Phys. Rev. C 96, 064901 (2017) The fraction of $J/\psi$ mesons which come from B-meson decay,
$\textrm{F}_{B{\rightarrow}J/\psi}$, is measured for J/$\psi$ rapidity
\mbox{$1.2<|y|<2.2$} and $p_T>0$ ...in $p$+$p$ and Cu+Au collisions at
$\sqrt{s_{_{NN}}}$=200 GeV with the PHENIX detector. The extracted fraction is
$\textrm{F}_{B{\rightarrow}J/\psi}$ = 0.025 $\pm$ 0.006(stat) $\pm$ 0.010(syst)
for $p$+$p$ collisions. For Cu+Au collisions,
$\textrm{F}_{B{\rightarrow}J/\psi}$ is 0.094 $\pm$ 0.028(stat) $\pm$
0.037(syst) in the Au-going direction ($-2.2<y<-1.2$) and 0.089 $\pm$
0.026(stat) $\pm$ 0.040(syst) in the Cu-going direction ($1.2<y<2.2$). The
nuclear modification factor, $R_{\rm CuAu}$, of B mesons in Cu+Au collisions is
consistent with binary scaling of measured yields in $p$+$p$ at both forward
and backward rapidity.
Phys. Rev. D 95, 092002 (2017) We report the first measurement of the fraction of $J/\psi$ mesons coming
from $B$-meson decay ($F_{B{\rightarrow}J/\psi}$) in $p$+$p$ collisions at
$\sqrt{s}=$ 510 ...GeV. The measurement is performed using the forward silicon
vertex detector and central vertex detector at PHENIX, which provide precise
tracking and distance-of-closest-approach determinations, enabling the
statistical separation of $J/\psi$ due to $B$-meson decays from prompt
$J/\psi$. The measured value of $F_{B{\rightarrow}J/\psi}$ is 8.1\%$\pm$2.3\%
(stat)$\pm$1.9\% (syst) for $J/\psi$ with transverse momenta $0<p_T<5$ GeV/$c$
and rapidity $1.2<|y|<2.2$. The measured fraction $F_{B{\rightarrow}J/\psi}$ at
PHENIX is compared to values measured by other experiments at higher center of
mass energies and to fixed-order-next-to-leading-logarithm and
color-evaporation-model predictions. The $b\bar{b}$ cross section per unit
rapidity ($d\sigma/dy(pp{\rightarrow}b\bar{b})$) extracted from the obtained
$F_{B{\rightarrow}J/\psi}$ and the PHENIX inclusive $J/\psi$ cross section
measured at 200 GeV scaled with color-evaporation-model calculations, at the
mean $B$ hadron rapidity $y={\pm}1.7$ in 510 GeV $p$$+$$p$ collisions, is
$3.63^{+1.92}_{-1.70}\mu$b, and it is consistent with the
fixed-order-next-to-leading-logarithm calculations.
Phys. Rev. D 95, 072002 (2017) Dihadron and isolated direct photon-hadron angular correlations are measured
in $p$$+$$p$ collisions at $\sqrt{s}=510$ GeV. Correlations of charged hadrons
of ...$0.7<p_T<10$ GeV/$c$ with $\pi^0$ mesons of $4<p_T<15$ GeV/$c$ or isolated
direct photons of $7<p_T<15$ GeV/$c$ are used to study nonperturbative effects
generated by initial-state partonic transverse momentum and final-state
transverse momentum from fragmentation. The nonperturbative behavior is
characterized by measuring the out-of-plane transverse momentum component
$p_{\rm out}$ perpendicular to the axis of the trigger particle, which is the
high-$p_T$ direct photon or $\pi^0$. Nonperturbative evolution effects are
extracted from Gaussian fits to the away-side inclusive-charged-hadron yields
for different trigger-particle transverse momenta ($p_T^{\rm trig}$). The
Gaussian widths and root mean square of $p_{\rm out}$ are reported as a
function of the interaction hard scale $p_T^{\rm trig}$ to investigate possible
transverse-momentum-dependent evolution differences between the $\pi^0$-h$^\pm$
and direct photon-h$^\pm$ correlations and factorization breaking effects. The
widths are found to decrease with $p_T^{\rm trig}$, which indicates that the
Collins-Soper-Sterman soft factor is not driving the evolution with the hard
scale in nearly back-to-back dihadron and direct photon-hadron production in
$p$$+$$p$ collisions. This behavior is in contrast to Drell-Yan and
semi-inclusive deep-inelastic scattering measurements.
The PHENIX experiment at the Relativistic Heavy Ion Collider measured \(\pi^0\) and \(\eta\) mesons at midrapidity in U\(+\)U collisions at \(\sqrt{s_{_{NN}}}=192\) GeV in a wide transverse momentum ...range. Measurements were performed in the \(\pi^0(\eta)\rightarrow\gamma\gamma\) decay modes. A strong suppression of \(\pi^0\) and \(\eta\) meson production at high transverse momentum was observed in central U\(+\)U collisions relative to binary scaled $p$$+$$p\( results. Yields of \)\pi^0\( and \)\eta\( mesons measured in U\)+\(U collisions show similar suppression pattern to the ones measured in Au\)+\(Au collisions at \)\sqrt{s_{_{NN}}}=200\( GeV for similar numbers of participant nucleons. The \)\eta\(/\)\pi^0\( ratios do not show dependence on centrality or transverse momentum, and are consistent with previously measured values in hadron-hadron, hadron-nucleus, nucleus-nucleus, and \)e^+e^-$ collisions.
This article represents the proceedings of a symposium at the 2000 ISBRA Meeting in Yokohama, Japan. The chairs were Hidekazu Tsukamoto and Yoshiyuki Takei. The presentations were (1) Tribute to ...Professor Rajendar K. Chawla, by Craig J. McClain; (2) Dysregulated TNF signaling in alcoholic liver disease, by Craig J. McClain, S. Joshi‐Barve, D. Hill, J Schmidt, I. Deaciuc, and S. Barve; (3) The role of mitochondria in ethanol‐mediated sensitization of the liver, by Anna Colell, Carmen Garcia‐Ruiz, Neil Kaplowitz, and Jose C. Fernandez‐Checa; (4) A peroxisome proliferator (bezafibrate) can prevent superoxide anion release into hepatic sinusoid after acute ethanol administration, by Hirokazu Yokoyama, Yukishige Okamura, Yuji Nakamura, and Hiromasa Ishii; (5) S‐adenosylmethionine affects tumor necrosis factor‐α gene expression in macrophages, by Rajendar K. Chawla, S. Barve, S. Joshi‐Barve, W. Watson, W. Nelson, and C. McClain; (6) Iron, retinoic acid and hepatic macrophage TNFα gene expression in ALD, by Hidekazu Tsukamoto, Min Lin, Mitsuru Ohata, and Kenta Motomura; and (7) Role of Kupffer cells and gut‐derived endotoxin in alcoholic liver injury, by N. Enomoto, K. Ikejima, T. Kitamura, H. Oide, Y. Takei, M. Hirose, B. U. Bradford, C. A. Rivera, H. Kono, S. Peter, S. Yamashina, A. Konno, M. Ishikawa, H. Shimizu, N. Sato, and R. Thurman.
We present measurements from the PHENIX experiment of large parity-violating single spin asymmetries of high transverse momentum electrons and positrons from \(W^\pm/Z\) decays, produced in ...longitudinally polarized $p$$+$$p\( collisions at center of mass energies of \)\sqrt{s}\(=500 and 510~GeV. These asymmetries allow direct access to the anti-quark polarized parton distribution functions due to the parity-violating nature of the \)W\(-boson coupling to quarks and anti-quarks. The results presented are based on data collected in 2011, 2012, and 2013 with an integrated luminosity of 240 pb\)^{-1}\(, which exceeds previous PHENIX published results by a factor of more than 27. These high \)Q^2$ data provide an important addition to our understanding of anti-quark parton helicity distribution functions.
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