Proton-antiproton and proton-proton elastic scattering have been measured in the four-momentum transfer range 0.001⩽| t |⩽0.06 GeV 2 for center-of-mass energy 52.8 GeV at the CERN Intersecting Storage Rings (ISR). Using the known pp total cross section, a simultaneous fit to the pp̄ and pp differential cross sections yields the pp̄ total cross section; in addition, we obtain the ratio of the real-to-imaginary part of the forward nuclear-scattering amplitude and the nuclear-slope parameter for both pp̄ and pp. Our results show conclusively that the pp̄ total cross section is rising at ISR energies and lend support to conventional theories in which the difference between the pp̄ and pp total cross section vanishes at very high energy.
No description provided.
RESULTS OF FIT.
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We have observed exclusive production of K + K − and K S O K S O pairs and the excitation of the f′(1515) tensor meson in photon-photon collisions. Assuming the f′ to be production in a helicity 2 state, we determine Λ( f ′ → γγ) B( f ′ → K K ) = 0.11 ± 0.02 ± 0.04 keV . The non-strange quark of the f′ is found to be less than 3% (95% CL). For the θ(1640) we derive an upper limit for the product Λ(θ rarr; γγ K K ) < 0.03 keV (95% CL ) .
Data read from graph.. Errors are the square roots of the number of events.
Data read from graph.. Errors are the square roots of the number of events.
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No description provided.
Inclusive charged-current interactions of high-energy neutrinos and antineutrinos have been studied with high statistics in a counter experiment at the CERN Super Proton Synchrotron. The energy dependence of the total cross-sections, the longitudinal structure function, and the nucleon structure functionsF2,xF3, and\(\bar q^{\bar v} \) are determined from these data. The analysis of theQ2-dependence of the structure functions is used to test quantum chromodynamics, to determine the scale parameter Λ and the gluon distribution in the nucleon.
ABSOLUTE FLUXES HAVE NOT BEEN MEASURED. NORMALISED TO OLD RESULTS.
STUCTURE FUNCTIONS ARE EVALUATED ASSUMING R=SIG(L)/SIG(T)=0.1 AND M(W) IS INFINITE. NO CORRECTION FOR FERMI MOTION APPLIED. ERRORS ARE STATISTICAL AND SYSTEMATIC POINT-TO-POINT ERRORS. IN ADDITION OVER-ALL SCALE ERROR OF 6 PCT. FOR F2 , 8 PCT. FOR XF3.
STUCTURE FUNCTIONS ARE EVALUATED ASSUMING R=SIG(L)/SIG(T)=0.1 AND M(W) IS INFINITE. NO CORRECTION FOR FERMI MOTION APPLIED. ERRORS ARE STATISTICAL AND SYSTEMATIC POINT-TO-POINT ERRORS. IN ADDITION OVER-ALL SCALE ERROR OF 6 PCT. FOR F2 , 8 PCT. FOR XF3.
Inclusive neutrino and antineutrino charged current interactions were studied in the CHARM detector exposed to neutrino and antineutrino Wide Band Beams of the CERN 400 GeV SPS. The x and Q 2 dependence of the structure functions F 2 and xF 3 and of the antiquark momentum distribution q were determined. The data have been interpreted in terms of QCD theory using the Furmanski-Petronzio method. In this way we have determined Λ LO = [190 −40 +70 ( stat ) ± 70 ( syst .)] MeV and the structure functions of quarks and gluons without specific assumptions on their analytic dependence. The results agree with previous experiments which relied on model assumptions in the analysis. We conclude that the model independent simultaneous analysis of the xF 3 , F 2 , q structure functions gives a more reliable determination of the gluon distribution in the nucleon.
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HERE THE QBAR IS D2(SIG(ANU))/DX/DY - (1-Y)**2*D2(SIG(NU))/DX/DY.
Measurements of the K - p and K + p elastic differential cross sections at 20 and 50 GeV/ c , respectively, have been made in the momentum transfer range 0.7 < ∥ t ∥ < 8.0 GeV/ c .
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Two photon final states in e + e − annihilation have been analyzed at CM energies around 34 GeV. Good agreement with QED is observed. Lower limits for the QED cutoff parameters of Λ + > 59 GeV and Λ - > 44 GeV are determined. A search for two photons with missing energy yields an upper limit for the production of neutral particles which decay into a photon and a non-interacting particle. Constraints on the mass and the coupling strength of supersymmetric photinos are discussed.
Cross section for ABS(cos(theta)) <0.85.
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We have measured the production of one and two large transverse momentum hadrons in p p and pp interactions in the range 2 < p T < 6 GeV/ c for the central rapidity region |y| < 0.9 at s = 63 and 31 GeV . No statistically significant difference between p p and pp collisions is observed. The results are in accordance with lowest order QCS perturbative calculations and rule out a large contribution of Constituent Interchange Model (CIM), di-quark of quark-fusion subprocesses in this kinematic range.
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Results on charged particle production in pp̄ collision at s 1 2 = 540 GeV are presented. The data were obtained at the CERN pp̄ collider using the UA1 detector, operated without magnetic field. The central particle density is 3.3 + - 0.2 per unit o pseudo-rapidity for non-diffractive events. KNO scaling of the multiplicity distributions withresults from ISR energies is observed.
Pseudorapidity density distribution for all charged multiplicities corrected for acceptance and backgrounds by excluding NSD events. Data have been read from the plot.
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Inclusive ϕ-meson production has been measured for 100 GeV/cK−,\(\bar p\) andp incident on a Be target. Differential cross sectionsdσ/dxF anddσ/dp⊥2 are presented in the interval 0.075<xF<0.225 and 0<p⊥<1 GeV/c respectively. The shape of thedσ/dxF distributions agrees with predictions from a quark fusion model. Comparison with cross sections measured on a hydrogen target in the samexF andp⊥ range suggest a linearA-dependence fromA=1 toA=9.
No description provided.
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