Elliptic flow versus $p_{T}$ for charged hadrons from Cu+Cu collisions at 0–60% centrality at $\sqrt{s_{NN}}$ = 22.4 GeV measured with the subevent method with a pseudorapidity gap of 0.3 units compared with previously published STAR results for 200 and 62.4 GeV Cu+Cu [27] measured with full TPC event plane method $v_{2}${TPC} and full FTPC event plane method $v_{2}${FTPC}. The error bars are statistical. Results are also compared to $v_{2}$($p_{T}$) model calculations.

Elliptic flow $v_{2}(\eta)$ for charged hadrons fromCu+Cu collisions at 0–60% centrality at $\sqrt{s_{NN}}$ = 22.4 GeV. The present STAR results are compared to the measurement from the PHOBOS [29] collaboration for Cu+Cu at 22.4 GeV. The PHOBOS results include statistical and systematic errors whereas the STAR results are plotted with statistical uncertainties only, and systematic errors are discussed in Section III C. Results are also compared to $v_{2}(\eta)$ calculations from the indicated models.

Elliptic flow $v_{2}${TPC} and $v_{2}${4} as a function of centrality for charged hadrons from Cu+Cu collisions at 0 − 60% centrality at $\sqrt{s_{NN}}$ = 22.4 GeV, compared with previously published results from the STAR collaboration at 200 GeV and 62.4 GeV.

FIG. 1. (Color online) Perspective views of $2 \mathrm{D}$ charge-independent angular correlations $\Delta \rho / \sqrt{\rho_{\mathrm{ref}}}$ on $\left(\eta_{\Delta}, \phi_{\Delta}\right)$ for Au-Au collisions at $\sqrt{s_{N N}}=200$ and $62 \mathrm{GeV}$ (top and bottom rows, respectively). Centrality increases left to right from most peripheral to most central. Corrected total cross-section fractions are (left to right) $84 \%-93 \%, 55 \%-64 \%, 18 \%-28 \%,$ and $0 \%-5 \%$ for the $200-\mathrm{GeV}$ data and $84 \%-95 \%, 56 \%-65 \%$ $18 \%-28 \%,$ and $0 \%-5 \%$ for the $62 \mathrm{GeV}$ data (see Tables III and IV).

FIG. 1. (Color online) Perspective views of $2 \mathrm{D}$ charge-independent angular correlations $\Delta \rho / \sqrt{\rho_{\mathrm{ref}}}$ on $\left(\eta_{\Delta}, \phi_{\Delta}\right)$ for Au-Au collisions at $\sqrt{s_{N N}}=200$ and $62 \mathrm{GeV}$ (top and bottom rows, respectively). Centrality increases left to right from most peripheral to most central. Corrected total cross-section fractions are (left to right) $84 \%-93 \%, 55 \%-64 \%, 18 \%-28 \%,$ and $0 \%-5 \%$ for the $200-\mathrm{GeV}$ data and $84 \%-95 \%, 56 \%-65 \%$ $18 \%-28 \%,$ and $0 \%-5 \%$ for the $62 \mathrm{GeV}$ data (see Tables III and IV).

FIG. 1. (Color online) Perspective views of $2 \mathrm{D}$ charge-independent angular correlations $\Delta \rho / \sqrt{\rho_{\mathrm{ref}}}$ on $\left(\eta_{\Delta}, \phi_{\Delta}\right)$ for Au-Au collisions at $\sqrt{s_{N N}}=200$ and $62 \mathrm{GeV}$ (top and bottom rows, respectively). Centrality increases left to right from most peripheral to most central. Corrected total cross-section fractions are (left to right) $84 \%-93 \%, 55 \%-64 \%, 18 \%-28 \%,$ and $0 \%-5 \%$ for the $200-\mathrm{GeV}$ data and $84 \%-95 \%, 56 \%-65 \%$ $18 \%-28 \%,$ and $0 \%-5 \%$ for the $62 \mathrm{GeV}$ data (see Tables III and IV).

FIG. 1. (Color online) Perspective views of $2 \mathrm{D}$ charge-independent angular correlations $\Delta \rho / \sqrt{\rho_{\mathrm{ref}}}$ on $\left(\eta_{\Delta}, \phi_{\Delta}\right)$ for Au-Au collisions at $\sqrt{s_{N N}}=200$ and $62 \mathrm{GeV}$ (top and bottom rows, respectively). Centrality increases left to right from most peripheral to most central. Corrected total cross-section fractions are (left to right) $84 \%-93 \%, 55 \%-64 \%, 18 \%-28 \%,$ and $0 \%-5 \%$ for the $200-\mathrm{GeV}$ data and $84 \%-95 \%, 56 \%-65 \%$ $18 \%-28 \%,$ and $0 \%-5 \%$ for the $62 \mathrm{GeV}$ data (see Tables III and IV).

FIG. 1. (Color online) Perspective views of $2 \mathrm{D}$ charge-independent angular correlations $\Delta \rho / \sqrt{\rho_{\mathrm{ref}}}$ on $\left(\eta_{\Delta}, \phi_{\Delta}\right)$ for Au-Au collisions at $\sqrt{s_{N N}}=200$ and $62 \mathrm{GeV}$ (top and bottom rows, respectively). Centrality increases left to right from most peripheral to most central. Corrected total cross-section fractions are (left to right) $84 \%-93 \%, 55 \%-64 \%, 18 \%-28 \%,$ and $0 \%-5 \%$ for the $200-\mathrm{GeV}$ data and $84 \%-95 \%, 56 \%-65 \%$ $18 \%-28 \%,$ and $0 \%-5 \%$ for the $62 \mathrm{GeV}$ data (see Tables III and IV).

FIG. 2. (Color online) Fit decomposition of the $46 \%-56 \%$ centrality data for 62 -GeV Au-Au collisions. The top panels show from left to right the corrected data, model fit, fit residuals (data - model), and same-side 2D Gaussian. The bottom panels similarly show the away-side azimuth dipole, the nonjet azimuth quadrupole, the 1D $\eta_{\Delta}$ Gaussian, and the 2D exponential. This centrality is just below the sharp transition at $v_{\text {trans }}=3$. Fit residuals (c) are scaled up eightfold relative to the data.

FIG. 3. Fit parameters for $\left(\eta_{\Delta}, \phi_{\Delta}\right)$ correlation data from Au-Au collisions at $\sqrt{s_{N N}}=62$ (open symbols) and 200 GeV (solid symbols) versus centrality measure $\nu$ computed at fixed energy $(200 \mathrm{GeV})$. The SS $2 \mathrm{D}$ Gaussian amplitudes, $\eta_{\Delta}$ widths, and $\phi_{\Delta}$ widths are shown in the left, center, and right panels, respectively of the top row. The bottom row shows from left to right the amplitudes for the dipole, quadrupole, and SS peak width aspect ratio $\sigma_{\eta_{\Delta}} / \sigma_{\phi_{\Delta}} .$ Fitting errors are indicated by error bars where larger than the symbols. Solid lines connect the points for clarity. The dotted and dashed curves indicate Glauber linear superposition estimates for 62 - and 200 -GeV peak amplitudes respectively, as discussed in the text. The quadrupole data are consistent with Ref. [60]. The hatched regions indicate the full range of systematic uncertainties listed in Appendix F. The vertical dark bands indicate estimated $v$ equivalents for $N-N$ collisions and $b=0$ Au-Au collisions.

FIG. 3. Fit parameters for $\left(\eta_{\Delta}, \phi_{\Delta}\right)$ correlation data from Au-Au collisions at $\sqrt{s_{N N}}=62$ (open symbols) and 200 GeV (solid symbols) versus centrality measure $\nu$ computed at fixed energy $(200 \mathrm{GeV})$. The SS $2 \mathrm{D}$ Gaussian amplitudes, $\eta_{\Delta}$ widths, and $\phi_{\Delta}$ widths are shown in the left, center, and right panels, respectively of the top row. The bottom row shows from left to right the amplitudes for the dipole, quadrupole, and SS peak width aspect ratio $\sigma_{\eta_{\Delta}} / \sigma_{\phi_{\Delta}} .$ Fitting errors are indicated by error bars where larger than the symbols. Solid lines connect the points for clarity. The dotted and dashed curves indicate Glauber linear superposition estimates for 62 - and 200 -GeV peak amplitudes respectively, as discussed in the text. The quadrupole data are consistent with Ref. [60]. The hatched regions indicate the full range of systematic uncertainties listed in Appendix F. The vertical dark bands indicate estimated $v$ equivalents for $N-N$ collisions and $b=0$ Au-Au collisions.

FIG. 3. Fit parameters for $\left(\eta_{\Delta}, \phi_{\Delta}\right)$ correlation data from Au-Au collisions at $\sqrt{s_{N N}}=62$ (open symbols) and 200 GeV (solid symbols) versus centrality measure $\nu$ computed at fixed energy $(200 \mathrm{GeV})$. The SS $2 \mathrm{D}$ Gaussian amplitudes, $\eta_{\Delta}$ widths, and $\phi_{\Delta}$ widths are shown in the left, center, and right panels, respectively of the top row. The bottom row shows from left to right the amplitudes for the dipole, quadrupole, and SS peak width aspect ratio $\sigma_{\eta_{\Delta}} / \sigma_{\phi_{\Delta}} .$ Fitting errors are indicated by error bars where larger than the symbols. Solid lines connect the points for clarity. The dotted and dashed curves indicate Glauber linear superposition estimates for 62 - and 200 -GeV peak amplitudes respectively, as discussed in the text. The quadrupole data are consistent with Ref. [60]. The hatched regions indicate the full range of systematic uncertainties listed in Appendix F. The vertical dark bands indicate estimated $v$ equivalents for $N-N$ collisions and $b=0$ Au-Au collisions.

FIG. 3. Fit parameters for $\left(\eta_{\Delta}, \phi_{\Delta}\right)$ correlation data from Au-Au collisions at $\sqrt{s_{N N}}=62$ (open symbols) and 200 GeV (solid symbols) versus centrality measure $\nu$ computed at fixed energy $(200 \mathrm{GeV})$. The SS $2 \mathrm{D}$ Gaussian amplitudes, $\eta_{\Delta}$ widths, and $\phi_{\Delta}$ widths are shown in the left, center, and right panels, respectively of the top row. The bottom row shows from left to right the amplitudes for the dipole, quadrupole, and SS peak width aspect ratio $\sigma_{\eta_{\Delta}} / \sigma_{\phi_{\Delta}} .$ Fitting errors are indicated by error bars where larger than the symbols. Solid lines connect the points for clarity. The dotted and dashed curves indicate Glauber linear superposition estimates for 62 - and 200 -GeV peak amplitudes respectively, as discussed in the text. The quadrupole data are consistent with Ref. [60]. The hatched regions indicate the full range of systematic uncertainties listed in Appendix F. The vertical dark bands indicate estimated $v$ equivalents for $N-N$ collisions and $b=0$ Au-Au collisions.

FIG. 3. Fit parameters for $\left(\eta_{\Delta}, \phi_{\Delta}\right)$ correlation data from Au-Au collisions at $\sqrt{s_{N N}}=62$ (open symbols) and 200 GeV (solid symbols) versus centrality measure $\nu$ computed at fixed energy $(200 \mathrm{GeV})$. The SS $2 \mathrm{D}$ Gaussian amplitudes, $\eta_{\Delta}$ widths, and $\phi_{\Delta}$ widths are shown in the left, center, and right panels, respectively of the top row. The bottom row shows from left to right the amplitudes for the dipole, quadrupole, and SS peak width aspect ratio $\sigma_{\eta_{\Delta}} / \sigma_{\phi_{\Delta}} .$ Fitting errors are indicated by error bars where larger than the symbols. Solid lines connect the points for clarity. The dotted and dashed curves indicate Glauber linear superposition estimates for 62 - and 200 -GeV peak amplitudes respectively, as discussed in the text. The quadrupole data are consistent with Ref. [60]. The hatched regions indicate the full range of systematic uncertainties listed in Appendix F. The vertical dark bands indicate estimated $v$ equivalents for $N-N$ collisions and $b=0$ Au-Au collisions.

FIG. 3. Fit parameters for $\left(\eta_{\Delta}, \phi_{\Delta}\right)$ correlation data from Au-Au collisions at $\sqrt{s_{N N}}=62$ (open symbols) and 200 GeV (solid symbols) versus centrality measure $\nu$ computed at fixed energy $(200 \mathrm{GeV})$. The SS $2 \mathrm{D}$ Gaussian amplitudes, $\eta_{\Delta}$ widths, and $\phi_{\Delta}$ widths are shown in the left, center, and right panels, respectively of the top row. The bottom row shows from left to right the amplitudes for the dipole, quadrupole, and SS peak width aspect ratio $\sigma_{\eta_{\Delta}} / \sigma_{\phi_{\Delta}} .$ Fitting errors are indicated by error bars where larger than the symbols. Solid lines connect the points for clarity. The dotted and dashed curves indicate Glauber linear superposition estimates for 62 - and 200 -GeV peak amplitudes respectively, as discussed in the text. The quadrupole data are consistent with Ref. [60]. The hatched regions indicate the full range of systematic uncertainties listed in Appendix F. The vertical dark bands indicate estimated $v$ equivalents for $N-N$ collisions and $b=0$ Au-Au collisions.

FIG. 4. (Color online) (a) 2D data histogram from $0 \%-5 \%$ central 200 GeV Au-Au collisions $[(0,0)$ bin suppressed]. (b) Additional model component fitted to the $2 \mathrm{D}$ histogram and consisting of an AS azimuth dipole modulated by function $F\left(\eta_{\Delta}\right)$ described in the text. (c) Fit residuals including the new model component. (d) Data histogram in the first panel minus the additional model component and fitted offset. Remaining structure is described accurately by an AS dipole and SS 2D Gaussian.

FIG. 9. (a) Amplitude of SS 2D peak (jet-correlated pairs per final-state hadron) for data (solid points), GLS extrapolation from $p$ - $p$ data (dashed curve) and from the HIJING Monte Carlo (open points, dotted curve). (b) Single-particle production extrapolated from $p-p$ data (dashed curve, GLS), and from more-central Au-Au data (solid line) and HIJING (dash-dotted line, open points). (c) Single-particle hard-component production per $N-N$ binary collision from $p-p$ data, from more-central Au-Au data and from HIJING (open points). (d) Jet-correlated pair production (SS 2D peak) per $N-N$ binary collision extrapolated from $p-p$ data (GLS), and from Au-Au data (solid points) and HIJING (open points).

FIG. 9. (a) Amplitude of SS 2D peak (jet-correlated pairs per final-state hadron) for data (solid points), GLS extrapolation from $p$ - $p$ data (dashed curve) and from the HIJING Monte Carlo (open points, dotted curve). (b) Single-particle production extrapolated from $p-p$ data (dashed curve, GLS), and from more-central Au-Au data (solid line) and HIJING (dash-dotted line, open points). (c) Single-particle hard-component production per $N-N$ binary collision from $p-p$ data, from more-central Au-Au data and from HIJING (open points). (d) Jet-correlated pair production (SS 2D peak) per $N-N$ binary collision extrapolated from $p-p$ data (GLS), and from Au-Au data (solid points) and HIJING (open points).

FIG. 9. (a) Amplitude of SS 2D peak (jet-correlated pairs per final-state hadron) for data (solid points), GLS extrapolation from $p$ - $p$ data (dashed curve) and from the HIJING Monte Carlo (open points, dotted curve). (b) Single-particle production extrapolated from $p-p$ data (dashed curve, GLS), and from more-central Au-Au data (solid line) and HIJING (dash-dotted line, open points). (c) Single-particle hard-component production per $N-N$ binary collision from $p-p$ data, from more-central Au-Au data and from HIJING (open points). (d) Jet-correlated pair production (SS 2D peak) per $N-N$ binary collision extrapolated from $p-p$ data (GLS), and from Au-Au data (solid points) and HIJING (open points).

FIG. 9. (a) Amplitude of SS 2D peak (jet-correlated pairs per final-state hadron) for data (solid points), GLS extrapolation from $p$ - $p$ data (dashed curve) and from the HIJING Monte Carlo (open points, dotted curve). (b) Single-particle production extrapolated from $p-p$ data (dashed curve, GLS), and from more-central Au-Au data (solid line) and HIJING (dash-dotted line, open points). (c) Single-particle hard-component production per $N-N$ binary collision from $p-p$ data, from more-central Au-Au data and from HIJING (open points). (d) Jet-correlated pair production (SS 2D peak) per $N-N$ binary collision extrapolated from $p-p$ data (GLS), and from Au-Au data (solid points) and HIJING (open points).

FIG. 11. (Color online) (Left) Uncorrected angular correlations from 62-GeV $37 \%-46 \%$ central Au-Au collisions showing pileup distortions, especially evident as the W-shaped nonuniformity of the AS ridge on $\eta_{\Delta}$. (Right) The same data with pileup correction applied.

Sample correlations in $\Delta\phi$ ($|\Delta\eta|<$ 1.78) for 3 $<$ $p_T^{trigger}$ $<$ 6 GeV/$c$ and 1.5 GeV/$c$ $<$ $p_T^{associated}$ $<$ $p_T^{trigger}$ for 0-60% Cu+Cu at $\sqrt{s_{NN}}$ = 62.4 GeV, 0-80% Au+Au at $\sqrt{s_{NN}}$ = 62.4 GeV, 0-95% $d$+Au at $\sqrt{s_{NN}}$ = 200 GeV, 0-60% Cu+Cu at $\sqrt{s_{NN}}$ = 200 GeV, 40-80% Au+Au at $\sqrt{s_{NN}}$ = 200 GeV, and 0-12% central Au+Au at $\sqrt{s_{NN}}$ = 200 GeV. The data are averaged between positive and negative $\Delta\phi$ and reflected in the plot.

Background subtracted sample correlations for 3 $<$ $p_T^{trigger}$ $<$ 6 GeV/$c$ and 1.5 GeV/$c$ $<$ $p_T^{associated}$ $<$ $p_T^{trigger}$ on the near-side for 0-60% Cu+Cu at $\sqrt{s_{NN}}$ = 62.4 GeV, 0-80% Au+Au at $\sqrt{s_{NN}}$ = 62.4 GeV, 0-95% $d$+Au collisions at $\sqrt{s_{NN}}$ = 200 GeV, 0-60% Cu+Cu at $\sqrt{s_{NN}}$ = 200 GeV, 40-80% Au+Au at $\sqrt{s_{NN}}$ = 200 GeV and 0-12% central Au+Au at $\sqrt{s_{NN}}$ = 200 GeV. The dependence of the jet-like correlation is shown as a function of $\Delta\eta$ ($|\Delta\phi|<$ 0.78). The data are averaged between positive and negative $\Delta\eta$.

Background subtracted sample correlations for 3 $<$ $p_T^{trigger}$ $<$ 6 GeV/$c$ and 1.5 GeV/$c$ $<$ $p_T^{associated}$ $<$ $p_T^{trigger}$ on the near-side for 0-60% Cu+Cu at $\sqrt{s_{NN}}$ = 62.4 GeV, 0-80% Au+Au at $\sqrt{s_{NN}}$ = 62.4 GeV, 0-95% $d$+Au collisions at $\sqrt{s_{NN}}$ = 200 GeV, 0-60% Cu+Cu at $\sqrt{s_{NN}}$ = 200 GeV, 40-80% Au+Au at $\sqrt{s_{NN}}$ = 200 GeV and 0-12% central Au+Au at $\sqrt{s_{NN}}$ = 200 GeV. The dependence of the jet-like correlation is shown as a function of $\Delta\phi$ ($|\Delta\eta|<$ 1.78). The data are averaged between positive and negative $\Delta\phi$.

Dependence of jet-like yield on $N_{part}$ for 3 $<$ $p_T^{trigger}$ $<$ 6 GeV/$c$ and 1.5 GeV/$c$ $<$ $p_T^{associated}$ $<$ $p_T^{trigger}$ for Cu+Cu at $\sqrt{s_{NN}}$ = 62.4 GeV. 5% systematic error due to the uncertainty on the associated particle's efficiency is not shown.

Dependence of jet-like yield on $N_{part}$ for 3 $<$ $p_T^{trigger}$ $<$ 6 GeV/$c$ and 1.5 GeV/$c$ $<$ $p_T^{associated}$ $<$ $p_T^{trigger}$ for Au+Au at $\sqrt{s_{NN}}$ = 62.4 GeV. 5% systematic error due to the uncertainty on the associated particle's efficiency is not shown.

Dependence of jet-like yield on $N_{part}$ for 3 $<$ $p_T^{trigger}$ $<$ 6 GeV/$c$ and 1.5 GeV/$c$ $<$ $p_T^{associated}$ $<$ $p_T^{trigger}$ for $d$+Au at $\sqrt{s_{NN}}$ = 200 GeV. 5% systematic error due to the uncertainty on the associated particle's efficiency is not shown.

Dependence of jet-like yield on $N_{part}$ for 3 $<$ $p_T^{trigger}$ $<$ 6 GeV/$c$ and 1.5 GeV/$c$ $<$ $p_T^{associated}$ $<$ $p_T^{trigger}$ for Cu+Cu at $\sqrt{s_{NN}}$ = 200 GeV. 5% systematic error due to the uncertainty on the associated particle's efficiency is not shown.

Dependence of jet-like yield on $N_{part}$ for 3 $<$ $p_T^{trigger}$ $<$ 6 GeV/$c$ and 1.5 GeV/$c$ $<$ $p_T^{associated}$ $<$ $p_T^{trigger}$ for Au+Au at $\sqrt{s_{NN}}$ = 200 GeV. 5% systematic error due to the uncertainty on the associated particle's efficiency is not shown.

Dependence of jet-like yield on $p_T^{\mathrm{trigger}}$ for 0-60% Cu+Cu at $\sqrt{s_{NN}}$ = 62.4 GeV, 0-80% Au+Au at $\sqrt{s_{NN}}$ = 62.4 GeV, 0-95% $d$+Au collisions at $\sqrt{s_{NN}}$ = 200 GeV, 0-60% Cu+Cu at $\sqrt{s_{NN}}$ = 200 GeV, 40-80% Au+Au at $\sqrt{s_{NN}}$ = 200 GeV and 0-12% central Au+Au at $\sqrt{s_{NN}}$ = 200 GeV. The 5% systematic error due to the uncertainty on the associated particle's efficiency is not shown.

Dependence of jet-like yield on $p_T^{\mathrm{associated}}$ for 3 $<$ $p_T^{trigger}$ $<$ 6 GeV/$c$ for 0-60% Cu+Cu and 0-80% Au+Au collisions at $\sqrt{s_{NN}}$ = 62.4 GeV and 0-95% $d$+Au, 0-60% Cu+Cu, 0-12% Au+Au and 40-80% Au+Au collisions at $\sqrt{s_{NN}}$ = 200 GeV. The 5% systematic error due to the uncertainty on the associated particle's efficiency is not shown.

Dependence of the widths in $\Delta\phi$ on $p_T^{\mathrm{trigger}}$ for 1.5 GeV/$c$ $<$ $p_T^{associated}$ $<$ $p_T^{trigger}$ for 0-95% $d$+Au, 0-60% Cu+Cu at $\sqrt{s_{NN}}$ = 62.4 GeV and $\sqrt{s_{NN}}$ = 200 GeV, 0-80% Au+Au at $\sqrt{s_{NN}}$ = 62.4 GeV, and 0-12% and 40-80% Au+Au at $\sqrt{s_{NN}}$ = 200 GeV.

Dependence of the widths in $\Delta\phi$ on $p_T^{\mathrm{associated}}$ for 3 $<$ $p_T^{trigger}$ $<$ 6 GeV/$c$ for 0-95% $d$+Au, 0-60% Cu+Cu at $\sqrt{s_{NN}}$ = 62.4 GeV and $\sqrt{s_{NN}}$ = 200 GeV, 0-80% Au+Au at $\sqrt{s_{NN}}$ = 62.4 GeV, and 0-12% and 40-80% Au+Au at $\sqrt{s_{NN}}$ = 200 GeV.

Dependence of the widths in $\Delta\phi$ on $N_{part}$ for 3 $<$ $p_T^{trigger}$ $<$ 6 GeV/$c$ and 1.5 GeV/$c$ $<$ $p_T^{associated}$ $<$ $p_T^{trigger}$ for 0-60% Cu+Cu at $\sqrt{s_{NN}}$ = 62.4 GeV.

Dependence of the widths in $\Delta\phi$ on $N_{part}$ for 3 $<$ $p_T^{trigger}$ $<$ 6 GeV/$c$ and 1.5 GeV/$c$ $<$ $p_T^{associated}$ $<$ $p_T^{trigger}$ for 0-80% Au+Au at $\sqrt{s_{NN}}$ = 62.4 GeV.

Dependence of the widths in $\Delta\phi$ on $N_{part}$ for 3 $<$ $p_T^{trigger}$ $<$ 6 GeV/$c$ and 1.5 GeV/$c$ $<$ $p_T^{associated}$ $<$ $p_T^{trigger}$ for 0-95% $d$+Au at $\sqrt{s_{NN}}$ = 200 GeV.

Dependence of the widths in $\Delta\phi$ on $N_{part}$ for 3 $<$ $p_T^{trigger}$ $<$ 6 GeV/$c$ and 1.5 GeV/$c$ $<$ $p_T^{associated}$ $<$ $p_T^{trigger}$ for 0-60% Cu+Cu at $\sqrt{s_{NN}}$ = 200 GeV.

Dependence of the widths in $\Delta\phi$ on $N_{part}$ for 3 $<$ $p_T^{trigger}$ $<$ 6 GeV/$c$ and 1.5 GeV/$c$ $<$ $p_T^{associated}$ $<$ $p_T^{trigger}$ for Au+Au at $\sqrt{s_{NN}}$ = 200 GeV.

Dependence of the widths in $\Delta\eta$ on $p_T^{\mathrm{trigger}}$ for 1.5 GeV/$c$ $<$ $p_T^{associated}$ $<$ $p_T^{trigger}$ for 0-95% $d$+Au, 0-60% Cu+Cu at $\sqrt{s_{NN}}$ = 62.4 GeV and $\sqrt{s_{NN}}$ = 200 GeV, 0-80% Au+Au at $\sqrt{s_{NN}}$ = 62.4 GeV, and 0-12% and 40-80% Au+Au at $\sqrt{s_{NN}}$ = 200 GeV.

Dependence of the widths in $\Delta\eta$ on $p_T^{\mathrm{associated}}$ for 3 $<$ $p_T^{trigger}$ $<$ 6 GeV/$c$ for 0-95% $d$+Au, 0-60% Cu+Cu at $\sqrt{s_{NN}}$ = 62.4 GeV and $\sqrt{s_{NN}}$ = 200 GeV, 0-80% Au+Au at $\sqrt{s_{NN}}$ = 62.4 GeV, and 0-12% and 40-80% Au+Au at $\sqrt{s_{NN}}$ = 200 GeV.

Dependence of the widths in $\Delta\eta$ on $N_{part}$ for 3 $<$ $p_T^{trigger}$ $<$ 6 GeV/$c$ and 1.5 GeV/$c$ $<$ $p_T^{associated}$ $<$ $p_T^{trigger}$ for 0-60% Cu+Cu at $\sqrt{s_{NN}}$ = 62.4 GeV.

Dependence of the widths in $\Delta\eta$ on $N_{part}$ for 3 $<$ $p_T^{trigger}$ $<$ 6 GeV/$c$ and 1.5 GeV/$c$ $<$ $p_T^{associated}$ $<$ $p_T^{trigger}$ for 0-80% Au+Au at $\sqrt{s_{NN}}$ = 62.4 GeV.

Dependence of the widths in $\Delta\eta$ on $N_{part}$ for 3 $<$ $p_T^{trigger}$ $<$ 6 GeV/$c$ and 1.5 GeV/$c$ $<$ $p_T^{associated}$ $<$ $p_T^{trigger}$ for 0-95% $d$+Au at $\sqrt{s_{NN}}$ = 200 GeV.

Dependence of the widths in $\Delta\eta$ on $N_{part}$ for 3 $<$ $p_T^{trigger}$ $<$ 6 GeV/$c$ and 1.5 GeV/$c$ $<$ $p_T^{associated}$ $<$ $p_T^{trigger}$ for 0-60% Cu+Cu at $\sqrt{s_{NN}}$ = 200 GeV.

Dependence of the widths in $\Delta\eta$ on $N_{part}$ for 3 $<$ $p_T^{trigger}$ $<$ 6 GeV/$c$ and 1.5 GeV/$c$ $<$ $p_T^{associated}$ $<$ $p_T^{trigger}$ for Au+Au at $\sqrt{s_{NN}}$ = 200 GeV.

Dependence of ridge yield on $N_{part}$ for 3 $<$ $p_T^{trigger}$ $<$ 6 GeV/$c$ and 1.5 GeV/$c$ $<$ $p_T^{associated}$ $<$ $p_T^{trigger}$ for Cu+Cu at $\sqrt{s_{NN}}$ = 62.4 GeV.

Dependence of ridge yield on $N_{part}$ for 3 $<$ $p_T^{trigger}$ $<$ 6 GeV/$c$ and 1.5 GeV/$c$ $<$ $p_T^{associated}$ $<$ $p_T^{trigger}$ for Au+Au at $\sqrt{s_{NN}}$ = 62.4 GeV.

Dependence of ridge yield on $N_{part}$ for 3 $<$ $p_T^{trigger}$ $<$ 6 GeV/$c$ and 1.5 GeV/$c$ $<$ $p_T^{associated}$ $<$ $p_T^{trigger}$ for Cu+Cu at $\sqrt{s_{NN}}$ = 200 GeV.

Dependence of ridge yield on $N_{part}$ for 3 $<$ $p_T^{trigger}$ $<$ 6 GeV/$c$ and 1.5 GeV/$c$ $<$ $p_T^{associated}$ $<$ $p_T^{trigger}$ for Au+Au at $\sqrt{s_{NN}}$ = 200 GeV.

Ratio of the ridge and jet-like yields on $N_{part}$ for 3 $<$ $p_T^{trigger}$ $<$ 6 GeV/$c$ and 1.5 GeV/$c$ $<$ $p_T^{associated}$ $<$ $p_T^{trigger}$ for Cu+Cu at $\sqrt{s_{NN}}$ = 62.4 GeV.

Ratio of the ridge and jet-like yields on $N_{part}$ for 3 $<$ $p_T^{trigger}$ $<$ 6 GeV/$c$ and 1.5 GeV/$c$ $<$ $p_T^{associated}$ $<$ $p_T^{trigger}$ for Au+Au at $\sqrt{s_{NN}}$ = 62.4 GeV.

Ratio of the ridge and jet-like yields on $N_{part}$ for 3 $<$ $p_T^{trigger}$ $<$ 6 GeV/$c$ and 1.5 GeV/$c$ $<$ $p_T^{associated}$ $<$ $p_T^{trigger}$ for Cu+Cu at $\sqrt{s_{NN}}$ = 200 GeV.

Ratio of the ridge and jet-like yields on $N_{part}$ for 3 $<$ $p_T^{trigger}$ $<$ 6 GeV/$c$ and 1.5 GeV/$c$ $<$ $p_T^{associated}$ $<$ $p_T^{trigger}$ for Au+Au at $\sqrt{s_{NN}}$ = 200 GeV.

Dependence of $V_{3\Delta}/V_{2\Delta}$ on $N_{part}$ for 3 $<$ $p_T^{trigger}$ $<$ 6 GeV/$c$ and 1.5 GeV/$c$ $<$ $p_T^{associated}$ $<$ $p_T^{trigger}$ for Cu+Cu at $\sqrt{s_{NN}}$ = 62.4 GeV.

Dependence of $V_{3\Delta}/V_{2\Delta}$ on $N_{part}$ for 3 $<$ $p_T^{trigger}$ $<$ 6 GeV/$c$ and 1.5 GeV/$c$ $<$ $p_T^{associated}$ $<$ $p_T^{trigger}$ for Au+Au at $\sqrt{s_{NN}}$ = 62.4 GeV.

Dependence of $V_{3\Delta}/V_{2\Delta}$ on $N_{part}$ for 3 $<$ $p_T^{trigger}$ $<$ 6 GeV/$c$ and 1.5 GeV/$c$ $<$ $p_T^{associated}$ $<$ $p_T^{trigger}$ for $d$+Au at $\sqrt{s_{NN}}$ = 200 GeV.

Dependence of $V_{3\Delta}/V_{2\Delta}$ on $N_{part}$ for 3 $<$ $p_T^{trigger}$ $<$ 6 GeV/$c$ and 1.5 GeV/$c$ $<$ $p_T^{associated}$ $<$ $p_T^{trigger}$ for Cu+Cu at $\sqrt{s_{NN}}$ = 200 GeV.

Dependence of $V_{3\Delta}/V_{2\Delta}$ on $N_{part}$ for 3 $<$ $p_T^{trigger}$ $<$ 6 GeV/$c$ and 1.5 GeV/$c$ $<$ $p_T^{associated}$ $<$ $p_T^{trigger}$ for Au+Au at $\sqrt{s_{NN}}$ = 200 GeV.

The invariant yields $d^2N/(2\pi p_T dp_T dy)$ of $K + p(\bar{p})$ in central Au+Au collisions, and NLO calculations with AKK [9] and DSS [10] FF. The uncertainty of yields due to the scale dependence as evaluated in [10] is about a factor of 2. Bars and boxes (bands) represent statistical and systematic uncertainties, respectively.

The invariant yields $d^2N/(2\pi p_T dp_T dy)$ of $\rho^0$ in central Au+Au collisions, and NLO calculations with AKK [9] and DSS [10] FF. The uncertainty of yields due to the scale dependence as evaluated in [10] is about a factor of 2. Bars and boxes (bands) represent statistical and systematic uncertainties, respectively.

The invariant yields $d^2N/(2\pi p_T dp_T dy)$ of $K^0_S$ in central Au+Au collisions, and NLO calculations with AKK [9] and DSS [10] FF. The uncertainty of yields due to the scale dependence as evaluated in [10] is about a factor of 2. Bars and boxes (bands) represent statistical and systematic uncertainties, respectively.

Yield ratios $\pi^−/\pi^+$, $\bar{p}/p$, $K^−/K^+$, $p/\pi^+$, $\bar{p}/\pi^−$, and $K^{\pm}/\pi^{\pm}$ versus $p_T$ in p+p collisions, and nominal NLO calculations with AKK [9] and DSS [10] FFs without theoretical uncertainties. Bars and boxes (bands) represent statistical and systematic uncertainties, respectively.

Yield ratio $K^0_S$)/$\pi^{\pm}$ versus $p_T$ in p+p collisions, and nominal NLO calculations with AKK [9] and DSS [10] FFs without theoretical uncertainties. Bars and boxes (bands) represent statistical and systematic uncertainties, respectively.

Yield ratios $p/\pi^+$ and $\bar{p}/\pi^−$ versus $p_T$ in central Au+Au collisions [14] with updated uncertainties at high $p_T$. Bars and boxes (bands) represent statistical and systematic uncertainties, respectively.

$R_{AA}$ of $\pi^{\pm} in central Au+Au collisions as a function of $p_T$. Bars and boxes (bands) represent statistical and systematic uncertainties, respectively. The height of the band at unity represents the normalization uncertainty.

$R_{AA}$ of $K^{\pm}+p(\bar{p})$ in central Au+Au collisions as a function of $p_T$. Bars and boxes (bands) represent statistical and systematic uncertainties, respectively. The height of the band at unity represents the normalization uncertainty.

$R_{AA}$ of $K^0_S$ in central Au+Au collisions as a function of $p_T$. The curves are the calculations for $K^0_S$ $R_{AA}$ with and without jet conversion in medium [15]. Bars and boxes (bands) represent statistical and systematic uncertainties, respectively. The height of the band at unity represents the normalization uncertainty.

$R_{AA}$ of $\rho^0$ in central Au+Au collisions as a function of $p_T$. Bars and boxes (bands) represent statistical and systematic uncertainties, respectively. The height of the band at unity represents the normalization uncertainty.

The ratios of $R_{AA}[K^{\pm} + p(\bar{p})]$ to $R_{AA}(\pi^{\pm})$. The boxes and shaded bands represent the systematic uncertainties for $R_{AA}[K^{\pm} +p(\bar{p})]/R_{AA}(\pi^{\pm})$, respectively.

The ratios of $R_{AA}(K^− + \bar{p})$ to $R_{AA}(K^+ p)$. The systematic uncertainties for $R_{AA}(K^− + \bar{p})/R_{AA}(K^+ +p)$ are 2–12% and left off for clarity.

The ratios of $R_{AA}[\rho^0]$ to $R_{AA}(\pi^{\pm})$. The boxes and shaded bands represent the systematic uncertainties for $R_{AA}(\rho^0)/R_{AA}(\pi^{\pm})$, respectively.

The difference of charge-independent (CI) v2{2} and like-sign (LS) $v_2\{2\}$ for Au+Au and Cu+Cu collisions at 200 (top panel) and 62.4 (bottom panel) GeV vs. the log of $\langle dN_{ch}/d\eta\rangle$.The statistical errors are smaller than the marker size and not visible for most of the data.

The LS and CI four-particle cumulant $v_2\{4\}^4$ for Au+Au collisions at 200 and 62.4 GeV for $0.15 < pT < 2.0$ GeV/$c$. The systematic errors are shown as narrow lines with wide caps at the end and statistical errors are shown as thick lines with narrow caps at the end. Statistical errors are not visible for most of the points.

The LS and CI four-particle cumulant $v_2\{4\}^4$ for Cu+Cu collisions at 200 and 62.4 GeV for $0.15 < p_T < 2.0$ GeV/c. The most central points (two points for Cu+Cu 62.4 GeV) gives $v_2\{4\}^4 < 0$ for all the data sets. The negative values are probably due to large fluctuations in agreement with Eq. (1). These may include contributions from impact parameter spread and finite multiplicity bin width.

The difference of charge-independent (CI) $v_2\{4\}$ and like-sign (LS) $v_2\{4\}$ for Au+Au collisions at 200 and 62.4 GeV vs. the log of $\langle dN_{ch}/d\eta\rangle$.

(Left) The difference between $v_2\{2\}^2$ and $v_2\{4\}^2$ for 200 GeV Au+Au and Cu+Cu collisions for both LS and CI combinations.

(Right) The difference between $v_2\{2\}^2$ and $v_2\{4\}^2$ for 62.4 GeV Au+Au and Cu+Cu collisions for both LS and CI combinations. The statistical and systematic errors are shown as in previous figures.

The upper limit on $\sigma_{v_2}/\langle v_2 \rangle$ for 200 GeV (left) and 62.4 GeV (right) Au+Au collisions from Eq. (9) compared to $\sigma_\varepsilon/\varepsilon$ from Eq. (10) for three different models. The upper limit is found using the LS results for $v_2\{2\}$. Data are from the range $0.15 < p_T < 2.0$ GeV/$c$. The shaded bands reflect the uncertainties on the models which are dominated by uncertainty on the distribution of nucleons inside the nucleus. The uncertainty is only shown for the MCG-N and fKLN-CGC models. The uncertainty on the MCG-Q model is the same as for the MCG-N model but is not shown for the visual clarity.

The upper limit on $\sigma_{v_2}/\langle v_2 \rangle$ for 200 GeV (left) and 62.4 GeV (right) Au+Au collisions from Eq. (9) compared to $\sigma_\varepsilon/\varepsilon$ from Eq. (10) for three different models. The upper limit is found using the LS results for $v_2\{2\}$. Data are from the range $0.15 < p_T < 2.0$ GeV/$c$. The shaded bands reflect the uncertainties on the models which are dominated by uncertainty on the distribution of nucleons inside the nucleus. The uncertainty is only shown for the MCG-N and fKLN-CGC models. The uncertainty on the MCG-Q model is the same as for the MCG-N model but is not shown for the visual clarity.

The STAR data compared to PHOBOS data [34] on $\sigma_{v_2}/\langle v_2 \rangle$ with $\delta_2$ for $\Delta\eta > 2$ taken to be zero (see Fig. 6 from Ref. [34]). The shaded band shows the errors quoted from Ref. [34].

The upper limit on $\sigma_{v_2}/\langle v_2 \rangle$ for 200 GeV (left) and 62.4 GeV (right) Cu+Cu collisions from Eq. (9) compared to $\sigma_\varepsilon/\varepsilon$ from Eq. (10) for three different models.

The upper limit on $\sigma_{v_2}/\langle v_2 \rangle$ for 200 GeV (left) and 62.4 GeV (right) Cu+Cu collisions from Eq. (9) compared to $\sigma_\varepsilon/\varepsilon$ from Eq. (10) for three different models.

The measured scaled momentum distributions for (LAMBDA+LAMBDABAR) production as a function of Q^2 in six XP regions.

The measured scaled momentum distributions for (LAMBDA+LAMBDABAR) production as a function of XP in five Q^2 regions.

The measured scaled momentum distributions for (LAMBDA+LAMBDABAR) production as a function of XP in two Q^2 regions.

Charged particle multiplicity distribution for hard QCD events in the full pseudorapidity range. The first quoted uncertainty is statistical and the second is systematic.

Charged particle density as function of pseudorapidity ($\eta$) for minimum bias events in $-2.0 < \eta < -2.5$. Minimum bias events are required to have at least one prompt final state charged particle in fiducial range $2.0 < \eta < 4.5$. Only total uncertainties are listed.

Charged particle density as function of pseudorapidity($\eta$) for minimum bias events in $2.0 < \eta < 4.5$. Minimum bias events are required to have at least one prompt final state charged particle in fiducial range $2.0 < \eta < 4.5$. Only total uncertainties are listed.

Charged particle density as function of pseudorapidity ($\eta$) for hard QCD events in $-2.0 < \eta < -2.5$. Hard QCD events are required to have at least one prompt final state charged particle in fiducial range $2.5 < \eta < 4.5$ with $p_\perp > 1.0$ GeV/c. Only total uncertainties are listed.

Charged particle density as function of pseudorapidity ($\eta$) for hard QCD events in $2.0 < \eta < 4.5$. Hard QCD events are required to have at least one prompt final state charged particle in fiducial range $2.5 < \eta < 4.5$ with $p_\perp > 1.0$ GeV/c. Only total uncertainties are listed.

(Color online) Distribution of the product of the TPC reconstructed charge sign and 1/$p_{T}$ for candidates satisfying all the W signal selection criteria and $E^{e}_{T}$ > 25 GeV.

(Color online) Distributions of the invariant mass of pairs of oppositely charged $e^{\pm}$ candidates after sequentially applying the selection criteria described in Sec. IV A to both $e^{\pm}$ candidates.

(Color online) Distributions of the invariant mass of $Z/\gamma^{*} \to e^{+}e^{−}$ candidate events satisfying all selection criteria described in Sec. IVC. The $Z/\gamma^{*} \to e^{+}e^{−}$ MC distribution (dashed line) is shown for comparison. Note the larger bin widths relative to Fig. 7

(Color online) $E^{e}_{T}$ distribution of $W^{+}$ (top) and $W^{−}$ (bottom) candidate events, background components, and $W \to e\nu$ MC signal for comparison. Note the factor of two difference in the vertical scales.

(Color online) $E^{e}_{T}$ distribution of $W^{+}$ (top) and $W^{−}$ (bottom) candidate events, background components, and $W \to e\nu$ MC signal for comparison. Note the factor of two difference in the vertical scales.

(Color online) Lepton pseudorapidity distribution of $W^{+}$ (left) and $W^{−}$ (right) candidate events, background components, and $W \to e\nu$ MC signal for comparison.

(Color online) Lepton pseudorapidity distribution of $W^{+}$ (left) and $W^{−}$ (right) candidate events, background components, and $W \to e\nu$ MC signal for comparison.

(Color online) W cross section ratio, $R_{W}$, for the two $e^{\pm}$ pseudorapidity bins. Theory calculations at NLO from the fewz program using the MSTW08 and CTEQ 6.6 PDF sets (with 90% confidence level error eigenvector uncertainties) are shown for comparison.

Model calculations of pion (left panel) and proton (right panel) $v_1$(y) for 10-70$\%$ $Au + Au$ collisions at $\sqrt{s_{NN}} = 200$ GeV. QGSM model presents the basic Quark-Gluon String model with parton recombination. Hydro model presents the hydrodynamic expansion from a tilted source (Please note that proton v1 in this figure is the same as in Figure 1 right).

Charged pions (solid stars), protons (solid circles) and antiprotons (solid squares) $v_1$(y) slope (d$v_1$/dy) at midrapidity as a function of centrality for $Au + Au$ collisions at $\sqrt{s_{NN}} = 200$ GeV.

Proton $v_1$($y^{\prime}$) slope (d$v_1$/d$y^{\prime}$) at midrapidity as a function of center of mass collision energy, where $y^{\prime} = y/y_{beam}$.