From: Hironori Ito (hito@rcf.rhic.bnl.gov)
Date: Mon Jun 16 2003 - 11:01:06 EDT
Hello. I wrote a very little note about effect of deuteron wave functions to the estimated number of collisions. It is http://pii3.brahms.bnl.gov/~hito/dAu/wave_func/effect_of_deuteron_wave_function.html Hiro Hironori Ito wrote: > 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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