Hi Claus Nice set of plots for inspiration. I comment in-line below. Look forward to the nest set! JJ ____________________________________________________________ Jens Jørgen Gaardhøje, Assoc. Prof., Dr. Sc. Niels Bohr Institute, Blegdamsvej 17, 2100 Copenhagen, Denmark. Tlf: (+45) 35 32 53 09, secr. (+45) 35 32 52 09, Fax: (+45) 35 32 50 16. UNESCO Natl. Comm., secr. (+45) 33 92 52 16. Email: gardhoje@nbi.dk. ____________________________________________________________ ----- Original Message ----- From: "Claus O. E. Jorgensen" <ekman@nbi.dk> To: "brahms-l" <brahms-l@bnl.gov> Sent: Friday, July 05, 2002 2:31 AM Subject: High Pt analysis > > I've made some preliminary plots for my qm2002 talk. You can find them > here: > > http://www.nbi.dk/~ekman/highpt/highpt.html > > The main physics plots will be > > - (h++h-)/2 pt spectra for 0-5, 5-10, 10-20 and ~40-60% centrality at > eta=0. > I ASSUME THAT THIS PLOT WILL BE ACCOMPANIED BY A SET OF FIT RESULTS TO THE FUNCTIONAL C*(1+P/P0)**N. IT WOULD BE INTERESTING TO SEE THE SYSTEMATICS OF P0 AND N VS CENTRALITY. CAN YOU DO A SIMILAR ANALYSIS FOR THE Y02.2 SPECTRA ? EVEN THOUGH THE STAT AT THE HIGH END MAY BE INADEQUATE? > - pt ratio (R) of central (0-10) to semi-peripheral (~40-60). Here I > conlude that we our measurements indicate a suppression of high pt > particles when comparing central to semi-peripheral collisions - this > comparison is of course independent on fit ranges and reference data > taken with another experiment. THAT ONE WAS NOT INCLUDED? DOES IT LOOK LIKE THE STAR RESULTS? SEE COMMENTS BELOW ALSO. > - ratios of spectra to p+pbar reference (ua1) data. These ratios are > dependent on the choice of reference data and fit ranges/methods. > However, suppression of high pt hadrons is observed and it is more > pronounced for the central collisions. > THIS IS A CENTRAL PLOT. THE LABEL ON THE ORDINATE IS MUCH TOO SMALL. THERE IS ALSO TOO MUCH WHITE SPACE. WHAT ARE THE RED LINES? FOR 0-5 THE RED LINE SEEMS TO GO WELL TROUGH THE POINTS. THAT IS CERTAINLY NOT THE CASE FOR THE MOST PERIPHERAL - WHICH THEN IS MISLEADIN. YOU COULD TRY TO QUANTIFY THE SUPPRESSION BY MAKING A PLOT OF THE RATIO AT SOME GIVEN PT AS A FUNCTION OF THE CHOSEN CENTRALITY BINS. > - ratios of protons to all hadrons as function of pt. Mesonic vs. baryonic > jets??? Who knows about this stuff? Is my result reasonalbe (I just > pulled out the numbers)? > I THINK THIS IS AN INTERESTING PLOT. I ASSUME IT IS FOR Y=0. WHAT IS THE PID FOR THE P AND PBARS+ IS IT REALLY CLEAN UP TO 4.5 . ELSE DROP THE HIGEST POINTS. CAN YOU FIT THE REGION FROM 2.5 GEV/C AND UP TO A STRAIGHT LINE. IS IT FLAT ? WHAT IS THE SCALE ON THE ORDNINATE. ABSOLUTE OR ARB. UNITS? CAN YOU MAKE THE SAME FOR P AND PBAR INDIVIDUALLY? A PLOT OF PBAR/P TO HIGH PT WOULD ALSO BE INTERSTING. THE STATEMENT THAT I READ FROM THIS PLOT IS THAT 1) THE HIGH PT PART OF TOTAL HADRON AND BARYONS ARE THE SAME. OR/AND 2) THE HIGH PT PART IS ALL BARYONS, SO THAT BARYONS/TOTAL IS FLAT. THE LATTER CONCLUSION SAYS THAT MESONIC JETS ARE VERY SUPPRESSED. SO IT WOULD BE GOOD TO SUPPLEMENT THIS PLOT WITH A SET OF SPECTRA (PI, k, P) TO HIGH PT, NORMALIZED AND ON THE SAME PLOT, SO THAT WE CAN SEE BY HOW MUCH THE P DOMINATE. IF YOU CANNOT SEPARATE PI AND K, PLOT THESE TWO TOGETHER. > - pi- spectrum at y approx 2.2 for 0-15% central. The statistics are > unfortunately not good enough to make qualitative statements on the > slope at high pt. YOU SHOULD PROB. DROP THE LOWEST POINT IN EACH SETTING (EDSGE OF ACCEPTANCE). HOW ARE THESE NORMALIZED? DOESN'T LOOK TOO BAD. YOU COULD BIN DIFFERENTLY AT THE HIGH FIELD SETTINGS. tHERE SEEMS TO BE A CHANGE OF SLOPE (UPWARDS SLOPING) AFTER 2 GEV. IS THIS THE PROTONS? cAN YOU PALY THE SAME GAME PI (POSSIBLY WITH k) VS P ? > > - pi- pt ratios of central (0-10) to semi-peripheral (~40-60). The ratio > constant (within the erros). What do we expect at forward rapidities? > THIS IS OF COURSE VERY INTERESTING IF TRUE. IT SUGGESTS THAT THE SUPPRESION BETWEEN CENTRAL AN PERIPHERAL IS MUCH LESS PRONOUNCED AT FORWARD RAP. IF WE BELIEVE THE SUPRESSION HAS ANYTHING TO DO WITH THE CENTRAL ZONE AND THE QGP, THIS EFFECT SHOULD DISAPPEAR AT FWD. RAP., ALTHOUGH THE ARGUMENT IS PROB. NOT SO CLEAR IF ALL JETS ARE PRODUCED IN HARD SCATTERINGS IN FIRST COLLISIONS. PERHAPS LONGITUDINAL JETS SEE FEWER COMOVERS??? YOU MAY WANT TO PLOT ONTO THIS CURVE THE RATIO THAT YOU SEE AT Y00 FOR COMPARISON- SUITABLY SCALED. CAN YOU FIND A FUNCTIONAL FORM THAT WILL REPRODUCE THE SET OF POINTS. STRAIGHT LINE OR SOME OTHER FUNCTION. IF THE PRIMARY SPECTR CAN BE FITTED WITH (1+P/P0)**N THEN THE RATIO YOU SHOW SHOULD BE FITTABLE BY A FUNCTION WHICH IS THE RATIO OF THESE TWO FUNCTIONALS. IF P0 IS THE SAME THEN YOU SHOULD BE ABLE TO FIT THE RATIO WITH A FUNCTIONAL (1+P/P0)**N WHERE N<0 AND PROB. ALSO >-1. I LIKE THE ACCEPTANCE PLOTS. BUT NOT SO MUCH THE COLORS (GREY BACKGROUND). CHEERS JJ > Comments and suggestions are very welcome... > > Cheers, > > Claus > > > +-------------------------------------------------------------+ > | Claus Jørgensen | > | Cand. Scient. Phone : (+45) 33 32 49 49 | > | Cell : (+45) 27 28 49 49 | > | Niels Bohr Institute, Ta-2, Office : (+45) 35 32 53 07 | > | Blegdamsvej 17, DK-2100, E-mail : ekman@nbi.dk | > | University of Copenhagen Home : www.nbi.dk/~ekman/ | > +-------------------------------------------------------------+ > > >
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