-
A. Adare,
S. Afanasiev,
C. Aidala,
N. N. Ajitanand,
Y. Akiba,
R. Akimoto,
H. Al-Bataineh,
H. Al-Ta'ani,
J. Alexander,
A. Angerami, [......],
G. R. Young,
I. Younus,
I. E. Yushmanov,
W. A. Zajc,
O. Zaudtke,
A. Zelenski,
C. Zhang,
S. Zhou,
J. Zimányi,
L. Zolin
[show abstract]
[hide abstract]
ABSTRACT: The jet fragmentation function is measured with direct photon-hadron
correlations in p+p and Au+Au collisions at sqrt(s_NN)=200 GeV. The p_T of the
photon is an excellent approximation to the initial p_T of the jet and the
ratio z_T=p_T^h/p_T^\gamma is used as a proxy for the jet fragmentation
function. A statistical subtraction is used to extract the direct photon-hadron
yields in Au+Au collisions while a photon isolation cut is applied in p+p. I_
AA, the ratio of jet fragment yield in Au+Au to that in p+p, indicates
modification of the jet fragmentation function. Suppression, most likely due to
energy loss in the medium, is seen at high z_T. The fragment yield at low z_T
is enhanced at large angles. Such a trend is expected from redistribution of
the lost energy into increased production of low-momentum particles.
12/2012;
-
A. Adare,
S. Afanasiev,
C. Aidala,
N. N. Ajitanand,
Y. Akiba,
R. Akimoto,
H. Al-Bataineh,
H. Al-Ta'ani,
J. Alexander,
K. R. Andrews, [......],
Z. You,
G. R. Young,
I. Younus,
I. E. Yushmanov,
W. A. Zajc,
O. Zaudtke,
A. Zelenski,
C. Zhang,
S. Zhou,
L. Zolin
[show abstract]
[hide abstract]
ABSTRACT: The three Upsilon states, Upsilon(1S+2S+3S), are measured in d+Au and p+p
collisions at sqrt(s_NN)=200 GeV and rapidities 1.2<|y|<2.2 by the PHENIX
experiment at the Relativistic Heavy-Ion Collider. Cross sections for the
inclusive Upsilon(1S+2S+3S) production are obtained. The inclusive yields per
binary collision for d+Au collisions relative to those in p+p collisions
(R_dAu) are found to be 0.62 +/- 0.26 (stat) +/- 0.13 (syst) in the gold-going
direction and 0.91 +/- 0.33 (stat) +/- 0.16 (syst) in the deuteron-going
direction. The measured results are compared to a nuclear-shadowing model,
EPS09 [JHEP 04, 065 (2009)], combined with a final-state breakup cross section,
sigma_br, and compared to lower energy p+A results. We also compare the results
to the PHENIX J/psi results [Phys. Rev. Lett. 107, 142301 (2011)]. The rapidity
dependence of the observed Upsilon suppression is consistent with lower energy
p+A measurements.
11/2012;
-
A. Adare,
S. Afanasiev,
C. Aidala,
N. N. Ajitanand,
Y. Akiba,
H. Al-Bataineh,
J. Alexander,
H. Al-Ta'ani,
A. Angerami,
K. Aoki, [......],
S. Yokkaichi,
G. R. Young,
I. Younus,
Z. You,
I. E. Yushmanov,
W. A. Zajc,
O. Zaudtke,
C. Zhang,
S. Zhou,
L. Zolin
[show abstract]
[hide abstract]
ABSTRACT: We previously reported [Phys. Rev. D 82, 112008 (2010)] measurements of
transverse single-spin asymmetries, A_N, in J/psi production from transversely
polarized p+p collisions at sqrt(s)=200 GeV with data taken by the PHENIX
experiment at the Relativistic Heavy Ion Collider in 2006 and 2008.
Subsequently, we have found errors in the analysis procedures for the 2008
data, which resulted in an erroneous value for the extracted A_N. The errors
affected the sorting of events into the correct left/right and forward/backward
bins. This produced an incorrect value for the 2008 result, but the 2006 result
is unaffected. We have conducted two independent reanalyses with these errors
corrected, and we present here the corrected values for the 2008 data and the
combined results for 2006 and 2008. The new combined spin asymmetry in the
forward region is A_N = -0.026+/-0.026(stat)+/-0.003(sys). Since this asymmetry
is consistent with zero, we no longer claim that our results suggest a possible
non-zero trigluon correlation function in transversely polarized protons.
10/2012;
-
A. Adare,
S. Afanasiev,
C. Aidala,
N. N. Ajitanand,
Y. Akiba,
H. Al-Bataineh,
J. Alexander,
K. Aoki,
L. Aphecetche,
J. Asai, [......],
J. Ying,
S. Yokkaichi,
G. R. Young,
I. Younus,
I. E. Yushmanov,
W. A. Zajc,
O. Zaudtke,
C. Zhang,
S. Zhou,
L. Zolin
[show abstract]
[hide abstract]
ABSTRACT: The energy dependence of the single-transverse-spin asymmetry, A_N, and the
cross section for neutron production at very forward angles were measured in
the PHENIX experiment at RHIC for polarized p+p collisions at sqrt(s)=200 GeV.
The neutrons were observed in forward detectors covering an angular range of up
to 2.2 mrad. We report results for neutrons with momentum fraction of x_F=0.45
to 1.0. The energy dependence of the measured cross sections were consistent
with x_F scaling, compared to measurements by an ISR experiment which measured
neutron production in unpolarized p+p collisions at sqrt(s)=30.6--62.7 GeV. The
cross sections for large x_F neutron production for p+p collisions, as well as
those in e+p collisions measured at HERA, are described by a pion exchange
mechanism. The observed forward neutron asymmetries were large, reaching
A_N=-0.08+/-0.02 for x_F=0.8; the measured backward asymmetries, for negative
x_F, were consistent with zero. The observed asymmetry for forward neutron
production is discussed within the pion exchange framework, with interference
between the spin-flip amplitude due to the pion exchange and nonflip amplitudes
from all Reggeon exchanges. Within the pion exchange description, the measured
neutron asymmetry is sensitive to the contribution of other Reggeon exchanges
even for small amplitudes.
09/2012;
-
A. Adare,
S. S. Adler,
S. Afanasiev,
C. Aidala,
N. N. Ajitanand,
Y. Akiba,
H. Al-Bataineh,
A. Al-Jamel,
J. Alexander,
A. Angerami, [......],
G. R. Young,
I. Younus,
I. E. Yushmanov,
W. A. Zajc,
O. Zaudtke,
C. Zhang,
S. Zhou,
J. Zimányi,
L. Zolin,
X. Zong
[show abstract]
[hide abstract]
ABSTRACT: Direct photons have been measured in sqrt(s_NN)=200 GeV d+Au collisions at
midrapidity. A wide p_T range is covered by measurements of nearly-real virtual
photons (1<p_T<6 GeV/c) and real photons (5<p_T<16 GeV/c). The invariant yield
of the direct photons in d+Au collisions over the scaled p+p cross section is
consistent with unity. Theoretical calculations assuming standard cold nuclear
matter effects describe the data well for the entire p_T range. This indicates
that the large enhancement of direct photons observed in Au+Au collisions for
1.0<p_T<2.5 GeV/c is due to a source other than the initial-state nuclear
effects.
08/2012;
-
A. Adare,
S. Afanasiev,
C. Aidala,
N.N. Ajitanand,
Y. Akiba,
H. Al-Bataineh,
J. Alexander,
K. Aoki,
L. Aphecetche,
J. Asai, [......],
J. Ying,
S. Yokkaichi,
G.R. Young,
I. Younus,
I.E. Yushmanov,
W.A. Zajc,
O. Zaudtke,
C. Zhang,
S. Zhou,
L. Zolin
[show abstract]
[hide abstract]
ABSTRACT: The differential cross section for the production of direct photons in p+p collisions at √s = 200
GeV at midrapidity was measured in the PHENIX detector at the Relativistic Heavy Ion Collider.
Inclusive-direct photons were measured in the transverse momentum range from 5.5–25 GeV/c,
extending the range beyond previous measurements. Event structure was studied with an isolation
criterion. Next-to-leading-order perturbative-quantum-chromodynamics calculations give a good
description of the spectrum. When the cross section is expressed versus xT , the PHENIX data
are seen to be in agreement with measurements from other experiments at different center-of-mass
energies.
Physical Review C 06/2012; · 3.31 Impact Factor
-
A. Adare,
S. Afanasiev,
C. Aidala,
N. N. Ajitanand,
Y. Akiba,
H. Al-Bataineh,
J. Alexander,
K. Aoki,
L. Aphecetche,
J. Asai, [......],
J. Ying,
S. Yokkaichi,
G. R. Young,
I. Younus,
I. E. Yushmanov,
W. A. Zajc,
O. Zaudtke,
C. Zhang,
S. Zhou,
L. Zolin
[show abstract]
[hide abstract]
ABSTRACT: The differential cross section for the production of direct photons in p+p
collisions at sqrt(s)=200 GeV at midrapidity was measured in the PHENIX
detector at the Relativistic Heavy Ion Collider. Inclusive-direct photons were
measured in the transverse-momentum range from 5.5--25 GeV/c, extending the
range beyond previous measurements. Event structure was studied with an
isolation criterion. Next-to-leading-order perturbative-quantum-chromodynamics
calculations give a good description of the spectrum. When the cross section is
expressed versus x_T, the PHENIX data are seen to be in agreement with
measurements from other experiments at different center-of-mass energies.
05/2012;
-
A. Adare,
S. Afanasiev,
C. Aidala,
N. N. Ajitanand,
Y. Akiba,
H. Al-Bataineh,
J. Alexander,
A. Angerami,
K. Aoki,
N. Apadula, [......],
S. Yokkaichi,
Z. You,
G. R. Young,
I. Younus,
I. E. Yushmanov,
W. A. Zajc,
O. Zaudtke,
C. Zhang,
S. Zhou,
L. Zolin
[show abstract]
[hide abstract]
ABSTRACT: We report on charmonium measurements [J/ψ (1S), ψ′ (2S), and χc (1P)] in p+p collisions at √s=200 GeV. We find that the fraction of J/ψ coming from the feed-down decay of ψ′ and χc in the midrapidity region (|y|<0.35) is 9.6±2.4% and 32±9%, respectively. We also present the pT and rapidity dependencies of the J/ψ yield measured via dielectron decay at midrapidity (|y|<0.35) and via dimuon decay at forward rapidity (1.2<|y|<2.2). The statistical precision greatly exceeds that reported in our previous publication [ Phys. Rev. Lett. 98 232002 (2007)]. The new results are compared with other experiments and discussed in the context of current charmonium production models.
Phys. Rev. D. 05/2012; 85(9).
-
A. Adare,
S. Afanasiev,
C. Aidala,
N. N. Ajitanand,
Y. Akiba,
H. Al-Bataineh,
J. Alexander,
A. Angerami,
K. Aoki,
N. Apadula, [......],
S. Yokkaichi,
Z. You,
G. R. Young,
I. Younus,
I. E. Yushmanov,
W. A. Zajc,
O. Zaudtke,
C. Zhang,
S. Zhou,
L. Zolin
[show abstract]
[hide abstract]
ABSTRACT: We report on charmonium measurements [J/ψ (1S), ψ′ (2S), and χc (1P)] in p+p collisions at √s=200 GeV. We find that the fraction of J/ψ coming from the feed-down decay of ψ′ and χc in the midrapidity region (|y|<0.35) is 9.6±2.4% and 32±9%, respectively. We also present the pT and rapidity dependencies of the J/ψ yield measured via dielectron decay at midrapidity (|y|<0.35) and via dimuon decay at forward rapidity (1.2<|y|<2.2). The statistical precision greatly exceeds that reported in our previous publication [ Phys. Rev. Lett. 98 232002 (2007)]. The new results are compared with other experiments and discussed in the context of current charmonium production models.
Physical Review D 05/2012; 85:092004. · 4.56 Impact Factor
-
A. Drees,
PHENIX Collaboration,
K. Adcox,
S. S. Adler,
N. N. Ajitanand,
Y. Akiba,
J. Alexander,
L. Aphecetche,
Y. Arai,
S. H. Aronson, [......],
F. K. Wohn,
C. L. Woody,
W. Xie,
K. Yagi,
S. Yokkaichi,
G. R. Young,
I. E. Yushmanov,
W. A. Zajc,
Z. Zhang,
S. Zhou
Pramana 04/2012; 60(4):639-650. · 0.57 Impact Factor
-
Tarun Kanti Ghosh,
K Adcox,
S S Adler,
N Ajitanand,
Y Akiba,
J Alexander,
L Aphecetche,
Y Arai,
S H Aronson,
R Averbeck, [......],
F K Wohn,
C L Woody,
W Xie,
K Yagi,
S Yokkaichi,
G R Young,
I E Yushmanov,
W A Zajc,
Z Zhang,
S Zhou
[show abstract]
[hide abstract]
ABSTRACT: The PHENIX experiment consists of a large detector system located at the newly commissioned relativistic heavy ion collider
(RHIC) at the Brookhaven National Laboratory. The primary goal of the PHENIX experiment is to look for signatures of the QCD
prediction of a deconfined high-energy-density phase of nuclear matter quark gluon plasma. PHENIX started data taking for
Au+Au collisions at √sNN=130 GeV in June 2000. The signals from the beam-beam counter (BBC) and zero degree calorimeter (ZDC) are used to determine
the centrality of the collision. A Glauber model reproduces the ZDC spectrum reasonably well to determine the participants
in a collision. Charged particle multiplicity distribution from the first PHENIX paper is compared with the other RHIC experiment
and the CERN, SPS results. Transverse momentum of photons are measured in the electro-magnetic calorimeter (EMCal) and preliminary
results are presented. Particle identification is made by a time of flight (TOF) detector and the results show clear separation
of the charged hadrons from each other.
Pramana 04/2012; 57(2):355-369. · 0.57 Impact Factor
-
S H Hwang,
K Hicks,
J K Ahn,
T Nakano,
D S Ahn, W C Chang,
J Y Chen,
S Daté,
H Ejiri,
H Fujimura, [......],
J Parker,
C Rangacharyulu,
S Y Ryu,
T Sawada,
Y Sugaya,
M Sumihama,
T Tsunemi,
M Uchida,
M Ungaro,
M Yosoi
[show abstract]
[hide abstract]
ABSTRACT: The exclusive reaction γp→K(+)π(-)Σ(+) was measured for the first time using linearly polarized photons at beam energies from 1.85 to 2.96 GeV. Angular distributions in the rest frame of the K(+)π(-) system were fitted to extract spin-density matrix elements of the K(*0) decay. The measured parity spin asymmetry shows that natural-parity exchange is dominant in this reaction. This result clearly indicates the need for t-channel exchange of the κ(800) scalar meson.
Physical Review Letters 03/2012; 108(9):092001. · 7.37 Impact Factor
-
A. Adare,
S. Afanasiev,
C. Aidala,
N. N. Ajitanand,
Y. Akiba,
H. Al-Bataineh,
J. Alexander,
K. Aoki,
L. Aphecetche,
J. Asai, [......],
J. Ying,
S. Yokkaichi,
G. R. Young,
I. Younus,
I. E. Yushmanov,
W. A. Zajc,
O. Zaudtke,
C. Zhang,
S. Zhou,
L. Zolin
[show abstract]
[hide abstract]
ABSTRACT: Unpolarized cross sections and double-helicity asymmetries of
single-inclusive positive and negative charged hadrons at midrapidity from p+p
collisions at sqrt(s)=62.4 GeV are presented. The PHENIX measurements for 1.0 <
p_T < 4.5 GeV/c are consistent with perturbative QCD calculations at
next-to-leading order in the strong coupling constant, alpha_s. Resummed pQCD
calculations including terms with next-to-leading-log accuracy, yielding
reduced theoretical uncertainties, also agree with the data. The
double-helicity asymmetry, sensitive at leading order to the gluon polarization
in a momentum-fraction range of 0.05 ~< x_gluon ~< 0.2, is consistent with
recent global parameterizations disfavoring large gluon polarization.
02/2012;
-
A Adare,
S Afanasiev,
C Aidala,
N N Ajitanand,
Y Akiba,
H Al-Bataineh,
J Alexander,
A Angerami,
K Aoki,
N Apadula, [......],
S Yokkaichi,
Z You,
G R Young,
I Younus,
I E Yushmanov,
W A Zajc,
O Zaudtke,
C Zhang,
S Zhou,
L Zolin
[show abstract]
[hide abstract]
ABSTRACT: We present measurements of J/ψ yields in d+Au collisions at sqrt[s(NN)]=200 GeV recorded by the PHENIX experiment and compare them with yields in p+p collisions at the same energy per nucleon-nucleon collision. The measurements cover a large kinematic range in J/ψ rapidity (-2.2<y<2.4) with high statistical precision and are compared with two theoretical models: one with nuclear shadowing combined with final state breakup and one with coherent gluon saturation effects. In order to remove model dependent systematic uncertainties we also compare the data to a simple geometric model. The forward rapidity data are inconsistent with nuclear modifications that are linear or exponential in the density weighted longitudinal thickness, such as those from the final state breakup of the bound state.
Physical Review Letters 09/2011; 107(14):142301. · 7.37 Impact Factor
-
A. Adare,
S. Afanasiev,
C. Aidala,
N. N. Ajitanand,
Y. Akiba,
H. Al-Bataineh,
J. Alexander,
A. Angerami,
K. Aoki,
N. Apadula, [......],
S. Yokkaichi,
Z. You,
G. R. Young,
I. Younus,
I. E. Yushmanov,
W. A. Zajc,
O. Zaudtke,
C. Zhang,
S. Zhou,
L. Zolin
[show abstract]
[hide abstract]
ABSTRACT: We report on charmonium measurements [J/psi(1S), psi'(2S), and chi_c(1P)] in
p+p collisions at sqrt(s)=200 GeV. We find that the fraction of J/psi coming
from the feed-down decay of psi' and chi_c in the midrapidity region
($|\eta|<0.35$) is 9.6+/-2.4% and 32+/-9%, respectively. We also report new,
higher statistics p_T and rapidity dependencies of the J/psi yield via
dielectron decay in the same midrapidity range and at forward rapidity
(1.2<|eta|<2.4) via dimuon decay. These results are compared with measurements
from other experiments and discussed in the context of current charmonium
production models.
05/2011;
-
A. Adare,
S. Afanasiev,
C. Aidala,
N. N. Ajitanand,
Y. Akiba,
H. Al-Bataineh,
J. Alexander,
K. Aoki,
L. Aphecetche,
Y. Aramaki, [......],
S. Yokkaichi,
G. R. Young,
I. Younus,
Z. You,
I. E. Yushmanov,
W. A. Zajc,
O. Zaudtke,
C. Zhang,
S. Zhou,
L. Zolin
[show abstract]
[hide abstract]
ABSTRACT: Measurements of electrons from the decay of open-heavy-flavor mesons have shown that the yields are suppressed in Au+Au collisions compared to expectations from binary-scaled p+p collisions. These measurements indicate that charm and bottom quarks interact with the hot dense matter produced in heavy-ion collisions much more than expected. Here we extend these studies to two-particle correlations where one particle is an electron from the decay of a heavy-flavor meson and the other is a charged hadron from either the decay of the heavy meson or from jet fragmentation. These measurements provide more detailed information about the interactions between heavy quarks and the matter, such as whether the modification of the away-side-jet shape seen in hadron-hadron correlations is present when the trigger particle is from heavy-meson decay and whether the overall level of away-side-jet suppression is consistent. We statistically subtract correlations of electrons arising from background sources from the inclusive electron-hadron correlations and obtain two-particle azimuthal correlations at √sNN=200 GeV between electrons from heavy-flavor decay with charged hadrons in p+p and also first results in Au+Au collisions. We find the away-side-jet shape and yield to be modified in Au+Au collisions compared to p+p collisions.
Phys. Rev. C. 04/2011; 83(4).
-
A. Adare,
S. Afanasiev,
C. Aidala,
N. N. Ajitanand,
Y. Akiba,
H. Al-Bataineh,
J. Alexander,
K. Aoki,
L. Aphecetche,
R. Armendariz, [......],
S. Yokkaichi,
G. R. Young,
I. Younus,
I. E. Yushmanov,
W. A. Zajc,
O. Zaudtke,
C. Zhang,
S. Zhou,
J. Zimányi,
L. Zolin
[show abstract]
[hide abstract]
ABSTRACT: The PHENIX experiment at the Relativistic Heavy Ion Collider has measured the invariant differential cross section for production of KS0, ω, η′, and ϕ mesons in p+p collisions at √s=200 GeV. Measurements of ω and ϕ production in different decay channels give consistent results. New results for the ω are in agreement with previously published data and extend the measured pT coverage. The spectral shapes of all hadron transverse momentum distributions measured by PHENIX are well described by a Tsallis distribution functional form with only two parameters, n and T, determining the high-pT and characterizing the low-pT regions of the spectra, respectively. The values of these parameters are very similar for all analyzed meson spectra, but with a lower parameter T extracted for protons. The integrated invariant cross sections calculated from the fitted distributions are found to be consistent with existing measurements and with statistical model predictions.
Phys. Rev. D. 03/2011; 83(5).
-
A. Adare,
S. Afanasiev,
C. Aidala,
N. N. Ajitanand,
Y. Akiba,
H. Al-Bataineh,
J. Alexander,
K. Aoki,
L. Aphecetche,
R. Armendariz, [......],
S. Yokkaichi,
G. R. Young,
I. Younus,
I. E. Yushmanov,
W. A. Zajc,
O. Zaudtke,
C. Zhang,
S. Zhou,
J. Zimányi,
L. Zolin
[show abstract]
[hide abstract]
ABSTRACT: Transverse momentum distributions and yields for $\pi^{\pm}$, $K^{\pm}$, $p$
and $\bar{p}$ in $p+p$ collisions at $\sqrt{s}$=200 and 62.4 GeV at midrapidity
are measured by the PHENIX experiment at the Relativistic Heavy Ion Collider
(RHIC). These data provide important baseline spectra for comparisons with
identified particle spectra in heavy ion collisions at RHIC. We present the
inverse slope parameter $T_{\rm inv}$, mean transverse momentum $ $ and
yield per unit rapidity $dN/dy$ at each energy, and compare them to other
measurements at different $\sqrt{s}$ in $p+p$ and $p+\bar{p}$ collisions. We
also present the scaling properties such as $m_T$ scaling, $x_T$ scaling on the
$p_T$ spectra between different energies. To discuss the mechanism of the
particle production in $p+p$ collisions, the measured spectra are compared to
next-to-leading-order or next-to-leading-logarithmic perturbative quantum
chromodynamics calculations.
02/2011;
-
A. Adare,
S. Afanasiev,
C. Aidala,
N. N. Ajitanand,
Y. Akiba,
H. Al-Bataineh,
J. Alexander,
K. Aoki,
L. Aphecetche,
R. Armendariz, [......],
S. Yokkaichi,
G. R. Young,
I. Younus,
I. E. Yushmanov,
W. A. Zajc,
O. Zaudtke,
C. Zhang,
S. Zhou,
J. Zimányi,
L. Zolin
[show abstract]
[hide abstract]
ABSTRACT: Measurements of double-helicity asymmetries in inclusive hadron production in polarized p+p collisions are sensitive to helicity-dependent parton distribution functions, in particular, to the gluon helicity distribution, Δg. This study focuses on the extraction of the double-helicity asymmetry in η production (p⃗+p⃗→η+X), the η cross section, and the η/π0 cross section ratio. The cross section and ratio measurements provide essential input for the extraction of fragmentation functions that are needed to access the helicity-dependent parton distribution functions.
Phys. Rev. D. 01/2011; 83(3).
-
A. Adare,
S. Afanasiev,
C. Aidala,
N. N. Ajitanand,
Y. Akiba,
H. Al-Bataineh,
J. Alexander,
K. Aoki,
L. Aphecetche,
Y. Aramaki, [......],
S. Yokkaichi,
G. R. Young,
I. Younus,
Z. You,
I. E. Yushmanov,
W. A. Zajc,
O. Zaudtke,
C. Zhang,
S. Zhou,
L. Zolin
[show abstract]
[hide abstract]
ABSTRACT: Measurements of electrons from the decay of open-heavy-flavor mesons have
shown that the yields are suppressed in Au+Au collisions compared to
expectations from binary scaled p+p collisions. These measurements indicate
that charm and bottom quarks interact with the hot-dense matter produced in
heavy-ion collisions much more than expected. Here we extend these studies to
two-particle correlations where one particle is an electron from the decay of a
heavy-flavor meson and the other is a charged hadron from either the decay of
the heavy meson or from jet fragmentation. These measurements provide more
detailed information about the interactions between heavy quarks and the
matter, such as whether the modification of the away-side-jet shape seen in
hadron-hadron correlations is present when the trigger particle is from
heavy-meson decay and whether the overall level of away-side jet suppression is
consistent. We statistically subtract correlations of electrons arising from
background sources from the inclusive electron-hadron correlations and obtain
two-particle azimuthal correlations at sqrt(s_NN)=$200 GeV between electrons
from heavy-flavor decay with charged hadrons in p+p and also first results in
Au+Au collisions. We find the away-side-jet shape and yield to be modified in
Au+Au collisions compared to p+p collisions.
11/2010;
