K. Kondo Horikawa
A5064791214- Quantum Chromodynamics and Particle Interactions
- High-Energy Particle Collisions Research
- Particle physics theoretical and experimental studies
- DNA and Biological Computing
- Nuclear physics research studies
- Analytical Chemistry and Sensors
- Superconducting Materials and Applications
- Radio Frequency Integrated Circuit Design
- Advanced Optical Sensing Technologies
- Cellular Automata and Applications
- Integrated Circuits and Semiconductor Failure Analysis
- Quantum, superfluid, helium dynamics
- Bayesian Methods and Mixture Models
- Analog and Mixed-Signal Circuit Design
- Cold Atom Physics and Bose-Einstein Condensates
- Particle Accelerators and Free-Electron Lasers
- Atomic and Subatomic Physics Research
- Radiation Effects in Electronics
- Pulsars and Gravitational Waves Research
- Random Matrices and Applications
Yamagata University Hospital
2024
A. Alikhanyan National Laboratory
2023
University of Aveiro
2020-2023
Yamagata University
2021-2023
University of L'Aquila
2023
The COMPASS experiment recently discovered a new isovector resonance-like signal with axial-vector quantum numbers, the $a_1(1420)$, decaying to $f_0(980)\pi$. With mass too close and width smaller than ground state $a_1(1260)$, it was immediately interpreted as light exotic meson, similar $X$, $Y$, $Z$ states in hidden-charm sector. We show that fully matching experimental data is produced by decay of $a_1(1260)$ resonance into $K^\ast(\to K\pi)\bar{K}$ subsequent rescattering through...
We report on a measurement of hard exclusive $\pi^0$ muoproduction the proton by COMPASS using 160 GeV/$c$ polarised $\mu^+$ and $\mu^-$ beams CERN SPS impinging liquid hydrogen target. From average measured cross sections, virtual-photon section is determined as function squared four-momentum transfer between initial final in range $0.08\,(\text{GeV/}c)^2 < |t| 0.64\,(\text{GeV/}c)^2$. The kinematics are $\langle Q^2 \rangle =2.0\; {(\text{GeV}/c)^2}$, \nu = 12.8\; {\text{GeV}}$, x_{Bj}...
The production of vector mesons in deep inelastic scattering is an interesting yet scarsely explored channel to study the transverse spin structure nucleon and related phenomena. COMPASS collaboration has performed first measurement Collins Sivers asymmetries for inclusively produced $\rho^0$ mesons. analysis based on data set collected $2010$ using a $160\,\,\rm{GeV}/c$ $\mu^+$ beam impinging transversely polarized $\rm{NH}_3$ target. $\rho^{0}$ are selected from oppositely charged hadron...
We report on a measurement of Spin Density Matrix Elements (SDMEs) in hard exclusive $\omega$ meson muoproduction the proton at COMPASS using 160 GeV/$c$ polarised $ \mu ^{+}$ and ^{-}$ beams impinging liquid hydrogen target. The covers range 5.0 GeV/$c^2$ $< W <$ 17.0 GeV/$c^2$, with average kinematics $\langle Q^{2} \rangle=$ 2.1 (GeV/$c$)$^2$, \rangle= 7.6$ p^{2}_{\rm T} \rangle = 0.16$ (GeV/$c$)$^2$. Here, $Q^2$ denotes virtuality exchanged photon, $W$ mass final hadronic system $p_T$...
A set of measurements azimuthal asymmetries in the production pairs identified hadrons deep-inelastic scattering muons on transversely polarised 6LiD (deuteron) and NH3 (proton) targets is presented. All available data collected years 2003–2004 2007/2010 with COMPASS spectrometer using a muon beam 160GeV/c at CERN SPS were analysed. The provide access to transversity distribution functions via fragmentation function that principle may be independently obtained from e+e− annihilation data....
New results are presented on a high-statistics measurement of Collins and Sivers asymmetries charged hadrons produced in deep inelastic scattering muons transversely polarized ^{6}LiD target. The data were taken 2022 with the COMPASS spectrometer using 160 GeV muon beam at CERN, statistically balancing existing proton targets. first from about two-thirds new have total uncertainties smaller by up to factor three compared previous deuteron measurements. Using all results, both transversity...
Based on the observation of sizeable target-transverse-spin asymmetries in single-hadron and hadron-pair production Semi-Inclusive measurements Deep Inelastic Scattering (SIDIS), chiral-odd transversity quark distribution functions $h_1^q$ are nowadays well established. Several possible channels to access these were originally proposed. One candidate is measurement polarisation $\Lambda$ hyperons produced SIDIS off transversely polarised nucleons, where transverse struck might be transferred...
Abstract We report on a measurement of Spin Density Matrix Elements (SDMEs) in hard exclusive $$\rho ^0$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:msup> <mml:mi>ρ</mml:mi> <mml:mn>0</mml:mn> </mml:msup> </mml:math> meson muoproduction at COMPASS using 160 GeV/ c polarised $$ \mu ^{+}$$ <mml:mi>μ</mml:mi> <mml:mo>+</mml:mo> and ^{-}$$ <mml:mo>-</mml:mo> beams impinging liquid hydrogen target. The covers the kinematic range 5.0 $$c^2$$ <mml:mi>c</mml:mi>...
Hadron leptoproduction in Semi-Inclusive measurements of Deep-Inelastic Scattering (SIDIS) on unpolarised nucleons allows one to get information the intrinsic transverse momentum quarks a nucleon and Boer-Mulders function through measurement azimuthal modulations cross section. These were recently measured by HERMES experiment at DESY proton deuteron targets, COMPASS using CERN SPS muon beam $^6$LiD target. In both cases, amplitudes $\cosϕ_h$ $\cos 2ϕ_h$ show strong kinematic dependences for...
The antiparticle-over-particle multiplicity ratio is measured in deep-inelastic scattering for negatively and positively charged kaons and, the first time, antiprotons protons. data were obtained by COMPASS Collaboration using a 160 GeV muon beam impinging on an isoscalar 6LiD target. regime of ensured requiring Q2 > 1 (GeV/c)2 photon virtuality W>5 GeV/c2 invariant mass produced hadronic system. Bjorken-x restricted to range 0.01 0.40. Protons are identified momentum from 20 GeV/c 60...
New results are presented on a high-statistics measurement of Collins and Sivers asymmetries charged hadrons produced in deep inelastic scattering muons transversely polarised $^6$LiD target. The data were taken 2022 with the COMPASS spectrometer using 160 \gevv\ muon beam at CERN, balancing existing proton targets. first from about two-thirds new have total uncertainties smaller by up to factor three compared previous deuteron measurements. Using all results, both transversity distribution...
The COMPASS Collaboration performed measurements of the Drell-Yan process in 2015 and 2018 using a 190 GeV/c π^{-} beam impinging on transversely polarized ammonia target. Combining data both years, we present final results amplitudes five azimuthal modulations, which correspond to transverse-spin-dependent asymmetries (TSAs) dimuon production cross section. Three them probe nucleon leading-twist Sivers, transversity, pretzelosity transverse-momentum dependent (TMD) parton distribution...
The multiplicities of positive and negative pions, kaons unidentified hadrons produced in deep-inelastic scattering are measured bins the Bjorken scaling variable $x$, relative virtual-photon energy $y$ fraction transferred to final-state hadron $z$. Data were obtained by COMPASS Collaboration using a 160 GeV muon beam both electric charges liquid hydrogen target. These measurements cover kinematic domain with photon virtuality $Q^2 > 1$ (GeV/$c)^2$, $0.004 < x 0.4$, $0.1 y 0.7$ $0.2 z...
A new and detailed measurement of the cross section for hard exclusive neutral-pion muoproduction on proton was performed in a wide kinematic region, with photon virtuality $Q^2$ ranging from 1 to 8 (GeV/$c$)$^{\rm\, 2}$ Bjorken variable $x_{\rm Bj}$ 0.02 0.45. The data were collected at COMPASS CERN using 160 GeV/$c$ longitudinally polarised $\mu^+$ $\mu^-$ beams scattering off 2.5 m long liquid hydrogen target. From average measured sections, virtual-photon--proton is determined as...
We report on a measurement of Spin Density Matrix Elements (SDMEs) in hard exclusive $ω$ meson muoproduction the proton at COMPASS using 160 GeV/$c$ polarised $ μ^{+}$ and μ^{-}$ beams impinging liquid hydrogen target. The covers range 5.0 GeV/$c^2$ $< W <$ 17.0 GeV/$c^2$, with average kinematics $\langle Q^{2} \rangle=$ 2.1 (GeV/$c$)$^2$, \rangle= 7.6$ p^{2}_{\rm T} \rangle = 0.16$ (GeV/$c$)$^2$. Here, $Q^2$ denotes virtuality exchanged photon, $W$ mass final hadronic system $p_T$...
We present the study of production double $J/\psi$ mesons using COMPASS data collected with a 190 GeV/$c$ $\pi^-$ beam scattering off NH$_{3}$, Al and W targets. Kinematic distributions events are analysed, cross section is estimated for each The results compared to predictions from single- double-parton models as well pion intrinsic charm tetraquark exotic resonance hypotheses. It demonstrated that single parton mechanism gives dominant contribution sufficient describe data. An upper limit...
The COMPASS Collaboration performed measurements of the Drell-Yan process in 2015 and 2018 using a 190 GeV/c $\pi^{-}$ beam impinging on transversely polarised ammonia target. Combining data both years, we present final results amplitudes five azimuthal modulations dimuon production cross section. Three these transverse-spin-dependent asymmetries (TSAs) probe nucleon leading-twist Sivers, transversity, pretzelosity transverse-momentum dependent (TMD) parton distribution functions (PDFs)....
We present the study of production double $J/ψ$ mesons using COMPASS data collected with a 190 GeV/$c$ $π^-$ beam scattering off NH$_{3}$, Al and W targets. Kinematic distributions events are analysed, cross section is estimated for each The results compared to predictions from single- double-parton models as well pion intrinsic charm tetraquark exotic resonance hypotheses. It demonstrated that single parton mechanism gives dominant contribution sufficient describe data. An upper limit on...