Workshop on the Physics of Excited Nucleons, Sept. 5-8, 2007, Bonn, Germany – Alexander Titov 1 Alexander Titov Forschungzentrum Rossendorf/Dresden and Joint Institute for Nuclear Research Dubna Photoproduction of  meson off the deuteron near threshold Workshop on the Physics of Excited Nucleons PRC 76, (2007)

Workshop on the Physics of Excited Nucleons, Sept. 5-8, 2007, Bonn, Germany – Alexander Titov 2 Talk Outline  Motivation: puzzles in  p->  p photoproduction (LEPS)  Coherent  D->  D  reaction  In-coherent  D->  np  reaction  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

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 19Summary 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