A5062924802- Quantum Chromodynamics and Particle Interactions
- Particle physics theoretical and experimental studies
- High-Energy Particle Collisions Research
- Atomic and Molecular Physics
- Nuclear physics research studies
- Quantum, superfluid, helium dynamics
- Cold Atom Physics and Bose-Einstein Condensates
- Atomic and Subatomic Physics Research
- Advanced Chemical Physics Studies
- Muon and positron interactions and applications
- Particle accelerators and beam dynamics
- Dark Matter and Cosmic Phenomena
- Nuclear reactor physics and engineering
- Radioactive contamination and transfer
- Nuclear Physics and Applications
- Superconducting Materials and Applications
- Particle Detector Development and Performance
- Advanced NMR Techniques and Applications
- Radioactivity and Radon Measurements
- X-ray Spectroscopy and Fluorescence Analysis
- High-pressure geophysics and materials
- Particle Accelerators and Free-Electron Lasers
- Radiation Detection and Scintillator Technologies
- Neutrino Physics Research
- Mass Spectrometry Techniques and Applications
The University of Tokyo
2015-2024
Tokyo University of Science
2013-2024
Augustana University
2014-2023
Banaras Hindu University
2003-2023
Abilene Christian University
2003-2023
PHENIX laboratory
2003-2023
Charles University
2018-2023
Bhabha Atomic Research Centre
2023
Bunkyo University
1998-2020
Brookhaven National Laboratory
1992-2019
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.
Zero- and low-field spin-relaxation functions have been studied for the first time by using positive muons, results are compared with stochastic theory of relaxation formulated Kubo Toyabe. The dipolar broadening zero-field has in detail. In Zr${\mathrm{H}}_{2}$, function ${\ensuremath{\mu}}^{+}$ found to decay ${(5)}^{\mathrm{\textonehalf{}}}$ times faster than high-field function, which is explained terms contribution nonsecular part interaction. Advantages method over conventional...
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.
The largest concern on the cesium-137 ( 137 Cs) deposition and its soil contamination due to emission from Fukushima Daiichi Nuclear Power Plant (NPP) showed up after a massive quake March 11, 2011. Cesium-137 with half-life of 30.1 y causes concerns because deleterious effect agriculture stock farming, and, thus, human life for decades. Removal Cs contaminated soils or land use limitations in areas where removal is not possible is, therefore, an urgent issue. A challenge lies fact that...
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...
The $\bar{K}N$ system at threshold is a sensitive testing ground for low energy QCD, especially the explicit chiral symmetry breaking. Therefore, we have measured $K$-series x rays of kaonic hydrogen atoms DA$\Phi$NE electron-positron collider Laboratori Nazionali di Frascati, and determined most precise values strong-interaction energy-level shift width $1s$ atomic state. As x-ray detectors, used large-area silicon drift detectors having excellent timing resolution, which were developed...
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 have measured the shift and width of kaonic hydrogen $1s$ state due to $\overline{K}N$ strong interaction. observed, for first time, distinct $K$-series x rays with good signal-to-noise ratio in energy spectrum. The were determined be $\ensuremath{\Delta}E(1s)\phantom{\rule{0ex}{0ex}}=\phantom{\rule{0ex}{0ex}}\ensuremath{-}323\ifmmode\pm\else\textpm\fi{}63(\mathrm{stat})\ifmmode\pm\else\textpm\fi{}11(\mathrm{syst})\mathrm{eV}$ (repulsive)...
Delayed annihilation of antiprotons stopped in liquid helium has been observed, revealing that about 3.6% are trapped long-lived metastable states. No delayed component was found either nitrogen or argon. The observed time distribution shows fast-decaying components followed by a major part with decay constant 3 \ensuremath{\mu}sec.
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...
The QCD vacuum shows the dynamical breaking of chiral symmetry. In hot and/or dense medium, order parameter such as $⟨\overline{q}q⟩$ is expected to change a function temperature $T$ and density $\ensuremath{\rho}$ its experimental detection one main challenges in modern hadron physics. this paper, theoretical expectations for in-medium spectra associated with partial restoration symmetry are discussed well current status experiments an emphasis on measurements properties mesons produced...
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...
The Fukushima Dai-ichi NPP accident contaminated the soil of densely-populated regions in Prefecture with radioactive cesium, which poses significant risks internal and external exposure to residents. If we apply knowledge post-Chernobyl studies, exposures excess a few mSv/y would be expected frequent Fukushima.Extensive whole-body-counter surveys (n = 32,811) carried out at Hirata Central Hospital between October, 2011 November, 2012, however show that levels residents are much lower than...