Nuclear modification factor $R_{dA}$ for $\pi^0$, d + Au, compared to the STAR $\pi^{+-}$ [23,24] and PHENIX $\pi^0$ measurements [27,28]. Nucleon-nucleon inelastic cross section $\sigma^{NN}$ = 42 mb and expected number of collisions $<N_{coll}>$ = 7.5 +- 0.4 from Glauber model. Shaded bands in plot are $p_T$-correlated systematic uncertainties and the error bars are statistical uncertainties. Normalization uncertainty of 14.0% indicated by a shaded band around unity.

Nuclear modification factor $R_{dA}$ for eta, d + Au, compared to PHENIX $\eta$ measurements [27,28]. Nucleon-nucleon inelastic cross section $\sigma^{NN}$ = 42 mb and expected number of collisions $<N_{coll}>$ = 7.5 +- 0.4 from Glauber model. Shaded bands in plot are $p_T$-correlated systematic uncertainties and the error bars are statistical uncertainties. Normalization uncertainty of 14.0% indicated by a shaded band around unity.

Nuclear modification factor $R_{CP}$ for $\pi^0$ measured in d + Au collisions, compared to STAR $\pi^{+-}$ measurements [24]. Peripheral d + Au collisions were used where $R_{CP}$ = ratio of particle production in 40-100% centrality (P) events and 0-20% centrality (C) events. Shaded bands in plot are $p_T$-correlated systematic uncertainties and the error bars are statistical uncertainties. Normalization uncertainty of 11.0% indicated by a shaded band around unity.

Direct photon yield in p + p collisions at $\sqrt{s_{NN}}$ = 200 GeV in terms of the double ration $R_{\gamma}$. Shaded bands in plot are $p_T$-correlated systematic uncertainties and the error bars are statistical uncertainties. The curves correspond to NLO pQCD calculations of the differential cross sections for direct photon [68] and $\pi^0$ [52] production in p + p collisions for different factorization scales $\mu$ (the upper pQCD curve corresponds to $\mu$ = $p_T$/2). The upper limit of the fractional neutral hadron contamination $C_0$ is shown as the shaded band at $R_{\gamma}$ = 0.

Direct photon yield in d + Au collisions at $\sqrt{s_{NN}}$ = 200 GeV in terms of the double ration $R_{\gamma}$. Shaded bands in plot are $p_T$-correlated systematic uncertainties and the error bars are statistical uncertainties. The curves correspond to NLO pQCD calculations of the differential cross sections for direct photon [68] and $\pi^0$ [52] production in p + p collisions for different factorization scales $\mu$ (the upper pQCD curve corresponds to $\mu$ = $p_T$/2). The upper limit of the fractional neutral hadron contamination $C_0$ is shown as the shaded band at $R_{\gamma}$ = 0.

Cross sections for direct photon production at midrapidity in p + p and d + Au collisions at $\sqrt{s_{NN}}$ = 200 GeV, compared to the PHENIX measurement [29] and to the NLO pQCD calculation [68], which was scaled with $<T_{dA}>$ [Eq. (23)] in case of d + Au collisions. The error bars are statistical the shaded bands are $p_T$-correlated systematic uncertainties. The arrows correspond to the 95% confidence limits, as defined in the text. Normalization uncertainties of 11.7% for p+p and 5.3% for d+Au are not shown. Separate columns in the table show upper 95% confidence limits. The 95% confidence limits for the cross section are used when $R_{\gamma}$ did not correspond to a significant direct photon signal, assuming that the statistical and systematic errors both followed a Gaussian distribution, and using the fact that $R_{\gamma}\geq 1$ by definition.