From: Hironori Ito (hito@rcf.rhic.bnl.gov)
Date: Fri Jun 13 2003 - 14:10:32 EDT
Hello. Regarding a value for Ncol, I have a word of caution. (Note: I hate to use these unmeasurable number.) Our standard hijing (version 1.36) uses a wrong form of deutron wave function (and with a wrong parameter). Hijing version 1.82 (or newer 1.83) uses correct Hulthen wave function (supposedly). (I am checking it currently.) The difference in a wave function obviously cause different values in number of participants and collisions. From quick check (with simple glauber calcuation), it seems that using Hulthen wave function reduces mean number of collisions by "one" for minimum bias events. The mean number of collision in old (standard) hijing is about 7.5 whereas the mean number of collisions using Hulthen wave function is about 6.5. Of course, we have to include efficiency of our minimum bias detectors (INEL). Anyway, I will post more detail comments later after running GEANT with the newest Hijing. Hiro Flemming Videbaek wrote: > Dear Claus, > > This looks very good. I will talk more to Hiro we also understand the Ncoll (Npart) well. There are some changes > dependening on the wawe functions, so this is understood. > > Could you also point us to the macro's you are using; as you say both fresh eyes and air > helps in this regards. My point is just we even though it looks and feels like the other three exp does not mean this is > the final results, but it is certainly encouraging. > > Flemming > > > ------------------------------------------------------ > Flemming Videbaek > Physics Department > Brookhaven National Laboratory > > tlf: 631-344-4106 > fax 631-344-1334 > e-mail: videbaek@bnl.gov > > ----- Original Message ----- > From: "Claus O. E. Jorgensen" <ekman@nbi.dk> > To: "Flemming Videbaek" <videbaek@bnl.gov> > Cc: "Peter Christiansen" <pchristi@nbi.dk>; "Jens Jorgen Gaardhoje" <gardhoje@nbi.dk>; "Ian Bearden" <bearden@nbi.dk>; > <jhlee@bnl.gov>; "Hironori Ito" <hito@rcf.rhic.bnl.gov> > Sent: Friday, June 13, 2003 4:58 AM > Subject: Re: d+Au analysis > > > | > | Hi, > | > | As seen so often before mistakes are not revealed when one sits in front > | of the screen. When I biked home through the streets of Copenhagen early > | this morning I went through the analysis in my head and I though about the > | differences between d+Au and Au+Au. Where are the pitfalls? I've basically > | copied the Au+Au analysis. Have I missed something? Have I changed bb to > | inel in all my numerous loops? This morning I went through the code, > | checking every detail and I've made exactly that mistake in one of the > | loops. You can see the new result in the web-page. > | > | Today I will go though the code again with Ian to make sure that there are > | no more stupid mistakes. > | > | Cheers, > | > | Claus > | > | > | On Thu, 12 Jun 2003, Flemming Videbaek wrote: > | > | > Dear Claus, > | > > | > It is good that the different pol now gives consistent results. As you point out it is most bothering that the values > are > | > below one. > | > Do I have any suggestions? Not really. > | > I guess you already include 5% tracking effeciency ? Maybe it could be 10 but that would not change the overall > | > numbers.The estimate for Ncoll is maybe down to ~7 with the Hulthen wawefucntion for our centrality > | > value, but certainly not lower. > | > > | > The tofw slats are from 21-125 - I talked to JH and they are symmetric around the center i.e panel 4 is centered, as > also > | > in the database. (for dAu, the pp is a different story) > | > > | > Could you look at the Inel vertex distribution for the 1 hit in each side and see if it is very different. As a check > one > | > could also make the analysis requiring 2 hits in each side for both spectrometer data and the INEL conditions. One > then > | > has to re-evaluate the Ncoll (which certainly will get higher.) > | > As before the trigger effeciency is good, as you recall JH's plot where one looked at tracks for minbias evebts > | > which did not have the trigger set. > | > > | > If we have a result that is below one we really have to be sure about it, since 3 others have a value at or above 1- > and > | > it would at this point be a contradictory results. I know it is difficult to get down to these > | > levels but anyhow. > | > > | > You mentioned you lookedd at the (+) an (-) seperately with a ratio of 0.95 I will guess this means the > | > RdA would just be close to ienticla for each side. > | > > | > One last suggestion before closing up would be to see what happens with a vertex of +-15, vs +-10. > | > > | > Let us talk tomorrow morning when I get in around 9 (15) - if anyone else has suggestions please supply these. > | > > | > cheers and thanks for the great effort. > | > > | > Flemming > | > > | > ------------------------------------------------------ > | > Flemming Videbaek > | > Physics Department > | > Brookhaven National Laboratory > | > > | > tlf: 631-344-4106 > | > fax 631-344-1334 > | > e-mail: videbaek@bnl.gov > | > > | > ----- Original Message ----- > | > From: "Claus O. E. Jorgensen" <ekman@nbi.dk> > | > To: "Flemming Videbaek" <videbaek@bnl.gov> > | > Cc: "Peter Christiansen" <pchristi@nbi.dk>; "Jens Jorgen Gaardhoje" <gardhoje@nbi.dk>; "Ian Bearden" <bearden@nbi.dk>; > | > <jhlee@bnl.gov> > | > Sent: Thursday, June 12, 2003 6:38 PM > | > Subject: Re: d+Au analysis > | > > | > > | > | > | > | Hi, > | > | > | > | I've found the reason for the difference in the A and B polarity. It's > | > | really stupid (and a bit embarrassing) and maybe only interesting for > | > | BRAT experts. > | > | > | > | When I get the scale down factors from the runinfo I of course use the > | > | runinfomanager. In the beginning of my program I register all the runs I > | > | want to look at. When I look over the runs I update the manager and get > | > | the current run. This is the problem. The update does not give me the next > | > | run, since this is not incremented in my program. I guess I'm used to > | > | bratmain where all this is taken care of. Anyway the result is that I used > | > | the scaledown factor of the first run in my loop for all the run :-( > | > | > | > | This is now fixed now and the two polarities give consistent results. I > | > | also tried to group the run differently and there is no variations. The > | > | problem now is that the R_dA flattens out at a somewhat lower value (~0.8). > | > | You can see the result in the web-page (www.nbi.dk/~ekman/highpt/dAuAnalysis.html). > | > | > | > | As always when one obtains a result that is different from the expected > | > | one starts to think about explanations. I'm wondering if there could > | > | be background in the inelastic counters? I checked the n hits left vs > | > | right and there is a small bump at 1,1 (compared to the neighbor bins. Is > | > | it fair to cut these events away? Apart from that I'm blank right now. Of > | > | course there is also the possibility that the other experiments are wrong;-) > | > | > | > | Maybe I should do the event norm run by run - I'll look at that tomorrow. > | > | > | > | Any other ideas? > | > | > | > | Flemming, could you remind me of the TOF trigger configuration? What slats > | > | go into the trigger? If I compare the data and the maps there is data > | > | missing in one side. I suspect that the two outer panels where not used? > | > | > | > | Cheers, > | > | > | > | Claus > | > | > | > | > | > | > | > | > | > | +------------------------------------------------------------+ > | > | | Claus E. Jørgensen Phone : (+45) 33 32 49 49 | > | > | | Cand. Scient. (M. Sc.) Cell : (+45) 27 29 49 49 | > | > | | Office : (+45) 35 32 54 04 | > | > | | Niels Bohr Institute, Ta-2, Fax : (+45) 35 32 50 16 | > | > | | Blegdamsvej 17, DK-2100, E-mail : ekman@nbi.dk | > | > | | University of Copenhagen Home : www.nbi.dk/~ekman/ | > | > | +------------------------------------------------------------+ > | > | > | > > | > > |
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