[Brahms-l] Minutes/Brahms 17 Apr 09

Minutes of Brahms Analysis Meeting 17 April 2009
================================================

Present: Kris, Selemon, Flemming, Pawel, Ionut, JH
========
Agenda & slides
http://indico.cern.ch/conferenceDisplay.py?confId=56798


AuAu 200+papers  Flemming
Cu Cu         Selemon
K/pi 62 GeV paper  Ionut
Spin talk           JH

Because of technical problems we started first with Selemon

Copper-Copper: Selemon
=======================
He has been looking at hydro+cascade and has recently overcome some  
technical difficulties. For CuCu --10% pure hydro works well for pi,k  
up to Pt = 1 and 1.5 GeV respectively. Hydro+cascade falls below the  
data for all species. JH wondered about the transition in the shape  
of the curve around 2GeV. HydroJet seems to work better than  
HydroJamJet (which includes cascade). Ionut suggested increasing the  
temperature and flow velocity.
SB says particles freeze-out at 100MeV.

CGC initial conditions seem to overestimate the data. He plans to  
contact Hirano and Ramiro. He has heard that there is a new version  
of the code.

Flemming: AuAu
==============
A number of settings from run-2 allows us to extend the rapidity and  
pTrange
These in particular are 30, 35 and deg settings, as well as 90 A/B 164.
Have setup these settings to be analyzed with the dst2spec package.

Overall the agreement with run-4 data are pretty good. There is an  
difference in TPC efficiencies that may make up a 5-10% difference in  
yield. He believe we will have to add a ~8% systematic error due to  
this. based on the difference between run-2 at 40 deg can be used to  
settle the systematic difference.•The 30 and 35 degree data will  
enable us to have pions out to y=1.5. Run-4 by itself only to ~1 due  
to lack of low field .This is a good extension of the run-4 data and  
matches what Djamel did.

Paper Status:
=============
*** Stopping: re-submitted!
* coalescense: MJM revisit exp details, get updates from CN FV look  
at deuterons.
* K/pi IA; reduce figs with model calculations. See comments from  
Dieter, Peter C.
* P/pi: PS: Next draft in a few weeks what is status?:
* V2(pt): needs a few more hydro. Material otherwise done (Cu?)
pp 62 200; Some new ideas what to include: Total E , dE/dy finalize  
figs, text.
*CuCu -Selemon has lots of figures and he is not sure what to  
include. This looks like a PRC.

* AuAu.--include 62 GeV. IA have a few weeks to revisit centrality  
dependence. Longer term prospects. Need work from FV/Pawel (after pp  
and p/pi paper)

* Ramiro working on dAu paper.
* JH working on spin paper.

Flemming is concerned on having enough time to write all these papers.

Ionut 62 Gev K/pi
===================
He has received comments from Kris, Peter, Dieter and Flemming:
Regarding pbar/p ratio used in the K/pi paper, should we show pbar and p
spectra? I did not put them in the paper from the begining just because
these were shown in Hans's stopping paper. We decided not show these  
and just refer to the reference. (The dN/dys in the submitted paper  
were corrected for contamination.)

In Tables 1&2 he will show the integrated yield in the fitted pt  
range instead of fiducial ratio. For pion yields d at y=0 and y=1 he  
will
1)  Check the measured (not fitted) integrated yields in the same pt  
range
for pi/K at y=0 and y=1. (This is related to A/B problem.)
2) Check simultaneous fit for spectra at y<1 using fixed or slowly  
varying <pt>

The pion point at y=3.32 has a coverage of ~8%, remove it? We decided  
to drop it.
For our K-/K+ vs pbar/p uRqmd seems to have a universal behavior  
versus AMPT which does not. This may be because of the large number  
of hadronic channels in uRqmd.


JH: Spin talk for DIS09
========================
He wants to concentrate and energy and multiplicity dependence for  
single spin asymmetries for pi,k,p and compares them to PYTHIA6.2.  
For pt spectra there are significant discrepancies in charge  
separation at most forward rapidities.
proton fragmentation/transport in PYTHIA need to be improved.
NLO pQCD calculations in a reasonable agreement/under-predict with  , K+
The K  data are suppressed order of magnitude (valence quark dominance)

JH believes we have found a non-"trivial" pT -xF dependence but this  
may complicated by limited kinematic sampling at higher-pT.
He has looked at the pt distribution of low multiplicity/high  
multiplicity normalised by total yield. At y=0 this ratio drops with  
pt presumably since the high  multiplicity events come from harder  
collisions. This effect also works at high rapidity. Assymetries  
increase with multiplicities. Note if he takes pt=1-1.2 assymmetry  
increases with multiplicity.
Warning. Tile array is centered on forward rapidities so this could  
have some effect.


===================== Submitted by Michael Murray   
==============================

_______________________________________________
Brahms-l mailing list
Brahms-l_at_lists.bnl.gov
https://lists.bnl.gov/mailman/listinfo/brahms-l