The spin-parity analysis of the data on the ¯pp → 2π+ 2π − annihilation reaction at rest in liquid and in gaseous hydrogen at 3 bar pressure and in flight at p momentum of 50 MeV/c, collected by the Obelix spectrometer at the LEAR complex of CERN, is presented. The relative branching ratios (a1(1260) → σπ)/(a1(1260) → ρπ) = 0.06 ± 0.05 and (π(1300) → σπ)/(π(1300) → ρπ) = 2.2 ± 0.4 are obtained. It is also shown that the inclusion of the exotic meson π1(1400), JPC= 1−+, mass and width M = 1.384 ± 0.028, Γ = 0.378 ± 0.058 GeV/c2, in its decay to ρπ, improves the fit and some implications of these results are briefly discussed. The relative S and P-wave annihilation percentages in four charged pions at two target densities are obtained.

Anti-pp annihilation into four charged pions at rest and in flight / P., Salvini; V. I., Tretyak; V., Filippini; A., Fontana; P., Montagna; A., Panzarasa; A., Rotondi; M., Bargiotti; A., Bertin; M., Bruschi; M., Capponi; A., Carbone; S., De Castro; L., Fabbri; P., Faccioli; D., Galli; B., Giacobbe; F., Grimaldi; U., Marconi; I., Massa; M., Piccinini; N., Semprini Cesari; R., Spighi; S., Vecchi; M., Villa; A., Vitale; A., Zoccoli; A., Bianconi; M., Corradini; A., Donzella; E., Lodi Rizzini; L., Venturelli; A., Zenoni; C., Cicalò; A., De Falco; A., Masoni; G., Puddu; S., Serci; G., Usai; O. E., Gorchakov; S. N., Prakhov; A. M., Rozhdestvensky; M. G., Sapozhnikov; M., Poli; P., Gianotti; C., Guaraldo; A., Lanaro; V., Lucherini; C., Petrascu; D., Panzieri; F., Balestra; M. P., Bussa; L., Busso; P., Cerello; O., Denisov; L., Ferrero; A., Grasso; A., Maggiora; F., Tosello; E., Botta; T., Bressani; D., Calvo; F., De Mori; A., Feliciello; A., Filippi; S., Marcello; Agnello, Michelangelo; Iazzi, Felice. - In: THE EUROPEAN PHYSICAL JOURNAL. C, PARTICLES AND FIELDS. - ISSN 1434-6044. - 35:(2004), pp. 21-33. [10.1140/epjc/s2004-01811-8]

Anti-pp annihilation into four charged pions at rest and in flight

AGNELLO, MICHELANGELO;IAZZI, Felice
2004

Abstract

The spin-parity analysis of the data on the ¯pp → 2π+ 2π − annihilation reaction at rest in liquid and in gaseous hydrogen at 3 bar pressure and in flight at p momentum of 50 MeV/c, collected by the Obelix spectrometer at the LEAR complex of CERN, is presented. The relative branching ratios (a1(1260) → σπ)/(a1(1260) → ρπ) = 0.06 ± 0.05 and (π(1300) → σπ)/(π(1300) → ρπ) = 2.2 ± 0.4 are obtained. It is also shown that the inclusion of the exotic meson π1(1400), JPC= 1−+, mass and width M = 1.384 ± 0.028, Γ = 0.378 ± 0.058 GeV/c2, in its decay to ρπ, improves the fit and some implications of these results are briefly discussed. The relative S and P-wave annihilation percentages in four charged pions at two target densities are obtained.
File in questo prodotto:
Non ci sono file associati a questo prodotto.
Pubblicazioni consigliate

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11583/1849410
 Attenzione

Attenzione! I dati visualizzati non sono stati sottoposti a validazione da parte dell'ateneo