{"@context":"http://schema.org","@id":"https://doi.org/10.17182/hepdata.152620.v1","@reverse":{"isBasedOn":[{"@type":"ScholarlyArticle","identifier":{"@type":"PropertyValue","propertyID":"URL","value":"https://inspirehep.net/literature/2645172"}},{"@id":"https://doi.org/10.1103/PhysRevLett.134.022302","@type":"JournalArticle"}]},"@type":"Dataset","additionalType":"Collection","author":{"@type":"Organization","name":"PHENIX Collaboration"},"creator":{"@type":"Organization","name":"PHENIX Collaboration"},"datePublished":"2025","description":"PHENIX presents a simultaneous measurement of the production of direct $\\gamma$ and $\\pi^0$ in d+Au collisions at $\\sqrt{s_{NN}} = 200$ GeV over a $p_T$ range of 7.5 to 18 GeV/c for different event samples selected by event activity, i.e. charged-particle multiplicity detected at forward rapidity. Direct-photon yields are used to empirically estimate the contribution of hard-scattering processes in the different event samples. Using this estimate, the average nuclear-modification factor $R^{\\gamma^{dir}}_{dAu,EXP}$ is 0.925$\\pm$0.023(stat)$\\pm$0.15(scale), consistent with unity for minimum-bias (MB) d+Au events. For event classes with moderate event activity, $R^{\\gamma^{dir}}_{dAu,EXP}$ is consistent with the MB value within 5% uncertainty. These results confirm that the previously observed enhancement of high-$p_T$ $\\pi^0$ production found in small system collisions with low event activity is a result of a bias in interpreting event activity within the Glauber framework. In contrast, for the top 5% of events with the highest event activity, $R^{\\gamma^{dir}}_{dAu,EXP}$ is suppressed by 20% relative to the MB value with a significance of 4.5$\\sigma$, which may be due to final-state effects.","hasPart":[{"@id":"https://doi.org/10.17182/hepdata.152620.v1/t1","@type":"Dataset","description":"The $p_{T}$ distribution at high $p_{T}$ of neutral pions (panel (a)) for different d+Au event activity classes compared to those...","name":"Figure1a"},{"@id":"https://doi.org/10.17182/hepdata.152620.v1/t2","@type":"Dataset","description":"The $p_{T}$ distribution at high $p_{T}$ of direct photons (panel (b)) for different d+Au event activity classes compared to those...","name":"Figure1b"},{"@id":"https://doi.org/10.17182/hepdata.152620.v1/t3","@type":"Dataset","description":"Panel (c) shows the ratio $\\gamma^{dir}/\\pi^{0}$. For better visibility the points are slightly shifted in $p_{T}$ .","name":"Figure1c"},{"@id":"https://doi.org/10.17182/hepdata.152620.v1/t4","@type":"Dataset","description":"Values of $N^{EXP}_{coll}$ versus $p_{T}$ as defined in Eq. 2 for three d+Au event classes, (a) $0\\%\u2013100\\%$, (b) $0\\%\u20135\\%$ and...","name":"Figure2abc"},{"@id":"https://doi.org/10.17182/hepdata.152620.v1/t5","@type":"Dataset","description":"Panels (d) to (f) show the nuclear modification factors $R^{\\pi^{0}}_{dAu,EXP}$, calculated with Eq. 3, for the same event selections as...","name":"Figure2def"},{"@id":"https://doi.org/10.17182/hepdata.152620.v1/t6","@type":"Dataset","description":"The Ratio $N^{EXP}_{coll}/N^{GL}_{coll}$ as a function of $N^{EXP}_{coll}$. Horizontal and vertical bars are the statistical uncertainties. The values for $0\\%\u2013100\\%$...","name":"Figure3a"},{"@id":"https://doi.org/10.17182/hepdata.152620.v1/t7","@type":"Dataset","description":"Average $R^{\\pi^{0}}_{dAu,EXP}$ as a function of $N^{EXP}_{coll}$. Horizontal and vertical bars are the statistical uncertainties. The values for $0\\%\u2013100\\%$ d+Au...","name":"Figure3b"},{"@id":"https://doi.org/10.17182/hepdata.152620.v1/t8","@type":"Dataset","description":"Average $R^{\\pi^{0}}_{dAu,EXP}$ as a function of $N^{EXP}_{coll}$. Horizontal and vertical bars are the statistical uncertainties. The values for $0\\%\u2013100\\%$ d+Au...","name":"Figure3_1"}],"identifier":[{"@type":"PropertyValue","propertyID":"HEPDataRecord","value":"https://www.hepdata.net/record/ins2645172?version=1"},{"@type":"PropertyValue","propertyID":"HEPDataRecordAlt","value":"https://www.hepdata.net/record/152620"}],"inLanguage":"en","name":"Disentangling centrality bias and final-state effects in the production of high-$p_T$$\\pi^0$ using direct $\\gamma$ in $d$$+$Au collisions at $\\sqrt{s_{_{NN}}}=200$ GeV","provider":{"@type":"Organization","name":"HEPData"},"publisher":{"@type":"Organization","name":"HEPData"},"url":"https://www.hepdata.net/record/ins2645172?version=1","version":1}