Transcript Prezentacja programu PowerPoint

Oscillations of the quark-gluon plasma
or
from oscillations to fast thermalization
Wojciech Florkowski
dedicated to Professor Andrzej Białas on the occasion of His 70-th birthday
1. Development of the color-flux-tube model
by Białas and Czyż
color-flux-tube model: Casher, Neuberger, Nussinov, PR D20 (1979) 179
development by Białas and Czyż in the series of papers published in the 1980s
-
A. Białas and W. Czyż, Boost-invariant Boltzmann-Vlasov equations
for relativistic quark-antiquark plasma, Phys. Rev. D30 (1984) 2371
-
A. Białas and W. Czyż, Chromoelectric flux tubes and the transverse
momentum distribution in high-energy nucleus-nucleus collisions,
Phys. Rev. D31 (1985) 198
-
A. Białas and W. Czyż, Oscillations of relativistic, boost-invariant
quark-antiquark plama, Z. Phys. C28 (1985) 255
-
A. Białas and W. Czyż, Conversion of color field into q anti-q matter
in the central region of high-energy heavy-ion collisions, Nucl. Phys.
B267 (1986) 242
-
A. Białas and W. Czyż, Production and collective motion of q anti-q
plasma in heavy-ion collisions, Acta Phys. Pol. B17 (1986) 635
-
and more others ...
- chromoelectric fields stronger than in „elementary” e+ e- annihilations
Biro, Nielsen, Knoll, Nucl. Phys. B245 (1984) 449
(increased multiplicity, increased production of strange particles)
- oscillations of the quark-antiquark plasma
- fast (t0<1 fm/c) production of dense matter
k number of color charges q which span the initial field, g coupling constant
A. Białas, W. Czyż, A. Dyrek, and WF, Oscillations of quark-gluon
plasma generated in strong color fields, Nucl. Phys. B296 (1988) 611
time dependence of the chromoelectric field (LHS) and the energy density
of quarks and gluons (RHS) for various values of the parameter k
time dependence of the average transverse (LHS) and longitudinal (RHS)
momentum of quarks and gluons for various values of the parameter k
[8 gluon fields are separated into 2 „neutral fields” (chromoelectric field E3 ,
E8) and 6 „charged gluons” (treated as particles together with quarks)]
A. Dyrek and WF, Production of heavy quarks in strong chromoelectric fields,
Nuovo Cim. A102 (1989) 1013
the ratio of strange quarks to
up and down quarks
R1 
ss
u u d d
quantitatively similar results to those obtained by
P. Koch, B. Muller, and J. Rafelski,
Phys. Rep. 142 (1986) 167
2. Early-thermalization in relativistic heavy-ion
collisions
1) the data collected at RHIC suggest that matter is well thermalized and
exhibits collective behavior (bound states above TC, Shuryak; plasma
instabilities, Mrówczyński; Hawking-Unruh effect, Kharzeev)
2) already in more elementary collisions we observe thermal features,
Boltzmann distributions in transverse momentum, Hagedorn, 1960s
A. Białas, Fluctuations of string tension and transverse-mass
distribution Phys. Lett. B31 (1999) 301
gaussian fluctuations of the string tension can account for the „thermal”
distribution of transverse mass of particles created in decay of a color string
the measured transverse-momentum spectra have thermal (exponential)
shape, Hagedorn, 1960s
 m 
~
exp

,
d 2 p
 T 
dNexp
m  m2  p 2 
string models of hadronic collisions use the Schwinger formula
dNSchwinger
d 2 p
  m2  

~ exp 
2



Białas: appropriate averaging over κ may produce an exponential function
  m2  
 m 




d

P

exp

~
exp

,
2



 
 T 

T
2
2
fluctuations may appear due to stochastic nature of the QCD vacuum
(H.G. Dosch, Yu. A. Simonov)
my personal follow-up of this idea, WF, Schwinger tunneling and
thermal character of hadron spectra, Acta Phys. Pol. B35 (2004) 799
quark spectra in the color-flux tube model are exponential due to the
dynamic oscillations of the chromoelectric field E
  m2  
 m 




dt
P
t
exp

~
exp



 E 2 (t ) 
T




'
oscillations in varying chromoelectric fields may explain the origin of
the thermal spectra in heavy-ions but this effect is not capable of
describing thermal features observed in elementary processes
it is conceivable, however, that the effect of the stochastic vacuum
plays an additional role in heavy-ion collisions leading to even more
pronounced thermalization effects
Instead of Conclusions ...
Drogi Panie Profesorze!
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