Enhancement of Compton scattering by an effective coupling constant

by Dr Bernardo Barbiellini Amidei (Northwestern University Boston)

Friday 15 Oct 2010, 11:30 → 12:30 Europe/Zurich

Auditoire 234 (Geneva University)

Max Born suggested that the Compton scattering cross section is connected to an absolute length scale [1]. Understanding this fundamental relationship could enable us to enhance the Compton scattering cross sections by engineering an effective quantum electro-dynamics (QED) interaction. In fact, by using a general thermodynamic argument, we predict [2] that the Thomson scattering length depends on the QED coupling constant inverse by an exponential function, so that the corresponding Compton scattering cross section enhancement can change enormously by varying the coupling constant. This behavior could be obtained by modifying the dielectric response, for instance, by tuning the incident photon energy near the binding energy of a deep lying core level. A Compton cross section enhancement of almost a factor four is predicted for Compton scattering experiments at the K edge in graphite by using realistic dielectric data [3]. This new effect can enable us to propose experiments opening the door to the possibility of validating quantum gravity theories without invoking huge and expensive experimental apparatuses. [1] Max Born, Nature 169, 1105 (1952). [2] Bernardo Barbiellini and Piero Nicolini, arXiv:1005.5496v2. [3] B.T. Draine, The Astrophysical Journal 598, 1026 (2003).