Measurements of phi meson production in relativistic heavy-ion collisions at RHIC

The collaboration
Phys.Rev.C 79 (2009) 064903, 2009.

Abstract (data abstract)
BNL-RHIC. We present results for the measurement of $\phi$ meson production via its charged kaon decay channel $\phi$ → $K^{+}K^{-}$ in Au + Au collisions at $\sqrt{s_{NN}} = 62.4, 130,$ and $200 GeV$, and in p + p and d + Au collisions at $\sqrt{s_{NN}} = 200 GeV$ from the STAR experiment at the BNL Relativistic Heavy Ion Collider (RHIC). The midrapidity (|y| < 0.5) $\phi$ meson transverse momentum ($p_{T}$) spectra in central Au + Au collisions are found to be well described by a single exponential distribution. On the other hand, the $p_{T}$ spectra from p + p, d + Au, and peripheral Au + Au collisions show power-law tails at intermediate and high pT and are described better by Levy distributions. The constant $\phi/K^{-}$ yield ratio vs beam species, collision centrality, and colliding energy is in contradiction with expectations from models having kaon coalescence as the dominant mechanism for $\phi$ production at RHIC. The $\Omega/\phi$ yield ratio as a function of $p_{T}$ is consistent with a model based on the recombination of thermal s quarks up to $p_{T}$ ∼ 4 GeV/c, but disagrees at higher transverse momenta. The measured nuclear modification factor, RdAu, for the $\phi$ meson increases above unity at intermediate $p_{T}$ , similar to that for pions and protons, while $R_{AA}$ is suppressed due to the energy loss effect in central Au + Au collisions. Number of constituent quark scaling of both $R_{cp}$ and $v_{2}$ for the $\phi$ meson with respect to other hadrons in Au + Au collisions at $\sqrt{s_{NN}} = 200 GeV$ at intermediate $p_{T}$ is observed. These observations support quark coalescence as being the dominant mechanism of hadronization in the intermediate $p_{T}$ region at RHIC.

• #### Figure 2, ($Result$ $with$ $dip-angle$ $cut:$)

Data from Figure 2

10.17182/hepdata.99047.v1/t1

Background-subtracted invariant mass distributions at 0.4 < $p_{T}$ < 0.8 GeV/c in d + Au 200 GeV collisions (0–100%) with...

• #### Figure 2, ($Result$ $without$ $dip-angle$ $cut:$)

Data from Figure 2

10.17182/hepdata.99047.v1/t2

Background-subtracted invariant mass distributions at 0.4 < $p_{T}$ < 0.8 GeV/c in d + Au 200 GeV collisions (0–100%) with...

• #### Figure 3(a) Au+Au 62.4GeV

Data from Figure 3(a)

10.17182/hepdata.99047.v1/t3

Upper panels: same-event (full points) and mixed-event (solid line) $K^{+}K^{-}$ invariant mass distributions at 0.6 < $p_{T}$ < 1.4 GeV/c...

• #### Figure 3(b) Au+Au 62.4GeV

Data from Figure 3(b)

10.17182/hepdata.99047.v1/t4

Upper panels: same-event (full points) and mixed-event (solid line) $K^{+}K^{-}$ invariant mass distributions at 0.6 < $p_{T}$ < 1.4 GeV/c...

• #### Figure 3(c) Au+Au 200GeV

Data from Figure 3(c)

10.17182/hepdata.99047.v1/t5

Upper panels: same-event (full points) and mixed-event (solid line) $K^{+}K^{-}$ invariant mass distributions at 0.6 < $p_{T}$ < 1.4 GeV/c...

• #### Figure 3(d) Au+Au 200GeV

Data from Figure 3(d)

10.17182/hepdata.99047.v1/t6

Upper panels: same-event (full points) and mixed-event (solid line) $K^{+}K^{-}$ invariant mass distributions at 0.6 < $p_{T}$ < 1.4 GeV/c...

• #### Figure 4, Au+Au 200GeV

Data from Figure 4

10.17182/hepdata.99047.v1/t7

Reconstruction efficiency including acceptance of $\phi$ meson as a function of $p_{T}$ in several centrality bins of Au + Au,...

• #### Figure 4, d+Au 200GeV

Data from Figure 4

10.17182/hepdata.99047.v1/t8

Reconstruction efficiency including acceptance of $\phi$ meson as a function of $p_{T}$ in several centrality bins of Au + Au,...

• #### Figure 4, p+p 200GeV

Data from Figure 4

10.17182/hepdata.99047.v1/t9

Reconstruction efficiency including acceptance of $\phi$ meson as a function of $p_{T}$ in several centrality bins of Au + Au,...

• #### Figure 5

Data from Figure 5

10.17182/hepdata.99047.v1/t10

Event plane $\Phi_{2}$ resolution as a function of centrality in Au + Au 200 GeV collisions, where the vertical axis...

• #### Figure 6

Data from Figure 6

10.17182/hepdata.99047.v1/t11

$\phi−\Phi_{2}$ distribution for $\phi$ meson at 1.5 < $p_{T}$ < 2.0 GeV/c in Au + Au collisions (0–80$\%$) at 200...

• #### Figure 7

Data from Figure 7

10.17182/hepdata.99047.v1/t12

(full red points) and (open blue points) as a function of $m_{inv}$ of $K^{+}K^{-}$ pairs at 0.5 <...

• #### Figure 8, (top, AuAu 62.4GeV exp)

Data from Figure 8

10.17182/hepdata.99047.v1/t13

Masses and widths (FWHMs) of $\phi$ as a function of $p_{T}$ in p + p 200 GeV (NSD), d +...

• #### Figure 8, (top, AuAu 62.4GeV MC)

Data from Figure 8

10.17182/hepdata.99047.v1/t14

Masses and widths (FWHMs) of $\phi$ as a function of $p_{T}$ in p + p 200 GeV (NSD), d +...

• #### Figure 8, (top, AuAu 200GeV exp)

Data from Figure 8

10.17182/hepdata.99047.v1/t15

Masses and widths (FWHMs) of $\phi$ as a function of $p_{T}$ in p + p 200 GeV (NSD), d +...

• #### Figure 8, (top, AuAu 200GeV exp 3.75 point)

Data from Figure 8

10.17182/hepdata.99047.v1/t16

Masses and widths (FWHMs) of $\phi$ as a function of $p_{T}$ in p + p 200 GeV (NSD), d +...

• #### Figure 8, (top, AuAu 200GeV MC)

Data from Figure 8

10.17182/hepdata.99047.v1/t17

Masses and widths (FWHMs) of $\phi$ as a function of $p_{T}$ in p + p 200 GeV (NSD), d +...

• #### Figure 8, (top, dAu 200GeV)

Data from Figure 8

10.17182/hepdata.99047.v1/t18

Masses and widths (FWHMs) of $\phi$ as a function of $p_{T}$ in p + p 200 GeV (NSD), d +...

• #### Figure 8, (top, pp 200GeV exp)

Data from Figure 8

10.17182/hepdata.99047.v1/t19

Masses and widths (FWHMs) of $\phi$ as a function of $p_{T}$ in p + p 200 GeV (NSD), d +...

• #### Figure 8, (top, pp 200GeV MC)

Data from Figure 8

10.17182/hepdata.99047.v1/t20

Masses and widths (FWHMs) of $\phi$ as a function of $p_{T}$ in p + p 200 GeV (NSD), d +...

• #### Figure 8, (bottom, AuAu 62.4GeV)

Data from Figure 8

10.17182/hepdata.99047.v1/t21

Masses and widths (FWHMs) of $\phi$ as a function of $p_{T}$ in p + p 200 GeV (NSD), d +...

• #### Figure 8, (bottom, AuAu 200GeV)

Data from Figure 8

10.17182/hepdata.99047.v1/t22

Masses and widths (FWHMs) of $\phi$ as a function of $p_{T}$ in p + p 200 GeV (NSD), d +...

• #### Figure 8, (bottom, dAu 200GeV)

Data from Figure 8

10.17182/hepdata.99047.v1/t23

Masses and widths (FWHMs) of $\phi$ as a function of $p_{T}$ in p + p 200 GeV (NSD), d +...

• #### Figure 8, (bottom, pp 200GeV exp)

Data from Figure 8

10.17182/hepdata.99047.v1/t24

Masses and widths (FWHMs) of $\phi$ as a function of $p_{T}$ in p + p 200 GeV (NSD), d +...

• #### Figure 8, (bottom, pp 200GeV MC)

Data from Figure 8

10.17182/hepdata.99047.v1/t25

Masses and widths (FWHMs) of $\phi$ as a function of $p_{T}$ in p + p 200 GeV (NSD), d +...

• #### Figure 9, p+p 200GeV Exp.data

Data from Figure 9

10.17182/hepdata.99047.v1/t26

Invariant mass distributions of $\phi$ meson at 0.6 < $p_{T}$ < 1.0 GeV/c in p + p 200 GeV (NSD)...

• #### Figure 9, p+p 200GeV MC.data

Data from Figure 9

10.17182/hepdata.99047.v1/t27

Invariant mass distributions of $\phi$ meson at 0.6 < $p_{T}$ < 1.0 GeV/c in p + p 200 GeV (NSD)...

• #### Figure 9, Au+Au 200GeV Exp.data

Data from Figure 9

10.17182/hepdata.99047.v1/t28

Invariant mass distributions of $\phi$ meson at 0.6 < $p_{T}$ < 1.0 GeV/c in p + p 200 GeV (NSD)...

• #### Figure 9, Au+Au 200GeV MC(1).data

Data from Figure 9

10.17182/hepdata.99047.v1/t29

Invariant mass distributions of $\phi$ meson at 0.6 < $p_{T}$ < 1.0 GeV/c in p + p 200 GeV (NSD)...

• #### Figure 9, Au+Au 200GeV MC(2).data

Data from Figure 9

10.17182/hepdata.99047.v1/t30

Invariant mass distributions of $\phi$ meson at 0.6 < $p_{T}$ < 1.0 GeV/c in p + p 200 GeV (NSD)...

• #### Figure 10, table (a)

Data from Figure 10

10.17182/hepdata.99047.v1/t31

$\phi$ meson transverse mass distributions for different collision systems and different energies. For clarity, distributions for some centrality bins have...

• #### Figure 10, table (b) (0-11$\%$)

Data from Figure 10

10.17182/hepdata.99047.v1/t32

$\phi$ meson transverse mass distributions for different collision systems and different energies. For clarity, distributions for some centrality bins have...

• #### Figure 10, table (b) (11-26$\%$)

Data from Figure 10

10.17182/hepdata.99047.v1/t33

$\phi$ meson transverse mass distributions for different collision systems and different energies. For clarity, distributions for some centrality bins have...

• #### Figure 10, table (b) (26-85$\%$)

Data from Figure 10

10.17182/hepdata.99047.v1/t34

$\phi$ meson transverse mass distributions for different collision systems and different energies. For clarity, distributions for some centrality bins have...

• #### Figure 10, table (c)

Data from Figure 10

10.17182/hepdata.99047.v1/t35

$\phi$ meson transverse mass distributions for different collision systems and different energies. For clarity, distributions for some centrality bins have...

• #### Figure 10, table (d) (d+Au 200GeV)

Data from Figure 10

10.17182/hepdata.99047.v1/t36

$\phi$ meson transverse mass distributions for different collision systems and different energies. For clarity, distributions for some centrality bins have...

• #### Figure 10, table (d) (p+p 200GeV(NSD))

Data from Figure 10

10.17182/hepdata.99047.v1/t37

$\phi$ meson transverse mass distributions for different collision systems and different energies. For clarity, distributions for some centrality bins have...

• #### Figure 11, table (top) (Au+Au 200GeV(0-5$\%$)/$N_{binary}$)

Data from Figure 11

10.17182/hepdata.99047.v1/t38

Comparison of transverse momentum spectra shape among different 200 GeV collision systems: Au + Au (0–5$\%$), d + Au (0–20$\%$),...

• #### Figure 11, table (top) (d+Au 200GeV(0-20$\%$)/$N_{binary}$)

Data from Figure 11

10.17182/hepdata.99047.v1/t39

Comparison of transverse momentum spectra shape among different 200 GeV collision systems: Au + Au (0–5$\%$), d + Au (0–20$\%$),...

• #### Figure 11, table (top) (p+p 200GeV)

Data from Figure 11

10.17182/hepdata.99047.v1/t40

Comparison of transverse momentum spectra shape among different 200 GeV collision systems: Au + Au (0–5$\%$), d + Au (0–20$\%$),...

• #### Figure 11, table (bottom) (Au+Au 200GeV(0-5$\%$)/($N_{part}$/2))

Data from Figure 11

10.17182/hepdata.99047.v1/t41

Comparison of transverse momentum spectra shape among different 200 GeV collision systems: Au + Au (0–5$\%$), d + Au (0–20$\%$),...

• #### Figure 11, table (bottom) (d+Au 200GeV(0-20$\%$)/($N_{part}$/2))

Data from Figure 11

10.17182/hepdata.99047.v1/t42

Comparison of transverse momentum spectra shape among different 200 GeV collision systems: Au + Au (0–5$\%$), d + Au (0–20$\%$),...

• #### Figure 11, table (bottom) (p+p 200GeV)

Data from Figure 11

10.17182/hepdata.99047.v1/t43

Comparison of transverse momentum spectra shape among different 200 GeV collision systems: Au + Au (0–5$\%$), d + Au (0–20$\%$),...

• #### Figure 12, (Au+Au 62.4GeV)

Data from Figure 12

10.17182/hepdata.99047.v1/t44

$N_{part}$ dependence of $(dN/dy)/0.5N_{part}$ in five different collision systems: Au + Au 62.4, 130, 200 GeV; p + p 200...

• #### Figure 12, (Au+Au 130GeV)

Data from Figure 12

10.17182/hepdata.99047.v1/t45

$N_{part}$ dependence of $(dN/dy)/0.5N_{part}$ in five different collision systems: Au + Au 62.4, 130, 200 GeV; p + p 200...

• #### Figure 12, (Au+Au 200GeV)

Data from Figure 12

10.17182/hepdata.99047.v1/t46

$N_{part}$ dependence of $(dN/dy)/0.5N_{part}$ in five different collision systems: Au + Au 62.4, 130, 200 GeV; p + p 200...

• #### Figure 12, (d+Au 200GeV)

Data from Figure 12

10.17182/hepdata.99047.v1/t47

$N_{part}$ dependence of $(dN/dy)/0.5N_{part}$ in five different collision systems: Au + Au 62.4, 130, 200 GeV; p + p 200...

• #### Figure 12, (p+p 200GeV)

Data from Figure 12

10.17182/hepdata.99047.v1/t48

$N_{part}$ dependence of $(dN/dy)/0.5N_{part}$ in five different collision systems: Au + Au 62.4, 130, 200 GeV; p + p 200...

• #### Figure 13, table(top) (Au+Au 200GeV)

Data from Figure 13

10.17182/hepdata.99047.v1/t49

• #### Figure 13, table(top) (Au+Au 62.4GeV)

Data from Figure 13

10.17182/hepdata.99047.v1/t51

• #### Figure 13, table(top) (p+p 200GeV)

Data from Figure 13

10.17182/hepdata.99047.v1/t53

• #### Figure 14, table(top) (A+A)

Data from Figure 14

10.17182/hepdata.99047.v1/t55

Top panel: Energy dependence of the ratio $\phi/\pi^{-}$ in A + A (full points) and p + p (open points)...

• #### Figure 14, table(top) (p+p)

Data from Figure 14

10.17182/hepdata.99047.v1/t56

Top panel: Energy dependence of the ratio $\phi/\pi^{-}$ in A + A (full points) and p + p (open points)...

• #### Figure 14, table(bottom) (Au+Au 62.4 GeV)

Data from Figure 14

10.17182/hepdata.99047.v1/t57

Top panel: Energy dependence of the ratio $\phi/\pi^{-}$ in A + A (full points) and p + p (open points)...

• #### Figure 14, table(bottom) (Au+Au 130 GeV)

Data from Figure 14

10.17182/hepdata.99047.v1/t58

Top panel: Energy dependence of the ratio $\phi/\pi^{-}$ in A + A (full points) and p + p (open points)...

• #### Figure 14, table(bottom) (Au+Au 200 GeV)

Data from Figure 14

10.17182/hepdata.99047.v1/t59

Top panel: Energy dependence of the ratio $\phi/\pi^{-}$ in A + A (full points) and p + p (open points)...

• #### Figure 14, table(bottom) (d+Au 200 GeV)

Data from Figure 14

10.17182/hepdata.99047.v1/t60

Top panel: Energy dependence of the ratio $\phi/\pi^{-}$ in A + A (full points) and p + p (open points)...

• #### Figure 14, table(bottom) (p+p 200 GeV)

Data from Figure 14

10.17182/hepdata.99047.v1/t61

Top panel: Energy dependence of the ratio $\phi/\pi^{-}$ in A + A (full points) and p + p (open points)...

• #### Figure 15, table(top) (A + A)

Data from Figure 15

10.17182/hepdata.99047.v1/t62

Top panel: Energy dependence of ratio $\phi/K^{-}$ in $A + A$ and elementary ($e + e$ and $p + p$)...

• #### Figure 15, table(top) (p + p)

Data from Figure 15

10.17182/hepdata.99047.v1/t63

Top panel: Energy dependence of ratio $\phi/K^{-}$ in $A + A$ and elementary ($e + e$ and $p + p$)...

• #### Figure 15, table(top) (e + e)

Data from Figure 15

10.17182/hepdata.99047.v1/t64

Top panel: Energy dependence of ratio $\phi/K^{-}$ in $A + A$ and elementary ($e + e$ and $p + p$)...

• #### Figure 15, table(bottom) (Au+Au 62.4 GeV)

Data from Figure 15

10.17182/hepdata.99047.v1/t65

Top panel: Energy dependence of ratio $\phi/K^{-}$ in $A + A$ and elementary ($e + e$ and $p + p$)...

• #### Figure 15, table(bottom) (Au+Au 130 GeV)

Data from Figure 15

10.17182/hepdata.99047.v1/t66

Top panel: Energy dependence of ratio $\phi/K^{-}$ in $A + A$ and elementary ($e + e$ and $p + p$)...

• #### Figure 15, table(bottom) (Au+Au 200 GeV)

Data from Figure 15

10.17182/hepdata.99047.v1/t67

Top panel: Energy dependence of ratio $\phi/K^{-}$ in $A + A$ and elementary ($e + e$ and $p + p$)...

• #### Figure 15, table(bottom) (d+Au 200 GeV)

Data from Figure 15

10.17182/hepdata.99047.v1/t68

Top panel: Energy dependence of ratio $\phi/K^{-}$ in $A + A$ and elementary ($e + e$ and $p + p$)...

• #### Figure 15, table(bottom) (p+p 200 GeV)

Data from Figure 15

10.17182/hepdata.99047.v1/t69

Top panel: Energy dependence of ratio $\phi/K^{-}$ in $A + A$ and elementary ($e + e$ and $p + p$)...

• #### Figure 16, ($\Omega/\phi$ (0-12$\%$))

Data from Figure 16

10.17182/hepdata.99047.v1/t70

The $\Omega/\phi$ ratio vs $p_{T}$ for three centrality bins in $\sqrt{s_{NN}} = 200 GeV$ Au + Au collisions, where the...

• #### Figure 16, ($\Omega/\phi$ (20-40$\%$), (40-60$\%$))

Data from Figure 16

10.17182/hepdata.99047.v1/t71

The $\Omega/\phi$ ratio vs $p_{T}$ for three centrality bins in $\sqrt{s_{NN}} = 200 GeV$ Au + Au collisions, where the...

• #### Figure 17, (Au+Au 200 GeV) ((0-5$\%$)/(40-60$\%$))

Data from Figure 17

10.17182/hepdata.99047.v1/t72

$p_{T}$ dependence of the nuclear modification factor $R_{cp}$ in Au + Au 200 GeV collisions. The top and bottom panels...

• #### Figure 17, (Au+Au 200 GeV) ((0-5$\%$)/(60-80$\%$))

Data from Figure 17

10.17182/hepdata.99047.v1/t73

$p_{T}$ dependence of the nuclear modification factor $R_{cp}$ in Au + Au 200 GeV collisions. The top and bottom panels...

• #### Figure 18, (Au+Au 62.4 GeV)

Data from Figure 18

10.17182/hepdata.99047.v1/t74

$p_{T}$ dependence of the nuclear modification factor $R_{cp}$ in Au + Au 62.4 and 200 GeV and d + Au...

• #### Figure 18, (Au+Au 200 GeV)

Data from Figure 18

10.17182/hepdata.99047.v1/t75

$p_{T}$ dependence of the nuclear modification factor $R_{cp}$ in Au + Au 62.4 and 200 GeV and d + Au...

• #### Figure 18, (d+Au 200 GeV)

Data from Figure 18

10.17182/hepdata.99047.v1/t76

$p_{T}$ dependence of the nuclear modification factor $R_{cp}$ in Au + Au 62.4 and 200 GeV and d + Au...

• #### Figure 19, ($R_{AB}$ for $\phi$ in d+Au 200 GeV)

Data from Figure 19

10.17182/hepdata.99047.v1/t77

$p_{T}$ dependence of the nuclear modification factor $R_{AB}$ for $\phi$ in Au + Au 200 GeV and d + Au...

• #### Figure 19, ($R_{AB}$ for $\phi$ in Au+Au 200 GeV)

Data from Figure 19

10.17182/hepdata.99047.v1/t78

$p_{T}$ dependence of the nuclear modification factor $R_{AB}$ for $\phi$ in Au + Au 200 GeV and d + Au...

• #### Figure 20

Data from Figure 20

10.17182/hepdata.99047.v1/t79

$p_{T}$ dependence of the elliptic flow $v_{2}$ of $\phi$, $\Lambda$, and $K_{s}^{0}$ in Au + Au collisions (0–80$\%$) at 200...

• #### Figure 21 (Au+Au 200GeV 0-5$\%$)

Data from Figure 21

10.17182/hepdata.99047.v1/t80

Elliptic flow $v_{2}$ as a function of $p_{T}$ , $v_{2}$($p_{T}$), for the $\phi$ meson from different centralities. The vertical error...

• #### Figure 21 (Au+Au 200GeV 10-40$\%$, 40-80$\%$)

Data from Figure 21

10.17182/hepdata.99047.v1/t81

Elliptic flow $v_{2}$ as a function of $p_{T}$ , $v_{2}$($p_{T}$), for the $\phi$ meson from different centralities. The vertical error...