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.
Inclusive production of∑±(1385) resonances is studied in\(\bar pp\) interactions at 12 GeV/c. The cross sections for∑+(1385)+cc and∑− are determined to be 251±38 μb and 123±30 μb, respectively. The inclusive spectra are presented as a function of Feynman x, c.m. rapidity and the squared transverse momentumpT2. Significant differences with the correspondingpp data are found in the longitudinal momentum distributions. The qualitative features of the production can be explained by simple quark ideas.
Axis error includes +- 0.0/0.0 contribution (?////DUE TO CHOISE OF THE BACKGROUND PARAMETRIZATIONRES-DEF(RES= SIG(1385P13) ,BACK=CORRECTED,DEF=1.26 < M(P PI) < 1.80 GEV,C=PDG 1978)//RES-DEF(RES= ASIG(1385P13) ,BACK=CORRECTED,DEF=1.26 < M(AP PI) < 1.80 GEV,C=PDG 1978)).
We have measured the differential cross-section for the process π-+p → π- + Δ+ in thet interval (1.74/3.5) (GeV/c)2 at 5 GeV/c. At the largestt-values, the cross-sections have the same magnitude as the π-p elastic cross-sections.
No description provided.
In a high statistics ( ∼150 eV μb ) bubble chamber experiment on K − p interactions at 8.25 GeV c , the study of the reaction K − p → KK Λ provides evidence for an enhancement in the KK system with a mass of (1850 ± 10) MeV and a width of (80 −30 +40 ) MeV. Its possible identification with the missing isosinglet of the 3 − nonet is discussed. A K ∗ K decay mode is also observed.
No description provided.
We present results for the hypercharge exchange reaction K − p→f' λ from a high statistics experiment at 8.25 GeV/ c using the CERN 2m HBC. The total and differential cross sections have been measured; the polarisation of the Λ hyperon and the f' density matrix elements have been calculated as functions of momentum transfer. We also present detailed information on the relative strength of the natural and unnatural parity exchange contributions to the production mechanism.
D-WAVE RELATIVISTIC BREIT-WIGNER RESONANCE PLUS POLYNOMIAL BACKGROUND FIT.
FITTED FOR INDIVIDUAL TP BINS.
No description provided.
Evidence is presented for inclusive photoproduction of F ± mesons in three decay modes, ηπ ± , ηπ ± π + π − and ηπ ± π + π + π − π − . The average mass of the F ± is found to be 2.020±0.010 GeV.
No description provided.
Measurements have been made of the polarised target asymmetry parameter T for eta photoproduction from protons at a photon energy of 4 GeV and t -values of −0.4, −0.6 and −0.8 (GeV/ c ) 2 . The results are compared with predictions for this quantity.
No description provided.
Differential cross sections and polarizations are presented for the reactions K − p → Λπ 0 , Λη , Λη ′ at 8.25 GeV/ c incident K − momentum. The data, which come from a high statistics experiment in the CERN 2 m bubble chamber, are compared with previous experimental results on the same reactions and with current theoretical ideas.
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Additional systematic uncertainty 25% not included.
Production of pions, kaons, protons and antiprotons has been studied in e + e − annihilations at 12 and 30 GeV centre of mass energy using time of flight techniques. The fractional yield of charged kaons and baryons appears to rise with outgoing particle momentum. At our highest energy at least 40% of e + e − annihilations into hadrons are estimated to contain baryons.
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