Study of level-0 trigger for neutral pions

This note reports on possibility of providing neutral pion Level-0 trigger. Dedicated algorithms are proposed for two configurations of pi0 decays into two photons that could enter into Level-0 architecture : o the 2 photon hits in two FE-Cards handled by the same Validation-Card. o the 2 photon hits in the same FE_Card. For each of these two configurations, two strategies are considered. The first and simplest strategy algorithm holds irrespectively of the photons separation while the second one, that implies extended algorithms, aims to enhance the fraction of well separated photons. The choice between the two strategies implementation will depend on the performance of pi0's offline reconstruction, in particular their possibility to reconstruct pi0's from not well separated photons.