Reactions involving Λ and Σ 0 production are studied in 7.3 GeV/ c K + p interactions. Cross sections and angular distributions are given.
Axis error includes +- 0.0/0.0 contribution (?////Corrected for detection and scanning losses and LAMBDAbar neutral decay modes).
In a study of K + p interactions at 12.7 GeV/ c we have carried out a search for meson resonances having any one of the following properties: (a) a strangeness of S =2, (b) S =1 and isotopic spin of I= 3 2 , or (c) S =1, I= 1 2 and decaying into an antihyperon ( Y ) and a nucleon (N).
No description provided.
The total cross sections for interactions of K+ and 1r+ mesons with protons were measured. The following values were obtained: 21.3 ± 4.6 mb and 21 ± 4.3 mb for 4.75 ± 0.15 Bev/c and 3.7 ± 0.1 Bev/c K+ mesons, respectively; the corresponding values for 1r+ mesons of the same momenta were 33.3 ± 1.3mb and 30 ± 1.2mb. Data on the cross sections for inelastic collisions of K+ and 1r+ mesons with various nuclei have also been obtained.
No description provided.
No description provided.
The center of mass longitudinal momentum distributions of π− mesons produced in K+p interactions at 12.7 GeV/c and in π+p interactions at 7 GeV/c exhibit an asymmetry similar to that observed, for example, in single particle production in 25 GeV/c π−p interactions. This asymmetry is discussed in terms of quark structure of hadrons and other dynamical models.
No description provided.
No description provided.
Mean PL and PT of PI-.
In the course of a systematic study of K+p interactions at 3.0 GeV/c, the elastic-scattering reaction has been investigated. A total of 1720 events were identified as elastic scatters, giving a cross-section of (4.8±0.4) mb. The angular distribution shows characteristic diffraction peaking and was fitted using dσ/d|t|=(dσ/d|t|)0 exp [αt+βt 2], in the momentum-transfer region (0.05÷1.14) (GeV/c)2. The best fit gaveα=(4.55±0.39) (GeV/c)−2 andβ=(0.64±0.42)(GeV/c)−4. The extrapolated experimental cross-section at 0°, (dσ/dt)0, is found to be (19.5±2.3) mb/(GeV/c)2, and exceeds the optical-theorem prediction by (3.8±2.3) mb/(GeV/c)2, implying that there is a contribution from the real part of the K+p scattering amplitude at 3.0 GeV/c.
No description provided.
We report a study of 20 exclusive reactions measured at the AGS at 5.9 GeV/c incident momentum, 90° center of mass. This experiment confirms the strong quark flow dependence of two-body hadron-hadron scattering at large angle. At 9.9 GeV/c an upper limit had been set for the ratio of cross sections for (p¯p→p¯p)(pp→pp) at 90° c.m., with the ratio less than 4%. The present experiment was performed at lower energy to gain sensitivity, but was still within the fixed angle scaling region. A ratio R(p¯ppp)≈140 was measured at 5.9 GeV/c, 90° c.m. in comparison to a ratio near 1.7 for small angle scattering. In addition, many other reactions were measured, often for the first time at 90° c.m. in the scaling region, using beams of π±, K±, p, and p¯ on a hydrogen target. There are similar large differences in cross sections for other reactions: R(K−p→π+Σ−K−p→π−Σ+)≈112, for example. The relative magnitudes of the different cross sections are consistent with the dominance of quark interchange in these 90° reactions, and indicate that pure gluon exchange and quark-antiquark annihilation diagrams are much less important. The angular dependence of several elastic cross sections and the energy dependence at a fixed angle of many of the reactions are also presented.
Cross sections at 90 degrees in the centre-of-mass.
No description provided.
No description provided.
Inclusive production of ϕ,K*0, and\(\overline {K*^0 } \) mesons has been measured in γp, π±p andK± p collisions at beam energies of 65 GeV<Eγ<175 GeV andEπ/K =80 and 140 GeV. Cross sections have been determined over the range 0<xF<1.0 and 0<PT<1.8 GeV/c. Emphasis is put on the comparison of cross sections for different projectiles as a function ofxF so as to study the effects of common quarks between the beam particle and the detected ϕ,K*0 or\(\overline {K*^0 } \). The data are compared with a parton fusion model. Many features of the data are well explained. In detail the strange quark appears to carry a large fraction of the kaon momentum and the contribution of the valence quarks from the proton is small.
Statistical errors only.
Statistical errors only.
Statistical errors only.. An entry 0.00 indicates a statistical error of < 0.005.
Measurements are reported of inclusivef2(1270) andf0(975) production in γp, π±p andK±p collisions at photon beam energies of 65 to 175 GeV and hadron beam energies of 80 and 140 GeV. Thef2 andf0 mesons were found at masses of 1.250 GeV and 0.961 GeV respectively. Inclusivef2 production at lowxF was found to have a similarpT dependence for each beam type, whereas an additional pion-exchange contribution was found for production by pions at highxF. Cross sections are compared with those for ρ0 production and give no indication of a non-q\(\bar q\) component in eitherf-meson state.
No description provided.
No description provided.
No description provided.
Measurements are reported of inclusive production of η-mesons in the beam fragmentation region in γp, πp andKp collisions. Results include a small but significant departure from VMD, and a pronounced rise in theη/π0 ratio with increasingpT.
No description provided.
No description provided.
No description provided.
The inclusive production of ρ0 mesons was measured in γp andh±p collisions at beam energies of 65 GeV≦Eγ≦175 GeV andEh=80, 140 GeV, respectively, whereh is π orK. Cross sections were determined for all beams and energies as functions ofxF (−0.1≦xF≦1.0),pT (0≦pT≦3.5 GeV/c) and the polar decay angle of the ρ0 by fitting the ρ0 signal in π+π- mass distributions. The ρ0 line shape is found to be distorted from a pure Breit-Wigner distribution throughout most of thexF−pT plane for both photon and hadron beams and a simple explanation is suggested. Throughout the paper emphasis is put on the comparison of photon and hadron beam data. The comparison of cross sections of γp andhp data provides a measure of the Vector Meson Dominance factor throughout thexF−pT range of the ρ0. The ρ0 production at lowpT can be described for both photon and hadron beams by a triple regge model at largexF. Similarly central production is well described by the quark-antiquark fusion model. At largepT there is an excess of ρ0 photoproduction which is consistent with the expected onset of pointlike photon interactions.
No description provided.
No description provided.
No description provided.
Forum