Exclusive measurements of pi+- p --> pi+ pi+- n near threshold.

The CHAOS collaboration Kermani, M. ; Amaudruz, P.A. ; Bonutti, F. ; et al.
Phys.Rev.C 58 (1998) 3419-3430, 1998.
Inspire Record 483005 DOI 10.17182/hepdata.25726

The pion induced pion production reactions π±p→π+π±n were studied at projectile incident energies of 223, 243, 264, 284, and 305 MeV, using a cryogenic liquid hydrogen target. The Canadian High Acceptance Orbit Spectrometer was used to detect the two outgoing pions in coincidence. The experimental results are presented in the form of single differential cross sections. Total cross sections obtained by integrating the differential quantities are also reported. In addition, the invariant mass distributions from the (π+π−) channel were fitted to determine the parameters for an extended model based on that of Oset and Vicente-Vacas. We find the model parameters obtained from fitting the (π+π−) data do not describe the invariant mass distributions in the (π+π+) channel.

2 data tables

Total cross sections were obtained by integrating the differential cross section over all three variables: M(pi,pi)**2, t, Cos(Theta(pi)).

Total cross sections were obtained by integrating the differential cross section over all three variables: M(pi,pi)**2, t, Cos(Theta(pi)).


Spin-Parity Analysis of the Diffractively Produced Low Mass n pi System in the Reaction pi+- p --> pi+- (n pi)+ at 16-GeV/c

The Aachen-Berlin-Bonn-CERN collaboration Otter, G. ; Rudolph, G. ; Wieczorek, H. ; et al.
Nucl.Phys.B 130 (1977) 349, 1977.
Inspire Record 119192 DOI 10.17182/hepdata.35244

The dominant partial waves of the diffractively produced N π system at low Nπ masses (⩽ 1.4 GeV) are determined in the reactions π ± p → π (N π ) at 16 GeV/ c . A satisfactory description of our data can only be obtained by strong contributions of both a 1 2 − S-wave and a 3 2 + P-wave, violating the Gribov-Morrison rule. Spin and parity of the diffractively produced states are found from the interference between diffraction and Δ (1236) production. The interference term is obtained by an isospin analysis.

2 data tables

No description provided.

<NUCLEON PION> MASS DEPENDENCE.


Study of s-Channel and t-Channel Helicity Conservation in the Diffractive Part of the Reaction pi+- p --> pi (n pi) at 16-GeV/c

The Aachen-Berlin-Bonn-CERN-Heidelberg collaboration Grässler, H. ; Kirk, H. ; Otter, G. ; et al.
Nucl.Phys.B 95 (1975) 1-11, 1975.
Inspire Record 99495 DOI 10.17182/hepdata.31974

By means of an isospin analysis of the reaction π ± p→ π (N π ) at 16 GeV/ c we have determined the decay angular distributions of the N π system with I= 1 2 produced by isospin zero exchange. Helicity conservation is not observed in the t -channel for the N π mass region below 1.6 GeV, where diffraction dissociation of the proton is supposed to dominate. There are indications for approximate t -channel helicity conservation for N ∗ (1690) production. In the helicity frame, the experimental data are not in agreement with s -channel helicity conservation over the whole N π mass range investigated. Thus the diffractive process N→N π differs both from the process N→N ππ (or π → πππ and K→K ππ ) which approximately conserves t -channel helicity and from the elastic scattering N→N which conserves helicity in the s -channel.

2 data tables

No description provided.

FIT TO ISOSPIN HALF NUCLEON RESONANCE PRODUCTION WITH ISOSPIN ZERO EXCHANGE.