H. Hamagaki
A5021983254- High-Energy Particle Collisions Research
- Particle physics theoretical and experimental studies
- Quantum Chromodynamics and Particle Interactions
- Particle Detector Development and Performance
- Nuclear physics research studies
- Nuclear reactor physics and engineering
- Radiation Detection and Scintillator Technologies
- Nuclear Physics and Applications
- X-ray Spectroscopy and Fluorescence Analysis
- Superconducting Materials and Applications
- Particle Accelerators and Free-Electron Lasers
- Atomic and Subatomic Physics Research
- Ion-surface interactions and analysis
- Photocathodes and Microchannel Plates
- CCD and CMOS Imaging Sensors
- Dark Matter and Cosmic Phenomena
- Statistical Methods and Bayesian Inference
- Stochastic processes and statistical mechanics
- Plasma Diagnostics and Applications
- Pulsars and Gravitational Waves Research
- Particle accelerators and beam dynamics
- Muon and positron interactions and applications
- Cosmology and Gravitation Theories
- Radiation Effects in Electronics
- Quantum, superfluid, helium dynamics
Nagasaki Institute of Applied Science
2017-2025
The University of Tokyo
2014-2024
University of Houston
2023-2024
A. Alikhanyan National Laboratory
2015-2024
Tokyo University of Science
2013-2023
Banaras Hindu University
2003-2023
Central China Normal University
2022-2023
Augustana University
2014-2023
Charles University
2020-2023
PHENIX laboratory
2003-2023
Interaction cross sections (${\ensuremath{\sigma}}_{I}$) for all known Li isotopes ($^{6}\mathrm{Li}$-$^{11}\mathrm{Li}$) and $^{7}\mathrm{Be}$, $^{9}\mathrm{Be}$, $^{10}\mathrm{Be}$ on targets Be, C, Al have been measured at 790 MeV/nucleon. Root mean square radii of these as well He deduced from the ${\ensuremath{\sigma}}_{I}$ by a Glauber-type calculation. Appreciable differences among isobars ($^{6}\mathrm{He}$-$^{6}\mathrm{Li}$, $^{8}\mathrm{He}$-$^{8}\mathrm{Li}$,...
Transverse momentum spectra for charged hadrons and neutral pions in the range 1 GeV/c<p(T)<5 GeV/c have been measured by PHENIX experiment at RHIC Au+Au collisions root square[s(NN)] = 130 GeV. At high p(T) from peripheral nuclear are consistent with scaling p+p average number of binary nucleon-nucleon collisions. The central significantly suppressed when compared to binary-scaled expectation, also similarly collisions, indicating a novel nuclear-medium effect energies.
The centrality dependence of transverse momentum distributions and yields for ${\ensuremath{\pi}}^{\ifmmode\pm\else\textpm\fi{}},{K}^{\ifmmode\pm\else\textpm\fi{}},p$, $\overline{p}$ in $\text{Au}+\text{Au}$ collisions at $\sqrt{{s}_{NN}}=200\phantom{\rule{0.3em}{0ex}}\text{GeV}$ midrapidity are measured by the PHENIX experiment Relativistic Heavy Ion Collider. We observe a clear particle mass shapes spectra central below $\ensuremath{\sim}2\phantom{\rule{0.3em}{0ex}}\text{GeV}∕c$ ${p}_{T}$....
The anisotropy parameter (v(2)), the second harmonic of azimuthal particle distribution, has been measured with PHENIX detector in Au+Au collisions at sqrt[s(NN)]=200 GeV for identified and inclusive charged production central rapidities (|eta|<0.35) respect to reaction plane defined high (|eta|=3-4 ). We observe that v(2) mesons falls below (anti)baryons p(T)>2 GeV/c, marked contrast predictions a hydrodynamical model. A quark-coalescence model is also investigated.
Transverse momentum spectra of neutral pions in the range 1<pT<10 GeV/c have been measured at midrapidity by PHENIX experiment BNL RHIC Au+Au collisions sNN=200 GeV. The π0 multiplicity central reactions is significantly below yields same sNN peripheral and p+p scaled number nucleon-nucleon collisions. For most bin, suppression factor ∼2.5 pT=2 increases to ∼4–5 pT≈4 GeV/c. At larger pT, remains constant within errors. deficit already apparent semiperipheral smoothly with centrality.Received...
Transverse momentum spectra of charged hadrons with p(T)<8 GeV/c and neutral pions p(T)<10 have been measured at midrapidity by the PHENIX experiment BNL RHIC in d+Au collisions sqrt[s(NN)]=200 GeV. The yields are compared to those p+p same sqrt[s(NN)] scaled up number underlying nucleon-nucleon d+Au. yield ratio does not show suppression observed central Au+Au RHIC. Instead, there is a small enhancement high particles.
The PHENIX experiment has measured midrapidity ([FORMULA: SEE TEXT]) transverse momentum spectra of electrons as a function centrality in Au+Au collisions at [FORMULA: TEXT]. Contributions from photon conversions and light hadron decays, mainly Dalitz decays pi0 eta mesons, were removed. resulting nonphotonic electron are primarily due to the semileptonic hadrons carrying heavy quarks. Nuclear modification factors determined by comparison p+p collisions. A significant suppression high pT is...
Azimuthal correlations of jet-induced high-pT charged hadron pairs are studied at midrapidity in Au+Au collisions √sNN=200 GeV. The distribution jet-associated partner hadrons (1.0<pT<2.5 GeV/c) per trigger (2.5<pT<4.0 is found to vary with collision centrality, both shape and yield, indicating a significant effect the nuclear medium on jet fragmentation process.Received 1 July 2005DOI:https://doi.org/10.1103/PhysRevLett.97.052301©2006 American Physical Society
The PHENIX experiment at RHIC has measured charged hadron yields mid-rapidity over a wide range of transverse momentum (0.5 < p_T 10 GeV/c) in Au+Au collisions sqrt(s_NN)=200 GeV. data are compared to pi^zero measurements from the same experiment. For both hadrons and neutral pions, per nucleon-nucleon collision significantly suppressed central peripheral collisions. suppression sets gradually increases with increasing centrality Above 4-5 GeV/c p_T, constant almost identical pi^zeroes is...
The invariant differential cross section for inclusive neutral-pion production in p+p collisions at √s=200 GeV has been measured midrapidity (|η|<0.35) over the range 1<pT≲14 GeV/c by PHENIX experiment Relativistic Heavy Ion Collider. Predictions of next-to-leading order perturbative QCD calculations are consistent with these measurements. precision our result is sufficient to differentiate between prevailing gluon-to-pion fragmentation functions.Received 28 April...
Identified ${\ensuremath{\pi}}^{+/\ensuremath{-}}$, ${K}^{+/\ensuremath{-}}$, $p$, and $\overline{p}$ transverse momentum spectra at midrapidity in $\sqrt{{s}_{\mathrm{NN}}}\phantom{\rule{0ex}{0ex}}=\phantom{\rule{0ex}{0ex}}130\phantom{\rule{0ex}{0ex}}\mathrm{GeV}\phantom{\rule{0ex}{0ex}}\mathrm{Au}+\mathrm{Au}$ collisions were measured by the PHENIX experiment RHIC as a function of collision centrality. Average momenta increase with number participating nucleons similar way for all particle...
The first measurement of direct photons in Au + collisions at (square root)S(NN) = 200 GeV is presented. photon signal extracted as a function the collision centrality and compared to next-to-leading order perturbative quantum chromodynamics calculations. yield shown scale with number nucleon-nucleon for all centralities.
We present results for the charged-particle multiplicity distribution at midrapidity in Au-Au collisions square root of [s(NN)] = 130 GeV measured with PHENIX detector RHIC. For 5% most central we find dN(ch)/d eta(vertical line eta 0) 622+/-1(stat)+/-41(syst). The results, analyzed as a function centrality, show steady rise particle density per participating nucleon centrality.
The PHENIX experiment at the relativistic heavy ion collider (RHIC) has measured transverse energy and charged particle multiplicity midrapidity in $\mathrm{Au}+\mathrm{Au}$ collisions center-of-mass energies $\sqrt{{s}_{\mathrm{NN}}}=19.6,130$, $200\phantom{\rule{0.3em}{0ex}}\text{GeV}$ as a function of centrality. presented results are compared to measurements from other RHIC experiments lower energies. $\sqrt{{s}_{\mathrm{NN}}}$ dependence $dE{}_{T}/d\ensuremath{\eta}$...
We report on the yield of protons and antiprotons, as a function centrality transverse momentum, in Au+Au collisions at sqrt[s(NN)]=200 GeV measured midrapidity by PHENIX experiment BNL Relativistic Heavy Ion Collider. In central intermediate momenta (1.5<p(T)<4.5 GeV/c) significant fraction all produced particles are antiprotons. They show centrality-scaling behavior different from that pions. The pmacr;/pi p/pi ratios enhanced compared to peripheral Au+Au, p+p, e(+)e(-) collisions. This...
Inclusive transverse momentum spectra of $\ensuremath{\eta}$ mesons have been measured within ${p}_{T}=2--10\text{ }\text{ }\mathrm{GeV}/c$ at midrapidity by the PHENIX experiment in $\mathrm{Au}+\mathrm{Au}$ collisions $\sqrt{{s}_{NN}}=200\text{ }\mathrm{GeV}$. In central yields are significantly suppressed compared to peripheral $\mathrm{Au}+\mathrm{Au}$, $d+\mathrm{Au}$, and $p+p$ scaled corresponding number nucleon-nucleon collisions. The magnitude, centrality, ${p}_{T}$ dependence...
Semi-inclusive spectra of ${\ensuremath{\pi}}^{\ifmmode\pm\else\textpm\fi{}}$, ${K}^{\ifmmode\pm\else\textpm\fi{}}$, and p have been measured near midrapidity for central collisions 14.6A-GeV/c $^{28}\mathrm{Si}$ with $^{197}\mathrm{Au}$ nuclei. The invariant cross sections are all well fit by exponential distributions in transverse mass, within the ranges. \ensuremath{\pi} K can also be Boltzmann distributions. From integrated yields, at midrapidity, kaon/pion yield ratios...
The dependence of transverse momentum spectra neutral pions and $\ensuremath{\eta}$ mesons with ${p}_{T}<16\text{ }\text{ }\mathrm{GeV}/c$ ${p}_{T}<12\text{ }\mathrm{GeV}/c$, respectively, on the centrality collision has been measured at midrapidity by PHENIX experiment BNL Relativistic Heavy Ion Collider (RHIC) in $d+\mathrm{Au}$ collisions $\sqrt{{s}_{NN}}=200\text{ }\mathrm{GeV}$. yields are compared to those $p+p$ same $\sqrt{{s}_{NN}}$ scaled number underlying nucleon-nucleon...
Two-particle azimuthal correlation functions are presented for charged hadrons produced in Au+Au collisions at the Relativistic Heavy Ion Collider (sqrt [s(NN)]=130 GeV). The measurements permit determination of elliptic flow without event-by-event estimation reaction plane. extracted values (v2) show significant sensitivity to both collision centrality and transverse momenta emitted hadrons, suggesting rapid thermalization relatively strong velocity fields. When scaled by eccentricity zone...
Transverse momentum spectra and yields of hadrons are measured by the PHENIX collaboration in $\text{Au}+\text{Au}$ collisions at $\sqrt{{s}_{NN}}=130\phantom{\rule{0.3em}{0ex}}\text{GeV}$ Relativistic Heavy Ion Collider. The time-of-flight resolution allows identification pions to transverse momenta $2\phantom{\rule{0.3em}{0ex}}\text{GeV}∕c$ protons antiprotons $4\phantom{\rule{0.3em}{0ex}}\text{GeV}∕c$. yield rises approximately linearly with number nucleons participating collision, while...
Semi-inclusive proton and pion distributions from central Au+Au reactions at 11.6A GeV/c have been measured. The rapidity distribution shows significantly increased stopping compared to lighter systems, providing strong evidence for the formation of a state matter with baryon density substantially greater than normal nuclear matter. Unlike this energy induced by heavy ions, low mt−m0 invariant spectra deviate single exponential shape become flatter, while π− are found rise faster π+...