5,076 research outputs found
Diffractive dissociation in proton-nucleus collisions at collider energies
The cross section for the nuclear diffractive dissociation in proton-lead
collisions at the LHC is estimated. Based on the current theoretical
uncertainties for the single (target) diffactive cross section in hadron-hadron
reactions one obtains sigma_SD(5.02 TeV) = 19.67 \pm 5.41 mb and sigma_SD(8.8
TeV) = 18.76 \pm 5.77 mb, respectively. The invariant mass M_X for the reaction
pPb -> pX is also analyzed. Discussion is performed on the main theoretical
uncertainties associated to the calculations.Comment: 04 pages, 2 figures. Final version to be published in European
Physical Journal A - "Hadrons and Nuclei
Exclusive photoproduction of quarkonium in proton-nucleus collisions at energies available at the CERN Large Hadron Collider
In this work we investigate the coherent photoproduction of psi(1S), psi(2S)
and Upsilon (1S) states in the proton-nucleus collisions in the LHC energies.
Predictions for the rapidity distributions are presented using the color dipole
formalism and including saturation effects that are expected to be relevant at
high energies. Calculations are done at the energy 5.02 TeV and also for the
next LHC run at 8.8 TeV in proton-lead mode. Discussion is performed on the
main theoretical uncertainties associated to the calculations.Comment: 05 pages, 5 figures. Version to be published in Phys. Rev.
Light vector meson photoproduction in hadron-hadron and nucleus-nucleus collisions at the energies available at the CERN Large Hadron Collider
In this work we analyse the theoretical uncertainties on the predictions for
the photoproduction of light vector mesons in coherent pp, pA and AA collisions
at the LHC energies using the color dipole approach. In particular, we present
our predictions for the rapidity distribution for rh0 and phi photoproduction
and perform an analysis on the uncertainties associated to the choice of vector
meson wavefunctionand the phenomenological models for the dipole cross section.
Comparison is done with the recent ALICE analysis on coherent production of rho
at 2.76 TeV in PbPb collisions.Comment: 07 pages, 6 figures. Version to be published in Phys. Rev.
Static and dynamic properties of vortices in anisotropic magnetic disks
We investigate the effect of the magnetic anisotropy () on the static
and dynamic properties of magnetic vortices in small disks. Our micromagnetic
calculations reveal that for a range of there is an enlargement of the
vortex core. We analyze the influence of on the dynamics of the vortex
core magnetization reversal under the excitation of a pulsed field. The
presence of , which leads to better resolved vortex structures, allows us
to discuss in more details the role played by the in-plane and perpendicular
components of the gyrotropic field during the vortex-antivortex nucleation and
annihilation.Comment: 4 pages, 4 figure
Neutral-current neutrino reactions in the supernova environment
We study the neutral-current neutrino scattering for four nuclei in the iron
region. We evaluate the cross sections for the relevant temperatures during the
supernova core collapse and derive Gamow-Teller distributions from large-scale
shell-model calculations. We show that the thermal population of the excited
states significantly enhances the cross sections at low neutrino energies.
Calculations of the outgoing neutrino spectra indicate the prospect of neutrino
upscattering at finite temperatures. Both results are particularly notable in
even-even nuclei.Comment: 14 pages, 4 figures, accepted in Phys. Lett. B
One-loop conformal anomaly in an implicit momentum space regularization framework
In this paper we consider matter fields in a gravitational background in
order to compute the breaking of the conformal current at one-loop order.
Standard perturbative calculations of conformal symmetry breaking expressed by
the non-zero trace of the energy-momentum tensor have shown that some violating
terms are regularization dependent, which may suggest the existence of spurious
breaking terms in the anomaly. Therefore, we perform the calculation in a
momentum space regularization framework in which regularization dependent terms
are judiciously parametrized. We compare our results with those obtained in the
literature and conclude that there is an unavoidable arbitrariness in the
anomalous term .Comment: in European Physical Journal C, 201
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