pi+ p differential cross sections at low energies
Abstract
Differential cross sections for pi p and pi+ p elastic scattering were measured at five energies between 19.9 and 43.3 MeV. The use of the CHAOS magnetic spectrometer at TRIUMF, supplemented by a range telescope for muon background suppression, provided simultaneous coverage of a large part of the full angular range, thus allowing very precise relative cross section measurements. The absolute normalization was determined with a typical accuracy of 5 %. This was verified in a simultaneous measurement of muon proton elastic scattering. The measured cross sections show some deviations from phase shift analysis predictions, in particular at large angles and low energies. From the new data we determine the real part of the isospin forward scattering amplitude.
 Authors:
 more »
 Publication Date:
 Research Org.:
 Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA
 Sponsoring Org.:
 USDOE  Office of Energy Research (ER)
 OSTI Identifier:
 862053
 Report Number(s):
 JLABPHY05455; DOE/ER/401503665; nuclex/0512006; 6447759
TRN: US0600108
 DOE Contract Number:
 AC0584ER40150
 Resource Type:
 Journal Article
 Country of Publication:
 United States
 Language:
 English
 Subject:
 72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS; ACCURACY; CROSS SECTIONS; DIFFERENTIAL CROSS SECTIONS; ELASTIC SCATTERING; ISOSPIN; MAGNETIC SPECTROMETERS; MUONS; PHASE SHIFT; PROTONS; SCATTERING AMPLITUDES; TELESCOPES
Citation Formats
H. Denz, P. Amaudruz, J.T. Brack, J. Breitschopf, P. Camerini, J.L. Clark, H. Clement, L. Felawka, E. Fragiacomo, E.F. Gibson, N. Grion, G.J. Hofman, B. Jamieson, E.L. Mathie, R. Meier, G. Moloney, D. Ottewell, O. Patarakin, J.D. Patterson, M.M. Pavan, S. Piano, K. Raywood, R.A. Ristinen, R. Rui, M.E. Sevior, G.R. Smith, J. Stahov, R. Tacik, G.J. Wagner, F. von Wrochem, and D.M. Yeomans. pi+ p differential cross sections at low energies. United States: N. p., 2005.
Web.
H. Denz, P. Amaudruz, J.T. Brack, J. Breitschopf, P. Camerini, J.L. Clark, H. Clement, L. Felawka, E. Fragiacomo, E.F. Gibson, N. Grion, G.J. Hofman, B. Jamieson, E.L. Mathie, R. Meier, G. Moloney, D. Ottewell, O. Patarakin, J.D. Patterson, M.M. Pavan, S. Piano, K. Raywood, R.A. Ristinen, R. Rui, M.E. Sevior, G.R. Smith, J. Stahov, R. Tacik, G.J. Wagner, F. von Wrochem, & D.M. Yeomans. pi+ p differential cross sections at low energies. United States.
H. Denz, P. Amaudruz, J.T. Brack, J. Breitschopf, P. Camerini, J.L. Clark, H. Clement, L. Felawka, E. Fragiacomo, E.F. Gibson, N. Grion, G.J. Hofman, B. Jamieson, E.L. Mathie, R. Meier, G. Moloney, D. Ottewell, O. Patarakin, J.D. Patterson, M.M. Pavan, S. Piano, K. Raywood, R.A. Ristinen, R. Rui, M.E. Sevior, G.R. Smith, J. Stahov, R. Tacik, G.J. Wagner, F. von Wrochem, and D.M. Yeomans. Sat .
"pi+ p differential cross sections at low energies". United States.
doi:. https://www.osti.gov/servlets/purl/862053.
@article{osti_862053,
title = {pi+ p differential cross sections at low energies},
author = {H. Denz and P. Amaudruz and J.T. Brack and J. Breitschopf and P. Camerini and J.L. Clark and H. Clement and L. Felawka and E. Fragiacomo and E.F. Gibson and N. Grion and G.J. Hofman and B. Jamieson and E.L. Mathie and R. Meier and G. Moloney and D. Ottewell and O. Patarakin and J.D. Patterson and M.M. Pavan and S. Piano and K. Raywood and R.A. Ristinen and R. Rui and M.E. Sevior and G.R. Smith and J. Stahov and R. Tacik and G.J. Wagner and F. von Wrochem and D.M. Yeomans},
abstractNote = {Differential cross sections for pi p and pi+ p elastic scattering were measured at five energies between 19.9 and 43.3 MeV. The use of the CHAOS magnetic spectrometer at TRIUMF, supplemented by a range telescope for muon background suppression, provided simultaneous coverage of a large part of the full angular range, thus allowing very precise relative cross section measurements. The absolute normalization was determined with a typical accuracy of 5 %. This was verified in a simultaneous measurement of muon proton elastic scattering. The measured cross sections show some deviations from phase shift analysis predictions, in particular at large angles and low energies. From the new data we determine the real part of the isospin forward scattering amplitude.},
doi = {},
journal = {},
number = ,
volume = ,
place = {United States},
year = {Sat Dec 03 00:00:00 EST 2005},
month = {Sat Dec 03 00:00:00 EST 2005}
}

Differential cross sections have been measured for ..pi../sup +/p elastic scattering at incidentpion energies 442, 490, 530, 560, and 600 MeV, and for ..pi../sup /p elastic scattering at pion energies 425, 465, 490, 530, 560, 600, and 640 MeV. The differential cross sections were measured in the angular range theta/sub ..pi../*=40176/sup 0/ with an accuracy of about 25%. The resulting data were used to calculate the isospin boundaries for the ..pi../sup /p..> pi../sup 0/n chargeexchange cross sections. It is shown that the published chargeexchange cross sections for large scattering angles cluster near the lower boundary and that those for energiesmore »

Dynamics of charge transfer Ar/sup + +/ (/sup 3/P)+He(/sup 1/S). >. Ar/sup +/(/sup 2/P)+He/sup +/(/sup 2/S) at low collision energies: Comparison of experimental results with quasiclassical calculations of the differential cross sections
Differential cross sections of the elementary process Ar/sup + +/(/sup 3/P)+He(/sup 1/S)..>..Ar/sup +/(/sup 2/P)+He/sup +/(/sup 2/S) at collision energies between 0.6 and 1.6 eV were calculated using the quasiclassical treatment. Analytic potentials providing an approximation of the electronic energy of the system were employed to calculate deflection functions. Coupling of the diabatic terms was evaluated using the asymptotic method, and the LandauZener model was applied to account for the transition probability. Semiquantitative agreement of the calculated differential cross sections with those obtained in crossed beam experiments was achieved. 
Lowenergy differential cross sections of pionproton ([pi][sup [plus minus]][ital p]) scattering. II. Phase shifts at [ital T][sub [pi]]=32. 7, 45. 1, and 68. 6 MeV
We report on measurements of the differential [pi][sup [plus minus]][ital p] cross section at pion energies [ital T][sub [pi]]=32.7, 45.1, and 68.6 MeV. The measurements, covering the angular range 25[degree][le][theta][sub lab][le]123[degree], have been carried out at the PaulScherrerInstitute (PSI) in Villigen, Switzerland, employing the magnet spectrometer LEPS. The absolute normalization of the [pi][sup [plus minus]][ital p] cross sections have been achieved by relating them to the electromagnetic cross sections of [mu][sup [plus minus] 12]C scattering. The results are in agreement with those of our preceding measurements at [ital T][sub [pi]]=32.2 and 45.1 MeV insofar as they overlap with the regionmore » 
Lowenergy differential cross sections of pionproton ([pi][sup [plus minus]][ital p]) scattering. I. The isospineven forward scattering amplitude at [ital T][sub [pi]]=32. 2 and 44. 6 MeV
The values of the pion nucleon ([pi][ital N]) [sigma] term, as determined, on the one hand, from experimental pion nucleon scattering by means of dispersion relations and, on the other hand, from baryon masses by means of chiral perturbation theory, differ by 10 to 15 MeV. The origin of this discrepancy is not yet understood. If the difference between the two values is attributed to the scalar current of strange sea quark pairs within the proton, the contribution to the proton mass would be of the order of 120 MeV. The discrepancy may hint at either theoretical deficiencies or anmore »