Investigation of nuclear charge symmetry by pion elastic scattering from H-3 and He-3

Dhuga, K.S. ; Berman, B.L. ; Briscoe, W.J. ; et al.
Phys.Rev.C 54 (1996) 2823-2830, 1996.
Inspire Record 433024 DOI 10.17182/hepdata.25746

We have measured differential cross sections for pion elastic scattering from H3 and He3 in the angular region near the minimum in the non-spin-flip amplitude. Data were acquired for incident pion energies of 180, 220, 256, and 295 MeV. Nuclear charge symmetry is investigated with the aid of several charge-symmetric ratios formed from combinations of measured cross sections. A particularly intriguing result is obtained from the superratio R, which is defined as R=dσ(π+3H)dσ(π−3H)/dσ(π+3He)dσ(π−3He). R is found to be greater than unity at 180 MeV and significantly smaller than unity at 256 MeV, with the transition occurring at around 210 MeV. The charge-symmetry prediction for this ratio (after allowance for the Coulomb force) is one, and is independent of energy and angle. © 1996 The American Physical Society.

8 data tables

Axis error includes +- 3/3 contribution.

Axis error includes +- 3/3 contribution.

Axis error includes +- 3/3 contribution.

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Elastic scattering of pions from H-3 and He-3 into the backward hemisphere

Matthews, S.K. ; Briscoe, W.J. ; Bennhold, C. ; et al.
Phys.Rev.C 51 (1995) 2534-2541, 1995.
Inspire Record 405001 DOI 10.17182/hepdata.25941

We have measured differential cross sections for the elastic scattering of charged pions from H3 and He3 into the backward hemisphere. Near the peak of the delta resonance, at Tπ=180 MeV, an angular distribution covering 114° to 168° in the laboratory extends our earlier measurements. At Tπ=142, 180, 220, and 256 MeV, we have measured an excitation function at angles approaching 170°. The cross sections for the reactions He3(π+,π+)3He, H3(π−,π−)3H show a rise at back angles which is not seen for He3(π−,π−)3He and H3(π+,π+)3H. There is a dip in the cross sections near 130° for Tπ=180 MeV.

4 data tables

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Superratio and the simple ratios of pi+ and pi- elastic scattering on H-3 and He-3 at 180-MeV to investigate charge symmetry

Nefkens, B.M.K. ; Briscoe, W.J. ; Eichon, A.D. ; et al.
Phys.Rev.C 41 (1990) 2770-2782, 1990.
Inspire Record 306209 DOI 10.17182/hepdata.26180

Results are presented for the charge-symmetry superratio R, simple ratios r1 and r2, and the differential cross sections of π+ and π− elastic scattering on H3 and He3: R=r1r2, r1=σ(θ)[π+ π+3 ]3/σ(θ)[π− π−3 ]3, and r2=σ(θ)[π− π−3 ]3/σ(θ)[π+ He3 →π+ ]3. The measurements were made at Tπ=180 MeV and θπ(lab)=40°–90°; some data were obtained at Tπ=143 MeV also. At all angles, R>1 and r2>1 indicative of a violation of charge symmetry; however, we also find that r1≃1. Our data are consistent with Fp(3H)≃Fn(3He) and Fn(3H)>Fp(3He), where Fp and Fn are the proton and neutron matter form factors. σ(θ)[π± π±3 ]3 decreases with increasing magnitude of the four-momentum transfer t up to θc.m.≃70°; the t dependence of the F ’s is comparable to that of the electromagnetic form factors. σ(θ)[π− π−33H] has a non-spin-flip dip at θc.m.≃78°.

4 data tables

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Inclusive inelastic scattering of 96.5-MeV pi+ and pi- by the hydrogen and helium isotopes

Khandaker, M.A. ; Doss, M. ; Halpern, I. ; et al.
Phys.Rev.C 44 (1991) 24-36, 1991.
Inspire Record 323112 DOI 10.17182/hepdata.26156

Spectra, angular distributions, and integrated cross sections for inclusive inelastic scattering of 96.5-MeV π+ and π− from H2, He3, and He4 are presented. The measurements were made using a high-pressure gas cell, which permits an accurate determination of relative cross sections for all targets. The data are compared with distorted-wave impulse-approximation calculations and with a modified plane-wave impulse-approximation calculation. In addition, by combining the total inelastic cross sections from this work with estimates of single-charge-exchange cross sections and with published values and reasonable estimates of the other π+ cross sections at the same energy, values for total reaction and pion absorption cross sections are obtained for all the targets. The dependence of these cross sections on Z, N, nuclear density, and nuclear binding energy is discussed in terms of a simple model.

2 data tables

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