Experimental antiproton nuclear stopping power in H2 and D2

Data about antiprotons slowing down in gaseous targets at very low energies (E<1 keV) show that the stopping power in D2 is lower than in H2; the right way to explain this behavior seems to be through a nuclear stopping power derived from the classical Rutherford formula

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

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

Coupled channel analysis of pi(+)pi(-)pi(0), K+K-pi(0) and (KKs0)-K-+/-pi(-/+) from (p)over-bar-p annihilation at rest in hydrogen targets at three densities

The pi(+)pi(-)pi(0), K(+)K(-)pi(0) and K(+/-)K(0)pi(-/+) final states produced by (p) over barp annihilation at rest at three different hydrogen target densities have been analyzed in the frame of a coupled channel analysis together with pipi, piK and K (K) over bar scattering data. The percentages of the different partial waves, the branching ratios and the parameters (masses, widths, pipi and K (K) over bar partial widths) of all the involved resonances (J(P) = 0(+), 1(-), 2(+)) have been measured. The main results on meson spectroscopy concern the determination of the Gamma(K (K) over bar)/Gamma(pipi) ratio for f(0)(1370) and f(0)(1500) (Gamma(K (K) over bar)/Gamma(pipi) = 0.91 +/- 0.20 and Gamma(K (K) over bar)/Gamma(pipi) = 0.25 +/- 0.03 respectively), the determination of a(0)(1300) parameters (M = 1303 +/- 16 MeV; Gamma = 92 +/- 16 MeV) and the observation of two different rho signals associated to rho(1450) and rho(1700) (M = 1182 +/- 30 MeV; Gamma = 389 +/- 20 MeV and M = 1594 +/- 20 MeV; Gamma = 259 +/- 20 MeV respectively)

(p)over-barD and (p)over-bar He-4 annihilation cross sections at very low energy

72nonenoneZENONI A; BIANCONI A; BONOMI G; CORRADINI M; DONZELLA A; E. LODI RIZZINI; VENTURELLI L; BERTIN A; BRUSCHI M; CAPPONI M; DE CASTRO S; DONA R; GALLI D; GIACOBBE B; MARCONI U; MASSA I; PICCININI M; CESARI NS; SPIGHI R; VAGNONI V; VECCHI S; VILLA M; VITALE A; ZOCCOLI A; POLI M; CICALO C; MASONI A; MAURO S; PUDDU G; SERCI S; USAI G; GORCHAKOV OE; PRAKHOV SN; ROZHDESTVENSKY AM; TRETYAK VI; GIANOTTI P; GUARALDO C; LANARO A; LUCHERINI V; PETRASCU C; GASTALDI U; VANNUCCI L; RICCI RA; BENDISCIOLI G; FONTANA A; MONTAGNA P; ROTONDI A; SALVINI P; MIRFAKHRAI N; BALESTRA F; BUSSA MP; BUSSO L; CERELLO P; DENISOV OY; FERRERO L; GARFAGNINI R; GRASSO A; PANZARASA A; PANZIERI D; TOSELLO F; BOTTA E; BRESSANI T; CALVO D; COSTA S; D'ISEP F; FELICIELLO A; FILIPPI A; MARCELLO S; AGNELLO M; IAZZI F; MINETTI B; TESSARO SZenoni, Aldo; Bianconi, Andrea; Bonomi, Germano; Corradini, Maurizio; Donzella, Antonietta; LODI RIZZINI, Evandro; Venturelli, Luca; Bertin, A; Bruschi, M; Capponi, M; DE CASTRO, S; Dona, R; Galli, D; Giacobbe, B; Marconi, U; Massa, I; Piccinini, M; Cesari, Ns; Spighi, R; Vagnoni, V; Vecchi, S; Villa, M; Vitale, A; Zoccoli, A; Poli, M; Cicalo, C; Masoni, A; Mauro, S; Puddu, G; Serci, S; Usai, G; Gorchakov, Oe; Prakhov, Sn; Rozhdestvensky, Am; Tretyak, Vi; Gianotti, P; Guaraldo, C; Lanaro, A; Lucherini, V; Petrascu, C; Gastaldi, U; Vannucci, L; Ricci, Ra; Bendiscioli, G; Fontana, A; Montagna, P; Rotondi, A; Salvini, P; Mirfakhrai, N; Balestra, F; Bussa, Mp; Busso, L; Cerello, P; Denisov, Oy; Ferrero, L; Garfagnini, R; Grasso, A; Panzarasa, A; Panzieri, D; Tosello, F; Botta, E; Bressani, T; Calvo, D; Costa, S; D'Isep, F; Feliciello, A; Filippi, A; Marcello, S; Agnello, M; Iazzi, F; Minetti, B; Tessaro, S

(p)over-barD and (p)over-bar He-4 annihilation cross sections at very low energy

The (p) over bar D and (p) over bar(4) He total annihilation cross sections have been measured with the Obelix apparatus at LEAR at, respectively, three and two values of the (p) over bar incident momentum between 70 MeV/c and 36 MeV/c. The values of the (p) over bar D annihilation cross section, at such low energies, are in agreement with a surprising result obtained in a recent low statistics measurement of the antiprotonic deuterium K-alpha X-rays [M. Augsburger et al., Phys. Lett. B 461 (1999) 417] (see following article), concerning the unexpected narrow width of the antiprotonic deuterium Is level. (C) 1999 Published by Elsevier Science B.V. All rights reserved