CERN Accelerating science

• Peter Seyboth - Fri, 6 Nov 1998
  

Dear Berndt and Peter,

   Thank you for preparing the second draft of the status report.
In general it reads very well, however I am still not completely
happy. The report is intended as a political statement and
therefore I would like to have also the interests of NA49 fully
represented. Thus I ask you for the following modifications:

(1) first sentence of section strangeness enhancement: Earlier
    results from NA35/NA49 of an enhanced production of strangeness
    in nuclear collisions ...

(2) section on collective flow and hadron thermometry: insert the
    following sentences after at the end of the first paragraph:
    The interpretation in terms of  equilibrium models is supported
    by the observation in NA49 of only small, purely statistical
    event by event fluctuations of the average transverse momentum
    (tempereature) and the kaon/pion ratio (flavor). This result
    points to early equilibration of the produced hadronic matter,
    a prerequisite of QGP formation.

(3) concluding outlook section, replace the last sentence of the
    second to last paragraph: ... dilepton spectrum). At lower
    beam energies one also has a smaller early stage energy density
    and one may be able to identify the energy region in which 
    the transition to the QGP possibly occurs. Characteristic
    signatures are a change in the energy behavior of pion and
    strange particle production, in the magnitude of event to event
    fluctuations and effects connected with the softening of the
    equation of state of the hadronic matter ( lifetime of the 
    fireball, azimuthal anisotropies, flow ). 
       Detection of a threshold at lower collision energy and/or in
    lighter colliding systems could provide strongly supporting
    evidence for the proposition that matter created in Pb+Pb
    collisions at the highest SPS energy indeed is initially in the
    QGP state. 
 
Thank you and best regards,  Peter