RE: [Brahms-dev-l] PANIC05 abstract

Hi All,

   Following coments from JH, I have slightly modified the abstract for PANIC
Please send comments and suggestions

-------------------------------

Collisions between hadronic systems at relativistic energies provide 
a window on the small-x gluon distributions of fast moving nuclei. It has been 
predicted that gluon saturation effects will manifest themselves as a suppression
in the transverse momentum distribution at a scale which is connected with the
rapidity of the measured particles. Saturation effects are most evident at large 
(pseudo)-rapidity, i.e at small angles relative to the beam direction. BRAHMS has
already studied the rapidity dependence of the nuclear modification factor as a 
function of rapidity in dAu and AuAu collisions. While the absence of high Pt suppression
 around midrapidity rules out initial state effects, a marked high Pt suppression with
 increasing pseudorapidity may be related to the initial conditions of the colliding 
deutron and gold nuclei, in particular to the possible existence of the color glass 
condensate(CGC) which is a theory that describes the ground state of fast moving nuclei
 prior to collision. For AuAu collisions, we do see a suppression at (pseudo)-rapidity ~ 3.
This may be due to final state effects such as parton recombination, energy loss, 
or initial state effects such as CGC. The dependence of the nuclear modification factors 
on the number of participants also provides an additional constraint on the mechanism 
underlying the observed suppression. This was the motivation for studying CuCu collisions.
We will present results for the nuclear modification factor Rcp at forward rapidities for 
CuCu collsions at 200 GeV/NN. The results will be compared to previous results in AuAu
 and dAu collisions at the same energy.
--------------------------------------

Selemon,


-----Original Message-----
From: J.H. Lee [mailto:jhlee@rcf.rhic.bnl.gov]
Sent: Tue 8/16/2005 9:41 PM
To: Bekele, Selemon
Cc: 'devlist'
Subject: RE: [Brahms-dev-l] PANIC05 abstract
 
Hi, Selemon,

I am not sure that your physics statement for
the high-pt suppression in AuAu is in sync with
our current understandings.
"For AuAu collisions, we do see a suppression
at (pseudo)-rapidity ~ 3 which seems to favor 
the CGC scenario."

I think our high-pt suppression results at forward 
rapidity in AuAu is understood mainly as final 
state effects (energy loss, hydro...) 
rather than initial state effects. 
In AuAu collision, coherent interactions in the 
initial state (Saturation/CGC) is claimed to be 
"realized" mainly as "small" hadron multiplicities.

JH

> -----Original Message-----
> From: 
> brahms-dev-l-bounces+jhlee=rcf.rhic.bnl.gov@lists.bnl.gov 
> [mailto:brahms-dev-l-bounces+jhlee=rcf.rhic.bnl.gov@lists.bnl.
> gov] On Behalf Of Bekele, Selemon
> Sent: Tuesday, August 16, 2005 5:43 PM
> To: brahms-dev-l@lists.bnl.gov
> Subject: [Brahms-dev-l] PANIC05 abstract
> 
> 
> 
> Hi All,
> 
>    please find the abstract I intend to submit to PANIC05. I 
> appreciate suggestions and comments. Thanks!
> 
> --------------------------------------------------
> High Pt suppression in CuCu Collsions at 200 GeV/NN.
> 
> 
> Collisions between hadronic systems at relativistic energies provide 
> a window on the small-x gluon distributions of fast moving 
> nuclei. It has been 
> predicted that gluon saturation effects will manifest 
> themselves as a suppression in the transverse momentum 
> distribution at a scale which is connected with the rapidity 
> of the measured particles. Saturation effects are most 
> evident at large 
> (pseudo)-rapidity, i.e at small angles relative to the beam 
> direction. BRAHMS has already studied the rapidity dependence 
> of the nuclear modification factor as a 
> function of rapidity in dAu and AuAu collisions. While the 
> absence of high Pt suppression  around midrapidity rules out 
> initial state effects, a marked high Pt suppression with  
> increasing pseudorapidity may be related to the initial 
> conditions of the colliding 
> deutron and gold nuclei, in particular to the possible 
> existence of the color glass 
> condensate(CGC) which is a theory that describes the ground 
> state of fast moving nuclei  prior to collision. For AuAu 
> collisions, we do see a suppression at (pseudo)-rapidity ~ 3 
> which seems to favor the CGC scenario. The dependence of the 
> nuclear modification factors 
> on the number of participants also provides additional 
> information on the mechanism 
> underlying the observed suppression. We present results for 
> the nuclear modification 
> factor Rcp at forward rapidities for CuCu collsions at 200 
> GeV/NN. The results will 
> be compared to previous results in AuAu and dAu collisions at 
> the same enrgy.
> -------------------------------------------
> 
> Selemon,
> 
> _______________________________________________
> Brahms-dev-l mailing list
> Brahms-dev-l@lists.bnl.gov 
> http://lists.bnl.gov/mailman/listinfo/brahms-dev-l
> 



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