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

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 3H and 3He: R=r1r2, r1=σ(θ)[π+3H→π+ H]/σ(θ)[π- He→π-3He], and r2=σ(θ)[π-3H→π- H]/σ(θ)[π+3He →π+3He]. The measurements were made at Tπ=180 MeV and θπ(lab)=40 degree--90 degree; 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 congruent 1. Our data are consistent with Fp(3H)congruent Fn(3He) and Fn(3H)>Fp(3He), where Fp and Fn are the proton and neutron matter form factors. σ(θ)[π±3H→π± H] decreases with increasing magnitude of the four-momentum transfer t up to θc.m.congruent 70 degree; the t dependence of the F 's is comparable to that of the electromagnetic form factors. σ(θ)[π- H→π-3H] has a non-spin-flip dip at θc.m.congruent 78 degree