T. W. Danley
A5086702198- High-Energy Particle Collisions Research
- Quantum Chromodynamics and Particle Interactions
- Particle physics theoretical and experimental studies
- Nuclear physics research studies
- Nuclear Physics and Applications
- Nuclear reactor physics and engineering
- Radiation Detection and Scintillator Technologies
- Stochastic processes and statistical mechanics
- Astronomical and nuclear sciences
- Particle accelerators and beam dynamics
- Atomic and Molecular Physics
- Atomic and Subatomic Physics Research
- Fusion materials and technologies
- Markov Chains and Monte Carlo Methods
- Cold Atom Physics and Bose-Einstein Condensates
- Particle Detector Development and Performance
- Quantum, superfluid, helium dynamics
- Particle Accelerators and Free-Electron Lasers
- Superconducting Materials and Applications
- Radiation Therapy and Dosimetry
Augustana University
2024
Banaras Hindu University
2024
Bhabha Atomic Research Centre
2024
Ohio University
2014-2022
Thomas Jefferson National Accelerator Facility
2022
Virginia Tech
2022
Joint Institute for Nuclear Astrophysics
2020
Kurchatov Institute
2020
Rikkyo University
2018
Petersburg Nuclear Physics Institute
2018
We present measurements of ${e}^{+}{e}^{\ensuremath{-}}$ production at midrapidity in $\mathrm{Au}+\mathrm{Au}$ collisions $\sqrt{{s}_{{}_{NN}}}=200$ GeV. The invariant yield is studied within the PHENIX detector acceptance over a wide range mass (${m}_{ee}<5 \mathrm{GeV}/{c}^{2}$) and pair transverse momentum (${p}_{T}<5 \mathrm{GeV}/c$) for minimum bias five centrality classes. compared to expectations from known sources. In low-mass region (${m}_{ee}=0.30--0.76 there an enhancement that...
We report high-precision measurements of the deeply virtual Compton scattering (DVCS) cross section at high values Bjorken variable x_{B}. DVCS is sensitive to generalized parton distributions nucleon, which provide a three-dimensional description its internal constituents. Using exact analytic expression for all possible polarization states initial and final electron state photon, we present first experimental extraction four helicity-conserving form factors (CFFs) nucleon as function...
The PHENIX Collaboration at the Relativistic Heavy Ion Collider has measured open heavy-flavor production in minimum bias Au$+$Au collisions $\sqrt{s_{_{NN}}}=200$ GeV via yields of electrons from semileptonic decays charm and bottom hadrons. Previous electron measurements indicated substantial modification momentum distribution parent heavy quarks due to quark-gluon plasma created these collisions. For first time, using silicon vertex detector measure precision displaced tracking, relative...
We present measurements of the elliptic flow (v2) as a function transverse momentum (pT), pseudorapidity (η), and centrality in d+Au collisions at sNN=200, 62.4, 39, 19.6 GeV. The beam-energy scan provides testing ground for onset signatures small collision systems. measure nonzero v2 signal all four energies, which, midrapidity low pT, is consistent with predictions from viscous hydrodynamic models. Comparisons calculations parton transport models (based on ampt Monte Carlo generator) show...
The PHENIX Collaboration has measured the ratio of yields $\ensuremath{\psi}(2S)$ to $\ensuremath{\psi}(1S)$ mesons produced in $p+p$, $p+\mathrm{Al}$, $p+\mathrm{Au}$, and $^{3}\mathrm{He}+\mathrm{Au}$ collisions at $\sqrt{{s}_{{}_{\mathit{NN}}}}=200$ GeV over forward backward rapidity intervals $1.2<|y|<2.2$. We find that $p+p$ is consistent with measurements other collision energies. In nuclei, we ($p$-going or $^{3}\mathrm{He}$-going) direction, relative yield value collisions. However,...
We present new precision measurements of the elastic electron-proton scattering cross section for momentum transfer (Q^{2}) up to 15.75 (GeV/c)^{2}. Combined with existing data, these provide an improved extraction proton magnetic form factor at high Q^{2} and double range over which a longitudinal or transverse separation can be performed. The difference between our results polarization data agrees that observed lower attributed hard two-photon exchange (TPE) effects, extending 8...
The PHENIX collaboration presents a systematic study of $\pi^0$ production from $p$$+$$p$, $p$$+$Al, $p$$+$Au, $d$$+$Au, and $^{3}$He$+$Au collisions at $\sqrt{s_{_{NN}}}=200$ GeV. Measurements were performed with different centrality selections as well the total inelastic, 0%--100%, selection for all collision systems. For 0%--100% collisions, nuclear modification factors, $R_{xA}$, are consistent unity $p_T$ above 8 GeV/$c$, but exhibit an enhancement in peripheral suppression central...
We present measurements of the transverse-momentum dependence elliptic flow ${v}_{2}$ for identified pions and (anti)protons at midrapidity ($|\ensuremath{\eta}|<0.35$), in 0%--5% central $p+\mathrm{Au}$ $^{3}\mathrm{He}+\mathrm{Au}$ collisions $\sqrt{{s}_{{}_{NN}}}=200$ GeV. When taken together with previously published $d+\mathrm{Au}$ GeV, results cover a broad range small-collision-system multiplicities intrinsic initial geometries. observe clear mass-dependent splitting...
There is strong evidence for the formation of small droplets quark-gluon plasma in $p/d/^{3}\mathrm{He}+\mathrm{Au}$ collisions at Relativistic Heavy Ion Collider (RHIC) and $p+p/\mathrm{Pb}$ Large Hadron Collider. In particular, analysis data RHIC different geometries obtained by varying projectile size shape has proved insightful. present analysis, we find excellent agreement with previously published PHENIX results on elliptical triangular flow an independent via two-particle correlation...
The level densities of $^{74,76}\mathrm{Ge}$ nuclei are studied with $^{68,70}\mathrm{Zn}(^{7}\mathrm{Li},\mathrm{Xp})$ reactions. Proton evaporation spectra measured at backward angles in a wide energy region, from about 2 to 25 MeV. analysis allows for the testing density models used modern reaction codes practical cross-section calculations. Our results show that excitation energies above discrete all tested this work overestimate needed reproduce proton these Gilbert and Cameron model,...
Measurements of the fractional momentum loss ($S_{\rm loss}\equiv{\delta}p_T/p_T$) high-transverse-momentum-identified hadrons in heavy ion collisions are presented. Using $\pi^0$ Au$+$Au and Cu$+$Cu at $\sqrt{s_{_{NN}}}=62.4$ 200 GeV measured by PHENIX experiment Relativistic Heavy Ion Collider charged Pb$+$Pb ALICE Large Hadron Collider, we studied scaling properties $S_{\rm loss}$ as a function number variables: participants, $N_{\rm part}$, quark qp}$, charged-particle density, $dN_{\rm...
Charmonium is a valuable probe in heavy-ion collisions to study the properties of quark gluon plasma, and also an interesting small collision systems cold nuclear matter effects, which are present large systems. With recent observations collective behavior produced particles system collisions, measurements modification charmonium have become increasingly relevant. We results $J/\psi$ at forward backward rapidity various systems, $p$$+$$p$, $p$$+$Al, $p$$+$Au $^3$He$+$Au,...
The PHENIX experiment has studied nuclear effects in $p$$+$Al and $p$$+$Au collisions at $\sqrt{s_{_{NN}}}=200$ GeV on charged hadron production forward rapidity ($1.4<\eta<2.4$, $p$-going direction) backward ($-2.2<\eta<-1.2$, $A$-going direction). Such are quantified by measuring modification factors as a function of transverse momentum pseudorapidity various collision multiplicity selections. In central collisions, suppression (enhancement) is observed (backward) compared to the binary...
We report measurements of the exclusive neutral pion electroproduction cross section off protons at large values x_{B} (0.36, 0.48, and 0.60) Q^{2} (3.1 to 8.4 GeV^{2}) obtained from Jefferson Lab Hall A experiment E12-06-014. The corresponding structure functions dσ_{T}/dt+εdσ_{L}/dt, dσ_{TT}/dt, dσ_{LT}/dt, dσ_{LT^{'}}/dt are extracted as a function proton momentum transfer t-t_{min}. results suggest amplitude for transversely polarized virtual photons continues dominate throughout this...
We have measured the cross section and single-spin asymmetries from forward ${W}^{\ifmmode\pm\else\textpm\fi{}}\ensuremath{\rightarrow}{\ensuremath{\mu}}^{\ifmmode\pm\else\textpm\fi{}}\ensuremath{\nu}$ production in longitudinally polarized $p+p$ collisions at $\sqrt{s}=510\text{ }\text{ }\mathrm{GeV}$ using PHENIX detector Relativistic Heavy Ion Collider. The sections are consistent with previous measurements this collision energy, while most backward longitudinal single spin provide new...
Production of $π^0$ and $η$ mesons has been measured at midrapidity in Cu$+$Au collisions $\sqrt{s_{_{NN}}}$=200 GeV. Measurements were performed $π^0(η)\rightarrowγγ$ decay channel the 1(2)-20 GeV/$c$ transverse momentum range. A strong suppression is observed for meson production high central relative to $p$$+$$p$ results scaled by number nucleon-nucleon collisions. In similar Au$+$Au with comparable nuclear overlap. The $η/π^0$ ratio as a function consistent $m_T$-scaling parameterization...
We present a measurement of the transverse single-spin asymmetry for $\pi^0$ and $\eta$ mesons in $p^\uparrow$$+$$p$ collisions pseudorapidity range $|\eta|<0.35$ at center-of-mass energy 200 GeV with PHENIX detector Relativistic Heavy Ion Collider. In comparison previous measurements this kinematic region, these results have factor 3 smaller uncertainties. As hadrons, are sensitive to both initial- final-state nonperturbative effects mix parton flavors. Comparisons differences their...
Background: A multitude of broad interfering resonances characterize the $^{10}\mathrm{B}(p,\ensuremath{\alpha})^{7}\mathrm{Be}$ cross section at low energies. The complexity reaction mechanism, as well conflicting experimental measurements, have so far prevented a reliable prediction over energy ranges pertinent for boron-proton fusion reactor environment.Purpose: To improve evaluated reaction, this study targets proton region from 0.8 to 2.0 MeV, where kinematic overlap scattered protons...
We report a measurement of $e^+e^-$ pairs from semileptonic heavy-flavor decays in $p$+$p$ collisions at $\sqrt{s_{NN}}=200$~GeV. The pair yield $b\bar{b}$ and $c\bar{c}$ is separated by exploiting double differential fit done simultaneously dielectron invariant mass $p_T$. used three different event generators, {\sc pythia}, mc@nlo}, powheg}, to simulate the spectra production. data can be well described all generators within detector acceptance. However, when using extrapolate $4\pi$,...
We present measurements of azimuthal correlations charged hadron pairs in $\sqrt{{s}_{\mathit{NN}}}=200$ GeV $\mathrm{Au}+\mathrm{Au}$ collisions for the trigger and associated particle transverse-momentum ranges $1<{p}_{T}^{t}<10\phantom{\rule{4pt}{0ex}}\mathrm{GeV}/c$ $0.5<{p}_{T}^{a}<10\phantom{\rule{4pt}{0ex}}\mathrm{GeV}/c$. After subtraction an underlying event using a model that includes higher-order anisotropy ${v}_{2}, {v}_{3}$, ${v}_{4}$, away-side yield highest...
We present measurements of elliptic and triangular azimuthal anisotropy charged particles detected at forward rapidity $1<|\ensuremath{\eta}|<3$ in Au + collisions $\sqrt{{s}_{{}_{NN}}}=200$ GeV, as a function centrality. The multiparticle cumulant technique is used to obtain the flow coefficients ${v}_{2}{2},{v}_{2}{4},{v}_{2}{6}$, ${v}_{2}{8}$, ${v}_{3}{2}$ ${v}_{3}{4}$. Using small-variance limit, we estimate mean variance event-by-event ${v}_{2}$ distribution from ${v}_{2}{2}$...