Measurement of partial-wave contributions in p p --> p p pi0.

Meyer, H.O. ; Balewski, J.T. ; Doskow, J. ; et al.
Phys.Rev.Lett. 83 (1999) 5439-5442, 1999.
Inspire Record 504512 DOI 10.17182/hepdata.31354

We report a measurement of the spin-dependent total cross section ratios delta_sigma_T/sigma_tot and delta_sigma_L/sigma_tot of the pp --> pp pi^0 reaction between 325 MeV and 400 MeV. The experiment was carried out with a polarized internal target in a storage ring. Non-vertical beam polarization was obtained by the use of solenoidal spin rotators. Near threshold, the knowledge of both spin-dependent total cross sections is sufficient to deduce the strength of certain participating partial waves, free of any model.

2 data tables

SIG(C=T1-1) and SIG(C=T11) means opposite and parallel transverse beam and target polarizations. The same is for longitudunal (L) polarizations. SIG(C=TOT)is unpolarized total cross section.

SIG(C=L1-1) and SIG(L=11) means opposite and parallel longitudinal beam andtarget polarizations. SIG(C=TOT) is unpolarized total cross section.


Dependence of p(pol.) p(pol.) --> p p pi0 near threshold on the spin of the colliding nucleons.

Meyer, H.O. ; Balewski, J.T. ; Dzemidzic, M. ; et al.
Phys.Rev.Lett. 81 (1998) 3096-3099, 1998.
Inspire Record 472992 DOI 10.17182/hepdata.39971

A polarized internal atomic hydrogen target and a stored, polarized beam are used to measure the spin-dependent total cross section Delta_sigma_T/sigma_tot, as well as the polar integrals of the spin correlation coefficient combination A_xx-A_yy, and the analyzing power A_y for pp-> pp pi0 at four bombarding energies between 325 and 400 MeV. This experiment is made possible by the use of a cooled beam in a storage ring. The polarization observables are used to study the contribution from individual partial waves.

1 data table

SIG(C=DEL_T) defined as the cross section with the spins of the colliding protons antiparallel, minus the cross section with spins parallel, using transversely polarized beam and target.


Total cross-section for p + p ---> p + p + pi0 near threshold measured with the Indiana cooler

Meyer, H.O. ; Ross, M.A. ; Pollock, R.E. ; et al.
Phys.Rev.Lett. 65 (1990) 2846-2849, 1990.
Inspire Record 305682 DOI 10.17182/hepdata.19936

The total cross section for the reaction pp→ppπ0 was measured at nine center-of-mass energies from 1.5 to 23 MeV above threshold. The experiment was carried out with the Indiana Cooler, a recently constructed storage ring. The experimental advantages of an electron-cooled proton beam were utilized. The data cover an energy range where only the lowest possible angular momentum state contributes in the exit channel. The measured energy dependence of the total cross section is not compatible with that predicted by models of s-wave pion production and rescattering.

1 data table

No description provided.