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.
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The first observation of (anti)deuterons in deep inelastic scattering at HERA has been made with the ZEUS detector at a centre-of-mass energy of 300--318 GeV using an integrated luminosity of 120 pb-1. The measurement was performed in the central rapidity region for transverse momentum per unit of mass in the range 0.3<p_T/M<0.7. The particle rates have been extracted and interpreted in terms of the coalescence model. The (anti)deuteron production yield is smaller than the (anti)proton yield by approximately three orders of magnitude, consistent with the world measurements.
Measured invariant cross section for P production.
Measured invariant cross section for DEUT production.
Measured invariant cross section for PBAR production.
K+ meson production in pA (A = C, Cu, Au) collisions has been studied using the ANKE spectrometer at an internal target position of the COSY-Juelich accelerator. The complete momentum spectrum of kaons emitted at forward angles, theta < 12 degrees, has been measured for a beam energy of T(p)=1.0 GeV, far below the free NN threshold of 1.58 GeV. The spectrum does not follow a thermal distribution at low kaon momenta and the larger momenta reflect a high degree of collectivity in the target nucleus.
Double differential K+ production cross section for forward K+ angles < 12 degs. Statistical errors only.
The invariant cross section for K+ production. Statistical errors only.
Ratio of K+ production cross sections for CU/C and AU/C.
New data for the reaction e + e − →ϒ(9.46) have been obtained using the DASP detector at the DORIS storage ring. The electronic width Γ ee is (1.5±0.4) keV. The branching ratio for the decay into muon pairs is (2.5 ± 2.1)%. Energy spectra for inclusive production of hadrons are given.
VISIBLE HADRONIC TOTAL CROSS SECTION.
INVARIANT INCLUSIVE PRODUCTION CROSS SECTION E*D3(SIG)/DP**3 BOTH ON AND OFF THE UPSILON(9.46) RESONANCE. NO SIGNIFICANT DIFFERENCE IN EXPONENTIAL SLOPE AS A FUNCTION OF PARTICLE ENERGY E(P=3).
We have measured large-transverse-momentum (p⊥) inclusive π0 production at c.m. angles centered near 90° for π±p and pp interactions at 100 and 200 GeV/c. This is the first such measurement using a pion beam. The ratio σ(pp→π0X)σ(πp→π0X) decreases with increasing p⊥ and is independent of energy when expressed as a function of x⊥=p⊥pmax. We compare the data with predictions of various models.
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We report the 24-GeV/c inclusive π− yield near θc.m.=90° for 0.5<~PT≲2.2 GeV/c. No high-PT excess is seen at this energy. In addition we have obtained the inclusive γ-ray yield from a measurement of low-mass e+e− pairs. This yield is compared with that expected from π0-, η-, and ω-meson decay, to provide limits on possible direct photon production.
No description provided.
The inclusive cross section for larger p T π 0 production near 90° in p-p collisions at the CERN ISR is presented for centre-of-mass energies 30.7, 53.1 and 62.4 GeV. The data are inconsistent with scaling of the form p T − n F ( x T ), with constant n or with n allowed to depend on x T = 2p T / s . For s = 53.1 and 62.4 GeV , the value of n found for 3.5 < p T < 7.0 GeV/ c is n = 8.0 ± 0.5, in agreement with previous experiments. However, for 7.5 < p T < 14.0 GeV/ c the value becomes n = 5.1 ± 0.4.
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We report on measurements of inclusive π 0 production at c.m. energies of 53 and 63 GeV, θ ≅90°, from p-p collisions at the CERN ISR. In the range 0.2< x t <0.45 the data can be described by a form: Ed 3 σ d p 3 ∝p − (6.6±0.8) t (1−x t ) (9.6±1.0) .
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We report final results of a series of measurements of continuum dimuon production in proton-nucleus collisions at Fermilab. New results with 6 times more statistics are included. A full description of the apparatus and methods used in the analysis of this series of measurements is given. The sea quark distribution of the nucleon is determined within the context of Drell-Yan and quantum-chromodynamic description of dilepton production in hadron collisions.
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We report measurements of the inclusive π− and π+ yields in 24-GeV proton-proton collisions at θc.m.=90° for 2.2≤PT≤2.8 GeV/c. There is a high-PT deficit, rather than excess, at this incident energy.
THIS DATA IS FROM AN 'UNBIASED TRIGGER' WHICH RESPONDS TO ANY CHARGED PARTICLE.
THIS DATA IS FROM AN 'ELECTRON TRIGGER' WHICH RESPONDS ONLY TO PARTICLES THAT ARE ABOVE THRESHOLD IN > OR = 2 OF THE 3 CERENKOV COUNTERS IN THE LEAD- GLASS DETECTORS.
THIS DATA IS FROM AN 'ELECTRON TRIGGER' WHICH RESPONDS ONLY TO PARTICLES THAT ARE ABOVE THRESHOLD IN > OR = 2 OF THE 3 CERENKOV COUNTERS IN THE LEAD- GLASS DETECTORS.
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