Jet production rates are measured in $p+p$ and $d+\mathrm{Au}$ collisions at $\sqrt{s_{NN}}=200\mathrm{GeV}$ recorded in 2008 with the PHENIX detector at the Relativistic Heavy Ion Collider. Jets are reconstructed using the $R=0.3$ anti-$k_t$ algorithm from energy deposits in the electromagnetic calorimeter and charged tracks in multiwire proportional chambers, and the jet transverse momentum ($p_T$) spectra are corrected for the detector response. Spectra are reported for jets with $12<p_T<50\mathrm{GeV}/c$, within a pseudorapidity acceptance of $|\eta |<0.3$. The nuclear-modification factor ($R_{d\mathrm{Au}}$) values for 0%–100% $d+\mathrm{Au}$ events are found to be consistent with unity, constraining the role of initial state effects on jet production. However, the centrality-selected $R_{d\mathrm{Au}}$ values and central-to-peripheral ratios ($R_{\mathrm{CP}}$) show large, $p_T$-dependent deviations from unity, challenging the conventional models that relate hard-process rates and soft-particle production in collisions involving nuclei.

• Received 5 October 2015

DOI:https://doi.org/10.1103/PhysRevLett.116.122301