Nigro, M.
Astrophysics
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Anti-proton helium-3 annihilation at 55-MeV/c

Bianconi, A. ; Bonomi, G. ; Bussa, M.P. ; et al.
Phys.Lett.B 492 (2000) 254-258, 2000.
Inspire Record 538722 DOI 10.17182/hepdata.27999

The p̄ 3 He annihilation cross section is measured for the first time in the momentum interval (50÷60) MeV/ c . About 9000 pictures collected by the Streamer Chamber Collaboration (PS179) at LEAR–CERN have been scanned. Six events are found, corresponding to σ ann =1850±700 mb. The result is compared to the set of measurements presently available in the region of low p̄ momentum.

1 data table
Table 1

The mean beam momentum at the center of the fiducial volume = 55 MeV.


A measurement of the Coulomb dissociation of B-8 at 254-MeV/nucleon and the B-8 solar neutrino flux.

Iwasa, N. ; Boue, F. ; Surowka, G. ; et al.
Phys.Rev.Lett. 83 (1999) 2910-2913, 1999.
Inspire Record 507363 DOI 10.17182/hepdata.50399

We have measured the Coulomb dissociation of 8B into 7Be and proton at 254 MeV/nucleon using a large-acceptance focusing spectrometer. The astrophysical S17 factor for the 7Be(p,gamma)8B reaction at E{c.m.} = 0.25-2.78 MeV is deduced yielding S17(0)=20.6 \pm 1.2 (exp.) \pm 1.0 (theo.) eV-b. This result agrees with the presently adopted zero-energy S17 factor obtained in direct-reaction measurements and with the results of other Coulomb-dissociation studies performed at 46.5 and 51.2 MeV/nucleon.

1 data table
Table 1

S17(0) = E * SIG * EXP(CONST(C=ZOMMERFELD PARAMETER)). CONST(C=ZOMMERFELD PARAMETER) = 31.29*Z1*Z2*SQRT(M/E), where Z1 and Z2 are the nuclear charges of the interacting particles, M is the reduced mass, E is the center-of-mass energy. P BE7 reaction is extrapolation to inverse kinematics.