On rigid projectile approximation in high energy nucleus-nucleus scattering

Rigid projectile approximation in high energy nucleus-nucleus collisions is discussed. The results are demonstrated ond- elastic scattering.Dedicated to Professor Ivan Úlehla on the occasion of his sixtieth birthday.     

Method for calculating the complete expansion of the Glauber amplitude for nucleus-nucleus scattering

A method for calculating the complete expansion of the Glauber amplitude for nucleus-nucleus scattering processes is proposed. An example of the calculation of the elastic differential cross section is given as an illustration.     

Optical limits of the Glauber approximation for nucleus-nucleus collisions

We derived a modification of an expression obtained previously for nucleus-nucleus scattering using the Glauber approximation, which considers certain collision processes originally assumed negligible. Our results cast doubt on the validity of previous applications of the optical limit of the Glauber approximation to collisions between finite nuclei.     

Approximate description of multiple scattering in nucleus-nucleus collisions at high energies

A new expression for the nucleus-nucleus profile function, obtained by symmetrizing the rigid nucleus approximation, is presented. The equivalence of the “rigid target” and “swarm projectile” approximations is shown.     

Test of the Glauber formula for nucleon-deuteron scattering at intermediate energies

A high-precision test of the Glauber formula for the amplitude of nucleon-deuteron scattering is performed. Nucleon-nucleon amplitudes used in the calculations depend on the spins of interacting particles, phase shifts, and mixing parameters. These amplitudes were derived by using the Njim I, Njim II, Njim 93, and Reid 93 realistic potentials. The differential cross sections for nucleon-deuteron scattering were calculated for the projectile-nucleon energies of 65, 95, 135, 150, 190, and 250 MeV, and the results of these calculations were compared with experimental data.     

Bounds on the elastic scattering amplitude at finite energies

A bound on the ratio of differential cross sections of particle and antiparticle at finite energies has been derived using the relation between phase and modulus of the scattering amplitude which follows from analyticity, unitarity and crossing symmetry.Presented by Yu. S.Vernov at the Symposium on Hadron-Hadron Scattering at High Energies, Liblice, Czechoslovakia, June 16–21, 1975.     

The validity of the factorization hypothesis for nucleus-nucleus cross sections at high energies

We have calculated nucleus-nucleus cross sections for a variety of projectile and target nuclei and a wide range of energy. Total, reaction and elastic cross sections, as well as the slopes of the elastic diffraction peak, exhibit an approximate factorization property when the nuclei differ by less than 50% in r.m.s. radii. A simple geometrical interpretation is provided for the failure of factorization which occurs when target and projectile differ greatly in size.     

Random matrix theory and analysis of nucleus-nucleus collision at high energies

We propose a novel method for analysis of experimental data obtained in relativistic nucleus—nucleus collisions. The method, based on the ideas of random matrix theory, is applied to detect systematic errors that occur in measurements of momentum distributions of emitted particles. The unfolded momentum distribution is well described by the Gaussian orthogonal ensemble of random matrices, when the uncertainty in the momentum distribution is maximal. The method is free from unwanted background contributions. The text was submitted by the authors in English.     

Sudden approximation for elastic scattering of composite projectiles at intermediate energies

Elastic scattering of deuterons by nuclei at intermediate energies is investigated by the sudden approximation. Scattering amplitudes of the deuteron are described in terms of those of the constituent nucleons. They consist of the amplitude of nucleon-nucleus single collision and that of double collision. The neglect of the latter explains similarity relations between the deuteron observables and the proton ones, which are found in experimental data. Cross sections and vector analyzing powers calculated with the single-collision terms successfully reproduce the measured ones for ¹⁶O, ⁴⁰Ca and ⁵⁸Ni targets in the energy region, E_d = 200 ˜ 700 MeV. Scattering of ⁶Li by ⁵⁸Ni is investigated in a similar way assuming the d + cluster model for ⁶Li.     

Hadron-nucleon elastic scattering at high energies

A review of experiments on high energy hadron-nucleon elastic scattering is given. Emphasis is placed on the most recent experiments at FNAL and CERN/ISR. Results (mostly preliminary) are discussed and compared with earlier experiments.Presented at the Symposium on Hadron-Hadron Scattering at High Energies, Liblice, Czechoslovakia, June 16–21, 1975.I like to thank the Czechoslovakian Academy of Sciences and the Organizing Committee of the Symposium, especially Dr. J.Fischer, for their invitation and hospitality. I am indebted to D. D.Jovanovitch of the Michigan-Argonne-Fermilab-Indiana collaboration for sending me their data prior to publication.     

A search at high energies for antineutrino-electron elastic scattering

We have searched for candidates for the weak neutral leptonic current reaction $\text{ν}{}_{\mathrm{\mu }}\text{+}\text{e}{}^{\mathrm{?}}\text{→}\text{ν}{}_{\mathrm{\mu }}\text{+}\text{e}{}^{\mathrm{?}}$ in the Fermilab 15 ft bubble chamber filled with a heavy neon-hydrogen mix. Based on zero observed events of this type we find the 90% confidence level upper limit for the rate for this reaction relative to the total antineutrino charged current rate to be 3.9 × 10^?4 and, in the Weinberg-Salam model, sin²θ_W ? 0.37.     

QCD factorization for forward hadron scattering at high energies

We calculate the branching ratios and CP asymmetries of the B???Ц?, ?Ц? decays in the perturbative QCD factorization approach up to the next-to-leading-order contributions. We find that the next-to-leading-order contributions can interfere with the leading-order part constructively or destructively for different decay modes. Our numerical results have a much better agreement with current available data than previous leading-order calculations, e.g., the next-to-leading-order corrections enhance the B ⁰???? ⁰ ?? ⁰ branching ratios by a factor 2.5, which is helpful to narrow the gaps between theoretic predictions and experimental data. We also update the direct CP-violation parameters, the mixing-induced CP-violation parameters of these modes, which show a better agreement with experimental data than many of the other approaches.     

Proton distributions in the target fragmentation region in proton-nucleus and nucleus-nucleus collisions at high energies

We present measurements of the rapidity and transverse-momentum distributions of the protons emitted in S+W, O+W, andp+W reactions at 200 GeV/A around the target rapidity (y=1). The rapidity density rises linearly with the transverse energy for all three systems, but the slope forp+W is much steeper than for O+W and S+W. The rapidity density forp+W is much higher than predicted by summing single nucleonnucleon collisions without any nuclear effects, indicating substantial rescattering of the produced particles. The predictions of the VENUS 3 model, including rescattering, show reasonable agreement with the data for all three systems. We do not have evidence for a strong collective flow of the outgoing particles.     

Alpha particle scattering in the rigid projectile approximation

We study elastic α-particle scattering offp,α-particle and¹²C targets at 17.9 GeV/c incident momentum in the rigid projectile approximation of the Glauber model. Differential and total cross-sections are computed and compared with the data. Reasonable agreement with the observed differential cross-sections is found for small momentum transfers but short-range dynamical correlations in the target will probably have to be taken into account to get better agreement at larger momentum transfers, particularly in the case of α-¹²C scattering.     

Systematics of hadron-proton diffractive scattering at high energies

We apply the eikonal formalism to existingπ ^±,K ^±,p, \(\bar p\) ,∑ ^? andΞ ^? elastic scattering data on a target proton in order to perform a detailed test of the additivity of eikonals of the constituent quark-quark interaction. The difference between the pion and kaon channels imposes an obvious flavor dependence. In addition, the systematic treatment of meson and baryon scattering for all values oft requires a renormalization of the fundamental interaction strength which persists in a rescattering treatment of the problem as well as with the inclusion of gluonic degrees of freedom. A variety of form factors and elementary amplitudes are studied with wide ranging consequences on the quality of the reproduction of the data.     

Spin effects in hadron scattering at very high energies

In this paper a spin-dependent diffractive model is studied for πN and NN elastic scattering. We find non-trivial results for spin correlation parameters which persist at high energies and have very distinct features in the dip region. It is stressed that these parameters provide good tests of pomeron factorization.