Cross Sections For Elastic Proton Research Articles

Evidence of Odderon-exchange from scaling properties of elastic scattering at TeV energies

We study the scaling properties of the differential cross section of elastic proton–proton (pp) and proton–antiproton (pbar{p}) collisions at high energies. We introduce a new scaling function, that scales – within the experimental errors – all the ISR data on elastic pp scattering from sqrt{s} = 23.5–62.5 GeV to the same universal curve. We explore the scaling properties of the differential cross-sections of the elastic pp and pbar{p} collisions in a limited TeV energy range. Rescaling the TOTEM pp data from sqrt{s} = 7 TeV to 2.76 and 1.96 TeV, and comparing it to D0 pbar{p} data at 1.96 TeV, our results provide an evidence for a t-channel Odderon exchange at TeV energies, with a significance of at least 6.26sigma . We complete this work with a model-dependent evaluation of the domain of validity of the new scaling and its violations. We find that the H(x) scaling is valid, model dependently, within 200~hbox {GeV}le sqrt{s} le 8 TeV, with a -t range gradually narrowing with decreasing colliding energies.

On the possibility for precision measurements of differential cross sections for elastic proton–proton scattering at the Protvino accelerator

Elastic-scattering data were analyzed, and it was concluded on the basis of this analysis that precisionmeasurements of differential cross sections for elastic proton–proton scattering at the accelerator of the Institute for High Energy Physics (IHEP, Protvino, Russia) over a broad momentum-transfer range are of importance and topical interest. The layout of the respective experimental facility detecting the scattered particle and recoil proton and possessing a high momentum-transfer resolution was examined along with the equipment constituting this facility. The facility in question is able to record up to a billion events of elastic proton–proton scattering per IHEP accelerator run (20 days). Other lines of physics research with this facility are briefly discussed.

Elastic proton-nucleus scattering in the Glauber-Sitenko approach and relativistic and nonrelativistic nuclear mean fields

The differential cross sections for elastic proton scattering on 40Ca and 208Pb nuclei at 800 MeV are analyzed along with respective spin observables on the basis of the Glauber-Sitenko approach with allowance for two-nucleon correlations, these correlations being taken into account via the inclusion of intermediate excitations of target nuclei and noneikonal corrections. The possibility of employing, in these calculations, realistic nucleon densities obtained in describing the structure of nuclei on the basis of the relativistic- and nonrelativistic-mean-field approximations with various versions of nucleon-interaction parameters is explored. It is shown that some of the nucleon-density versions considered here provide a reasonable description of experimental data, allowance for intermediate nuclear excitations and noneikonal corrections being substantial for ensuring agreement with these data.

Effect of the shell structure of nuclei on p 15C and p 15N scattering within diffraction theory

The differential cross sections for elastic proton scattering on 15C and 15N nuclei at energies of 150 and 800 MeV were calculated within the diffraction theory of Glauber multiple scattering. Shellmodel wave functions were used in these calculations, and particular attention was given to analyzing the sensitivity of the calculated features to distinctions between the shell structure of the 15C nucleus and the shell structure of the 15N nucleus. The calculations were performed in the approximation of double scattering. The multiple-scattering operator was written in a form that permits taking into account collisions with nucleons belonging to different shells. It is shown that the difference in structure between the two nuclei in question leads to substantial distinctions between the differential cross sections for scattering at an energy of 800 MeV and scattering angles larger than 25°.

Structure of neutron-rich Isotopes 8Li and 9Li and allowance for it in elastic scattering

The differential cross sections for elastic proton scattering on the unstable neutron-rich nuclei 8Li and 9Li at E = 700 and 60 MeV per nucleon were considered. The 8Li nucleus was treated on the basis of the three-body α-t-n model, while the 9Li nucleus was considered within the α-t-n and 7Li-n-n models. The cross sections in question were calculated within Glauber diffraction theory. A comparison of the results with available experimental data made it possible to draw conclusions on the quality of the wave functions and potential used in the calculations.

The (p, n) reaction between analog states in isotopes of Sn and Sb

The (p, n) reactions populating the target analog states of the isotope chain 115–120Sn have been investigated in the energy region between threshold and 2.3–3.7 MeV above thres-hold, by measuring total cross sections for the proton decay of the analog states and differential cross sections for elastic proton scattering on these targets. With a completely consistent analysis, all possible parameters of one single optical potential with an isovector coupling term for analyzing the (p, n) reactions and the elastic nucleon scattering in the entrance and exit channels, have been determined. In this way, a good description of all experimental cross sections and the extraction of branching ratios for the proton decay of all analog states are possible 1–3).