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Analysis of the Low-Energy π±p Elastic-Scattering Data  [PDF]
E. Matsinos, G. Rasche
Journal of Modern Physics (JMP) , 2012, DOI: 10.4236/jmp.2012.310174
Abstract: We report the results of a phase-shift analysis (PSA) of the low-energy π±p elastic-scattering data. Following the method which we had set forth in our previous PSA [1], we first investigate the self-consistency of the low-energy π±p elastic-scattering databases, via two separate analyses of (first) the π+p and (subsequently) the π-p elastic-scattering data. There are two main differences to our previous PSA: 1) we now perform only one test for the acceptance of each data set (based on its contribution to the overall 2) and 2) we adopt a more stringent acceptance criterion in the statistical tests. We show that it is possible to obtain self-consistent databases after removing a very small amount of the data (4.57% of the initial database). We subsequently fit the ETH model [38] to the truncatedπ±p elastic-scattering databases. The model-parameter values show reasonable stability when subjected to different criteria for the rejection of single data points and entire data sets. Our result for the pseudovector πNN coupling constant is 0.0726±0.0014. We extract the scattering lengths and volumes, as well as the s- and p-wave hadronic phase shifts up to T = 100 MeV. Large differences in the s-wave part of the interaction can be seen when comparing our hadronic phase shifts with the current SAID solution (WI08); there is general agreement in the p waves, save for the ~1/21- hadronic phase shift.
Low Energy Analyzing Powers in Pion-Proton Elastic Scattering  [PDF]
R. Meier,M. Cr?ni,R. Bilger,B. van den Brandt,J. Breitschopf,H. Clement,J. R. Comfort,H. Denz,A. Erhardt,K. F?hl,E. Friedman,J. Gr?ter,P. Hautle,G. J. Hofman,J. A. Konter,S. Mango,J. P?tzold,M. M. Pavan,G. J. Wagner,F. von Wrochem
Physics , 2004, DOI: 10.1016/j.physletb.2004.02.071
Abstract: Analyzing powers of pion-proton elastic scattering have been measured at PSI with the Low Energy Pion Spectrometer LEPS as well as a novel polarized scintillator target. Angular distributions between 40 and 120 deg (c.m.) were taken at 45.2, 51.2, 57.2, 68.5, 77.2, and 87.2 MeV incoming pion kinetic energy for pi+ p scattering, and at 67.3 and 87.2 MeV for pi- p scattering. These new measurements constitute a substantial extension of the polarization data base at low energies. Predictions from phase shift analyses are compared with the experimental results, and deviations are observed at low energies.
Electromagnetic corrections to the hadronic phase shifts in low energy pi+p elastic scattering  [PDF]
A. Gashi,E. Matsinos,G. C. Oades,G. Rasche,W. S. Woolcock
Physics , 2000, DOI: 10.1016/S0375-9474(00)00603-5
Abstract: We calculate the s and p-wave electromagnetic corrections which must be subtracted from the nuclear phase shifts obtained from the analysis of low energy pi+p elastic scattering data, in order to obtain hadronic phase shifts. We compare our results with earlier calculations and estimate the uncertainties in the corrections.
Electromagnetic corrections for the analysis of low energy pi-p scattering data  [PDF]
A. Gashi,E. Matsinos,G. C. Oades,G. Rasche,W. S. Woolcock
Physics , 2000, DOI: 10.1016/S0375-9474(00)00604-7
Abstract: We calculate the electromagnetic corrections to the isospin invariant mixing angle and to the two eigenphases for the s and p-waves for low energy pi-p elastic and charge exchange scattering. These corrections have to be applied to the nuclear quantities obtained from phase shift analyses of the experimental data in order to obtain the hadronic phases. We compare our results with earlier calculations and estimate the uncertainties in the corrections.
Electromagnetic corrections to the hadronic phase shifts in low energy pi+ p elastic scattering  [PDF]
A. Gashi,E. Matsinos,G. C. Oades,G. Rasche,W. S. Woolcock
Physics , 1999,
Abstract: We calculate for the s-, p(1/2)- and p(3/2)-waves the electromagnetic corrections which must be subtracted from the nuclear phase shifts obtained from the analysis of low energy pi+ p elastic scattering data, in order to obtain hadronic phase shifts. The calculation uses relativised Schroedinger equations containing the sum of an electromagnetic potential and an effective hadronic potential. We compare our results with those of previous calculations and qualitatively estimate the uncertainties in the corrections.
Analyses of Low-Energy π--12C Elastic Scattering Data  [PDF]
Zuhair F. Shehadeh
Journal of Modern Physics (JMP) , 2014, DOI: 10.4236/jmp.2014.516165
Abstract: A new updated simple local optical potential is proposed for analyzing low-energy π--12C elastic scattering data at 80 MeV and below. This potential is composed of two real terms and an imaginary term. The nature of the real part of the potential is repulsive at smaller radii and attractive at larger ones. In fact, the height of the repulsive term is found to change linearly with the incident pion kinetic energy. On the other hand, the imaginary part of the potential is attractive, shallow and non-monotonic with a dip at about 1.6 fm. Such a nature of the potential makes it feasible to predict π--12C cross sections at other energies in the energy region considered herein. Coulomb effects are incorporated by following Stricker’s prescription. This study will serve positively in studying both pionic atoms and the role of negative pions in radiotherapy.
Elastic scattering of low-energy positron by atom  [PDF]
Nikoli? M.R.,Tan?i? Aleksandar R.
Facta Universitatis Series : Physics, Chemistry and Technology , 2005, DOI: 10.2298/fupct0502141n
Abstract: In this paper, we present our calculation for the elastic scattering of the slow positron from atoms. The calculation is performed for He, Ne, Xe and Kr. In the calculations we used Random phase approximation. By slowing Dyson equation we take into account the correlation effects. Our results are consistent with experimental and other theoretical results.
Elastic scattering of low-energy electrons by carbon disulphide
Bettega, M. H. F.;Natalense, A. P. P.;Lima, M. A. P.;Ferreira, L. G.;
Brazilian Journal of Physics , 2000, DOI: 10.1590/S0103-97332000000100021
Abstract: we report results from an ab initio calculation of low-energy electron scattering by cs2 molecules using the schwinger multichannel method with pseudopotentials. we calculated elastic integral, differential and momentum transfer cross sections in an energy range from 5 ev up to 50 ev and compared our results with available theoretical results and experimental data. through the symmetry decomposition of our integral cross section and eigenphase sum analysis, we found cross section peaks that may be interpreted as broad shape resonances in the cases of the sg, pg, pu, and du symmetries. among these possible resonances, the pg, pu, and du are being reported for the first time.
Elastic scattering of low-energy electrons by carbon disulphide  [cached]
Bettega M. H. F.,Natalense A. P. P.,Lima M. A. P.,Ferreira L. G.
Brazilian Journal of Physics , 2000,
Abstract: We report results from an ab initio calculation of low-energy electron scattering by CS2 molecules using the Schwinger multichannel method with pseudopotentials. We calculated elastic integral, differential and momentum transfer cross sections in an energy range from 5 eV up to 50 eV and compared our results with available theoretical results and experimental data. Through the symmetry decomposition of our integral cross section and eigenphase sum analysis, we found cross section peaks that may be interpreted as broad shape resonances in the cases of the sigmag, pig, piu, and deltau symmetries. Among these possible resonances, the pig, piu, and deltau are being reported for the first time.
Elastic scattering and total reaction cross sections with low-energy light radioactive ion beams.  [cached]
Guimar?es Valdir
EPJ Web of Conferences , 2011, DOI: 10.1051/epjconf/20111713004
Abstract: Elastic scattering experiments have being performed with low-energy radioactive ion beams produced by the RIBRAS facility in Sao Paulo, Brazil. Here I present the results for elastic scattering of 6He on several targets and light beams on 12C target. Special emphasis is given to the analysis of experiments were angular distributions for the elastic scattering of beryllium isotopes projectiles, 7Be, 9Be and 10Be, on a light target 12C were obtained. These elastic scattering angular distributions have been analysed in terms of optical model using the double-folding Sao Paulo potential. From this analysis, the total reaction cross section were also deduced and compared to the total reaction cross sections for many other light projectiles on 12C target. The comparison was made in terms of Universal Function reduction method.
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