Speaker
Ms
Daniela Szilard Le Cocq D'Oliveira
(UFRJ)
Description
The multiple scattering theory was first developed in late 50´s by Glauber, and then applied extensively in various areas to calculate high-energy scattering amplitude of composite particles [1]. According to Glauber-Velasco model [2], the (anti-)proton is expressed as a cluster of partons, which pass through each other, and interact through the collisions of partons. It's well known since early 60's that the pp (or p anti-p) elastic cross section increases with the incident energy (limited by the Froissart bound of $~ln^2(\sqrt{s})$ ). This fact can now be understood in terms of QCD, as the number of partons also increase with the collision energy. This model has been successfully applied to a pp scattering data in TeV domain [3] by imposing unitary condition.
On the other hand, the Stochastic Vacuum Model [4] is a QCD-inspired model, proposed in mid-80's, which also well reproduced the available pp (and p anti-p) elastic scattering data from $\sqrt{s} \sim $ 20 GeV to 7 TeV [5]. The above two models reflect the two complementary aspects of QCD, particle and field. Our main goal with this work is clarify the relation between Glauber-Velasco model and the Stochastic Vacuum Model in view of QCD. Both models agree that the proton does not behaves as a black disk, in the way that the probability of a inelastic interaction decreases smoothly as the impact parameter increases, reaching the value less than the black disk limit, 50%. This certainly reflects the vacuum property of QCD and the mechanism of confinement.
References:
[1] R.J. Glauber, in W.E. Brittin (Ed.) et al., Lectures in theoretical physics, vol. I Interscience Publishers, New York (1959) 315.
[2] R.J. Glauber and J. Velasco, Phys Lett. B147 (1984) 380.
[3] T. Csorgo, R.J. Glauber and F. Nemes, arXiv: 1311.2308.
[4] H.G. Dosch, Phys. Lett. B190 (1987) 177; H.G. Dosch, E. Ferreira, A. Kramer, Phys. Rev. D50 (1984) 50.
[5] A.K. Kohara, E. Ferreira, T. Kodama, EPJ C74 (2014) 3175; A.K. Kohara, E. Ferreira, T. Kodama, J. Phys G41 (2014) 115003; A.K. Kohara, E. Ferreira, T. Kodama, Phys. Rev. D87 (2013) 054024.
