Fw: Phobos paper on comparison with e+e- multiplicity

From: Flemming Videbaek (videbaek@sgs1.hirg.bnl.gov)
Date: Thu Jan 16 2003 - 17:13:55 EST

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    FYI
    Another not unexpected Phobos paper -
    what about the participant energy loss in AA not beeing the full beam energy ?? 
    This seems not to be considered.
    
    Flemming
    ------------------------------------------------------
    Flemming Videbaek
    Physics Department
    Brookhaven National Laboratory
    
    tlf: 631-344-4106
    fax 631-344-1334
    e-mail: videbaek@bnl.gov
    
    ----- Original Message ----- 
    From: "Wit Busza" <busza@MIT.EDU>
    To: <tkirk@bnl.gov>
    Cc: <hallman@bnl.gov>; <videbaek@bnl.gov>; <zajc@columbia.edu>
    Sent: Thursday, January 16, 2003 10:47 AM
    Subject: Phobos paper on comparison with e+e- multiplicity
    
    
    | Dear Tom,
    | In a week's time the Phobos collaboration is planning to submit the 
    | following paper to PRL:
    | 
    | 
    | Title: Comparison of the Total Charged-Particle Multiplicity in 
    | High-Energy Heavy Ion Collisions with e+e- and pp/pbar-p Data.
    | 
    | Abstract:
    | The PHOBOS experiment at RHIC has measured the total multiplicity of
    | primary charged particles as a function of collision centrality
    | in Au+Au collisions at sqrt(s_NN) = 19.6, 130 and 200 GeV.
    | Above sqrt(s)~20 GeV, the total multiplicity per participating
    | nucleon pair (<Nch>/(<Npart>/2)) in central events scales with sqrt(s)
    | in the same way as <Nch> in e+e- data. This is suggestive of a universal
    | mechanism of particle production in strongly-interacting systems, controlled
    | mainly by the amount of energy available for particle production (per
    | participant pair for heavy ion collisions). The same effect has been
    | observed in pp/pbar-p data after correcting for the energy taken away 
    | by leading
    | particles.  An approximate independence of <Nch>/(<Npart>/2) on the number of
    | participating nucleons is also observed, reminiscent of ``wounded nucleon''
    | scaling (<Nch> proportional to <Npart>), but with the constant of
    | proportionality set by the multiplicity measured in e+e- data rather
    | than by pp/pbar-p data.
    | 
    | 
    | The results in this paper are essentially the same as those shown by 
    | Peter Steinberg at QM2002.
    | 
    | All the best,
    | Wit
    


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