Hi Catalin, I do not believe one should use the efficiency for now for the condition that H1 beta cut, but apply the H1 efficiency correction separately. (i.e. target cut only, as the default correction pickup ought to be) The reason is that the efficiency is calculated for one specific trajectory, and for high momenta the 'ref' track is close to the holes in H1 wall, and thus artificially falls. (this can be between a 0-5% fall depending on the specific trajectory). This thus has a small issue; The better thing may have been to generate the efficiency by introducing a small spread in angles around which the pions, are thrown to average out this kine of specific spatial effects. Too at the very low end of momenta I known there are tails of the hits distributions of the H1(H2) wall that falls outside the actual acceptance; This is indicative that the efficiency may have an angle/position dependence and thus cannot be factorized as has been assumed. Again this ought too to be checked and is the rational for a challenge at say 8 or 12 degrees with low fields. regards Flemming cc/ devlist -------------------------------------------- Flemming Videbaek Physics Department Bldg 510-D Brookhaven National Laboratory Upton, NY11973 phone: 631-344-4106 cell: 631-681-1596 fax: 631-344-1334 e-mail: videbaek @ bnl.gov ----- Original Message ----- From: "Catalin Ristea" <ristea@nbi.dk> To: "Flemming Videbaek" <videbaek@rcf.rhic.bnl.gov> Sent: Tuesday, June 13, 2006 7:52 AM Subject: ffs geant corrections > > Dear Flemming, > > I know that you must be very busy right now... I apologize for for > bothering you. > > The FFS efficiency, from your scripts, is dropping for high momenta > (more than 10-15 GeV/c), for H1 beta cut and derived. It is because > [pmin, pmax] is too narrow. > It is really physical this dropping? Or do I just change the limits? > > Running on your dst_ffs for run5 I get slightly lower numbers (1% > for all p) than the one on disk8, and still the decrease for h1 cuts. > Your official ascii file is not showing this... how do I get it? > > Not that I'll use h1 cuts at such high momenta, and even though the > target cut is ok, but I'll like to understand it from the point of > view of h1 also. > > Thank you so much. > > Kind regards, > Catalin. > > PS. > By the way, mysql is running smoothly now. > Changing the configuration of the mysql helped a lot, not only with > the number of maximum connections. Before, the connection was > persistent during the entire program execution, but now I see that > mysql closes the socket immediately after the query is finished. This > is I think the major step forward. > > -- > Catalin Ristea--------------------------------- > High Energy and Heavy Ions Group > Niels Bohr Institute > Blegdamsvej 17, 2100 Copenhagen, Denmark > Tel (+45) 35 32 54 04 / Fax (+45) 35 32 50 16 > > E-mail: catalin.ristea@nbi.dk > http : www.nbi.dk/~ristea > ----------------------------------------------- > _______________________________________________ Brahms-dev-l mailing list Brahms-dev-l@lists.bnl.gov http://lists.bnl.gov/mailman/listinfo/brahms-dev-lReceived on Tue Jun 13 08:05:47 2006
This archive was generated by hypermail 2.1.8 : Tue Jun 13 2006 - 08:05:59 EDT