The results of the spin-parity analysis of (p) over bar p --> 2 pi(+)2 pi(-) annihilations at very low momentum (p) over bar (approximate to 50 MeV/c) are reported. To describe the data the production of the rho,f(2),a(2) and a(1) mesons and the presence of the pi pi interaction in S-wave (the sigma term) in the final state are necessary. The best fit solution requires also the presence of a rho' state of mass and width M = 1.282 +/- 0.037, Gamma = 0.236 +/- 0.036 GeV/c(2) and of a heavy pion pi(1300) of mass and width M = 1.275 +/- 0.015, Gamma = 0.218 +/- 0.100 GeV/c(2). The measured fraction of the annihilation cross section into 2 pi(+)2 pi(-) is (7.61 +/- 0.35). 10(-2). (C) 1997 Elsevier Science B.V.
Study of the (p)over-bar-p -> 2 pi(+)2 pi(-) annihilation from S states
Cicalo C;PUDDU, GIOVANNA;USAI, GIANLUCA;
1997-01-01
Abstract
The results of the spin-parity analysis of (p) over bar p --> 2 pi(+)2 pi(-) annihilations at very low momentum (p) over bar (approximate to 50 MeV/c) are reported. To describe the data the production of the rho,f(2),a(2) and a(1) mesons and the presence of the pi pi interaction in S-wave (the sigma term) in the final state are necessary. The best fit solution requires also the presence of a rho' state of mass and width M = 1.282 +/- 0.037, Gamma = 0.236 +/- 0.036 GeV/c(2) and of a heavy pion pi(1300) of mass and width M = 1.275 +/- 0.015, Gamma = 0.218 +/- 0.100 GeV/c(2). The measured fraction of the annihilation cross section into 2 pi(+)2 pi(-) is (7.61 +/- 0.35). 10(-2). (C) 1997 Elsevier Science B.V.
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