Naslov
Hot and dense QCD medium and restoration of U_A(1) symmetry

Autori
Klabučar, Dubravko ; Benić, Sanjin ; Horvatić, Davor ; Kekez, Dalibor

Vrsta, podvrsta i kategorija rada
Radovi u zbornicima skupova, cjeloviti rad (in extenso), ostalo

Izvornik
Bled Workshops in Physics, Vol. 14, No. 1, proceedings of the Mini-Workshop "Looking into Hadrons" / Golli, Bojan ; Rosina, Mitja ; Širca, Simon - Ljubljana : DMFA - Založništvo, 2013, 11-24

Skup
Mini-Workshop "Looking into Hadrons"

Mjesto i datum
Bled, Slovenija, 07.07.2013. - 14.07.2013

Vrsta sudjelovanja
Pozvano predavanje

Vrsta recenzije
Međunarodna recenzija

Ključne riječi
QCD singlet chiral symmetry restoration hot medium

Sažetak
Recent RHIC results on eta' multiplicity in heavy-ion collisions are of great importance because they clearly signal a partial restoration of U_A(1) symmetry at high temperatures, and thus provide an unambiguous signature of the formation of a new state of matter. To explain these experimental results of STAR and PHENIX collaborations, a minimal generalization of the Witten-Veneziano relation to finite temperatures was proposed.The present paper provides a detailed, pedagogical discussion and explanation thereof. After explaining why these results show that the zero-temperature Witten-Veneziano relation cannot be straightforwardly extended to temperatures T too close to the chiral restoration temperature T_Ch and beyond, we find the quantity which should replace, at T>0, the Yang-Mills topological susceptibility appearing in the T=0 Witten-Veneziano relation, in order to avoid the conflict with experiment at T>0. This is illustrated through concrete T-dependences of pseudoscalar meson masses in a chirally well-behaved, Dyson-Schwinger approach, but our results and conclusions are of a more general nature and, essentially, model-independent.

Izvorni jezik
Engleski

Znanstvena područja
Fizika

POVEZANOST RADA