Hi, I have an idea that maybe can be used in order to remove the duplicates from our analysis: Given that we are choosing for each event only one B candidate I propose to use the serial number of the B processed in order to make a lookup table that can be used in order to tell anaRecoil to skip or not compute the recoil part of the event with a given "serial number". If we add more data the only thing that we have to do is to append the new data after the old one : and then recompute the right serial number. This avoid storing the timestamps and comparing the timestamps of all candidates with a given list. We just care about the "nevents" variable and we cut on it. Let me know any problem or comment that you have on this proposal. Thanks a lot, Alessio ______________________________________________________ Alessio Sarti Universita' & I.N.F.N. Ferrara tel +39-0532-781928 Ferrara "Quod non fecerunt barbari, fecerunt Berlusconi" "Che il bianco sia bianco, e che il nero sia nero che uno e uno fanno due e che la scienza dice il vero.... DIPENDE !"