How bright is the proton? A data driven determination of the photon content of the proton
by
DrPaolo Nason(MIB)
→
Europe/Rome
Aula Caianiello (Dipartimento di Fisica Ettore Pancini)
Aula Caianiello
Dipartimento di Fisica Ettore Pancini
Description
It is well known that a fast moving charged particle is accompanied by an
ensemble of virtual photons, that in collisions can give rise to photon
initiated processes. For electrons the distribution of photons is
calculable with arbitrary precision. For hadrons, the accompanying photon
system is calculable only for impact parameters larger than the hadron
size. There is interest in computing the impact of initial photons
subprocesses at the LHC, and it was generally though that
the photon distribution in the proton could only be obtained by
experimentally studying certain photon initiated processes. In this talk I
will illustrate recent progress on this matter, showing that in fact the
photon parton densities can be extracted with negligible errors from
existing data on the proton electromagnetic structure functions and form
factors.