An experiment has been performed to study the inclusive photoproduction of π 0 mesons. Photoproduced π 0 's were detected in a hodoscope consisting of 14 lead glass Cerenkov counters. To obtain the cross sections at a photon energy of 6 GeV we used the photon-difference method. Data are presented in terms of the Feynman variable x = q ‖ ∗ (√s/2) and the trnasverse momentum q⊥. We have measured four q ⊥ distributions at x = 0.2, 0.4, 0.6 and 0.8. The results dhow that the π 0 rate at small values of q ⊥ is smaller than the π± rate. The data can be fitted smoothly by a form A exp (− Bq ⊥ 2 ) with a value about 3.5 GeV −2 for the slope parameter B .
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We present an analysis, in the framework of the triple Regge model, of our recent experimental results on the reaction p+p→p+X between 50 and 400 GeV.
The cross sections is fitted in the framework of the triple Regge model. The symbols P and R in the (C=...) denote pomeron and reggeon, respectively. For fit I and II the authors used conventional trajectories alpha(P) = 1 +0.25*T, alpha(R) = 0.5 + T. Fit II is restricted to data with (1 - M(P=4)**2/S) > 0.84. In fit III they use alpha(R) = 0.2 + T for the RRP term. Fit IV is like fit I with additional fixed (pion pion P) term.
The cross sections is fitted in the farmework of the triple Regge model. The symbols P and R in teh (C=...) denote pomeron and reggeon, respectively. CONST(C=C) and SLOPE are from the replacement of the RRP term by the exponential one : CONST(C=C)*(SLOPE*(1-x)). See text for detail.
The v and v nucleon total cross-sections have been determined as a function of energy using a sample of 2500 v and 950 v event. The results are compared with predictions of scaling and charge symmetry hypotheses.
Measured charged current total cross section.
Measured charged current total cross section.
Invariant single-particle cross sections for pion and proton production in π ± p interactions at 8 and 16 GeV/ c are presented in terms of integrated distributions as functions of x , reduced rapidity ζ and p ⊥ 2 , and also in terms of double differential cross sections E d 2 σ /(d x d p ⊥ 2 ) and d ζ d p ⊥ 2 ). A comparison of π ± and π − induced reactions is made and the energy dependence is discussed. It is shown that the single-particle structure function cannot be factorized in its dependece on transverse and longitudinal momentum. For the beam-unlike pion, there is an indication for factorizability in terms of rapidity and transverse momentum in a small central region.
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We have studied high-energy proton scattering on Be, C, Cu and Pb targets using a single-arm spectrometer. The projectile momenta were 19 and 24 GeV/ c , the square of the four-momentum transfer varied from t = 0.1 to t = 4.4 GeV 2 . We have recorded momentum distributions of scattered protons in the high-momentum range. An application of multiple-scattering theory yielded agreement of calculation and experimental results to within a ± 30% uncertainty of the former.
X ERROR D(OMEGA) = 0.0076 MSR.
X ERROR D(OMEGA) = 0.0076 MSR.
X ERROR D(OMEGA) = 0.0076 MSR.
Data on the inclusive production spectra of K S 0 and Λ from proton-proton collisions at 19 GeV are presented and discussed in connection with the earlier studied inclusive π − production spectrum. The three single-particle spectra are compared with a crude two-center thermal model for the average radiation from the pp collisions.
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We present measurements of the invariant cross section for the inclusive reaction p+p→p+X in the region 0.14<|t|<0.38 GeV2, 100
The cross sections are fitted by the formula CONST(C=A)*EXP(SLOPE*T)*(1+CO NST(C=B)/SQRT(S)).
Reactions p p → p p and p p → n n were studied at the kinetic energy 230 MeV of incident p by using bubble chamber films. Total cross sections for both of the reactions were found to be 51.2 ± 1.6 mb and 9.1 ± 0.6 mb, respectively. Differential cross sections are well explained by the phenomenological theory given by Bryan and Phillips.
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Photoproduction is studied at 2.8 and 4.7 GeV using a linearly polarized monoenergetic photon beam in a hydrogen bubble chamber. We discuss the experimental procedure, the determination of channel cross sections, and the analysis of the channel γp→pπ+π−. A model-independent analysis of the ρ0-decay angular distribution allows us to measure nine independent density-matrix elements. From these we find that the reaction γp→pρ0 proceeds almost completely through natural parity exchange for squared momentum transfers |t|<1 GeV2 and that the ρ production mechanism is consistent with s-channel c.m. helicity conservation for |t|<0.4 GeV2. A cross section for the production of π+π− pairs in the s-channel c.m. helicity-conserving p-wave state is determined. The ρ mass shape is studied as a function of momentum transfer and is found to be inconsistent with a t-independent Ross-Stodolsky factor. Using a t-dependent parametrization of the ρ0 mass shape we derive a phenomenological ρ0 cross section. We compare our phenomenological ρ0 cross section with other experiments and find good agreement for 0.05<|t|<1 GeV2. We discuss the discrepancies in the various determinations of the forward differential cross section. We study models for ρ0 photoproduction and find that the Söding model best describes the data. Using the Söding model we determine a ρ0 cross section. We determine cross sections and nine density-matrix elements for γp→Δ++π−. The parity asymmetry for Δ++ production is incompatible with simple one-pion exchange. We compare Δ++ production with models.
FROM QUOTED TOPOLOGICAL CROSS SECTIONS. 1.44 GEV CROSS SECTION PUBLISHED PREVIOUSLY.
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NO TMIN CORRECTION HAS BEEN MADE.
Small angle elastic scattering events have been observed at the CERN Intersecting Storage Rings. Directions of both particles as well as the collision vertex are reconstructed with the help of four sets of spark chambers, two for each of the two arms. The elastic nature of the events is demonstrated by a collinearity requirement. We find values for the (diffraction) slope parameter in disagreement with the simple linear extrapolation of lower energy (Surpukov) data.
NUMBER OF EVENTS 87364.
NUMBER OF EVENTS 8305.
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