09-10-2009: Colloquium Zbigniew Was

06 - 10 - 2009

Friday 9 October 2009, 15:30h, at Nikhef in room H331

Speaker: Zbigniew Was (IFJ PAN Krakow)

Title: PHOTOS MC for bremsstrahlung in decays

The PHOTOS Monte Carlo program is used in the simulation of W/Z decays at LHC/TEVATRON for precision measurements and for simulation of New Physics signatures and backgrounds. Measurements of the CKM matrix in semileptonic decays of flavored resonances benefit as well.
Because of the precision demand, development of the program and to some degree also its use is challenging. It requires not only good control of higher order perturbative QED but also phenomenological limits of scalar QED. The parametrization of the phase space needs to be exact. Conformal symmetry is not applied for multi-photon configurations. Instead, parametrization of the iterative solution of the evolution equation is used.
Finally from simulation point of view numerical, stability has to be under control within PHOTOS itself but also in the program that generates the events that PHOTOS has to modify.