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Workshop on the Physics of Excited Nucleons, Sept. 5-8, 2007, Bonn, Germany – Alexander Titov 1
Alexander TitovForschungzentrum Rossendorf/Dresden
andJoint Institute for Nuclear Research Dubna
Photoproduction of meson off the deuteron
near threshold
Workshop on the Physics of Excited Nucleons
PRC 76, 035202 (2007)
Workshop on the Physics of Excited Nucleons, Sept. 5-8, 2007, Bonn, Germany – Alexander Titov 2
Talk OutlineTalk Outline
Motivation: puzzles in p->p photoproduction (LEPS)
Coherent D->Dreaction In-coherent D->npreaction Spin-density matrix elements Summary
Workshop on the Physics of Excited Nucleons, Sept. 5-8, 2007, Bonn, Germany – Alexander Titov 3
A.T.&T.-S.H.Lee, PRC 67 (2003)
previous experience in reaction
Motivation:
In following we discuss the diffractive part
Workshop on the Physics of Excited Nucleons, Sept. 5-8, 2007, Bonn, Germany – Alexander Titov 4
Puzzle # 1
Workshop on the Physics of Excited Nucleons, Sept. 5-8, 2007, Bonn, Germany – Alexander Titov 5
Puzzle # 2
Workshop on the Physics of Excited Nucleons, Sept. 5-8, 2007, Bonn, Germany – Alexander Titov 6
Nature of the bump: The large amount of un-natural parity ( meson)exchange can not produce the bump:
But this admixture of un-natural parity exchange gives sizable background for possible (real) interference
Workshop on the Physics of Excited Nucleons, Sept. 5-8, 2007, Bonn, Germany – Alexander Titov 7
Pomeron: modified Donnachie-Landshoff model
PS – exchange
Workshop on the Physics of Excited Nucleons, Sept. 5-8, 2007, Bonn, Germany – Alexander Titov 8
Workshop on the Physics of Excited Nucleons, Sept. 5-8, 2007, Bonn, Germany – Alexander Titov 9
coherent
incoherent
Workshop on the Physics of Excited Nucleons, Sept. 5-8, 2007, Bonn, Germany – Alexander Titov 10
coherent
incoherent
Workshop on the Physics of Excited Nucleons, Sept. 5-8, 2007, Bonn, Germany – Alexander Titov 11
Photoproduction from iso-scalar nucleon
Workshop on the Physics of Excited Nucleons, Sept. 5-8, 2007, Bonn, Germany – Alexander Titov 12
Workshop on the Physics of Excited Nucleons, Sept. 5-8, 2007, Bonn, Germany – Alexander Titov 13
Workshop on the Physics of Excited Nucleons, Sept. 5-8, 2007, Bonn, Germany – Alexander Titov 14
Workshop on the Physics of Excited Nucleons, Sept. 5-8, 2007, Bonn, Germany – Alexander Titov 15
GJ system
Workshop on the Physics of Excited Nucleons, Sept. 5-8, 2007, Bonn, Germany – Alexander Titov 16
H system
Workshop on the Physics of Excited Nucleons, Sept. 5-8, 2007, Bonn, Germany – Alexander Titov 17
Workshop on the Physics of Excited Nucleons, Sept. 5-8, 2007, Bonn, Germany – Alexander Titov 18
Workshop on the Physics of Excited Nucleons, Sept. 5-8, 2007, Bonn, Germany – Alexander Titov 19
SummarySummary
2. There is no bump-like behavior in reaction. The model satisfactory unpolarized cross sections and spin observables, which, in particular, indicate to elimination of the un-natural parity exchange processes.
3. Possible explanation of the existence of the bump-like structure in and its absence in reaction may indicate for contribution exotic channel with properties of the scalar – isovector meson exchange.
1. The model describes reasonably and spin
observables in reaction in diffraction region
at finite |t |, but it fails in description of the bump-like
behavior of at