Measurement of tensor polarization of deuterons from3He→d+pbreakup at momenta from 4.60 to 5.66 GeV/c

Abstract

The tensor polarization, ρ 20 , of deuterons emitted in the 1 H( 3 He, ↔ d )X reaction at 0 • in the laboratory system, was measured at the Saturne National Laboratory in Saclay, using the SPES-4 spectrometer with the HYPOM polarimeter located downstream from its focal plane. The momentum of the detected deuterons was kept fixed at 3.77 GeV/c, while the momentum of the 3 He beam was varied from 4.60 to 5.66 GeV/c, thus providing a range of internal momenta k of the deuteron in 3 He from 0 up to 0.4 GeV/c. The data obtained are compared with theoretical predictions.

Momentum distributions, spin-dependent observables, and theD2parameter for3He breakup

“…On the other hand, the experimental value of the D 2 protons in the deuteron was explained as an effect of the Coulomb interaction on the mechanism of 12 C(d, p) breakup. [10] are reversed to bring them into accordance with the preliminary results [11] of the same experiment, as well as with the sign of experimental data on the D2 parameter for 3 He.…”

“…Data on the tensor polarization ρ 20 of the deuteron in the reaction 12 C( 3 He, d) at several GeV have been published [10,11]. It should, however, be noted that the preliminary data [11] extracted from this experiment have the opposite sign to those tabulated in the final data set [10].…”

“…Furthermore, the spin-correlation parameter C yy for this reaction was recently measured for first time [9]. Finally, the tensor polarization of the deuteron (sometimes called its "alignment") in the 12 C( 3 He, d) reaction was also measured [10,11]. Both this and the C yy data [9] are sensitive to the spin structure of 3 He.…”

“…with the contradiction in signs of ρ 20 between Refs. [11] and [10], it is tempting to conclude that the data tabulated in Ref. [10] have the wrong sign.…”

“…We therefore use the data from Ref. [10] but with a reversed sign and compare them in Fig. 9 with ρ 20 calculated according Eq.…”