Lepton in the protons
by
https://fisica-unimi.zoom.us/j/93800786460
As is the case for all light coloured Standard Model particles, also photons and charged leptons appear as constituents in ultrarelativistic hadron beams, and admit a parton density function (PDF). It has been shown recently that the photon PDF can be computed in terms of the structure functions and form factors for electron-proton scattering.
The same holds for lepton PDFs. I present a calculation of the lepton
PDFs at next-to-leading order, using the same data input needed in the photon case. The lepton densities in the proton are extremely small, so that their contribution to Standard Model processes is generally shadowed by processes initiated by coloured partons. It turns out, however, that there are cases where these processes can be relevant, giving rise to rare Standard Model signatures and to new production channels, that can enlarge the discovery potential of New Physics at the LHC and future high energy colliders with hadrons in the initial state.