l - th / 9 80 30 09 v 2 2 7 M ay 1 99 8 Coherent Photoproduction of Pions on Spin - Zero Nuclei in a relativistic , non - local Model ∗ †
نویسندگان
چکیده
A relativistic and non-local model for the coherent photoproduction of pions on spin-zero nuclei is presented. The production operator is derived from an effective Lagrangian model that contains all the degrees of freedom known to contribute to the elementary process. Using the framework of DWIA, the matrix elements of this operator are evaluated using relativistic bound state wave functions. Final state interactions are accounted for via a pion-nucleus optical potential. The effects of in-medium modifications of the production operator are discussed. We give results for 12 C and 40 Ca, and compare our calculations to the data of the A2 collaboration at MAMI.
منابع مشابه
uc l - th / 9 80 70 02 v 2 2 2 A ug 1 99 8 Coherent Photoproduction of Eta - Mesons on Spin - Zero Nuclei in a Relativistic , Non - local Model ∗ †
The coherent photoproduction of η-mesons on spin-zero nuclei is studied in a relativistic, non-local model, which we have previously applied to the coherent photoproduction of pions. We find that different off-shell extrapolations of the elementary production operator lead to large effects in the cross section. We also show that the almost complete suppression of the N (1535) seen in earlier st...
متن کاملuc l - th / 9 80 70 02 v 1 1 J ul 1 99 8 Coherent Photoproduction of Eta - Mesons on Spin - Zero Nuclei in a Relativistic , Non - local Model ∗ †
The coherent photoproduction of η-mesons on spin-zero nuclei is studied in a relativistic, non-local model, which we have previously applied to the coherent photoproduction of pions. We find that different off-shell extrapolations of the elementary production operator lead to large effects in the cross section. We also show that the almost complete suppression of the N (1535) seen in earlier st...
متن کاملar X iv : n uc l - th / 9 80 80 61 v 1 2 6 A ug 1 99 8 Longitudinal and Transverse Spin Responses in Relativistic Many Body Theory
We study theoretically the spin response functions using the relativistic many body theory. The spin response functions in the relativistic theory are reduced largely from the ones of the non-relativistic theory. This happens particularly to the longitudinal spin responses. This fact is able to remove the difficulty in reproducing the ratio of the longitudinal and transverse response functions ...
متن کاملar X iv : n uc l - th / 9 80 80 61 v 3 1 9 D ec 1 99 8 Longitudinal and Transverse Spin Responses in Relativistic Many Body Theory
We study theoretically the spin response functions using the relativistic many body theory. The spin response functions in the relativistic theory are reduced largely from the ones of the non-relativistic theory. This happens particularly to the longitudinal spin responses. This fact is able to remove the difficulty in reproducing the ratio of the longitudinal and transverse response functions ...
متن کاملCoherent Photoproduction of Pions on Nuclei in a relativistic , non - local Model ∗ †
A relativistic and non-local model for the coherent photoproduction of pions on nuclei is presented. The production operator is derived from an effective Lagrangian model that contains all the degrees of freedom known to contribute to the elementary process. Using the framework of DWIA, the matrix elements of this operator are evaluated using relativistic bound state wave functions. Final state...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
عنوان ژورنال:
دوره شماره
صفحات -
تاریخ انتشار 1998