Observation of inverse diproton photodisintegration at intermediate energies.

Authors :: Komarov V
Azaryan T
Chiladze D
Dymov S
Dzyuba A
Hartmann M
Kacharava A
Keshelashvili I
Khoukaz A
Kulikov A
Kurbatov V
Macharashvili G
Merzliakov S
Mikirtychiants S
Papenbrock M
Nekipelov M
Rathmann F
Serdyuk V
Ströher H
Tsirkov D
Uzikov Y
Wilkin C
Source :: Physical review letters [Phys Rev Lett] 2008 Sep 05; Vol. 101 (10), pp. 102501. Date of Electronic Publication: 2008 Sep 03.
Publication Year :: 2008
Abstract: The fundamental reaction pp-->{pp}&#95;{s}gamma, where {pp}&#95;{s} is a proton pair with low excitation energy, has been observed with the ANKE spectrometer at COSY-Jülich for proton beam energies of T&#95;{p}=0.353, 0.500, and 0.550 GeV. This is equivalent to photodisintegration of a free 1S0 diproton for photon energies E&#95;{gamma} approximately T&#95;{p}/2. The differential cross sections measured for c.m. angles 0 degrees <theta&#95;{pp}<20 degrees exhibit a steep increase with angle that is compatible with E1 and E2 multipole contributions. The ratio of the measured cross sections to those of np-->gammad is on the 10;{-3}-10;{-2} level. The increase of the pp-->{pp}&#95;{s}gamma cross section with T&#95;{p} might reflect the influence of the Delta(1232) excitation.