The reaction γ p → K + K − p has been investigated with tagged photons in the energy range of 20 < E γ < 70 GeV. A structure in the 1.7 GeV mass region is observed and interpreted in terms of a recurrence of the ø.
No description provided.
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.
No description provided.
No description provided.
No description provided.
Inclusive production of ϱ0,K*±(892), andf is studied in\(\bar p\)p interactions at 12 GeV/c. The inclusive cross sections for ϱ0,K*±(892), andf are found to be 6.7±0.3 mb, 1.0±0.2 mb, and 1.4±0.3 mb, respectively. The differential cross sections are presented as a function of c.m. rapidity, Feynmanx and square of the transverse momentumpT2. Comparison with the correspondingpp data shows some interesting differences which can be attributed to the\(\bar p\)p annihilation. The results are compared with the predictions of the quark fusion model.
No description provided.
No description provided.
No description provided.
The p p elastic differential cross section at 50 GeV/c has been measured in a two-arm spectrometer experiment at the CERN SPS. The | t | range covered extends from 0.7 to 5 (GeV/c. A pronounced dip-bump structure is observed with a sharp minimum at | t | = 1.5 (GeV/ c ) 2 .
No description provided.
Charged-current neutrino interactions have been analysed in a sample of pictures from BEBC equipped with a TST. Using a method independent of both the neutrino flux and nuclear interaction corrections, the ratio R = σ n / σ p has been measured. The result is R =1.98±0.19 for the ratio of total cross sections. Bjorken x distributions for proton and neutron targets and for u and d quarks are compared.
No description provided.
No description provided.
No description provided.
Data on hadron production by e + e − annihilation at c.m. energies between 12 and 36.6 GeV have been collected using the JADE detector. They have been analysed in terms of single-photon and weak neutral-current exchange assuming production of quark-antiquark pairs with only d, u, s, c and b quarks to produce values for the quark weak neutral-current couplings. A further analysis in terms of the Glashow-Salam-Weinberg theory produced the result, sin 2 θ W = 0.22 ± 0.08 . The theory has therefore been tested in a new energy domain and within the context of the neutral weak couplings of the first, second and third generation quarks.
No description provided.
WIDTH(Z) = 2.5 GEV WAS ASSUMED. CONST(N=SIN2TW) WAS DETERMINED FROM RATIO(HADRONS/MU). FIRST ORDER QCD.
Measurements of the reaction γ p → p π + π − π + π − are presented, in which π + π − π + π − systems with masses up to 3 GeV are produced from fragmentation of the incident photon. The reaction is dominated by production of the large peak of the ϱ′(1600) meson and, at higher masses ≳2 GeV, y production of jet-like 4 π systems. The ϱ′(1600) meson is produced by a predominantly s -channel helicity conserving mechanism. At higher masses there are also indications of ϱπ peaks, of masses 1.3 GeV (the A 2 meson) and 1.75 GeV, produced with a recoiling π meson by a mechanism consistent with the Deck effect.
CORRECTED FOR TAILS OF BREIT-WIGNER RESONANCE USED IN FIT AND ALLOWING FOR 10 PCT BACKGROUND.
The final states of charged hadrons produced in 280 GeV μp scattering are analysed with respect to their planarity and jet structure. Distributions of p ⊥ 2 in and p ⊥ out 2 are presented. A two jet structure in the forward hemisphere is observed for events with high p ⊥ tracks are predicted by QCD models.
PTIN**2 is the sum of the PTIN components squared.
PTOUT**2 is the sum of the PTOUT components squared.
The inclusiveKn, ¶,and\(\bar \Lambda\) production has been studied in a\(\bar pp\) experiment performed in the Mirabelle bubble chamber at an incident beam momentum of 32.1 GeV/c. Total, topological and differential cross sections are presented and compared with those obtained at other energies. The invariant structure functions have been parametrised in the fragmentation region by a power law and are consistent with the expectations based on quark counting rules.
No description provided.
No description provided.
No description provided.
Inclusive production of ϱ0,f, andg0 mesons and ofKs0,K*0 (892), ϕ andK*0(1430)mesons has been measured at <y>∼2.6 and <pT>∼1.1 GeV/c in proton-proton interactions at\(\sqrt s= 52.5\) GeV. The negative particle from the two-body decays of these resonances were identified by a threshold Cerenkov counter and used for triggering. Starting from the measured differential cross section, total inclusive cross sections for the vector and tensor mesons were determined using various parametrizations for they andpT dependence of the differential cross section. The experimental results are discussed in the framework of production models based on the parton picture. The strangeness suppresion factor λ=(0.30±0.10) due toSU(3) symmetry breaking of the quark sea is derived.
No description provided.
Forum