Physics – High Energy Physics – High Energy Physics - Phenomenology
Scientific paper
2008-11-10
Eur.Phys.J.A39:71-80,2009
Physics
High Energy Physics
High Energy Physics - Phenomenology
15 pages, 16 figures, accepted for publication in European Physical Journal A
Scientific paper
10.1140/epja/i2008-10688-0
We calculate the one-photon loop radiative corrections to virtual pion Compton scattering $\pi^- \gamma^* \to \pi^- \gamma$, that subprocess which determines in the one-photon exchange approximation the pion-nucleus bremsstrahlung reaction $\pi^- Z\to \pi^- Z \gamma$. Ultraviolet and infrared divergencies of the loop integrals are both treated by dimensional regularization. Analytical expressions for the ${\cal O}(\alpha)$ corrections to the virtual Compton scattering amplitudes, $A(s,u,Q)$ and $B(s,u,Q)$, are derived with their full dependence on the (small) photon virtuality $Q$ from 9 classes of contributing one-loop diagrams. Infrared finiteness of these virtual radiative corrections is achieved (in the standard way) by including soft photon radiation below an energy cut-off $\lambda$. In the region of low $\pi^- \gamma$ center-of-mass energies, where the pion-nucleus bremsstrahlung process is used to extract the pion electric and magnetic polarizabilities, we find radiative corrections up to about -3% for $\lambda=5 $MeV. Furthermore, we extend our calculation of the radiative corrections to virtual pion Compton scattering $\pi^-\gamma^* \to \pi^- \gamma$ by including the leading pion structure effect in form of the polarizability difference $\alpha_\pi - \beta_\pi$. Our analytical results are particularly relevant for analyzing the data of the COMPASS experiment at CERN which aims at measuring the pion electric and magnetic polarizabilities with high statistics using the Primakoff effect.
Friedrich Jan M.
Kaiser Nicholas
No associations
LandOfFree
Radiative corrections to pion-nucleus bremsstrahlung does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Radiative corrections to pion-nucleus bremsstrahlung, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Radiative corrections to pion-nucleus bremsstrahlung will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-724632