ordered FeRh, we calculate
the transition temperature of the ferromagnetic-antiferromagnetic transition to
be 495K and a maximum isothermal entropy change in 2 Tesla of J~K~kg. A large (40\%) component of is
electronic. The transition results from a fine balance of competing electronic
effects which is disturbed by small compositional changes - e.g. swapping just
2\% Fe of `defects' onto the Rh sublattice makes drop by 290K. This
hypersensitivity explains the narrow compositional range of the transition and
impurity doping effects.Comment: 11 pages, 4 figure
Study of non-collinear parton dynamics in the prompt photon photoproduction at HERA
We investigate the prompt photon photoproduction at HERA within the framework
of kt-factorization QCD approach. Our consideration is based on the off-shell
matrix elements for the underlying partonic subprocesses. The unintegrated
parton densities in a proton and in a photon are determined using the
Kimber-Martin-Ryskin (KMR) prescription. Additionally, we use the CCFM-evolved
unintegrated gluon as well as valence and sea quark distributions in a proton.
A conservative error analisys is performed. Both inclusive and associated with
the hadronic jet production rates are investigated. The theoretical results are
compared with the recent experimental data taken by the H1 and ZEUS
collaborations. We study also the specific kinematical properties of the
photon-jet system which are strongly sensitive to the transverse momentum of
incoming partons. Using the KMR scheme, the contribution from the quarks
emerging from the earlier steps of the parton evolution is estimated and found
to be of 15 - 20 approximately.Comment: 22 pages, 13 figures, 2 tabl
Cloning and functional analysis of tipE, a novel membrane protein that enhances drosophila para sodium channel function
AbstractVoltage-dependent sodium channels are involved in the initiation and propagation of action potentials in many excitable cells. Here we report that tipE, a gene defined by a temperature-sensitive paralytic mutation in Drosophila, encodes a novel integral membrane protein that dramatically stimulates functional expression in Xenopus oocytes of the Drosophila sodium channel α subunit encoded by the paralytic (para) locus. Using a heat shock promoter to control tipE+ gene expression in transgenic flies, we demonstrate that tipE+ gene expression is required during pupal development to rescue adult paralysis. In addition, we demonstrate a role or the tipE gene product in adults
The CCFM Monte Carlo generator CASCADE 2.2.0
CASCADE is a full hadron level Monte Carlo event generator for ep, \gamma p
and p\bar{p} and pp processes, which uses the CCFM evolution equation for the
initial state cascade in a backward evolution approach supplemented with off -
shell matrix elements for the hard scattering. A detailed program description
is given, with emphasis on parameters the user wants to change and variables
which completely specify the generated events
Multi-gluon helicity amplitudes with one off-shell leg within high energy factorization
Basing on the Slavnov-Taylor identities, we derive a new prescription to
obtain gauge invariant tree-level scattering amplitudes for the process g*g->Ng
within high energy factorization. Using the helicity method, we check the
formalism up to several final state gluons, and we present analytical formulas
for the the helicity amplitudes for N=2. We also compare the method with
Lipatov's effective action approach.Comment: 25 pages, quite a few figures, an appendix added, typos correcte
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