1,610 research outputs found
Diffractive Higgs boson photoproduction in peripheral collisions
An alternative process is proposed for the diffractive Higgs boson production
in peripheral collisions, exploring it through the photon-proton
interaction by Double Pomeron Exchange. It is estimated the event rate of the
diffractive Higgs production in central rapidity for Tevatron and LHC energies,
being of the order of 1 fb, in agreement to the predictions from other
diffractive processes. The results are confronted with those obtained from a
similar approach of the Durham group.Comment: 4 pages, 7 figures, contribution to the proceedings of II Latin
American Workshop on High Energy Physics [IILAWHEP], 3-7 Dec. 2007, Sao
Miguel das Missoes, Brazi
Single and Central Diffractive Higgs Production at the LHC
The single and central diffractive production of the Standard Model Higgs
boson is computed using the diffractive factorization formalism, taking into
account a parametrization for the Pomeron structure function provided by the H1
Collaboration. We compute the cross sections at NLO accuracy for the gluon
fusion process, since it is the leading mechanism for the Higgs boson
production. The gap survival probability is also introduced to include the
rescattering corrections due to spectator particles present in the interaction.
The diffractive ratios are predicted for proton-proton collisions at the LHC,
since the beam luminosity is favorable to the Higgs boson detection. These
results provide updated estimations for the fraction of single and central
diffractive events in the LHC kinematical regime.Comment: To appear in the proceedings of Diffraction 2010: International
Workshop on Diffraction in High Energy Physics, Otranto, Italy, 10-15 Sep
201
Soft and hard QCD dynamics in hadroproduction of charmonium
Both hard and soft QCD dynamics are important in charmonium production, as
presented here through a next-to-leading order QCD matrix element calculation
combined with the colour evaporation model. Observed and
distributions of in hadroproduction at fixed target and
collider energies are reproduced. Quite similar results can also be obtained in
a more phenomenologically useful Monte Carlo event generator where the
perturbative production of \ccbar pairs is instead obtained through leading
order matrix elements and the parton shower approximation of the higher order
processes. The soft dynamics may alternatively be described by the soft colour
interaction model, originally introduced in connection with rapidity gaps. We
also discuss the relative rates of different charmonium states and introduce an
improved model for mapping the continuous \ccbar mass spectrum on the physical
charmonium resonances.Comment: 21 pages, 13 eps figure
Soft and hard QCD in charmonium production
Hard and soft QCD dynamics are both important in charmonium hadroproduction,
as presented here through a next-to-leading order QCD matrix element
calculation combined with the colour evaporation model. Observed and
distributions of in hadroproduction are reproduced. Quite
similar results can also be obtained with a Monte Carlo event generator where
\ccbar pairs are instead produced through leading order matrix elements and the
parton shower approximation of higher order processes. The soft dynamics may
alternatively be described by the soft colour interaction model. We also
discuss the relative rates of different charmonium states and introduce an
improved model for mapping the continuous ccbar mass spectrum on the physical
charmonium resonances.Comment: Presented at Pan American Advanced Studies Institute (PASI 2002),
Campos do Jord\~ao, Brazil, January 7-18, 200
Estimations for the Single Diffractive production of the Higgs boson at the Tevatron and the LHC
The single diffractive production of the standard model Higgs boson is
computed using the diffractive factorization formalism, taking into account a
parametrization for the Pomeron structure function provided by the H1
Collaboration. We compute the cross sections at next-to-leading order accuracy
for the gluon fusion process, which includes QCD and electroweak corrections.
The gap survival probability () is also introduced to account for
the rescattering corrections due to spectator particles present in the
interaction, and to this end we compare two different models for the survival
factor. The diffractive ratios are predicted for proton-proton collisions at
the Tevatron and the LHC for the Higgs boson mass of = 120 GeV.
Therefore, our results provide updated estimations for the diffractive ratios
of the single diffractive production of the Higgs boson in the Tevatron and LHC
kinematical regimes.Comment: 20 pages, 6 figures, 3 table
Higgs boson photoproduction at the LHC
We present the current development of the photoproduction approach for the
Higgs boson with its application to and collisions at the LHC. We
perform a different analysis for the Gap Survival Probability, where we
consider a probability of 3% and also a more optimistic value of 10% based on
the HERA data for dijet production. As a result, the cross section for the
exclusive Higgs boson production is about 2 fb and 6 fb in collisions and
617 and 2056 fb for Pb collisions, considering the gap survival factor of 3%
and 10%, respectively.Comment: To appear in the proceedings of Diffraction 2010: International
Workshop on Diffraction in High Energy Physics, Otranto, Italy, 10-15 Sep
201
Inclusive hadron and photon production at LHC in dipole momentum space
Using a momentum space model for the dipole scattering amplitude we present
an analysis of the saturation effects at LHC energies, describing the data on
proton-proton and proton-lead collisions. The model is based on the asymptotic
solutions of the Balitsky-Kovchegov equation, being ideal in the saturation
domain where the target wave function has a high occupation number. We also
make predictions for the nuclear modification ratios on charged hadron and
prompt photon production in the forward region, where the high parton density
effects are important.Comment: New section added and typos corrected. To be published in PR
Aspects of the Unitarized Soft Multipomeron Approach in DIS and Diffraction
We study in detail the main features of the unitarized Regge model (CFKS),
recently proposed to describe the small- domain. It takes into account a
two-component description with two types of unitarized contributions: one is
the multiple pomeron exchange contribution, interacting with the large dipole
configurations, and the other one consists of a unitarized dipole cross
section, describing the interaction with the small size dipoles. We analyze the
ratio between soft and hard pieces as a function of the virtuality, and also
compare the resulting dipole cross section to that from the saturation model.
Diffraction dissociation is also considered, showing the scaling violations in
diffractive DIS and estimating the corresponding logarithmic slope.Comment: 14 pages, 5 postscript figures. Version to be published in Eur. Phys.
J.
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