Aspects of a dynamical gluon mass approach to elastic hadron scattering at LHC

Exploring central opacity and asymptotic scenarios in elastic hadron scattering

Under the influence of standardly used description of Coulomb-hadronic interference proposed by West and Yennie the protons have been interpreted as transparent objects; elastic events have been interpreted as more central than inelastic ones. It will be shown that using eikonal model the protons may be interpreted in agreement with usual ontological conception; elastic processes being more peripheral than inelastic ones. The corresponding results (differing fundamentally from the suggested hitherto models) will be presented by analyzing the most ample elastic data set measured at the ISR energy of 52.8 GeV and the LHC energy of 8 TeV. Detailed analysis of measured differential cross section will be performed and possibility of peripheral behavior on the basis of eikonal model will be presented. The impact of recently established electromagnetic form factors on determination of quantities specifying hadron interaction determined from the fits of experimental elastic data in the broadest region of momentum transfers will be analyzed.

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Eikonal model analysis of elastic proton–proton collisions at 52.8 GeV and 8 TeV

We analyse the pp and elastic scattering amplitudes using the data of several CERN and FERMILAB experiments, revisiting ideas proposed by Andre Martin based on analytic continuation and crossing symmetry. Introducing a new form for the scaling function together with the analytical forms from COMPETE at t = 0 we show that the data are consistent with the crossing symmetry of the scattering amplitudes from 23 GeV to 13 TeV for −t ≤ 0.2 GeV2. Analiticity and crossing symmetry automatically satisfy the dispersion relations and their derivatives. The real part reproduces the zero predicted by Martin, which is crucial to describe with precision the differential cross section in the forward range at high energies. Since the free parameters of the model are energy independent, the analytical form of the amplitude allows predictions for intermediate and higher energies.

Forward scattering amplitudes of $pp$ and $p \bar{p}$ with crossing symmetry and scaling properties

With analytical representation for the pp scattering amplitudes introduced and tested at lower energies, a description of high precision is given of the $$d\sigma /dt$$
 data at $$\sqrt{s}= 13$$
  TeV for all values of the momentum transfer, with explicit identification of the real and imaginary parts. In both t and b coordinates the amplitudes have terms identified as of non-perturbative and perturbative nature, with distinction of their influences in forward and large |t| ranges and in central and peripheral regions respectively. In the forward range, the role of the Coulomb-nuclear interference phase is investigated. The energy dependence of the parameters of the amplitudes are reviewed and updated, revealing a possible emergence of a peculiar behavior of elastic and inelastic profiles in b-space for central collisions, which seems to be enhanced quickly at higher energies. Some other models are also briefly discussed in comparison, including the above mentioned behavior in b-space.

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Analytical representation for amplitudes and differential cross section of pp elastic scattering at 13 TeV

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.

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.

D. A. Fagundes

Papers

Applicability Of A Representation For The Martin's Real-part Formula In Model-independent Analyses

Applicability of a Representation for the Martin's Real-Part Formula in Model-Independent Analyses