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論文

First constraint on the P-odd/T-odd cross section in polarized neutron transmission through transversely polarized $$^{139}$$La

中部 倫太郎; 遠藤 駿典; 神原 理*; 河村 しほり; 木村 敦; 小林 龍珠; 奥 隆之; 奥平 琢也*; 酒井 健二; 篠原 武尚; et al.

Progress of Theoretical and Experimental Physics (Internet), 2026(6), p.063D01_1 - 063D01_15, 2026/06

https://doi.org/10.1093/ptep/ptag088
 被引用回数：0 パーセンタイル：0.00(Physics, Multidisciplinary)

本研究では、横偏極した$$^{139}$$La標的を透過する偏極中性子における時間反転対称性の破れ(TRIV)効果に対する初めての制限を報告する。我々は、密度行列形式に基づいて透過非対称度を定式化し、三階までのテンソル偏極項を含む$$^{139}$$Laの前方散乱振幅を明示的に取り入れた。この形式を、$$0.75$$ eVの$$p$$波共鳴近傍におけるスピン依存断面積を測定するために取得された既存の透過データに適用した。これらのデータはP奇・T奇観測量に最適化されたものではないため、到達可能な感度には本質的な制限があるものの、実験データに対して本形式を検証する有用な機会を与える。統計的に有意なTRIV信号は観測されなかった。パラメータ空間における大域的な$$chi^2$$構造を解析することにより、90%信頼水準で$$|W_T|<15~mathrm{eV}$$という上限値を得た。これは、共鳴平均されたTRIV断面積に対する上限値$$|Deltasigma_{not{T}not{P}}|<8.3times10^2~mathrm{b}$$に対応する。これらの結果は、本研究で用いた理論的枠組みの妥当性を示すとともに、偏極中性子透過実験における将来の専用TRIV探索に向けた指針を与えるものである。

論文

Absence of long-range V-V dimer and magnetic orderings in high-entropy (Mg$$_{0.2}$$Mn$$_{0.2}$$Co$$_{0.2}$$Ni$$_{0.2}$$Cu$$_{0.2}$$)VO$$_3$$

山本 孟*; 辻 卓也; 松村 大樹; 他16名*

Inorganic Chemistry, 64(34), p.17496 - 17502, 2025/08

https://doi.org/10.1021/acs.inorgchem.5c02779
 被引用回数：1 パーセンタイル：0.00(Chemistry, Inorganic & Nuclear)

V-V dimerization in ilmenite-type vanadium oxides is an intriguing phenomenon that induces structural and metal-to-insulator transitions. Herein, we report the high-pressure synthesis, crystal structure, and electronic states of high-entropy ilmenite-type (Mg$$_{0.2}$$Mn$$_{0.2}$$Co$$_{0.2}$$Ni$$_{0.2}$$Cu$$_{0.2}$$)VO$$_3$$. Although all the parent ilmenite-type compounds exhibit triclinic ($$P$$$$bar{1}$$) symmetry, this compound crystallizes in a rhombohedral ($$R$$$$bar{3}$$) structure, indicating the absence of V-V dimer ordering. The temperature dependence of the resistivity below room temperature follows a variable-range hopping conduction mechanism, suggesting the presence of short-range V-V dimer ordering. Magnetic susceptibility and heat capacity measurements revealed multi-step spin-glass transitions. This study demonstrates that a high-entropy composition hinders electronic and magnetic long-range ordering due to severe lattice distortions and competition between magnetic exchange interactions.

論文

Observation of gamma rays up to 320 TeV from the middle-aged TeV pulsar wind nebula HESS J1849-000

雨森 道紘*; 土屋 晴文; Tibet AS$$gamma$$ Collaboration*; 他116名*

Astrophysical Journal, 954(2), p.200_1 - 200_7, 2023/09

https://doi.org/10.3847/1538-4357/acebce
 被引用回数：7 パーセンタイル：45.98(Astronomy & Astrophysics)

Gamma rays from HESS J1849-000, a middle-aged TeV pulsar wind nebula (PWN), are observed by the Tibet air shower array and the muon detector array. The detection significance of gamma rays reaches $$4.0sigma$$ and $$4.4sigma$$ levels above 25 TeV and 100 TeV, respectively. The energy spectrum measured between 40 TeV $$<$$ E $$<$$ 320 TeV for the first time is described with a simple power-law function of dN/dE = $$(2.86pm1.44)times10^{-16}(E/40mathrm{TeV})^{-2.24pm0.41} mathrm{TeV^{-1} cm^{-2} s^{-1}}$$. The gamma-ray energy spectrum from the sub-TeV to sub-PeV ranges including the results of previous studies can be modeled with the leptonic scenario, Inverse Compton Scattering by high-energy electrons accelerated by the PWN of PSR J1849-0001, but the scenario requires sophisticated theoretical modeling. On the other hand, the gamma-ray energy spectrum can be simply modeled with the hadronic scenario in which gamma rays are generated from the decay of neutral pions produced by collisions between accelerated cosmic-ray protons and the ambient molecular cloud found in the gamma-ray emitting region. The cutoff energy of cosmic-ray protons $$E_{mathrm{p,cut}}$$ is estimated at $$log _{10}(E /mathrm{TeV})=3.73^{+2.98}_{-0.66}$$, suggesting that protons are accelerated up to the PeV energy range. Our study proposes that HESS J1849-000 should be further investigated as a new candidate for a Galactic PeV cosmic-ray accelerator, or "PeVatron".

論文

Measurements of branching fractions of $$Lambda_c^+ to Sigma^+ eta$$ and $$Lambda_c^+ to Sigma^+ eta'$$ and asymmetry parameters of $$Lambda_c^+ to Sigma^+ pi^0$$, $$Lambda_c^+ to Sigma^+ eta$$, and $$Lambda_c^+ to Sigma^+ eta'$$

Li, S. X.*; 谷田 聖; Belle Collaboration*; 他168名*

Physical Review D, 107(3), p.032003_1 - 032003_12, 2023/02

https://doi.org/10.1103/PhysRevD.107.032003
 被引用回数：6 パーセンタイル：48.05(Astronomy & Astrophysics)

We report a study of $$Lambda_c^+ to Sigma^+ pi^0$$, $$Lambda_c^+ to Sigma^+ eta$$, and $$Lambda_c^+ to Sigma^+ eta'$$ using the data sample corresponding to an integrated luminosity of 980 $$rm fb^{-1}$$ collected with the Belle detector at the KEKB asymmetric-energy $$e^+e^-$$ collider. The branching fractions relative to $$Lambda_c^+ to Sigma^+ pi^0$$ are measured as: $$mathcal{B}_{Lambda_c^+ to Sigma^+ eta}/mathcal{B}_{Lambda_c^+ to Sigma^+ pi^0}=0.25 pm 0.03 pm 0.01$$ and $$mathcal{B}_{Lambda_c^+ to Sigma^+ eta'}/mathcal{B}_{Lambda_c^+ to Sigma^+ pi^0}=0.33 pm 0.06 pm 0.02$$. Using $$mathcal{B}_{Lambda_c^+ to Sigma^+ pi^0}=(1.25 pm 0.10)%$$, we obtain $$mathcal{B}_{Lambda_c^+ to Sigma^+ eta}=(3.14 pm 0.35 pm 0.11 pm 0.25)times10^{-3}$$ and $$mathcal{B}_{Lambda_c^+ to Sigma^+ eta'}=(4.16 pm 0.75 pm 0.21 pm 0.33)times10^{-3}$$. Here the uncertainties are statistical, systematic, and from $$mathcal{B}_{Lambda_c^+ to Sigma^+ pi^0}$$, respectively. The ratio of the branching fraction of $$Lambda_c^+ to Sigma^+ eta'$$ with respect to that of $$Lambda_c^+ to Sigma^+ eta$$ is measured to be $$mathcal{B}_{Lambda_c^+ to Sigma^+ eta'}/mathcal{B}_{Lambda_c^+ to Sigma^+ eta}=1.34 pm 0.28 pm 0.06$$. We update the asymmetry parameter of $$Lambda_c^+ to Sigma^+ pi^0$$, $$alpha_{Sigma^+ pi^0} = -0.48 pm 0.02 pm 0.02$$, with a considerably improved precision. The asymmetry parameters of $$Lambda_c^+ to Sigma^+ eta$$ and $$Lambda_c^+ to Sigma^+ eta'$$ are measured to be $$alpha_{Sigma^+ eta} = -0.99 pm 0.03 pm 0.05$$ and $$alpha_{Sigma^+ eta'} = -0.46 pm 0.06 pm 0.03$$ for the first time.

論文

Search for charged lepton flavor violating decays of $$Upsilon(1S)$$

Patra, S.*; 谷田 聖; Belle Collaboration*; 他216名*

Journal of High Energy Physics (Internet), 2022(5), p.95_1 - 95_17, 2022/05

https://doi.org/10.1007/JHEP05(2022)095
 被引用回数：12 パーセンタイル：61.90(Physics, Particles & Fields)

We present a search for the charged lepton-flavor-violating decays $$Upsilon(1S)rightarrowellell^prime$$ and radiative charged lepton-flavour-violating decays $$Upsilon(1S)rightarrowgammaellell^prime$$ [$$ell,ell^prime = e, mu, tau$$] using the 158 million $$Upsilon(2S)$$ sample collected by the Belle detector at the KEKB collider. This search uses $$Upsilon(1S)$$ mesons produced in $$pi^+pi^-Upsilon(1S)$$ transitions. We do not find any significant signal, so we provide upper limits on the branching fractions at the 90% confidence level.

論文

Search for $$B^0$$ meson decays into $$Lambda$$ and missing energy with a hadronic tagging method at Belle

Hadjivasiliou, C.*; 谷田 聖; Belle Collaboration*; 他166名*

Physical Review D, 105(5), p.L051101_1 - L051101_8, 2022/03

https://doi.org/10.1103/PhysRevD.105.L051101
 被引用回数：11 パーセンタイル：55.35(Astronomy & Astrophysics)

We present a search for the decays of $$B^0$$ mesons into a final state containing a $$Lambda$$ baryon and missing energy. These results are obtained from a 711 fb$$^{-1}$$ data sample that contains 772 $$times$$10$$^{6}$$ $$B$$$$overline{B}$$ pairs and was collected near the $$Upsilon(4S)$$ resonance with the Belle detector at the KEKB asymmetric-energy $$e^+e^-$$ collider. We use events in which one $$B$$ meson is fully reconstructed in a hadronic decay mode and require the remainder of the event to consist of only a single $$Lambda$$. No evidence for these decays is found and we set 90% confidence level upper limits on the branching fractions in the range 2.1-3.8 $$times$$ 10$$^{-5}$$. This measurement provides the world's most restrictive limits, with implications for baryogenesis and dark matter production.

論文

TAF-ID: An International thermodynamic database for nuclear fuels applications

Gu$'e$neau, C.*; Dupin, N.*; Kjellqvist, L.*; Geiger, E.*; 倉田 正輝; 他16名*

CALPHAD; Computer Coupling of Phase Diagrams and Thermochemistry, 72, p.102212_1 - 102212_55, 2021/03

https://doi.org/10.1016/j.calphad.2020.102212
 被引用回数：91 パーセンタイル：98.03(Thermodynamics)

OECD/NEAのTAF-IDプロジェクトで開発中の、核燃料の熱力学データベースTAF-IDの開発状況と応用例を報告した。

論文

Observation of the radiative decays of $$Upsilon(1S)$$ to $$chi_{c1}$$

Katrenko, P.*; 谷田 聖; Belle Collaboration*; 他168名*

Physical Review Letters, 124(12), p.122001_1 - 122001_7, 2020/03

https://doi.org/10.1103/PhysRevLett.124.122001
 被引用回数：2 パーセンタイル：15.64(Physics, Multidisciplinary)

We report the first observation of the radiative decay of the $$Upsilon(1S)$$ into a charmonium state. The statistical significance of the observed signal of $$Upsilon(1S) to gamma chi_{c1}$$ is 6.3 standard deviations including systematics. The branching fraction is calculated to be Br($$Upsilon(1S) to gamma chi_{c1}$$) = $$(4.7^{+2.4}_{-1.8} (stat) ^{+0.4}_{-0.5} (sys)) times 10^{-5}$$. We also searched for $$Upsilon(1S)$$ radiative decays into $$chi_{c0,2}$$ and $$eta_c(1S,2S)$$ and set upper limits on their branching fractions. These results are obtained from a 24.9 fb$$^{-1}$$ data sample collected with the Belle detector at the KEKB asymmetric-energy $$e^+e^-$$ collider at a center-of-mass energy equal to the $$Upsilon(2S)$$ mass using $$Upsilon(1S)$$ tagging by the $$Upsilon(2S) to Upsilon(1S) pi^+pi^-$$ transitions.

論文

First measurement of the CKM angle $$phi_3$$ with $$B^{pm}to D(K_{rm S}^0pi^+pi^-pi^0)K^{pm}$$ decays

Resmi, P. K.*; 谷田 聖; Belle Collaboration*; 他166名*

Journal of High Energy Physics (Internet), 2019(10), p.178_1 - 178_27, 2019/10

https://doi.org/10.1007/JHEP10(2019)178
 被引用回数：0 パーセンタイル：0.00(Physics, Particles & Fields)

We present the first model-independent measurement of the CKM unitarity triangle angle $$phi_3$$ using $$B^{pm}to D(K_{rm S}^0pi^+pi^-pi^0)K^{pm}$$ decays, where $$D$$ indicates either a $$D^{0}$$ or $$overline{D}^{0}$$ meson. Measurements of the strong-phase difference of the $$D to K_{rm S}^0pi^+pi^-pi^0$$ amplitude obtained from CLEO-c data are used as input. This analysis is based on the full Belle data set of $$772times 10^{6}$$ $$Boverline{B}$$ events collected at the $$Upsilon(4S)$$ resonance. We obtain $$phi_3 = (5.7~^{+10.2}_{-8.8} pm 3.5 pm 5.7)^{circ}$$ and the suppressed amplitude ratio $$r_{B} = 0.323 pm 0.147 pm 0.023 pm 0.051$$. Here the first uncertainty is statistical, the second is the experimental systematic, and the third is due to the precision of the strong-phase parameters measured from CLEO-c data. The 95% confidence interval on $$phi_3$$ is $$(-29.7,~109.5)^{circ}$$, which is consistent with the current world average.

論文

First measurements of absolute branching fractions of the $$Xi_c^0$$ baryon at Belle

Li, Y. B.*; 谷田 聖; Belle Collaboration*; 他161名*

Physical Review Letters, 122(8), p.082001_1 - 082001_7, 2019/03

AA2019-0537.pdf:0.88MB

https://doi.org/10.1103/PhysRevLett.122.082001
 被引用回数：55 パーセンタイル：89.97(Physics, Multidisciplinary)

We present the first measurements of absolute branching fractions of $$Xi_c^0$$ decays into $$Xi^- pi^+$$, $$Lambda K^- pi^+$$, and $$p K^- K^- pi^+$$ final states. The measurements are made using a data set comprising $$(772pm 11)times 10^{6}$$ $$Bbar{B}$$ pairs collected at the $$Upsilon(4S)$$ resonance with the Belle detector at the KEKB $$e^+e^-$$ collider. We first measure the absolute branching fraction for $$B^- to bar{Lambda}_c^- Xi_c^0$$ using a missing-mass technique, the result is $${cal B}(B^- to bar{Lambda}_c^- Xi_c^0) = [9.51 pm 2.10(rm stat.) pm 0.88(rm syst.)] times 10^{-4}$$. We subsequently measure the product branching fractions $${cal B}(B^- to bar{Lambda}_c^- Xi_c^0){cal B}(Xi_c^0 to Xi^- pi^+)$$, $${cal B}(B^- to bar{Lambda}_c^- Xi_c^0) {cal B}(Xi_c^0 to Lambda K^- pi^+)$$, and $${cal B}(B^- to bar{Lambda}_c^- Xi_c^0) {cal B}(Xi_c^0 to p K^- K^- pi^+)$$ with improved precision. Dividing these product branching fractions by the result for $$B^- to bar{Lambda}_c^- Xi_c^0$$ yields the following branching fractions: $${cal B}(Xi_c^0 to Xi^- pi^+)= [1.80 pm 0.50(rm stat.) pm 0.14(rm syst.)]%$$, $${cal B}(Xi_c^0 to Lambda K^- pi^+)=[1.17 pm 0.37(rm stat.) pm 0.09(rm syst.)]%$$, and $${cal B}(Xi_c^0 to p K^- K^- pi^+)=[0.58 pm 0.23(rm stat.) pm 0.05(rm syst.)]%$$. Our result for $${cal B}(Xi_c^0 to Xi^- pi^+)$$ can be combined with $$Xi_c^0$$ branching fractions measured relative to $$Xi_c^0 to Xi^- pi^+$$ to yield other absolute $$Xi_c^0$$ branching fractions.

論文

Cross section measurements of $$^{155,157}$$Gd(n,$$gamma$$) induced by thermal and epithermal neutrons

Mastromarco, M.*; Manna, A.*; Aberle, O.*; Andrzejewski, J.*; 原田 秀郎; 木村 敦; n_TOF Collaboration*; 他116名*

European Physical Journal A, 55(1), p.9_1 - 9_20, 2019/01

https://doi.org/10.1140/epja/i2019-12692-7
 被引用回数：31 パーセンタイル：89.48(Physics, Nuclear)

Neutron capture cross section measurements on $$^{155}$$Gd and $$^{157}$$Gd were performed using the time-of-flight technique at the n_TOF facility at CERN on isotopically enriched samples. The measurements were carried out in the n TOF experimental area EAR1, at 185m from the neutron source, with an array of 4 C$$_6$$D$$_6$$ liquid scintillation detectors. At a neutron kinetic energy of 0.0253eV, capture cross sections of 62.2(2.2) and 239.8(8.4) kilobarn have been derived for $$^{155}$$Gd and $$^{157}$$Gd, respectively, with up to 6% deviation relative to values presently reported in nuclear data libraries, but consistent with those values within 1.6 standard deviations. A resonance shape analysis has been performed in the resolved resonance region up to 181eV and 307eV, respectively for $$^{155}$$Gd and $$^{157}$$Gd, where on average, resonance parameters have been found in good agreement with evaluations. Above these energies and up to 1keV, the observed resonance-like structure of the cross section has been analysed and characterised. From a statistical analysis of the observed neutron resonances we deduced: neutron strength function of 2.01(28) $$times$$ 10$$^{-4}$$ and 2.17(41) $$times$$ 10$$^{-4}$$; average total radiative width of 106.8(14)meV and 101.1(20)meV and s-wave resonance spacing 1.6(2)eV and 4.8(5)eV for n + $$^{155}$$Gd and n + $$^{157}$$Gd systems, respectively.

論文

Observation of $$Upsilon(4S)to eta' Upsilon(1S)$$

Guido, E.*; 谷田 聖; Belle Collaboration*; 他168名*

Physical Review Letters, 121(6), p.062001_1 - 062001_7, 2018/08

AA2018-0596.pdf:0.37MB

https://doi.org/10.1103/PhysRevLett.121.062001
 被引用回数：11 パーセンタイル：56.03(Physics, Multidisciplinary)

We report the first observation of the hadronic transition $$Upsilon(4S)toeta'Upsilon(1S)$$, using 496 fb$$^{-1}$$ data collected at the $$Upsilon(4S)$$ resonance with the Belle detector at the KEKB asymmetric-energy $$e^{+}e^{-}$$ collider. We reconstruct the $$eta'$$ meson through its decays to $$rho^0gamma$$ and to $$pi^+pi^-eta$$, with $$etatogammagamma$$. We measure: $${cal B}(Upsilon(4S)toeta'Upsilon(1S))=(3.43pm 0.88 {rm(stat.)} pm 0.21 {rm(syst.)})times10^{-5}$$, with a significance of 5.7$$sigma$$.

論文

Measurement of the branching fraction of $$B rightarrow D^{(*)}pi ellnu$$ at Belle using hadronic tagging in fully reconstructed events

Vossen, A.*; 谷田 聖; Belle Collaboration*; 他164名*

Physical Review D, 98(1), p.012005_1 - 012005_9, 2018/07

AA2018-0592.pdf:0.42MB

https://doi.org/10.1103/PhysRevD.98.012005
 被引用回数：5 パーセンタイル：19.05(Astronomy & Astrophysics)

We report a measurement of the branching fraction of the decay $$B rightarrow D^{(*)}pi ellnu$$. The analysis uses 772$$times 10^6$$ $$Bbar{B}$$ pairs produced in $$e^+e^-rightarrow Upsilon(4S)$$ data recorded by the Belle experiment at the KEKB asymmetric-energy $$e^+e^-$$ collider. The tagging $$B$$ meson in the decay is fully reconstructed in a hadronic decay mode. On the signal side, we reconstruct the decay $$B rightarrow D^{(*)}pi ellnu$$ $$(ell=e,mu)$$. The measured branching fractions are $$mathcal{B}(B^+ rightarrow D^-pi^+ ell^+nu)$$ = [4.55 $$pm$$ 0.27 (stat.) $$pm$$ 0.39 (syst.)]$$times 10^{-3}$$, $$mathcal{B}(B^0 rightarrow bar{D}^0pi^- ell^+nu)$$ = [4.05 $$pm$$ 0.36 (stat.) $$pm$$ 0.41 (syst.)]$$times 10^{-3}$$, $$mathcal{B}(B^+ rightarrow D^{*-}pi^+ ell^+nu)$$ = [6.03 $$pm$$ 0.43 (stat.) $$pm$$ 0.38 (syst.)]$$times 10^{-3}$$, and $$mathcal{B}(B^0 rightarrow bar{D}^{*0}pi^- ell^+nu)$$ = [6.46 $$pm$$ 0.53 (stat.) $$pm$$ 0.52 (syst.)]$$times 10^{-3}$$. These are in good agreement with the current world average values.

論文

Production cross sections of hyperons and charmed baryons from $$e^+e^-$$ annihilation near $$sqrt{s} = 10.52$$ GeV

新山 雅之*; 谷田 聖; Belle Collaboration*; 他167名*

Physical Review D, 97(7), p.072005_1 - 072005_21, 2018/04

AA2018-0515.pdf:1.37MB

https://doi.org/10.1103/PhysRevD.97.072005
 被引用回数：30 パーセンタイル：72.87(Astronomy & Astrophysics)

We measure the inclusive production cross sections of hyperons and charmed baryons from $$e^+e^-$$ annihilation using a 800 fb$$^{-1}$$ data sample taken near the $$Upsilon(4S)$$ resonance with the Belle detector at the KEKB asymmetric-energy $$e^+ e^-$$ collider. The feed-down contributions from heavy particles are subtracted using our data, and the direct production cross sections are presented for the first time. The production cross sections divided by the number of spin states for $$S=-1$$ hyperons follow an exponential function with a single slope parameter except for the $$Sigma(1385)^+$$ resonance. Suppression for $$Sigma(1385)^+$$ and $$Xi(1530)^0$$ hyperons is observed. Among the production cross sections of charmed baryons, a factor of three difference for $$Lambda_c^+$$ states over $$Sigma_c$$ states is observed. This observation suggests a diquark structure for these baryons.

論文

Measurement of the $$tau$$ Michel parameters $$bar{eta}$$ and $$xikappa$$ in the radiative leptonic decay $$tau^- rightarrow ell^- nu_{tau} bar{nu}_{ell}gamma$$

清水 信宏*; 谷田 聖; Belle Collaboration*; 他169名*

Progress of Theoretical and Experimental Physics (Internet), 2018(2), p.023C01_1 - 023C01_26, 2018/02

AA2018-0510.pdf:1.89MB

https://doi.org/10.1093/ptep/pty003
 被引用回数：12 パーセンタイル：58.31(Physics, Multidisciplinary)

We present a measurement of the Michel parameters of the $$tau$$ lepton, $$bar{eta}$$ and $$xikappa$$, in the radiative leptonic decay $$tau^- rightarrow ell^- nu_{tau} bar{nu}_{ell} gamma$$ using 711~f$$mathrm{b}^{-1}$$ of collision data collected with the Belle detector at the KEKB $$e^+e^-$$ collider. The Michel parameters are measured in an unbinned maximum likelihood fit to the kinematic distribution of $$e^+e^-rightarrowtau^+tau^-rightarrow (pi^+pi^0 bar{nu}_tau)(ell^-nu_{tau}bar{nu}_{ell}gamma)$$ $$(ell=e$$ or $$mu)$$. The measured values of the Michel parameters are $$bar{eta} = -1.3 pm 1.5 pm 0.8$$ and $$xikappa = 0.5 pm 0.4 pm 0.2$$, where the first error is statistical and the second is systematic. This is the first measurement of these parameters. These results are consistent with the Standard Model predictions within their uncertainties and constrain the coupling constants of the generalized weak interaction.

論文

Invariant-mass and fractional-energy dependence of inclusive production of dihadrons in $$e^+e^-$$ annihilation at $$sqrt{s}=$$ 10.58 GeV

Seidl, R.*; 谷田 聖; Belle Collaboration*; 他161名*

Physical Review D, 96(3), p.032005_1 - 032005_21, 2017/08

AA2017-0511.pdf:8.72MB

https://doi.org/10.1103/PhysRevD.96.032005
 被引用回数：21 パーセンタイル：61.90(Astronomy & Astrophysics)

The inclusive cross sections for dihadrons of charged pions and kaons ($$e^+e^- to hhX$$) in electron-positron annihilation are reported. They are obtained as a function of the total fractional energy and invariant mass for any di-hadron combination in the same hemisphere as defined by the thrust event-shape variable and its axis. Since same-hemisphere dihadrons can be assumed to originate predominantly from the same initial parton, di-hadron fragmentation functions are probed. These di-hadron fragmentation functions are needed as an unpolarized baseline in order to quantitatively understand related spin-dependent measurements in other processes and to apply them to the extraction of quark transversity distribution functions in the nucleon. The di-hadron cross sections are obtained from a 655 fb$$^{-1}$$ data sample collected at or near the $$Upsilon(4S)$$ resonance with the Belle detector at the KEKB asymmetric-energy $$e^+e^-$$ collider.

論文

Observation of an alternative $$chi_{c0}(2P)$$ candidate in $$e^+e^- to J/psi Dbar{D}$$

Chilikin, K.*; 谷田 聖; Belle Collaboration*; 他167名*

Physical Review D, 95(11), p.112003_1 - 112003_17, 2017/06

AA2017-0237.pdf:0.72MB

https://doi.org/10.1103/PhysRevD.95.112003
 被引用回数：65 パーセンタイル：90.77(Astronomy & Astrophysics)

We perform a full amplitude analysis of the process $$e^+e^- to J/psi Dbar{D}$$, where $$D$$ refers to either $$D^+$$ or $$D^0$$. A new charmonium-like state $$X^*(3860)$$ that decays to $$Dbar{D}$$ is observed with a significance of $$6.5sigma$$. Its mass is $$(3862^{+26}_{-32}{}^{+40}_{-13})$$ MeV/$$c^2$$ and width is $$(201^{+154}_{-67}{}^{+88}_{-82})$$ MeV. The $$J^{PC}=0^{++}$$ hypothesis is favored over the $$2^{++}$$ hypothesis at the level of $$2.5sigma$$. The analysis is based on the 980 fb$$^{-1}$$ data sample collected by the Belle detector at the asymmetric-energy $$e^+e^-$$ collider KEKB.

論文

Energy scan of the $$e^+e^- to h_b(nP) pi^+pi^-$$ $$(n=1,2)$$ cross sections and evidence for $$Upsilon(11020)$$ decays into charged bottomoniumlike states

Mizuk, R.*; 谷田 聖; Belle Collaboration*; 他166名*

Physical Review Letters, 117(14), p.142001_1 - 142001_7, 2016/09

AA2016-0386.pdf:0.36MB

https://doi.org/10.1103/PhysRevLett.117.142001
 被引用回数：11 パーセンタイル：56.01(Physics, Multidisciplinary)

Using data collected with the Belle detector at the KEKB asymmetric-energy $$e^+e^-$$ collider, we measure the energy dependence of the $$e^+e^- to h_b(nP) pi^+pi^-$$ $$(n=1,2)$$ cross sections from thresholds up to 11.02 GeV. We find clear $$Upsilon(10860)$$ and $$Upsilon(11020)$$ peaks with little or no continuum contribution. We study the resonant substructure of the $$Upsilon(11020) to h_b(nP) pi^+pi^-$$ transitions and find evidence that they proceed entirely via the intermediate isovector states $$Z_b(10610)$$ and $$Z_b(10650)$$. The relative fraction of these states is loosely constrained by the current data: The hypothesis that only $$Z_b(10610)$$ is produced is excluded at the level of 3.3 standard deviations, while the hypothesis that only $$Z_b(10650)$$ is produced is not excluded at a significant level.

論文

Study of $$D^{**}$$ production and light hadronic states in the $$B^0 to D^{*+} omega pi^-$$ decay

Matvienko, D.*; 谷田 聖; Belle Collaboration*; 他163名*

Physical Review D, 92(1), p.012013_1 - 012013_28, 2015/07

AA2015-0717.pdf:1.1MB

https://doi.org/10.1103/PhysRevD.92.012013
 被引用回数：17 パーセンタイル：53.30(Astronomy & Astrophysics)

We report on the first observations of $$bar{B}^0 to D_1(2430)^0 omega$$, $$bar{B}^0 to D_1(2420)^0 omega$$, and $$bar{B}^0 to D_2^*(2460)^0 omega$$ decays. The $$bar{B}^0 to D^{*+}rho(1450)^-$$ decay is also observed. The branching fraction measurements are based on $$(771.6 pm 10.6) times 10^6$$ $$Bbar{B}$$ events collected at the $$Upsilon(4S)$$ resonance with the Belle detector at the KEKB asymmetric-energy $$e^+e^-$$ collider. The fractions of longitudinal polarization of the $$D^{**}$$ states as well as partial wave fractions of the $$D_1(2430)^0$$ are obtained. We also set a 90% confidence level upper limit for the product of branching fractions of $${cal B}(bar{B}^0 to D^{*+}b_1(1235)^-) times {cal B}(b_1(1235)^- to omega pi^-)$$. The measurements show evidence of nontrivial final-state interaction phases for the $$rho$$-meson-like amplitudes.

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