M. Hazumi

ORCID: 0000-0001-6830-8309
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About
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Research Areas
  • Particle physics theoretical and experimental studies
  • Quantum Chromodynamics and Particle Interactions
  • High-Energy Particle Collisions Research
  • Radio Astronomy Observations and Technology
  • Cosmology and Gravitation Theories
  • Superconducting and THz Device Technology
  • Particle Detector Development and Performance
  • Neutrino Physics Research
  • Dark Matter and Cosmic Phenomena
  • Particle Accelerators and Free-Electron Lasers
  • Geophysics and Gravity Measurements
  • Radiation Detection and Scintillator Technologies
  • Atomic and Subatomic Physics Research
  • Medical Imaging Techniques and Applications
  • Astrophysics and Cosmic Phenomena
  • Superconducting Materials and Applications
  • Computational Physics and Python Applications
  • Nuclear physics research studies
  • CCD and CMOS Imaging Sensors
  • Astronomy and Astrophysical Research
  • Solar and Space Plasma Dynamics
  • Galaxies: Formation, Evolution, Phenomena
  • Black Holes and Theoretical Physics
  • Particle accelerators and beam dynamics
  • Adaptive optics and wavefront sensing

High Energy Accelerator Research Organization
2016-2025

The University of Tokyo
2016-2025

The Graduate University for Advanced Studies, SOKENDAI
2016-2025

Institute of Space and Astronautical Science
2017-2025

Kavli Institute for the Physics and Mathematics of the Universe
2015-2024

Japan Aerospace Exploration Agency
2016-2024

International Center for Quantum-field Measurement Systems for Studies of the Universe and Particles
2022-2024

Institute of Particle and Nuclear Studies
2012-2024

Istituto Nazionale di Fisica Nucleare, Sezione di Roma I
2024

Institute of Particle Physics
2024

We report the observation of a narrow charmoniumlike state produced in exclusive decay process B+/--->K+/-pi(+)pi(-)J/psi. This state, which decays into pi(+)pi(-)J/psi, has mass 3872.0+/-0.6(stat)+/-0.5(syst) MeV, value that is very near M(D0)+M(D(*0)) threshold. The results are based on an analysis 152M B-Bmacr; events collected at Upsilon(4S) resonance Belle detector KEKB collider. signal statistical significance excess 10sigma.

10.1103/physrevlett.91.262001 article EN Physical Review Letters 2003-12-23

The Simons Observatory (SO) is a new cosmic microwave background experiment being built on Cerro Toco in Chile, due to begin observations the early 2020s. We describe scientific goals of experiment, motivate design, and forecast its performance. SO will measure temperature polarization anisotropy six frequency bands: 27, 39, 93, 145, 225 280 GHz. initial configuration have three small-aperture 0.5-m telescopes (SATs) one large-aperture 6-m telescope (LAT), with total 60,000 cryogenic...

10.1088/1475-7516/2019/02/056 article EN Journal of Cosmology and Astroparticle Physics 2019-02-01

We present a measurement of the standard model $\mathrm{CP}$ violation parameter $\mathrm{sin}2{\ensuremath{\varphi}}_{1}$ based on $29.1{\mathrm{fb}}^{\ensuremath{-}1}$ data sample collected at $\ensuremath{\Upsilon}(4S)$ resonance with Belle detector KEKB asymmetric-energy ${e}^{+}{e}^{\ensuremath{-}}$ collider. One neutral $B$ meson is fully reconstructed as $J/\ensuremath{\psi}{K}_{S}$, $\ensuremath{\psi}(2S){K}_{S}$, ${\ensuremath{\chi}}_{c1}{K}_{S}$, ${\ensuremath{\eta}}_{c}{K}_{S}$,...

10.1103/physrevlett.87.091802 article EN Physical Review Letters 2001-08-14

A distinct peak is observed in the ${\ensuremath{\pi}}^{\ifmmode\pm\else\textpm\fi{}}{\ensuremath{\psi}}^{\ensuremath{'}}$ invariant mass distribution near 4.43 GeV $B\ensuremath{\rightarrow}K{\ensuremath{\pi}}^{\ifmmode\pm\else\textpm\fi{}}{\ensuremath{\psi}}^{\ensuremath{'}}$ decays. fit using a Breit-Wigner resonance shape yields and width of $M=4433\ifmmode\pm\else\textpm\fi{}4(\mathrm{stat})\ifmmode\pm\else\textpm\fi{}2(\mathrm{syst})\text{ }\text{ }\mathrm{MeV}$...

10.1103/physrevlett.100.142001 article EN Physical Review Letters 2008-04-08

We present the science case, reference design, and project plan for Stage-4 ground-based cosmic microwave background experiment CMB-S4.

10.48550/arxiv.1907.04473 preprint EN other-oa arXiv (Cornell University) 2019-01-01

We study B→K(*)ℓ+ℓ− decays (ℓ=e, μ) based on a data sample of 657×106 BB¯ pairs collected with the Belle detector at KEKB e+e− collider. report differential branching fraction, isospin asymmetry, K* polarization, and forward-backward asymmetry (AFB) as functions q2=Mℓℓ2c2. The fitted AFB spectrum exceeds standard model expectation by 2.7 deviations. measured fractions are B(B→K*ℓ+ℓ−)=(10.7−1.0+1.1±0.9)×10−7 B(B→Kℓ+ℓ−)=(4.8−0.4+0.5±0.3)×10−7, where first errors statistical second systematic,...

10.1103/physrevlett.103.171801 article EN Physical Review Letters 2009-10-20

The cross section for ${e}^{+}{e}^{\ensuremath{-}}\ensuremath{\rightarrow}{\ensuremath{\pi}}^{+}{\ensuremath{\pi}}^{\ensuremath{-}}\ensuremath{\psi}(2S)$ between threshold and $\sqrt{s}=5.5\text{ }\text{ }\mathrm{GeV}$ is measured using $673\text{ }{\mathrm{fb}}^{\ensuremath{-}1}$ of data on off the $\ensuremath{\Upsilon}(4S)$ resonance collected with Belle detector at KEKB. Two resonant structures are observed in...

10.1103/physrevlett.99.142002 article EN Physical Review Letters 2007-10-01

The cross section for ${e}^{+}{e}^{\ensuremath{-}}\ensuremath{\rightarrow}{\ensuremath{\pi}}^{+}{\ensuremath{\pi}}^{\ensuremath{-}}J/\ensuremath{\psi}$ between 3.8 and $5.5\text{ }\text{ }\mathrm{GeV}/{c}^{2}$ is measured using a $548\text{ }{\mathrm{fb}}^{\ensuremath{-}1}$ data sample collected on or near the $\ensuremath{\Upsilon}(4S)$ resonance with Belle detector at KEKB. A peak $4.25\text{ }\mathrm{GeV}/{c}^{2}$, corresponding to so called $Y(4260)$, observed. In addition, there another...

10.1103/physrevlett.99.182004 article EN Physical Review Letters 2007-11-02

We report a measurement of the B-mode polarization power spectrum in cosmic microwave background (CMB) using Polarbear experiment Chile. The faint signature carries information about universe's entire history gravitational structure formation, and inflation that may have occurred very early universe. Our covers angular multipole range 500 < ℓ 2100 is based on observations an effective sky area 25 with 35 resolution at 150 GHz. On these scales, lensing CMB by intervening universe expected to...

10.1088/0004-637x/794/2/171 article EN The Astrophysical Journal 2014-10-07

Abstract CMB-S4—the next-generation ground-based cosmic microwave background (CMB) experiment—is set to significantly advance the sensitivity of CMB measurements and enhance our understanding origin evolution universe. Among science cases pursued with CMB-S4, quest for detecting primordial gravitational waves is a central driver experimental design. This work details development forecasting framework that includes power-spectrum-based semianalytic projection tool, targeted explicitly toward...

10.3847/1538-4357/ac1596 article EN cc-by The Astrophysical Journal 2022-02-01

Abstract LiteBIRD, the Lite (Light) satellite for study of B-mode polarization and Inflation from cosmic background Radiation Detection, is a space mission primordial cosmology fundamental physics. The Japan Aerospace Exploration Agency (JAXA) selected LiteBIRD in May 2019 as strategic large-class (L-class) mission, with an expected launch late 2020s using JAXA’s H3 rocket. planned to orbit Sun–Earth Lagrangian point L2, where it will map microwave over entire sky three years, telescopes 15...

10.1093/ptep/ptac150 article EN cc-by Progress of Theoretical and Experimental Physics 2022-11-21

We report the observation of a near-threshold enhancement in omegaJ/psi invariant mass distribution for exclusive B-->KomegaJ/psi decays. The results are obtained from 253 fb(-1) data sample that contains 275 x 10(6) BB pairs were collected near Upsilon(4S) resonance with Belle detector at KEKB asymmetric energy e(+)e(-) collider. statistical significance is estimated to be greater than 8sigma.

10.1103/physrevlett.94.182002 article EN Physical Review Letters 2005-05-12

We report the observation of prompt J/psi via double cc; production from e+e- continuum. In this process one pair fragments into a meson while remaining either produces charmonium state or open charm. Both cases have been experimentally observed. find cross sections sigma[e+e- -->J/psieta(c)(gamma)]xB(eta(c)-->>or=4 charged)=(0.033(+0.007)(-0.006)+/-0.009) pb and sigma(e+e- -->J/psiD(*+)X)=(0.53(+0.19)(-0.15)+/-0.14) infer -->J/psicc;)/sigma(e+e- -->J/psiX)=0.59(+0.15)(-0.13)+/-0.12. These...

10.1103/physrevlett.89.142001 article EN Physical Review Letters 2002-09-16

We report a measurement of the exclusive e+ e- -->Lambda+_(c)Lambda-_(c) cross section as function center-of-mass energy near Lambda+_(c)Lambda-_(c) threshold. A clear peak with significance 8.2sigma is observed in invariant mass distribution just above With an assumption resonance origin for peak, and width M=[4634 (+8)_(-7)(stat)(+5)_(-8)(syst)] MeV/c(2) Gamma_(tot)=[92 (+40)_(-24)(stat)(+10)_(-21)(syst)] MeV are determined. The analysis based on study events initial-state-radiation...

10.1103/physrevlett.101.172001 article EN Physical Review Letters 2008-10-24

We report the results of a study charged B decays to D+- pi-+ and D*+- final states using complete D(*) reconstruction. The contributions two-body => D** pi with narrow (j=3/2) broad (j=1/2) have been determined masses widths four measured. This is first observation D*0_0 D'0_1 mesons. analysis based on data sample 65 million barB pairs collected in Belle experiment.

10.1103/physrevd.69.112002 article EN Physical review. D. Particles, fields, gravitation, and cosmology/Physical review. D, Particles, fields, gravitation, and cosmology 2004-06-28

We report the first observation of B-->Dmacr;D(sJ)(2317) and B-->Dmacr;D(sJ)(2457) decays based on 123.8x10(6) BBmacr; events collected with Belle detector at KEKB. observe D(sJ)(2317) decay to D(s)pi(0) D(sJ)(2457) D(*)(s)pi(0) D(s)gamma final states. also set 90% C.L. upper limits for D(sJ)(2317)-->D(*)(s)gamma, D(sJ)(2457)-->D(*)(s)gamma, D(sJ)(2457)-->D(s)pi(0), D(sJ)(2457)-->D(s)pi(+)pi(-).

10.1103/physrevlett.91.262002 article EN Physical Review Letters 2003-12-31

We report the first observation of a charmoniumlike state recoiling from J/psi in inclusive process e+e- -->J/psi+anything at mass (3.943+/-0.006+/-0.006) GeV/c{2}. also observe decay this into D*D[over ] and determine its intrinsic width to be less than 52 MeV/c{2} 90% C.L. These results are obtained 357 fb{-1} data sample collected with Belle detector near Upsilon(4S) resonance, KEKB asymmetric-energy collider.

10.1103/physrevlett.98.082001 article EN Physical Review Letters 2007-02-20

We report the first observation of two charmed strange baryons that decay into Lambda(c)(+)Kappa(-)pi(+). The broader states is measured to have a mass 2978.5+/-2.1+/-2.0 MeV/c2 and width 43.5+/-7.5+/-7.0 MeV/c2. narrow state are be 3076.7+/-0.9+/-0.5 MeV/c;{2} 6.2+/-1.2+/-0.8 MeV/c2, respectively. also perform search for isospin partner Lambda(c)(+)Kappa(0)/(s)pi(-) observe significant signal at 3082.8+/-1.8+/-1.5 data used this analysis were accumulated or near Upsilon(4S) resonance, using...

10.1103/physrevlett.97.162001 article EN Physical Review Letters 2006-10-17

We report the first observation of two resonance-like structures in pi+ chi_c1 invariant mass distribution near 4.1 GeV/c^2 exclusive B0-bar --> K- decays. From a Dalitz plot analysis which are represented by Breit-Wigner resonance amplitudes, we determine masses and widths of: M_1 = (4051 +-14 +20-41) MeV/c^2, Gamma_1 (82 +21-17 +47-22) MeV, M_2 (4248 +44-29 +180-35}) Gamma_2 =(177 +54-39 +316-61) MeV; product branching fractions BF(B0-bar Z+_1,2) x BF(Z+_1,2 chi_c1) (3.0 +1.5-0.8 +3.7-1.6)...

10.1103/physrevd.78.072004 article EN Physical review. D. Particles, fields, gravitation, and cosmology/Physical review. D, Particles, fields, gravitation, and cosmology 2008-10-10
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