Suppressedπ0Production at Large Transverse Momentum in CentralAu+AuCollisions atsNN=200 GeV

Transverse momentum spectra of neutral pions in the range $1<{p}_{T}<10\text{ }\text{ }\mathrm{G}\mathrm{e}\mathrm{V}/c$ have been measured at midrapidity by the PHENIX experiment at BNL RHIC in $\mathrm{A}\mathrm{u}+\mathrm{A}\mathrm{u}$ collisions at $\sqrt{{s}_{NN}}=200\text{ }\text{ }\mathrm{G}\mathrm{e}\mathrm{V}$. The ${\ensuremath{\pi}}^{0}$ multiplicity in central reactions is significantly below the yields measured at the same $\sqrt{{s}_{NN}}$ in peripheral $\mathrm{A}\mathrm{u}+\mathrm{A}\mathrm{u}$ and $p+p$ reactions scaled by the number of nucleon-nucleon collisions. For the most central bin, the suppression factor is $\ensuremath{\sim}2.5$ at ${p}_{T}=2\text{ }\text{ }\mathrm{G}\mathrm{e}\mathrm{V}/c$ and increases to $\ensuremath{\sim}4--5$ at ${p}_{T}\ensuremath{\approx}4\text{ }\text{ }\mathrm{G}\mathrm{e}\mathrm{V}/c$. At larger ${p}_{T}$, the suppression remains constant within errors. The deficit is already apparent in semiperipheral reactions and increases smoothly with centrality.

Suppressedπ0Production at Large Transverse Momentum in CentralAu+AuCollisions atsNN=200 GeV | Litlas