# FCC Week 2019

Jun 24 – 28, 2019
Crowne Plaza Brussels Le Palace
Europe/Zurich timezone

## Luminosity with e+e- -> gamma gamma: theory perspective

Jun 25, 2019, 5:30 PM
30m
Eva/Inno (1st floor)

### Eva/Inno

#### 1st floor

Presentation Physics

### Speaker

Carlo Michel Carloni Calame (INFN, Pavia (IT))

### Description

The unprecendented precision goal of the future FCC-ee machine in key measurements in the Standard Model and beyond will require that the accelerator luminosity is know with extremely high accuracy, at the $10^{-4}$ level and even better. In this context, QED processes (and their accurate theoretical prediction) play the role of precise luminosity monitoring processes: together with the standard Bhabha scattering, used in the past at LEP and flavour factories, it is interesting and worthwhile to consider also the $e^+e^-\to\gamma\gamma$ process, which, despite a lower statistics than Bhabha, can be predicted with very high accuracy. In this presentation, the current status of $e^+e^-\to\gamma\gamma$ calculations and Monte Carlo tools will be reviewed and the perspective for future theory improvements will be traced and discussed in detail.

### Primary authors

Carlo Michel Carloni Calame (INFN, Pavia (IT)) Mauro Chiesa (University of Würzburg) Guido Montagna (University of Pavia e INFN, Pavia (IT)) Oreste Nicrosini (INFN, Sezione di Pavia) Fulvio Piccinini (Universita and INFN (IT))