Measurement of T20(90 degrees) in the 1H(d

Abstract

The tensor analyzing powers of the {sup 1}H({ital d{searrow}},{gamma}){sup 3}He reaction are sensitive to the tensor component of the nucleon-nucleon force, which mixes the {ital L}=2 {ital D} state into the {sup 3}He ground state wave function. Modern Faddeev calculations of this reaction allow a quantitative comparison to the parametrization of the tensor force in the trinucleon system. The {ital T}{sub 20} analyzing power was measured at an incident beam energy of 5.25 MeV and a laboratory angle of 90{degree} ({theta}{sub c.m.}=92.9{degree}), where the comparison to theory is especially rigorous. The measured value of {ital T}{sub 20}(90{sub lab}{sup {degree}}) is {minus}0.035{plus_minus}0.004, which differs by {approx_equal}3{sigma} from a recent Faddeev calculation which uses the separable expansion of the Paris potential. {copyright} {ital 1996 The American Physical Society.}