Differential cross-section measurements for π − p → γ n, consisting of three angular distributions at 618, 676 and 718 MeV/ c , and the energy dependence at θ γ = 90° for seven incident pion momenta between 502 and 888 MeV/ c , are presented. Our data qualitatively support recent multipole analyses. Agreement with the Scheffler et al. results for the inverse reaction, γ n → π − p, using a ( π − -recoil p) coincidence technique is good excluding a large violation of time reversal invariance. The agreement with γ n → π − p data obtained using the R ( π − / π + ) ratio technique or a deuterium bubble chamber is only qualitative.
Axis error includes +- 6.6/6.6 contribution.
Axis error includes +- 6.2/6.2 contribution.
Axis error includes +- 6.0/6.0 contribution.
The spin rotation parameter R has been measured for elastic π − p scattering at 40 GeV/ c , at four momentum transfers t ranging from −0.19 to −0.52 (GeV/ c ) 2 . The average value within this interval is R π − p = -0.200± 0.023. The resulting constraints on the πN scattering amplitudes are discussed. The experiments also yields an average value for K − p scattering, R K − p scattering, R K − p = -0.16±0.16.
.
.
We report final results on the polarization parameter P in elastic scattering of π − , K − and antiprotons at 40 GeV/ c incident momentum. The energy dependence of P (t) in π − p above 10 GeV/ c is well fitted by P (t) α s αR(t)-α P (t) where α R (t) are the effective Regge and Pomeron trajectories respectively. The data in K − p are compatible with exchange degeneracy. The results inp¯p show an important structure for |t|> 0.3 (GeV/c) 2 demonstrating the existence of a large helicity flip amplitude.
.
.
.
Results are presented for the quasi two-body hypercharge exchange reactions of the type using data from a high statistics bubble chamber experiment. Total and differential cross sections and the momentum transfer dependence of the meson and hyperon resonance single density matrix elements are discussed. Amplitude analyses are performed for the first two reactions. The results are compared with quark model and duality predictions and with those from other related reactions.
No description provided.
No description provided.
No description provided.
Differential cross sections for π−p→π0n at five angles for 239, 264, 295, 323, and 375 MeV/c incident pions are presented. The measurements employ the neutron-photon coincidence method, using carefully calibrated neutron counters and an efficient, large-area photon detector. Good agreement is found with the results of the CERN phase-shift analysis.
Axis error includes +- 6.3/6.3 contribution.
Axis error includes +- 5.5/5.5 contribution.
Axis error includes +- 5.2/5.2 contribution.
Differential cross-section measurements are presented for π−p→γn at five energies around the p33(1232) resonance. A detailed comparison is made with γn→π−p deduced from γd experiments. In general, the results are in support of detailed balance. Using the Christ-Lee-Donnachie-Shaw model, our new data indicate that the T-violating phase in the isovector part of the M1+ multipole is less than 2°, which is a very sensitive test of time-reversal invariance. No evidence is found for a possible isotensor component of the electromagnetic current. Our data are compared to various multipole analyses. In general, the agreement is poor.
Axis error includes +- 6.3/6.3 contribution.
No description provided.
No description provided.
Differential cross sections for the reactions γp→π0p, π+n and γn→π−p, π0n were measured in a single experiment using tagged photons in the energy region 240-450 MeV incident on H21 and H22 targets. Results of the measurements of the ratios π0nπ0p and π−pπ+n are presented. The ratio of isotensor to isovector amplitude is found to be 0.00±0.02.
No description provided.
No description provided.
No description provided.
This paper presents the results of a counter experiment at the Rutherford Laboratory, in which the polarization parameter in π + p elastic scattering was measured. Data were taken at 64 incident pion momenta between 0.60 and 2.65 GeV/ c . The results are found to be in generally good agreement with those of other experiments, and have substantially higher precision at many momenta.
No description provided.
No description provided.
No description provided.
We present evidence for the decay A20→ωπ+π0 with a branching ratio Γ(A2→ωππ)Γ(A2→ρπ)=0.28±0.09 and for the decay ω(1675)→ωπ+π− with a branching ratio Γ(ω(1975)→ωπ+π−)Γ(ω(1675)→ρπ)=0.47±0.18. Evidence is given for an intermediate B(1235)π state in the ω(1675) decay.
FITTED WITH BREIT-WIGNER RESONANCES PLUS BACKGROUND.
BACKGROUND SUBTRACTED TP DISTRIBUTIONS.
The total hadronic photoabsorption cross sections of a number of nuclei (C, Al, Cu, Nb, Sn, Ta, Pb) have been studied in detail using a tagged photon beam over the energy range 1.7-4 GeV. The results are described, and compared with models of photoabsorption.
STATISTICAL ERRORS. MEAN CROSS SECTIONS FOR EACH OF THE TWO ELECTRON BEAM ENERGIES OF 3.5 AND 4.6 GEV ARE ALSO GIVEN.
A-EFFECTIVE/A, USING SIG(GAMMA P) = 137 MUB AND SIG(GAMMA N) = 126 MUB. STATISTICAL ERRORS.
A-EFFECTIVE/A, USING SIG(GAMMA P) = 129 MUB AND SIG(GAMMA N) = 123 MUB. STATISTICAL ERRORS.
Forum