Taking into Account the Centre-of-Mass Correlations in the Cross Sections for Elastic Scattering of Intermediate Energy Protons on the Exotic Nuclei <Superscript>6</Superscript>He and <Superscript>8</Superscript>He

We calculate the differential cross sections for proton elastic scattering on the exotic halo nuclei ⁶He and ⁸He at energies around ~0.7 GeV at the momentum transfers squared up to 0.30 (GeV/c)² and investigate the influence of the nucleon centre-of-mass correlations on the calculated cross sections. In particular, we show that the approximate account of the centre-of-mass correlations used previously considerably overestimates the cross sections at high values of the momentum transfer.     

Proton-proton elastic scattering and nucleon resonance production at high energies

Angular distributions of proton-proton elastic scattering have been measured for incident beam momenta of 10.0, 12.0, 14.2 and 24.0 GeV/c over a range of lab scattering angles from 12 to 152 mrad. This is equivalent to a range of four-momentum transfer squared from about 0.1 to 6.7 GeV² at the highest momentum. Nucleon resonance production in the two-body reaction p + p → p + X has been studied at 24.0 GeV/c incident momentum from 13.5 to 112 mrad by measuring the proton momentum spectra from the elastic peak down to a momentum corresponding to a missing mass of about 2.6 GeV. The new data are compared with previous results and theoretical models.     

Comparison of inelastic electron and positron scattering cross sections on 12C and 27Al

The ratio R = σ⁺/σ^? of the cross sections for inelastic and electron scattering on ¹²C and ²⁷Al has been measured for four momentum transfers 0.08 (GeV/c)² ?q² ?0.45 (GeV/c)² of the virtual photon and invariant masses 0.95 GeV ? W ? 3.3GeV of the hadronic system. The mean value of the ratio is R = (1.005 ± 0.027). No q², respectively, W dependence of the ratio is observed.     

K+P elastic scattering at 32 GeV/c

Elastic scattering of 32.1 GeV/c K⁺ on protons has been measured in a bubble chamber experiment. Results are presented in the momentum transfer interval 0.06–1.40 GeV² and compared with data at different energies. An effective Regge trajectory is calculated using K⁺p elastic data from 10 to 175 GeV/c.     

ΠN-scattering at high energies in the quasipotential approach

Experimental data on πN scattering in the momentum transfer region 0.01?|t|?1.0 (GeV/c)² and P_L?10 GeV/c are described in the framework of the quasipotential approach. The parameters of the quasipotential are found which allow the data to be described satisfactorily.     

Neutron-proton charge-exchange scattering from 8 to 29 GeV/c

The differential cross sections for neutron-proton charge-exchange scattering have been measured for incident neutron momenta between 8 and 29 GeV/c and for four-momentum transfers |t| between 0.002 and 1.0 (GeV/c)². A neutron beam with a broad momentum spectrum was scattered from a liquid hydrogen target. The momenta and scattering angles of the forward-scattered protons were measured by a spark-chamber magnet spectrometer. The flight times and scattering angles of the recoil neutrons were measured by a bank of thick scintillation counters. The efficiencies of the neutron counters were determined in a separate measurement. Absolute normalization of the data was obtained from a measurement of the diffraction dissociation of neutrons from carbon nuclei. Differential cross sections, based on ～ 23 000 events, are presented for 9 different momenta. The shape of the differential cross sections and the momentum dependence are examined in detail.     

Physics (and technique) of gas jet experiments

Recently gas jet targets have been used for the study of small momentum transfer p-p and p-d elastic and inelastic scattering. In these experiments, which were performed at Serpukhov in the USSR and at the Fermilab in the USA, the gas jet is introduced in the main ring of the accelerator. We review the techniques associated with these measurements and summarize the published results which cover 4-momentum transfers 0.001< |t|< 0.12 (GeV/c)^?2 and incident energies 8<E< 400 GeV. Elastic scattering data have yielded precise values for the slope of the nuclear scattering amplitude and for the ratio of the real to imaginary part as a function of energy. The implications of these data on the understanding of high energy hadronic interactions are discussed in some detail. We also present and discuss information on the diffractive dissociation of the proton to low mass states, obtained from inelastic scattering using the gas jet target.     

Elastic antiproton-deutron scattering below 1.0 GeV/c

We present differential cross sections for elastic $\text{p}$d scattering at beam momenta 0.735 and 0.940 GeV/c and momentum transfers in the range 0.04<|t|<0.5(GeV/c)². The $\text{p}$d elastic differential cross section is expressed in terms of a deutron form factor and the I=0 t-channel exchange $\text{N}$N amplitudes, enabling us to isolate the corresponding I=0 t-channel exchange cross sections.     

Measurement of the tensor A yy and vector A y analyzing powers of the deuteron inelastic scattering of beryllium at 5.0 GeV/c and 178 mrad

Tensor A _yy and vector A _y analyzing powers in the inelastic scattering of deuterons with a momentum of 5.0 GeV/c on beryllium at an angle of 178 mrad in the vicinity of the excitation of baryonic resonances with masses up to ～ 1.8 GeV/c ² have been measured. The A _yy data are in good agreement with the previous data obtained at 4.5 and 5.5 GeV/c. The results of the experiment are compared with the predictions of the plane-wave impulse approximation and ω meson-exchange models.     

Coulomb-nuclear interference in π±p and K±p elastic scattering below 3 GeV: Measurements,real parts and K±p dispersion relations

The differential cross sections for π⁺p elastic scattering at0.6, 1.0, 1.5, 2.0, GeV/c for π^-p at 1.0, 1.5, 2.0 GeV/c, for K^-p at 1.2, 1.8, 2.6 GeV/c and for K^-p at 0.9, 1.2, 1.4, 1.6, 1.8, 2.6 GeV/c have been measured with an overall accuracy ofthe order of 1 to 2% in an electronics experiment over the angular region corresponding to momentum transfer t between 0.0005 and 0.10 GeV². Making use of the interference effects between the Coulomb and the nuclear interaction, we have determined the magnitude and sign of the real part of the scattering amplitude near t = 0. The K^±p real parts have been used in a dispersion relation to derive the value of the KNΛ coupling constant.     

A study of e+e− pairs in the mass range 11 to 25 GeV/c2 at the CERN intersecting storage rings

A sample of 58e⁺e^? events with an invariant mass greater than 11 GeV/c² produced in pp collisions at a centre-of-mass energy of 62.3 GeV is discussed. The cross sections are presented as a function of the mass and transverse momentum. The electron pairs produced with a mean transverse momentum of 2.50 ± 0.25 GeV/c.     

Fluctuations in large-angle πp elastic scattering at 5 GeV/c

In a re-analysis of large-angle π^±p elastic scattering cross-sections at 5 GeV/c the data were divided in two momentum bins separated by approximately 80 MeV/c. For π^±p the differential cross-sections are found to fluctuate considerably between the two momentum bins, whereas for π^?p no fluctuations are observed. The result is interpreted as possible evidence for Ericson fluctuations.     

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.     

Proton spectra from 6.3 GeV/c deuteron break-up on 1H, 2H,C, A1 and Bi nuclei

The proton spectra resulting from 6.3 GeV/c deuteron break-up on ¹H, ²H, C, Al and Bi nuclei were measured at an angle of 103 mr (lab) in the momentum interval from 2.6 to 3.6 GeV/c. The measurements were made at the JINR synchrophasotron with a one-arm magnetic spectrometer on-line with a computer. The results, apart from the effects of pion production, are reasonably reproduced in the framework of the Glauber multiple scattering model, taking into account the relativistic deformation of the deuteron wave function.     

Energy dependence of transverse momentum invariant distribution of pions and neutral kaons in K−p interactions between 14.3 and 70 GeV/c

The energy dependence of the transverse momentum invariant distribution of pions and neutral kaons is studied in K^?p interactions between 14.3 and 70 GeV/c. The large P_T part of the distributions violates the Feynman scaling and, above P_T ? 1.5 GeV/c, appears to be reasonably described by hard scattering models. The variation of the average transverse momentum is also studied as a function of the c.m. reduced longitudinal momentum, and its behaviour is compared to the data obtained via the hadronic shower produced in lepton-hadron interactions.     

π− production with linearly polarized photons at 3.4 GeV

The asymmetry of the reaction $\text{γ}\text{d}\textcolor{red}{}\text{π}{}^{\mathrm{?}}\text{p}\text{(}\text{p}{}_{\mathrm{<mtext>S</mtext>}}\text{)}$ with linearly polarized photons has been measured at 3.4 GeV and momentum transfers √?t between 0.2 and 0.8 GeV/c. As in π⁺ production, the asymmetry is large and positive at small momentum transfers but drops rapidly with increasing √?t, crossing zero around √?t = 0.55 GeV/c.     

A measurement of π+p backward elastic differential cross sections from 1.282 to 2.472 GeV/c

New high-statistics measurements of π⁺p elastic scattering differential cross sections are presented at 30 momentum points between 1.282 and 2.472 GeV/c, covering most of the angular distribution outside the forward diffractive peak. These data show significant disagreements at some momenta with previous high-statistics experiments and with current partial wave analyses.     

On the theory of the 2H(π−, π−p)n reaction

The neutron momentum distribution, the Treiman-Yang angle and the polar angle distributions are calculated for the reaction ²H(π^?, π^? p)n at 1 GeV/c. Besides a simple quasielastic scattering, the nucleon rescatteri and the pion double rescattering have been considered. The results are compared with the available data.     

α-particle break-up in the interaction with protons at 8.6 GeV/c 4He momentum

Helium break-up reactions have been studied in ⁴He-proton interactions at 8.6 GeV/c⁴He momentum in the hydrogen bubble chamber. Total and differential cross sections for different reaction channels without pion production have been measured. The results have been compared with multiple scattering model predictions.     

Antiproton-proton elastic scattering at 6.2 GeV/c

Antiproton-proton elastic scattering data at 6.2 GeV/c in the range 0.3 (GeV/c)² ? ?t ? 10.0 (GeV/c)² is presented. The experiment, using spark chambers and proportional chambers, was performed at the CERN Proton Synchroton.The dip at about ?t = 0.5 and the structure at about ?t = 2.2 (GeV/c)² are equally strong at 6.2 GeV/c as they are at 5.0 GeV/c. The differential cross sections around 90° c.m. are not very different at 5.0 GeV/c and at 6.2 GeV/c, whereas in the backward region there is a decrease of the order of one magnitude.