Speaker
Description
Over the past decades a number of resonances have been discovered, mostly in the charm sector, that do not fit into a simple quark model picture. A rigorous understanding of how these states arise from QCD and how they can be classified is required, which can only be attained in conjunction with advances in the calculational methods.
In addition to the study of masses and widths of stable hadrons and hadronic resonances, more detailed information on the structure of hadrons can be obtained from radiative transitions and electromagnetic form factors, which are related to a hadron’s coupling to a photon. This is a first step before looking at exotic states (i.e. states that do not fit the simple quark model).
The aim of our project is to take the successful and well tested method of distillation with optimised profiles, which enables the construction of interpolating operators with increased overlap to the desired states, and further develop and implement the method for computing 3-point functions, and from these form factors. We aim to look at the radiative transitions between higher lying states, with preliminary results on $J/\psi \to \eta_c\gamma$. These simulations were done on a $n_f=3+1$ ensemble denoted A1, with pion mass $m_\pi\approx 420$ MeV and lattice spacing $a\approx 0.052$ fm.