Proton periphery activated by multiparticle dynamics

Abstract

It is shown that protons become more active at the periphery with increase of their collision energy. By computing the impact parameter distribution of the proton-proton overlap function at LHC energies and comparing it with ISR (and S$p\bar p$S for $p\bar p$) data, we conclude that the peripheral region of protons plays an increasing role in the rise of total cross sections through multiparticle dynamics. The size of the proton as well as its blackness increase with energy. The protons become more black both in the central region and, especially, at the periphery. This effect can be related to the ridge phenomenon and to the inelastic diffraction processes at LHC energies.Comment: 9 pages, 4 figure

Several Effects Unexplained by QCD

“…Therefore, the shape of the differential cross section outside the diffraction cone can be 13 Figure 7. The overlap function G(s, b) at 7 TeV (upper curve) [38] compared to those at ISR energies 23.5 GeV and 62.5 GeV (all of them are computed by using the fit of experimental data according to the phenomenological model [39]). The impact parameter, b, is defined as the transverse distance between the trajectories of the centers of the colliding protons.…”

The interaction region of high energy protons

“…The structure of the interaction region with a central core at energies 7 -8 TeV is also supported (see Fig. 2, where it is compared with corresponding structures at ISR energies) by direct computation [11] using the experimental data of the TOTEM collaboration [1,2] about the differential cross section in the region of |t| ≤ 2.5 GeV 2 . Fig.…”

“…It was also shown in [13] that this two-component structure with the central black core and more transparent periphery is well fitted by the expression with the abrupt (Heaviside-like) change of the exponential. However, it is still pretty far from the black disk limit because the peripheral region at b near 1 fm is very active and shows strong increase compared to ISR energies [11]. This is demonstrated in Fig.…”

“…2. The overlap function G(s, b) at 7 TeV (upper curve) [11] compared to those at ISR energies 23.5 GeV and 62.5 GeV (all of them are computed by using the fit of experimental data according to the phenomenological model [12]). …”

Dipole-based description of the $pp$ interaction

“…Если вместо оптической теоремы использовать соотношение унитарности в более общем виде, можно получить аналогичное выражение без интегриро-вания по [22].…”