A comprehensive amplitude analysis of photon-photon collision

por Lingyun Dai (Thomas Jefferson National Accelerator Facility, JLAB, Virginia (USA))

martes 15 abr. 2014 12:00 → 13:00 Europe/Madrid

Seminar Room 1.1.1. (IFIC)

We perform an amplitude analysis on photon-photon scattering into
 pion and kaon pairs below 1.5 GeV. To get a model independent amplitude as possible,
we impose the basic constraints required by analyticity, unitarity, and
crossing-symmetry. To fix the relative hadronic amplitudes, we include the
latest hadronic pipi, KK scattering amplitudes given by dispersive
analysis, supplemented in the KK threshold region by the recent Dalitz
plot analysis from BaBar. With these hadronic amplitudes and applying
Final State Interaction theorem, we give an overall fit of  gamma
gamma-->pi pi datasets, including the high statistics neutral pion data of
Belle. A region of solutions are found and what should be emphasized, the
relatively poor integrated cross-section data on  gamma gamma -->K K
narrows the patch of solutions to essentially a single form. Finally we
present the photon couplings of scalars and tensors appear in these
processes, which are quite helpful to distinguish their structure.

Slides Amplitude_analysis_in_photon.pdf