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NEUTRAL PION FLUCTUATION STUDIES AT U-70
E.S. Kokoulina 1† , A.M. Kolyada 2 and R.V. Salyanko 2
(1) JINR, Joliot-Curie 6, 141980 Dubna, Moscow region, Russia
(2) Gomel State University, Gomel, Belarus
† E-mail: kokoulin@sunse.jinr.ru
The results of -190experiment (project Thermalization) inppinteractions at theSVD-
2setup arepresented. Thephotonsareregistered bytheelectromagnetic calorimeter. MC
simulation confirms the linear dependence between number ofphotons N γ andtheaverage
multiplicity of neutral pions . Multiplicity distributions of neutral pions, N 0 , at the
given total multiplicity, N tot , including charged particles, N ch , have been obtained with
corrections on the setup acceptance, triggering and efficiency of the event reconstruction.
The scaled variance of neutral pionfluctuations, ω = D/ < N 0 >, versus total multiplicity
evidences for the neutral pion number fluctuation growth over N tot = 18 [1]. According
to ideal pion gas model [2] this behavior may point to the pion condensate formation in
high pion multiplicity system. This effect has been observed for the first time.
References
[1] E.S. Kokoulina (On behalf of the SVD-2 Collaboration), Progr. Theor. Phys., 193,
306 (2012); V. N. Ryadovikov (On behalf of the SVD-2 Collaboration), Phys. Atom.
Nucl., 75, 989 (2012).
[2] V. V. Begun and M. I. Gorenstein, Phys. Lett. B 653, 190 (2007).
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