Hi, Hiro, don't be pesimistic! There is at least one issue where we can reasonably hope to get some physics out of the 22GeV run; That's the limiting fragmentation (one of our specific physics corners). This does'nt require a fully efficient trigger. We know that LF is centrality independent and we can even check it at 22GeV (use just relative cuts in centrality). It would be really very nice to get the complete picture from 22GeV -> 200GeV under the same conditions (collider configuration, same detector, same people, etc..) and for the same reaction. This will be also important for LHC (as Jens Joergen has mentioned in one of his recent mails). One could even hope to publish a dedicated short paper on limiting fragmentation with the whole data (including hopefully also p+p data at 200GeV ?). The only problem that I see is statistics, whether it should be sufficient (24hours)? not clear to me. Anyway let's be optimistic and take data... Regards, Fouad On Sat, 17 Nov 2001, Hironori Ito wrote: > For 22 Gev run, I am not sure it is possible to get multiplicity > results because ZDC is only about 10 % efficient with this energy. This > means we (or I ) are not sure what fraction of the total cross section is > measured for those energy. (I do not know what PHOBOS is thinking. Also, > I need more statistics than what PHOBOS needs because our detector cover > smaller solid angle than they do.) Any ideas are welcome, but otherwise I > think it is a waist of shifters' time. > > hiro > > On Sat, 17 Nov 2001, [iso-8859-1] Jens Jørgen Gaardhøje wrote: > > > Hello friends > > As concerns the run. > > -Ian and I discussed the 12 deg statistics yesterday based on a fisrt analyis of a run at the present setting. > > It is still to early to really evaluate the present run, but it seems likely that we will not have time to do 2 polarities at this > > angle and high field setting. We will need to make a final decision by monady or tuesday. > > -I would think that we should run at 22 GeV. If nothing else we should be able to get the multiplicity distributions. > > regards > > JJ > > > > ________________________________ > > Jens Jørgen Gaardhøje > > Assoc. prof. Dr. Scient. > > Chair Ph.D: school of Physics NBI.f.AFG. > > (secretariat. 35 32 04 41) > > Chair science committee. UNESCO Natl. Commission. > > (secretariat. 33 92 52 16) > > Office: Niels Bohr Institute, Blegdamsvej 17, > > 2100, Copenhagen, Denmark. > > Tlf: (+45) 35 32 53 09 > > Fax: (+45) 35 32 50 16 > > ________________________________ > > ----- Original Message ----- > > From: Flemming Videbaek > > To: brahms-l@bnl.gov > > Sent: Saturday, November 17, 2001 5:10 PM > > Subject: run status > > > > > > > > The AuAu running is going into the last 8 days of running. The machine has run fairly well in recent eve+nights and this is expected > > to continue over the weekend. The yellow beam still has lifetime problems, and and 12 hour beam development period is scheduled from > > Monday morning 6.00 am. > > > > - Please turn magnets to 0 field, and standby at that time. > > > > - The running at 12 deg 2/3 fields has started (.66 M) collected > > aim up to 810M at 2/3 field (and at least 4M) > > - 40 deg 1.5 M for HBT is complete. > > - The high statistics program at 90 deg has started - there is an issue if the retracted position (i.e. reduced solid angle by 25%) is > > an issue. > > > > In the previous e-mail I requested, and will like to repeat a call for un-finished business. e.g angles, fields in the exsisting program > > that needs repeating, or special runs that enhanches our understanding of present data or in preparation for upcoming runs. > > > > So far there are a couple of items > > > > - Michael M. requested a short run ~100K minbias data with reduced ZDC HV to understand tube saturation. > > - I will like to take a several hours to develop the H1/H2 trigger setup, probably middle of the week (though not Thursday) > > - Michael suggested we study the 22GeV beam, not so much to take physics data, but to gain insight how to deal > > with lower energy beams in preparation for the future. E.g. ZDC threshold/settings/response triggering. He is planning to come to BNL > > for the weekend for this purpose. > > > > > > > > >
This archive was generated by hypermail 2b30 : Sun Nov 18 2001 - 09:31:33 EST