896 research outputs found
Preliminary Results on the Empirical Applicability of the Tsallis Distribution in Elastic Hadron Scattering
We show that the proton-proton elastic differential cross section data at dip
position and beyond can be quite well described by a parametrization based on
the Tsallis distribution, with only five free fit parameters. Extrapolation of
the results obtained at 7 TeV to large momentum transfer, suggests that hadrons
may not behave as a black-disk at the asymptotic energy region.Comment: 3 pages, 1 figure, version matching proceedings style, XII Hadron
Physics, 2012, AIP Proc. Con
Proton-proton forward scattering at the LHC
Recently the TOTEM experiment at the LHC has released measurements at
TeV of the proton-proton total cross section, ,
and the ratio of the real to imaginary parts of the forward elastic amplitude,
. Since then an intense debate on the -parity asymptotic nature of the
scattering amplitude was initiated. We examine the proton-proton and the
antiproton-proton forward data above 10 GeV in the context of an eikonal
QCD-based model, where nonperturbative effects are readily included via a QCD
effective charge. We show that, despite an overall satisfactory description of
the forward data is obtained by a model in which the scattering amplitude is
dominated by only crossing-even elastic terms, there is evidence that the
introduction of a crossing-odd term may improve the agreement with the
measurements of at TeV. In the Regge language the
dominant even(odd)-under-crossing object is the so called Pomeron (Odderon).Comment: 5 pages, 2 figures, 1 table. Phenomenological approach revised,
results and conclusions changed, suggesting now the presence of Odderon
effects in forward scattering (once confirmed the TOTEM data at 13 TeV
Hadronic Cross Sections, Elastic Slope and Physical Bounds
An almost model-independent parametrization for the ratio of the total
hadronic cross section to elastic slope is discussed. Its applicability in
studies of asymptotia and analyses of extensive air shower in cosmic-ray
physics is also outlined.Comment: Contribution to XII Hadron Physics, Bento Gon\c{c}alves - RS, Brazil,
22-27th April 2012; to be published in AIP Proc. Con
Applicability of a Representation for the Martin's Real-Part Formula in Model-Independent Analyses
Using a novel representation for the Martin's real-part formula without the
full scaling property, an almost model-independent description of the
proton-proton differential cross section data at high energies (19.4 GeV - 62.5
GeV) is obtained. In the impact parameter and eikonal frameworks, the extracted
inelastic overlap function presents a peripheral effect (tail) above 2 fm and
the extracted opacity function is characterized by a zero (change of sign) in
the momentum transfer space, confirming results from previous model-independent
analyses. Analytical parametrization for these empirical results are introduced
and discussed. The importance of investigations on the inverse problems in
high-energy elastic hadron scattering is stressed and the relevance of the
proposed representation is commented. A short critical review on the use of
Martin's formula is also presented.Comment: Two comments and one reference added at the end of Subsec. 3.3; 23
pages, 9 figures; to be published in Int. J. Mod. Phys.
QCD traveling waves phenomenology revisited
In this paper we review and update the Amaral-Gay Ducati-Betemps-Soyez
saturation model, by testing it against the recent H1-ZEUS combined data on
deep inelastic scattering, including heavy quarks in the dipole amplitude. We
obtain that this model, which is based on traveling wave solutions of the
Balitsky-Kovchegov equation and built in the momentum space framework, yields
very accurate descriptions of the reduced cross section,
, as well as DIS structure functions such as
and , all measured at HERA. Additionally, it
provides good descriptions of heavy quark structure functions, and
at small- and GeV. We also use the
improved model to make predictions for structure functions to be measured in
the near future at LHeC.Comment: 13 pages, 7 figure
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