https://doi.org/10.1140/epja/i2010-11024-y
Regular Article - Theoretical Physics
Nucleon polarizabilities from deuteron Compton scattering within a Green’s function hybrid approach
1
Institut für Theoretische Physik (T39), Physik-Department, Technische Universität München, D-85747, Garching, Germany
2
Institut für Theoretische Physik III, Naturwissenschaftliche Fakultät I, Universität Erlangen-Nürnberg, D-91058, Erlangen, Germany
3
Center for Nuclear Studies, Department of Physics, The George Washington University, 20052, Washington DC, USA
Received:
2
July
2010
Accepted:
5
August
2010
Published online:
16
September
2010
We examine elastic Compton scattering from the deuteron for photon energies ranging from zero to 100MeV, using state-of-the-art deuteron wave functions and NN potentials. Nucleon-nucleon rescattering between emission and absorption of the two photons is treated by Green’s functions in order to ensure gauge invariance and the correct Thomson limit. With this Green’s function hybrid approach, we fulfill the low-energy theorem of deuteron Compton scattering and there is no significant dependence on the deuteron wave function used. Concerning the nucleon structure, we use the chiral effective field theory with explicit 
(1232) degrees of freedom within the small-scale expansion up to leading-one-loop order. Agreement with available data is good at all energies. Our 2-parameter fit to all elastic 
d data leads to values for the static isoscalar dipole polarizabilities which are in excellent agreement with the isoscalar Baldin sum rule. Taking this value as additional input, we find 
= (11.3±0.7(stat)±0.6(Baldin)±1(theory)).10-4 fm^3 and 
= (3.2±0.7(stat)±0.6(Baldin)±1(theory)).10-4 fm^3 and conclude by comparison to the proton numbers that neutron and proton polarizabilities are the same within rather small errors.
© SIF, Springer-Verlag Berlin Heidelberg, 2010
