cometadata/datacite-titles-descriptions-related-identifiers huggingface dataset:
DOI: 10.17182/hepdata.145190.v1/t36
title: "Figure 30b pt.8" of "Detailed measurement of the $e^+ e^-$ pair continuum in $p+p$ and Au+Au collisions at $\sqrt{s_{NN}} = 200$ GeV and implications for direct photon production"

description: (Color online) $e^+e^-$ pair invariant mass distributions in $p$+$p$ (left) and minimum bias Au+Au collisions (right). The $p_T$ ranges are shown in the legend. The solid curves represent the cocktail of hadronic sources (see Sec. IV) and include contribution from charm calculated by PYTHIA using the cross section from Ref. [48] scaled by $N_{coll}$.
description: PHENIX has measured the $e^{+}e^{-}$ pair continuum in $\sqrt{s_{NN}}$=200 GeV Au+Au and $p+p$ collisions over a wide range of mass and transverse momenta. The $e^{+}e^{-}$ yield is compared to the expectations from hadronic sources, based on PHENIX measurements. In the intermediate mass region, between the masses of the $\phi$ and the $J/\psi$ meson, the yield is consistent with expectations from correlated $c\bar c$ production, though other mechanisms are not ruled out. In the low mass region (below the $\phi$) the $p+p$ inclusive mass spectrum is well described by known contributions from light meson decays. In contrast, the Au+Au minimum bias inclusive mass spectrum in this region shows an enhancement by a factor of $4.7\pm 0.4^{stat}\pm 1.5^{syst}\pm 0.9^{model}$ At low mass ($m_{ee}$&lt;0.3 GeV/$c^{2}$) and high $p_{T}$ (1&lt;$p_{T}$&lt;5 GeV/$c$) an enhanced $e^{+}e^{-}$ pair yield is observed that is consistent with production of virtual direct photons. This excess is used to infer the yield of real direct photons. In central Au+Au collisions, the excess of the direct photon yield over the $p+p$ is exponential in $p_{T}$, with inverse slope $T = 221\pm 19^{stat}\pm 19^{syst}$ MeV. Hydrodynamical models with initial temperatures ranging from $T_{init} \cong$300--600 MeV at times of 0.6--0.15 fm/$c$ after the collision are in qualitative agreement with the direct photon data in Au+Au. For low $p_{T}$&lt;1 GeV/$c$ the low mass region shows a further significant enhancement that increases with centrality and has an inverse slope of $T\cong$100 MeV. Theoretical models under predict the low mass, low $p_{T}$ enhancement. Error values of 9.99E+9 represent upper limit errors.
DOI: 10.17182/hepdata.145190.v1/t37
title: "Figure 30b pt.9" of "Detailed measurement of the $e^+ e^-$ pair continuum in $p+p$ and Au+Au collisions at $\sqrt{s_{NN}} = 200$ GeV and implications for direct photon production"

description: (Color online) $e^+e^-$ pair invariant mass distributions in $p$+$p$ (left) and minimum bias Au+Au collisions (right). The $p_T$ ranges are shown in the legend. The solid curves represent the cocktail of hadronic sources (see Sec. IV) and include contribution from charm calculated by PYTHIA using the cross section from Ref. [48] scaled by $N_{coll}$.
description: PHENIX has measured the $e^{+}e^{-}$ pair continuum in $\sqrt{s_{NN}}$=200 GeV Au+Au and $p+p$ collisions over a wide range of mass and transverse momenta. The $e^{+}e^{-}$ yield is compared to the expectations from hadronic sources, based on PHENIX measurements. In the intermediate mass region, between the masses of the $\phi$ and the $J/\psi$ meson, the yield is consistent with expectations from correlated $c\bar c$ production, though other mechanisms are not ruled out. In the low mass region (below the $\phi$) the $p+p$ inclusive mass spectrum is well described by known contributions from light meson decays. In contrast, the Au+Au minimum bias inclusive mass spectrum in this region shows an enhancement by a factor of $4.7\pm 0.4^{stat}\pm 1.5^{syst}\pm 0.9^{model}$ At low mass ($m_{ee}$&lt;0.3 GeV/$c^{2}$) and high $p_{T}$ (1&lt;$p_{T}$&lt;5 GeV/$c$) an enhanced $e^{+}e^{-}$ pair yield is observed that is consistent with production of virtual direct photons. This excess is used to infer the yield of real direct photons. In central Au+Au collisions, the excess of the direct photon yield over the $p+p$ is exponential in $p_{T}$, with inverse slope $T = 221\pm 19^{stat}\pm 19^{syst}$ MeV. Hydrodynamical models with initial temperatures ranging from $T_{init} \cong$300--600 MeV at times of 0.6--0.15 fm/$c$ after the collision are in qualitative agreement with the direct photon data in Au+Au. For low $p_{T}$&lt;1 GeV/$c$ the low mass region shows a further significant enhancement that increases with centrality and has an inverse slope of $T\cong$100 MeV. Theoretical models under predict the low mass, low $p_{T}$ enhancement. Error values of 9.99E+9 represent upper limit errors.
DOI: 10.17182/hepdata.145190.v1/t38
title: "Figure 30b pt.10" of "Detailed measurement of the $e^+ e^-$ pair continuum in $p+p$ and Au+Au collisions at $\sqrt{s_{NN}} = 200$ GeV and implications for direct photon production"

description: (Color online) $e^+e^-$ pair invariant mass distributions in $p$+$p$ (left) and minimum bias Au+Au collisions (right). The $p_T$ ranges are shown in the legend. The solid curves represent the cocktail of hadronic sources (see Sec. IV) and include contribution from charm calculated by PYTHIA using the cross section from Ref. [48] scaled by $N_{coll}$.
description: PHENIX has measured the $e^{+}e^{-}$ pair continuum in $\sqrt{s_{NN}}$=200 GeV Au+Au and $p+p$ collisions over a wide range of mass and transverse momenta. The $e^{+}e^{-}$ yield is compared to the expectations from hadronic sources, based on PHENIX measurements. In the intermediate mass region, between the masses of the $\phi$ and the $J/\psi$ meson, the yield is consistent with expectations from correlated $c\bar c$ production, though other mechanisms are not ruled out. In the low mass region (below the $\phi$) the $p+p$ inclusive mass spectrum is well described by known contributions from light meson decays. In contrast, the Au+Au minimum bias inclusive mass spectrum in this region shows an enhancement by a factor of $4.7\pm 0.4^{stat}\pm 1.5^{syst}\pm 0.9^{model}$ At low mass ($m_{ee}$&lt;0.3 GeV/$c^{2}$) and high $p_{T}$ (1&lt;$p_{T}$&lt;5 GeV/$c$) an enhanced $e^{+}e^{-}$ pair yield is observed that is consistent with production of virtual direct photons. This excess is used to infer the yield of real direct photons. In central Au+Au collisions, the excess of the direct photon yield over the $p+p$ is exponential in $p_{T}$, with inverse slope $T = 221\pm 19^{stat}\pm 19^{syst}$ MeV. Hydrodynamical models with initial temperatures ranging from $T_{init} \cong$300--600 MeV at times of 0.6--0.15 fm/$c$ after the collision are in qualitative agreement with the direct photon data in Au+Au. For low $p_{T}$&lt;1 GeV/$c$ the low mass region shows a further significant enhancement that increases with centrality and has an inverse slope of $T\cong$100 MeV. Theoretical models under predict the low mass, low $p_{T}$ enhancement. Error values of 9.99E+9 represent upper limit errors.
DOI: 10.17182/hepdata.145190.v1/t39
title: "Figure 31a" of "Detailed measurement of the $e^+ e^-$ pair continuum in $p+p$ and Au+Au collisions at $\sqrt{s_{NN}} = 200$ GeV and implications for direct photon production"

description: (Color online) Electron pair mass distribution for Au+Au (Min.Bias) for $1.0
description: PHENIX has measured the $e^{+}e^{-}$ pair continuum in $\sqrt{s_{NN}}$=200 GeV Au+Au and $p+p$ collisions over a wide range of mass and transverse momenta. The $e^{+}e^{-}$ yield is compared to the expectations from hadronic sources, based on PHENIX measurements. In the intermediate mass region, between the masses of the $\phi$ and the $J/\psi$ meson, the yield is consistent with expectations from correlated $c\bar c$ production, though other mechanisms are not ruled out. In the low mass region (below the $\phi$) the $p+p$ inclusive mass spectrum is well described by known contributions from light meson decays. In contrast, the Au+Au minimum bias inclusive mass spectrum in this region shows an enhancement by a factor of $4.7\pm 0.4^{stat}\pm 1.5^{syst}\pm 0.9^{model}$ At low mass ($m_{ee}$&lt;0.3 GeV/$c^{2}$) and high $p_{T}$ (1&lt;$p_{T}$&lt;5 GeV/$c$) an enhanced $e^{+}e^{-}$ pair yield is observed that is consistent with production of virtual direct photons. This excess is used to infer the yield of real direct photons. In central Au+Au collisions, the excess of the direct photon yield over the $p+p$ is exponential in $p_{T}$, with inverse slope $T = 221\pm 19^{stat}\pm 19^{syst}$ MeV. Hydrodynamical models with initial temperatures ranging from $T_{init} \cong$300--600 MeV at times of 0.6--0.15 fm/$c$ after the collision are in qualitative agreement with the direct photon data in Au+Au. For low $p_{T}$&lt;1 GeV/$c$ the low mass region shows a further significant enhancement that increases with centrality and has an inverse slope of $T\cong$100 MeV. Theoretical models under predict the low mass, low $p_{T}$ enhancement. Error values of 9.99E+9 represent upper limit errors.
DOI: 10.17182/hepdata.145190.v1/t40
title: "Figure 31b" of "Detailed measurement of the $e^+ e^-$ pair continuum in $p+p$ and Au+Au collisions at $\sqrt{s_{NN}} = 200$ GeV and implications for direct photon production"

description: (Color online) Electron pair mass distribution for Au+Au (Min.Bias) for $1.0
description: PHENIX has measured the $e^{+}e^{-}$ pair continuum in $\sqrt{s_{NN}}$=200 GeV Au+Au and $p+p$ collisions over a wide range of mass and transverse momenta. The $e^{+}e^{-}$ yield is compared to the expectations from hadronic sources, based on PHENIX measurements. In the intermediate mass region, between the masses of the $\phi$ and the $J/\psi$ meson, the yield is consistent with expectations from correlated $c\bar c$ production, though other mechanisms are not ruled out. In the low mass region (below the $\phi$) the $p+p$ inclusive mass spectrum is well described by known contributions from light meson decays. In contrast, the Au+Au minimum bias inclusive mass spectrum in this region shows an enhancement by a factor of $4.7\pm 0.4^{stat}\pm 1.5^{syst}\pm 0.9^{model}$ At low mass ($m_{ee}$&lt;0.3 GeV/$c^{2}$) and high $p_{T}$ (1&lt;$p_{T}$&lt;5 GeV/$c$) an enhanced $e^{+}e^{-}$ pair yield is observed that is consistent with production of virtual direct photons. This excess is used to infer the yield of real direct photons. In central Au+Au collisions, the excess of the direct photon yield over the $p+p$ is exponential in $p_{T}$, with inverse slope $T = 221\pm 19^{stat}\pm 19^{syst}$ MeV. Hydrodynamical models with initial temperatures ranging from $T_{init} \cong$300--600 MeV at times of 0.6--0.15 fm/$c$ after the collision are in qualitative agreement with the direct photon data in Au+Au. For low $p_{T}$&lt;1 GeV/$c$ the low mass region shows a further significant enhancement that increases with centrality and has an inverse slope of $T\cong$100 MeV. Theoretical models under predict the low mass, low $p_{T}$ enhancement. Error values of 9.99E+9 represent upper limit errors.
DOI: 10.17182/hepdata.145190.v1/t41
title: "Figure 31c" of "Detailed measurement of the $e^+ e^-$ pair continuum in $p+p$ and Au+Au collisions at $\sqrt{s_{NN}} = 200$ GeV and implications for direct photon production"

description: (Color online) Electron pair mass distribution for Au+Au (Min.Bias) for $1.0
description: PHENIX has measured the $e^{+}e^{-}$ pair continuum in $\sqrt{s_{NN}}$=200 GeV Au+Au and $p+p$ collisions over a wide range of mass and transverse momenta. The $e^{+}e^{-}$ yield is compared to the expectations from hadronic sources, based on PHENIX measurements. In the intermediate mass region, between the masses of the $\phi$ and the $J/\psi$ meson, the yield is consistent with expectations from correlated $c\bar c$ production, though other mechanisms are not ruled out. In the low mass region (below the $\phi$) the $p+p$ inclusive mass spectrum is well described by known contributions from light meson decays. In contrast, the Au+Au minimum bias inclusive mass spectrum in this region shows an enhancement by a factor of $4.7\pm 0.4^{stat}\pm 1.5^{syst}\pm 0.9^{model}$ At low mass ($m_{ee}$&lt;0.3 GeV/$c^{2}$) and high $p_{T}$ (1&lt;$p_{T}$&lt;5 GeV/$c$) an enhanced $e^{+}e^{-}$ pair yield is observed that is consistent with production of virtual direct photons. This excess is used to infer the yield of real direct photons. In central Au+Au collisions, the excess of the direct photon yield over the $p+p$ is exponential in $p_{T}$, with inverse slope $T = 221\pm 19^{stat}\pm 19^{syst}$ MeV. Hydrodynamical models with initial temperatures ranging from $T_{init} \cong$300--600 MeV at times of 0.6--0.15 fm/$c$ after the collision are in qualitative agreement with the direct photon data in Au+Au. For low $p_{T}$&lt;1 GeV/$c$ the low mass region shows a further significant enhancement that increases with centrality and has an inverse slope of $T\cong$100 MeV. Theoretical models under predict the low mass, low $p_{T}$ enhancement. Error values of 9.99E+9 represent upper limit errors.
DOI: 10.17182/hepdata.145190.v1/t42
title: "Figure 31d" of "Detailed measurement of the $e^+ e^-$ pair continuum in $p+p$ and Au+Au collisions at $\sqrt{s_{NN}} = 200$ GeV and implications for direct photon production"

description: (Color online) Electron pair mass distribution for Au+Au (Min.Bias) for $1.0
description: PHENIX has measured the $e^{+}e^{-}$ pair continuum in $\sqrt{s_{NN}}$=200 GeV Au+Au and $p+p$ collisions over a wide range of mass and transverse momenta. The $e^{+}e^{-}$ yield is compared to the expectations from hadronic sources, based on PHENIX measurements. In the intermediate mass region, between the masses of the $\phi$ and the $J/\psi$ meson, the yield is consistent with expectations from correlated $c\bar c$ production, though other mechanisms are not ruled out. In the low mass region (below the $\phi$) the $p+p$ inclusive mass spectrum is well described by known contributions from light meson decays. In contrast, the Au+Au minimum bias inclusive mass spectrum in this region shows an enhancement by a factor of $4.7\pm 0.4^{stat}\pm 1.5^{syst}\pm 0.9^{model}$ At low mass ($m_{ee}$&lt;0.3 GeV/$c^{2}$) and high $p_{T}$ (1&lt;$p_{T}$&lt;5 GeV/$c$) an enhanced $e^{+}e^{-}$ pair yield is observed that is consistent with production of virtual direct photons. This excess is used to infer the yield of real direct photons. In central Au+Au collisions, the excess of the direct photon yield over the $p+p$ is exponential in $p_{T}$, with inverse slope $T = 221\pm 19^{stat}\pm 19^{syst}$ MeV. Hydrodynamical models with initial temperatures ranging from $T_{init} \cong$300--600 MeV at times of 0.6--0.15 fm/$c$ after the collision are in qualitative agreement with the direct photon data in Au+Au. For low $p_{T}$&lt;1 GeV/$c$ the low mass region shows a further significant enhancement that increases with centrality and has an inverse slope of $T\cong$100 MeV. Theoretical models under predict the low mass, low $p_{T}$ enhancement. Error values of 9.99E+9 represent upper limit errors.
DOI: 10.17182/hepdata.145190.v1/t43
title: "Figure 32" of "Detailed measurement of the $e^+ e^-$ pair continuum in $p+p$ and Au+Au collisions at $\sqrt{s_{NN}} = 200$ GeV and implications for direct photon production"

description: (Color online) Ratio R=(data-cocktail)/$f_{dir}(m_{ee})$ of electron pairs for different $p_T$ bins in Min.Bias Au+Au collisions. The $p_T$ range of each panel is indicated in the figure.
description: PHENIX has measured the $e^{+}e^{-}$ pair continuum in $\sqrt{s_{NN}}$=200 GeV Au+Au and $p+p$ collisions over a wide range of mass and transverse momenta. The $e^{+}e^{-}$ yield is compared to the expectations from hadronic sources, based on PHENIX measurements. In the intermediate mass region, between the masses of the $\phi$ and the $J/\psi$ meson, the yield is consistent with expectations from correlated $c\bar c$ production, though other mechanisms are not ruled out. In the low mass region (below the $\phi$) the $p+p$ inclusive mass spectrum is well described by known contributions from light meson decays. In contrast, the Au+Au minimum bias inclusive mass spectrum in this region shows an enhancement by a factor of $4.7\pm 0.4^{stat}\pm 1.5^{syst}\pm 0.9^{model}$ At low mass ($m_{ee}$&lt;0.3 GeV/$c^{2}$) and high $p_{T}$ (1&lt;$p_{T}$&lt;5 GeV/$c$) an enhanced $e^{+}e^{-}$ pair yield is observed that is consistent with production of virtual direct photons. This excess is used to infer the yield of real direct photons. In central Au+Au collisions, the excess of the direct photon yield over the $p+p$ is exponential in $p_{T}$, with inverse slope $T = 221\pm 19^{stat}\pm 19^{syst}$ MeV. Hydrodynamical models with initial temperatures ranging from $T_{init} \cong$300--600 MeV at times of 0.6--0.15 fm/$c$ after the collision are in qualitative agreement with the direct photon data in Au+Au. For low $p_{T}$&lt;1 GeV/$c$ the low mass region shows a further significant enhancement that increases with centrality and has an inverse slope of $T\cong$100 MeV. Theoretical models under predict the low mass, low $p_{T}$ enhancement. Error values of 9.99E+9 represent upper limit errors.
DOI: 10.17182/hepdata.145190.v1/t44
title: "Figure 33a" of "Detailed measurement of the $e^+ e^-$ pair continuum in $p+p$ and Au+Au collisions at $\sqrt{s_{NN}} = 200$ GeV and implications for direct photon production"

description: (Color online) The fraction of the direct photon component as a function of $p_T$. The error bars and the error band represent statistical and systematic uncertainties, respectively. The curves are from a NLO pQCD calculation (see text).
description: PHENIX has measured the $e^{+}e^{-}$ pair continuum in $\sqrt{s_{NN}}$=200 GeV Au+Au and $p+p$ collisions over a wide range of mass and transverse momenta. The $e^{+}e^{-}$ yield is compared to the expectations from hadronic sources, based on PHENIX measurements. In the intermediate mass region, between the masses of the $\phi$ and the $J/\psi$ meson, the yield is consistent with expectations from correlated $c\bar c$ production, though other mechanisms are not ruled out. In the low mass region (below the $\phi$) the $p+p$ inclusive mass spectrum is well described by known contributions from light meson decays. In contrast, the Au+Au minimum bias inclusive mass spectrum in this region shows an enhancement by a factor of $4.7\pm 0.4^{stat}\pm 1.5^{syst}\pm 0.9^{model}$ At low mass ($m_{ee}$&lt;0.3 GeV/$c^{2}$) and high $p_{T}$ (1&lt;$p_{T}$&lt;5 GeV/$c$) an enhanced $e^{+}e^{-}$ pair yield is observed that is consistent with production of virtual direct photons. This excess is used to infer the yield of real direct photons. In central Au+Au collisions, the excess of the direct photon yield over the $p+p$ is exponential in $p_{T}$, with inverse slope $T = 221\pm 19^{stat}\pm 19^{syst}$ MeV. Hydrodynamical models with initial temperatures ranging from $T_{init} \cong$300--600 MeV at times of 0.6--0.15 fm/$c$ after the collision are in qualitative agreement with the direct photon data in Au+Au. For low $p_{T}$&lt;1 GeV/$c$ the low mass region shows a further significant enhancement that increases with centrality and has an inverse slope of $T\cong$100 MeV. Theoretical models under predict the low mass, low $p_{T}$ enhancement. Error values of 9.99E+9 represent upper limit errors.
DOI: 10.17182/hepdata.145190.v1/t45
title: "Figure 33b" of "Detailed measurement of the $e^+ e^-$ pair continuum in $p+p$ and Au+Au collisions at $\sqrt{s_{NN}} = 200$ GeV and implications for direct photon production"

description: (Color online) The fraction of the direct photon component as a function of $p_T$. The error bars and the error band represent statistical and systematic uncertainties, respectively. The curves are from a NLO pQCD calculation (see text).
description: PHENIX has measured the $e^{+}e^{-}$ pair continuum in $\sqrt{s_{NN}}$=200 GeV Au+Au and $p+p$ collisions over a wide range of mass and transverse momenta. The $e^{+}e^{-}$ yield is compared to the expectations from hadronic sources, based on PHENIX measurements. In the intermediate mass region, between the masses of the $\phi$ and the $J/\psi$ meson, the yield is consistent with expectations from correlated $c\bar c$ production, though other mechanisms are not ruled out. In the low mass region (below the $\phi$) the $p+p$ inclusive mass spectrum is well described by known contributions from light meson decays. In contrast, the Au+Au minimum bias inclusive mass spectrum in this region shows an enhancement by a factor of $4.7\pm 0.4^{stat}\pm 1.5^{syst}\pm 0.9^{model}$ At low mass ($m_{ee}$&lt;0.3 GeV/$c^{2}$) and high $p_{T}$ (1&lt;$p_{T}$&lt;5 GeV/$c$) an enhanced $e^{+}e^{-}$ pair yield is observed that is consistent with production of virtual direct photons. This excess is used to infer the yield of real direct photons. In central Au+Au collisions, the excess of the direct photon yield over the $p+p$ is exponential in $p_{T}$, with inverse slope $T = 221\pm 19^{stat}\pm 19^{syst}$ MeV. Hydrodynamical models with initial temperatures ranging from $T_{init} \cong$300--600 MeV at times of 0.6--0.15 fm/$c$ after the collision are in qualitative agreement with the direct photon data in Au+Au. For low $p_{T}$&lt;1 GeV/$c$ the low mass region shows a further significant enhancement that increases with centrality and has an inverse slope of $T\cong$100 MeV. Theoretical models under predict the low mass, low $p_{T}$ enhancement. Error values of 9.99E+9 represent upper limit errors.
DOI: 10.17182/hepdata.145190.v1/t46
title: "Figure 34a" of "Detailed measurement of the $e^+ e^-$ pair continuum in $p+p$ and Au+Au collisions at $\sqrt{s_{NN}} = 200$ GeV and implications for direct photon production"

description: (Color online) Invariant cross section ($p$+$p$) and invariant yield (Au+Au) of direct photons as a function of $p_T$. The filled points are from this analysis and open points are from [81,82]. The three curves on the $p$+$p$ data represent NLO pQCD calculations, and the dashed curves show a modified power-law fit to the $p$+$p$ data, scaled by $T_{AA}$. The dashed (black) curves are exponential plus the $T_{AA}$ scaled $p$+$p$ fit.
description: PHENIX has measured the $e^{+}e^{-}$ pair continuum in $\sqrt{s_{NN}}$=200 GeV Au+Au and $p+p$ collisions over a wide range of mass and transverse momenta. The $e^{+}e^{-}$ yield is compared to the expectations from hadronic sources, based on PHENIX measurements. In the intermediate mass region, between the masses of the $\phi$ and the $J/\psi$ meson, the yield is consistent with expectations from correlated $c\bar c$ production, though other mechanisms are not ruled out. In the low mass region (below the $\phi$) the $p+p$ inclusive mass spectrum is well described by known contributions from light meson decays. In contrast, the Au+Au minimum bias inclusive mass spectrum in this region shows an enhancement by a factor of $4.7\pm 0.4^{stat}\pm 1.5^{syst}\pm 0.9^{model}$ At low mass ($m_{ee}$&lt;0.3 GeV/$c^{2}$) and high $p_{T}$ (1&lt;$p_{T}$&lt;5 GeV/$c$) an enhanced $e^{+}e^{-}$ pair yield is observed that is consistent with production of virtual direct photons. This excess is used to infer the yield of real direct photons. In central Au+Au collisions, the excess of the direct photon yield over the $p+p$ is exponential in $p_{T}$, with inverse slope $T = 221\pm 19^{stat}\pm 19^{syst}$ MeV. Hydrodynamical models with initial temperatures ranging from $T_{init} \cong$300--600 MeV at times of 0.6--0.15 fm/$c$ after the collision are in qualitative agreement with the direct photon data in Au+Au. For low $p_{T}$&lt;1 GeV/$c$ the low mass region shows a further significant enhancement that increases with centrality and has an inverse slope of $T\cong$100 MeV. Theoretical models under predict the low mass, low $p_{T}$ enhancement. Error values of 9.99E+9 represent upper limit errors.