Top-quark effects in diphoton production through gluon fusion at NLO in QCD
by
Manoj Kumar Mandal(University Of Padova)
→
Europe/Berlin
313 (MPI Meeting rooms)
313
MPI Meeting rooms
Description
At hadron colliders, the leading production mechanism for a pair of photons is from quark-antiquark annihilation starting from the tree level. However, due to large gluon-gluon luminosity, the di-photon production from gluon fusion via a closed fermion loop provides a substantial contribution. In particular, the amplitudes mediated by the top quark become important at the top pair threshold and above. I will discuss the framework that allow us to evaluate the next-to-leading order (NLO) corrections in QCD to this process, retaining the full top quark mass effects. These entail two-loop diagrams with massive propagators whose analytic expressions are unknown and have been evaluated numerically. Specifically, I will present the results for the invariant mass distribution including the five massless quarks and the top quark contribution, thereby exhibiting the importance of the inclusion of the top quark mass effects.
