11,500 research outputs found
Photon plus heavy quark production in high energy collisions within the target rest frame formalism
We apply the target rest frame formalism to photon + heavy quark production
cross section in hadronic collisions at high energies. We investigate the
dependence of the production cross section on the photon and quark rapidities
and transverse momenta. It is shown that the photon transverse momentum
spectrum is a sensitive probe of color dipole scattering amplitude. The
theoretical results are compared to Tevatron measurements of the differential
\gamma + c + X and \gamma + b + X production cross sections at 1.96 TeV. An
analysis for proton-proton and proton-lead collisions at the LHC regime is also
performed.Comment: 6 pages, 3 figures. Version to be published in Physical Review
Geometric scaling in ultrahigh energy neutrinos and nonlinear perturbative QCD
The ultrahigh energy neutrino cross section is a crucial ingredient in the
calculation of the event rate in high energy neutrino telescopes. Currently
there are several approaches which predict different behaviors for its
magnitude for ultrahigh energies. In this contribution is presented a summary
of current predictions based on the non-linear QCD evolution equations, the
so-called perturbative saturation physics. In particular, predictions are shown
based on the parton saturation approaches and the consequences of geometric
scaling property at high energies are discussed. The scaling property allows an
analytical computation of the neutrino scattering on nucleon/nucleus at high
energies, providing a theoretical parameterization.Comment: 6 pages, one figure. Presented at First Caribbean Symposium on
Nuclear and Astroparticle Physics - STARS2011, La Habana, Cuba, 2011. arXiv
admin note: substantial text overlap with arXiv:1011.2718 by different
author
Geometric scaling in ultrahigh energy neutrinos and nonlinear perturbative QCD
It is shown that in ultrahigh energy inelastic neutrino-nucleon(nucleus)
scattering the cross sections for the boson-hadron(nucleus) reactions should
exhibit geometric scaling on the single variable tau_A =Q2/Q2_{sat,A}. The
dependence on energy and atomic number of the charged/neutral current cross
sections are encoded in the saturation momentum Q_{sat,A}. This fact allows an
analytical computation of the neutrino scattering on nucleon/nucleus at high
energies, providing a theoretical parameterization based on the scaling
property.Comment: 5 pages, 4 figure
The N-Vortex Problem on a Symmetric Ellipsoid: A Perturbation Approach
We consider the N-vortex problem on a ellipsoid of revolution. Applying
standard techniques of classical perturbation theory we construct a sequence of
conformal transformations from the ellipsoid into the complex plane. Using
these transformations the equations of motion for the N-vortex problem on the
ellipsoid are written as a formal series on the eccentricity of the ellipsoid's
generating ellipse. First order equations are obtained explicitly. We show
numerically that the truncated first order system for the three-vortices system
on the symmetric ellipsoid is non-integrable.Comment: 14 pages, 1 figur
Quasi-Dirac neutrinos and solar neutrino data
We present an analysis of the solar neutrino data in the context of a
quasi-Dirac neutrino model in which the lepton mixing matrix is given at tree
level by the tribimaximal matrix. When radiative corrections are taken into
account, new effects in neutrino oscillations, as , appear.
This oscillation is constrained by the solar neutrino data. In our analysis, we
have found an allowed region for our two free parameters and .
The radiative correction, , can vary approximately from to and the calculated fourth mass eigenstate, , 0.01 eV
to 0.2 eV at 2 level. These results are very similar to the ones
presented in the literature.Comment: 24 pages, 7 figures and 2 tables. Results and conclusion unchanged.
Version published in EPJC. Figures improve
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