Twenty-nine proton-proton differential elastic cross sections for lab momenta p0 from 11 to 31.8 BeV/c, at four-momentum transfers squared, −t, from 2.3 to 24.4 (BeV/c)2, have been measured at the Brookhaven alternating gradient synchrotron. The circulating proton beam impinged upon a thin CH2 internal target. Both scattered protons from p−p elastic events were detected by scintillation-counter telescopes which were placed downstream from deflection magnets set at the appropriate angles to the incident beam. The angular correlation of the protons, their momenta, and the coplanarity of the events were determined by the detection system. The results show that at high momentum transfers the differential cross section, dσdt, depends strongly upon the energy; for −t=10 (BeV/c)2, the value of dσdt at p0=30 BeV/c is smaller by a factor∼1000 than at p0=10 BeV/c. At all energies, dσdt falls rapidly with increasing |t| for scattering angles up to about 65° (c.m.), while in the range from 65 to 90° the cross section falls only by a factor of about 2. The smallest cross section measured was 9×10−37 cm2 sr−1 (c.m.), at p0=31.8 BeV/c and −t=20.4 (BeV/c)2; this is about 3×10−12 of the zero-degree cross section at the same energy.

Inclusive ϱ 0 and f(1270) production are analysed in π + p collisions at 8, 16 and 23 GeV/ c . The ϱ 0 cross section increases with energy such that the ϱ 0 /π − ratio remains constant. Emphasis is laid on cross sections as a function of the transverse momentum and of the Feynman x variable. The ϱ 0 's can be attributed to two sources: some ϱ 0 's are centrally produced, but there is a pronounced forward peak. The distribution of leptons coming from ϱ 0 decay is discussed.

The momentum spectra of protons scattered from carbon and deuterium at angles close to 60 mrad and for incident proton momenta between 12 and 27 Gev/c have been measured. The data show good agreement with calculations based on plural quasi-elastic proton-nucleon scattering within the nucleus.

212 interactions of 2.75-Bev protons have been observed in a hydrogen-filled diffusion cloud chamber. The data indicate an elastic cross section of 15 millibarns, with about 9 millibarns cross section for single pion production, 13 millibarns for double, and 4 for triple. There is one example of quadruple pion production. One definite example of the production of heavy unstable particles was observed, and two doubtful cases. The median elastic scattering angle was 19° in the c.m. system. Angle and momentum distributions for inelastic events are consistent with those observed at lower energies.

Data obtained from p-p collisions at centre-of-mass energies between 31 and 63 GeV are presented on correlations between momentum analysed forward π − , K − and p and charged particles observed in an omnidirectional hodoscope. The data show that significant correlations are present over the whole rapidity range for all three types of negative particles. The dependence on various kinematic variables suggests a cluster mechanism for the production of particles. In this picture, pions would be produced in clusters emitted in the fragmentation region while K − and p emanate from non-leading clusters.

Data, obtained from p-p collisions at centre-of-mass energies between 31 and 63 GeV, are presented on inclusive and semi-inclusive correlations between forward emitted neutrons and charged particles observed in an omnidirectional hodoscope. A total absorption spectrometer was used to detect the neutrons and to measure their energy. Significant correlations are observed over the whole rapidity range. The data suggest that neutrons result from the decay of clusters emitted in the fragmentation region.

Data from an exposure of BEBC filled with hydrogen to a wideband neutrino beam are analysed to yield the structure function F v p 2 ( x ) for x > 0.2. Using our results in combination with data from electron-proton and muon-proton scattering, the quark density ratio d/u is determined as a function of x . The dominance u at large x is clearly seen. The results are compared with theoretical predictions.

Inclusive ρ 0 production in neutrino-proton charged-current interactions is studied, using a sample of 7831 events obtained in BEBC filled with hydrogen and exposed to the CERN wideband neutrino beam. An average multiplicity of 0.14±0.02 ρ 0 per event is found, corresponding to a ratio 〈 ρ 0 〉/〈 π − 〉=0.13±0.02. The ρ 0 production characteristics are determined as functions of leptonic variables ( W , Q 2 , χ B ) and hadronic variables ( χ F , z , p t 2 ) and are found to be similar to those determined for hadron- and other lepton-induced reactions.

In a selected sample of 6770 charged current (CC) events of νp interactions with 〈 E ν 〉 = 43 GeV and 〈W〉 = 4.6 GeV , 359 K 0 , 180 Λ and 13 Λ have been observed, which corresponds to a corrected production rate at least one neutral strange particle in (17.4±0.8)% of the CC events. The ratio of the inclusive Λ to K 0 production cross section is found to be 0.26±0.03. The number of CC events containing at least one K 0 increases with increasing E ν and Q 2 , while the CC events containing at least one Λ remain practically constant. The fractions of the total hadronic energy carried by K 0 and Λ are found to be approximately the same in νp as in ep and μp interactions. In the hadronic c.m.s., the K 0 are produced mostly forwards, the Λ mostly backwards, with asymmetry parameters of +0.32±0.02 and −0.45±0.06, respectively. The total strange particle production cross section is estimated to be (25±4)% of the cross section for production of CC events with W >1.5 GeV and that for charm production (10±2)% of the CC cross section well above charm threshold ( W >3 GeV). The production of the resonances K ∗+ (890) and Σ + (1385) has been observed. The production rate of K ∗+ (890) is comparable to that of D ∗+ (2009), above the corresponding thresholds.

The production of K S 0 , Λ and Λ is measured in π + p reactions at 16 GeV/ c . The total strange particle cross section is found to be 4.0 ± 0.3 mb, about 20% of the inelastic cross section. Cross sections for single strange particles and for strange particle pairs are determined, both inclusively and as functions of the charged multiplicity. Relative production rates for different strange particle combinations are compared with the prediction of the isospin statistical model. Inclusive spectra for single particles are studied and it is found the K S 0 are produced mostly in the forward hemisphere, most probably by fragmentation of the incident pion into K K π . The Λ are mostly backwards, probably deriving from fragmentation of the proton into ΛK pairs. The Λ tend to be produced forwards, but evidence is found for central Λ Λ production. Distributions in rapidity of the Λ particles from π + p interactions are compared in terms of the factorisation hypothesis. Results are given on the Λ transversal polarisation.