Speaker
Paolo Pedroni
(INFN-Pavia)
Description
In this presentation I will discuss the results of a recent
work on the extraction of the scalar dipole dynamic polarizabilities (DDPs) from proton Real Compton Scattering (RCS) data below pion production threshold.
The dynamical polarizabilities are energy dependent functions which parametrize the response of the internal degrees of freedom of the
proton to an external, real-photon field of arbitrary energy.
As such, they contain enriched information with
respect to the static polarizabilities defined in the limit of
zero-frequency photon field.
After the description of the
theoretical framework, which combines dispersion relations, the low-energy
expansion and a multipole decomposition of the scattering amplitude,
I will discuss the statistical analysis, based on the
parametric bootstrap technique, that has been used for this evaluation.
This statistical tool have been applied for the first time to analyze RCS
data, and has been crucial to overcome problems inherent to the analysis of the available data set. I will present the main advantages of this fitting
method, including preliminary results about the statistical interpretation
of the chi-squared function when also systematical errors are taken into account.
Finally, I will show new results for the extraction of the static
polarizabilities alpha and beta, using subtracted dispersion
relations and the bootstrap technique.
