1.
Phys Rev Lett
; 100(16): 164802, 2008 Apr 25.
Artigo
em Inglês
| MEDLINE
| ID: mdl-18518209
RESUMO
Experimental results for the restricted energy loss of pairs created from 1-178 GeV photons in a thin Au target and subsequently passing a CCD detector are presented. It is shown that pairs--when detected close to the creation vertex--suffer a reduced energy loss due to the internal screening of the charges constituting the pair. Furthermore, the ability to measure directly the energy of the pair by calorimetry enables a comparison with theory as a function of energy. The observed phenomenon is in good qualitative agreement with general expectations from the Chudakov effect but indicates a quantitative disagreement with either of two mutually disagreeing theories.