The 2H,12C,40Ca,208Pb(π+,π+π±) reactions have been studied at Tπ+ = 282.7 MeV, and the π+π± invariant mass distributions Mπ+π±A measured down to the 2mπ threshold. The Mπ+π-A yield near threshold is close to zero for A = 2, and increases dramatically with increasing A (from 12 to 40 to 208). A phase analysis indicates that the π+π- pairs in this range of Mπ+π-A have J = I = 0. In the case of Mπ+π+A, there is some strength near threshold regardless of A, and the π+π+ pairs have J = 0,I = 2. The experimental results indicate that nuclear matter strongly modifies the ππ interaction in the J = I = 0 channel.
A dependence of the (pi+,pi+ pi+-) reaction near the 2m(pi) threshold / Bonutti, Faustino; Camerini, Paolo; Fragiacomo, Enrico; N., Grion; Rui, Rinaldo; P. A., Amaudruz3; J. T., Brack3; L., Felawka2; E. F., Gibson6; G. J., Hofman3; 4, ; M., Kermani3; 4, ; E. L., Mathie5; S., Mcfarland3; 4, ; R., Meier3; D., Ottewell3; K., Raywood3; M. E., Sevior7; G. R., Smith3; R., Tacik5. - In: PHYSICAL REVIEW LETTERS. - ISSN 0031-9007. - STAMPA. - 77:(1996), pp. 603-606. [10.1103/PhysRevLett.77.603]
A dependence of the (pi+,pi+ pi+-) reaction near the 2m(pi) threshold
BONUTTI, FAUSTINO;CAMERINI, Paolo;FRAGIACOMO, ENRICO;RUI, RINALDO;
1996-01-01
Abstract
The 2H,12C,40Ca,208Pb(π+,π+π±) reactions have been studied at Tπ+ = 282.7 MeV, and the π+π± invariant mass distributions Mπ+π±A measured down to the 2mπ threshold. The Mπ+π-A yield near threshold is close to zero for A = 2, and increases dramatically with increasing A (from 12 to 40 to 208). A phase analysis indicates that the π+π- pairs in this range of Mπ+π-A have J = I = 0. In the case of Mπ+π+A, there is some strength near threshold regardless of A, and the π+π+ pairs have J = 0,I = 2. The experimental results indicate that nuclear matter strongly modifies the ππ interaction in the J = I = 0 channel.Pubblicazioni consigliate
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