T. S. Miyashita
A5011833457- Particle physics theoretical and experimental studies
- Quantum Chromodynamics and Particle Interactions
- High-Energy Particle Collisions Research
- Neutrino Physics Research
- Particle Detector Development and Performance
- Medical Imaging Techniques and Applications
- Radiation Detection and Scintillator Technologies
- Dark Matter and Cosmic Phenomena
- Particle Accelerators and Free-Electron Lasers
- Nuclear physics research studies
- Atomic and Subatomic Physics Research
- Superconducting Materials and Applications
- Computational Physics and Python Applications
- Muon and positron interactions and applications
- Black Holes and Theoretical Physics
- Cosmology and Gravitation Theories
- Radiation Therapy and Dosimetry
- Advanced Data Storage Technologies
- Nuclear Physics and Applications
- Particle accelerators and beam dynamics
- Distributed and Parallel Computing Systems
- Stochastic processes and statistical mechanics
- Theoretical and Computational Physics
- Radiation Effects and Dosimetry
- Lanthanide and Transition Metal Complexes
California Institute of Technology
2014-2022
Fermi National Accelerator Laboratory
2021
Joint Institute for Nuclear Research
2021
Istituto Nazionale di Fisica Nucleare, Sezione di Pisa
2019-2021
Istituto Nazionale di Fisica Nucleare, Sezione di Trieste
2021
Istituto Nazionale di Fisica Nucleare, Laboratori Nazionali di Frascati
2018-2021
Istituto Nazionale di Fisica Nucleare, Sezione di Lecce
2021
Yale University
2021
University of Pisa
2019
Marconi University
2018
Dark sectors charged under a new Abelian interaction have recently received much attention in the context of dark matter models. These models introduce light mediator, so-called photon (A′), connecting sector to standard model. We present search for reaction e+e−→γA′, A′→e+e−, μ+μ− using 514 fb−1 data collected with BABAR detector. observe no statistically significant deviations from model predictions, and we set 90% confidence level upper limits on mixing strength between at 10−4−10−3...
The invariant mass spectra of e+e- pairs produced in 12 GeV proton-induced nuclear reactions are measured at the KEK Proton Synchrotron. On low-mass side meson peak, a significant enhancement over known hadronic sources has been observed. spectra, including excess, well reproduced by model that takes into account density dependence vector modification, as theoretically predicted.
The Mu2e experiment at Fermilab will search for charged lepton flavor violation via the coherent conversion process mu- N --> e- with a sensitivity approximately four orders of magnitude better than current world's best limits this process. experiment's offers discovery potential over wide array new physics models and probes mass scales well beyond reach LHC. We describe herein preliminary design proposed experiment. This document was created in partial fulfillment requirements necessary to...
We present a measurement of the total branching fraction flavor-changing neutral-current process B->Xsl+l-, along with partial fractions in bins dilepton and hadronic system (Xs) mass, using sample 471x10^6 Upsilon(4S)->BBbar events recorded BaBar detector at PEP-II e+e- collider. B mesons are reconstructed by combining pair, either or mu+mu-, 10 different Xs final states containing exactly one charged neutral kaon, two fewer pions, most pi0. Using sum over these exclusive modes as basis for...
We study the processes $e^+ e^-\to K_S^0 K_L^0 \gamma$, $K_S^0 \pi^+\pi^-\gamma$, and K^+K^-\gamma$, where photon is radiated from initial state, providing cross section measurements for hadronic states over a continuum of center-of-mass energies. The results are based on 469 fb$^{-1}$ data collected with BaBar detector at SLAC. observe $\phi(1020)$ resonance in K_L^0$ final state measure product its electronic width branching fraction about 3% uncertainty. present measurement $ energy range...
We measured the invariant mass spectra of electron-positron pairs in target rapidity region 12-GeV p+A reactions. have observed a significant difference below omega meson between p+C and p+Cu interactions. This indicates that spectral shape mesons is modified at normal nuclear-matter density.
We study the processes γγ→K+K−η and γγ→K+K−π0 using a data sample of 519 fb−1 recorded with BABAR detector operating at SLAC PEP-II asymmetric-energy e+e− collider center-of-mass energies near Υ(nS) (n=2,3,4) resonances. observe ηc→K+K−π0 ηc→K+K−η decays, measure their relative branching fraction, perform Dalitz plot analysis for each decay. K∗0(1430)→Kη decay its fraction to Kπ mode be R(K∗0(1430))=B(K∗0(1430)→Kη)B(K∗0(1430)→Kπ)=0.092±0.025+0.010−0.025. The results correspond first...
A dedicated measurement of additional radiation in e+e−→μ+μ−γ and e+e−→π+π−γ initial-state-radiation events is presented using the full BABAR data sample. For first time results are at next-to- next-to-next-to-leading order, with one two photons, respectively, for from initial final states. Comparison predictions phokhara afkqed Monte Carlo generators performed, revealing discrepancies one-photon rates angular distributions former. This disagreement has a negligible effect on e+e−→π+π−(γ)...
We study the processes $e^+ e^-\to K^0_S K^0_L\pi^0\gamma$, $K^0_S K^0_L\eta\gamma$, and K^0_L\pi^0\pi^0\gamma$, where photon is radiated from initial state, providing cross section measurements for hadronic final states over a continuum of center-of-mass energies. The results are based on 469~$fb^{-1}$ data collected at or near $\Upsilon(4S)$~ resonance with BaBar detector SLAC. present first K^0_L\pi^0$, K^0_L\eta$, K^0_L\pi^0\pi^0$ sections up to energy 4~GeV, their intermediate...
Axionlike particles (ALPs) are predicted in many extensions of the standard model, and their masses can naturally be well below electroweak scale. In presence couplings to bosons, these could emitted flavor-changing B meson decays. We report herein a search for an ALP, a, reaction B^{±}→K^{±}a, a→γγ using data collected by BABAR experiment at SLAC. No significant signal is observed, 90% confidence level upper limits on ALP coupling bosons derived as function mass, improving current...
We study the processes $\gamma \gamma \to K^0_S K^{\pm}\pi^{\mp}$ and K^+ K^- \pi^0$ using a data sample of 519~$fb^{-1}$ recorded with BaBar detector operating at SLAC PEP-II asymmetric-energy $e^+ e^-$ collider center-of-mass energies near $\Upsilon(nS)$ ($n = 2,3,4$) resonances. observe $\eta_c$ decays to both final states perform Dalitz plot analyses model-independent partial wave analysis technique. This allows measurement mass-dependence $I=1/2$ $K \pi$ $\mathcal{S}$-wave amplitude...
The invariant mass spectra of ϕ→K+K− are measured in 12 GeV p+A reactions order to search for the in-medium modification ϕ mesons. observed K+K− well reproduced by relativistic Breit-Wigner function with a combinatorial background shape three βγ regions between 1.0 and 3.5. nuclear number dependence yields decay channel is compared simultaneously e+e− carbon copper targets. We parameterize production as σ(A)=σ0Aα obtain αϕ→K+K−−αϕ→e+e− be 0.14±0.12. Limits obtained partial widths mesons...
This article presents a model-independent search for an additional, mostly sterile, heavy neutral lepton (HNL), that is capable of mixing with the Standard Model $\ensuremath{\tau}$ neutrino strength $|{U}_{\ensuremath{\tau}4}{|}^{2}$, corresponding to absolute square extended Pontecorvo-Maki-Nakagawa-Sakata matrix element. Data from BABAR experiment, total integrated luminosity $424\text{ }\text{ }{\mathrm{fb}}^{\ensuremath{-}1}$, are analyzed using kinematic approach makes no assumptions...
We study the processes ${e}^{+}{e}^{\ensuremath{-}}\ensuremath{\rightarrow}{K}^{+}{K}^{\ensuremath{-}}{\ensuremath{\pi}}^{0}{\ensuremath{\pi}}^{0}{\ensuremath{\pi}}^{0}\ensuremath{\gamma}$, ${K}_{S}^{0}{K}^{\ifmmode\pm\else\textpm\fi{}}{\ensuremath{\pi}}^{\ensuremath{\mp}}{\ensuremath{\pi}}^{0}{\ensuremath{\pi}}^{0}\ensuremath{\gamma}$, and...
A new mechanism has been proposed to simultaneously explain the presence of dark matter and matter-antimatter asymmetry in universe. This scenario predicts exotic $B$ meson decays into a baryon sector anti-baryon ($\psi_D$) with branching fractions accessible at factories. We present search for $B \rightarrow \Lambda \psi_D$ using data collected by $BABAR$ experiment SLAC. reaction is identified fully reconstructing accompanying requiring single $\Lambda$ remaining particles. No significant...
The inclusive production of ω and ϕ mesons is studied in the backward region interaction 12 GeV protons with polyethylene, carbon, copper targets. are measured e+e− decay channels. cross sections presented as functions rapidity y transverse momentum pT. nuclear mass number dependences (A dependences) found to be A0.710±0.021(stat)±0.037(syst) for A0.937±0.049(stat)±0.018(syst) 0.9<y<1.7 pT<0.75 GeV/c.1 MoreReceived 14 March 2006DOI:https://doi.org/10.1103/PhysRevC.74.025201©2006 American...
The Mu2e experiment at Fermilab searches for the charged-lepton flavour violating (CLFV) conversion of a negative muon into an electron in field aluminum nucleus, with distinctive signature mono-energetic energy slightly below rest mass (104.967 MeV). goal is to improve by four orders magnitude search sensitivity respect previous experiments. Any observation CLFV signal will be clear indication new physics. detector composed tracker, electro- magnetic calorimeter and external veto cosmic...
We report a Dalitz plot analysis of charmless hadronic decays charged $B$ mesons to the final state $K_{\rm S}^{0}\pi^{+}\pi^{0}$ using full BaBar dataset $470.9\pm2.8$ million $B\bar{B}$ events collected at $\Upsilon(4S)$ resonance. measure overall branching fraction and $CP$ asymmetry be ${\cal B}\left(B^{+}\to K^{0}\pi^{+}\pi^{0}\right) = \left(45.9 \pm 2.6 3.0^{+8.6}_{-0.0}\right)\times10^{-6}$ $A_{CP}\left(B^{+}\to 0.07 0.05 0.03^{+0.02}_{-0.03}$, where uncertainties are statistical,...
We measured invariant mass spectra of e+e− pairs produced in 12 GeV p + A interaction to investigate in-medium modification vector mesons. observed an enhancement over the known hadronic sources on low-mass side ω meson peak. The obtained ρ/ω ratio indicates that this mainly results from ρ mesons whose was modified nuclear matter. performed a toy model calculation based prediction using QCD sum rule. It reproduced well tendency our data.
The Mu2e experiment is constructing a calorimeter consisting of 1,348 undoped CsI crystals in two disks. Each crystal has dimension 34 x 200 mm, and readout by large area silicon PMT array. A series technical specifications was defined according to physics requirements. Preproduction were procured from three firms: Amcrys, Saint-Gobain Shanghai Institute Ceramics. We report the quality assurance on crystal's scintillation properties their radiation hardness against ionization dose neutrons....