A. Putzer

Measurement of the

Abstract The production of very large transverse momentum ( p T ) hadron jets has been measured in the UA2 experiment at the CERN p p Collider for s =630 GeV . The inclusive jet production cross sections exhibit a p T -dependent increase with respect to the s =546 GeV data from previous Collider runs. This increase can be described both by QCD calculations and by approximate x T =2 p T /√ s scaling. No significant deviation of the data from QCD predictions is observed at very large p T , placing a lower limit on the characteristic scale Λ c of a hypothetical superstrong contact interaction responsible for the binding of preons in the quark ( Λ c >370 GeV at 95% CL).

\sqrt s

We have measured the differential cross section for pp and pp elastic scattering at √s = 31, 53 and 62 GeV in the interval 0.05 < |t| < 0.85 GeV2 at the CERN ISR using the Split Field Magnet detector. At 53 and 62 GeV, for 0.17 < |t| < 0.85 GeV2 both pp and pp data show simple exponential behaviour in t; at √s = 31 GeV the data for 0.05 < |t| < 0.85 GeV2 are consistent with a change in slope near |t| = 0.15 GeV2.

dependence of jet production at the Cern

Abstract The production of very large transverse momentum ( p T ) hadron jets has been measured in the UA2 experiment at the CERN p p Collider for s =630 GeV . The inclusive jet production cross sections exhibit a p T -dependent increase with respect to the s =546 GeV data from previous Collider runs. This increase can be described both by QCD calculations and by approximate x T =2 p T /√ s scaling. No significant deviation of the data from QCD predictions is observed at very large p T , placing a lower limit on the characteristic scale Λ c of a hypothetical superstrong contact interaction responsible for the binding of preons in the quark ( Λ c >370 GeV at 95% CL).

\bar pp

Abstract Evidence for the forward production of D + mesons has been found in pp collisions at a c.m. energy of 52.5 GeV. A signal of 92 ± 18 events above background has been observed in the decay channel D + → K ∗ o π + → K − π + π + . The cross section in the phase space region of our experiment is given and implications for the total cross section for charmed D meson production are discussed.

collider

Abstract Inelastic events with an observed charged multiplicity n obs ⩾ 7 have been studied at the CERN ISR using the split field magnet detector. Correlations of particle densities, charges and transverse momenta have been determined and a phenomenological analysis in the framework of cluster models has been performed. A good description of all results is obtained if one allows for charged clusters, produced in a mechanism with limited charge exchange. The mean transverse momentum of clusters is 0.65 ± 0.10 GeV/ c . Short-range correlations of particles of like charge due to the Bose-Einstein effect can be described as a second-order interferrence phenomenon with a radius R = 1.34 ± 0.31 fm and a lifetime of cτ = 1.38 ± 0.60 fm for the pion source.

A measurement of p̄p and pp elastic scattering at ISR energies

Abstract The inclusive cross sections for the production of high transverse momentum π + and π − mesons in proton-proton interactions have been measured at the highest ISR energy √ s = 63 GeV and at a c.m. production angle of 50°. The cross sections for π + and π − mesons are compared as a function of transverse momentum. It is shown that the inclusive cross section of π − mesons decreases faster than the π + cross section. particle σ ( π ± )/ σ (charged particles) are presented as a function of transverse momentum.

Measurement of the s**(1/2) Dependence of Jet Production at the CERN anti-p p Collider

AbstractInclusive production of ϱ0,f, andg0 mesons and ofKs0,K*0 (892), ϕ andK*0(1430)mesons has been measured at ∼2.6 and ∼1.1 GeV/c in proton-proton interactions at

Density, charge and transverse momentum correlations of particles in non-diffractive proton-proton collissions at √s = 52.5 GeV

\sqrt s = 52.5