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論文

Multiharmonic vector rf voltage control for wideband cavities driven by vacuum tube amplifiers in a rapid cycling synchrotron

田村 文彦; 杉山 泰之*; 吉井 正人*; 山本 昌亘; 大森 千広*; 野村 昌弘; 島田 太平; 長谷川 豪志*; 原 圭吾*; 古澤 将司*

Physical Review Accelerators and Beams (Internet), 22(9), p.092001_1 - 092001_22, 2019/09

https://doi.org/10.1103/PhysRevAccelBeams.22.092001

ビーム誘起電流による影響の低減(ビームローディング補償)はJ-PARC 3GeVシンクロトロン(RCS)における大強度ビーム加速に最も重要な課題の一つである。RCSでは広帯域金属磁性体空胴が用いられており、ビームの誘起する電圧は周回周波数の整数倍の成分を含むことから、それら複数の周波数成分(マルチハーモニック)の誘起電圧を抑制するビームローディング補償が必要である。これまではビーム電流の測定から補償信号を生成するRFフィードフォワード法による補償が行われており、マルチハーモニックフィードフォワードシステムは1MWまでのビーム試験においてその役割を果たしてきた。しかしながら、大強度になるにつれて補償性能の低下が確認されていた。そこで、低電力高周波(LLRF)制御システムの更新にあたり、マルチハーモニックベクトル電圧制御によるフィードバック制御を採用することとした。フィードバック制御はゲインの変動についても安定性の範囲内で性能を発揮することが期待される。本論文では、システムの構成、調整方法、大強度ビーム試験の結果について報告する。設計パワーである1MW相当のビーム加速において、ビームローディングはよく補償されている。

論文

Identifying the $$Xi_{b}(6227)$$ and $$Sigma_{b}(6097)$$ as $$P$$-wave bottom baryons of $$J^P = 3/2^-$$

Cui, E.-L.*; Yang, H.-M.*; Chen, H.-X.*; 保坂 淳

Physical Review D, 99(9), p.094021_1 - 094021_15, 2019/05

https://doi.org/10.1103/PhysRevD.99.094021

We use the method of QCD sum rules within the framework of heavy quark effective theory to study the mass spectrum of the $$Sigma_b(6097)^{pm}$$ and $$Xi_b(6227)^-$$, and use the method of light cone sum rules still within the heavy quark effective theory to study their decay properties. Our results suggest that they can be well interpreted as $$P$$-wave bottom baryons with the spin-parity $$J^P=3/2^-$$. They belong to the baryon doublet $$[6_F,2,1,lambda]$$, where the total and spin angular momenta of the light degree of freedom are $$j_l=2$$ and $$s_l=1$$, and the orbital angular momentum is between the bottom quark and the two-light-quark system ($$lambda$$-type). This doublet contains six bottom baryons, and we predict masses (mass differences) and decay widths of the other four states to be $$M_{Omega_b(3/2^-)}=6.46pm 0.12$$ GeV, $$Gamma_{Omega_b(3/2^-)}=58^{+65}_{-33}$$ MeV, $$M_{Sigma_b(5/2^-)}-M_{Sigma_b(3/2^-)}=13pm 5$$ MeV, $$M_{Xi_b(5/2^-)}-M_{Xi_b(3/2^-)}=12pm 5$$ MeV, $$M_{Omega_b(5/2^-)}-M_{Omega_b(3/2^-)}=11pm 5$$ MeV. We propose to search for them in further LHCb experiments.

論文

Nucleon and $$Delta$$ isobar in a strong magnetic field

Yakhshiev, U.*; Kim, H.-C.; 岡 眞

Physical Review D, 99(5), p.054027_1 - 054027_11, 2019/03

https://doi.org/10.1103/PhysRevD.99.054027
 パーセンタイル：100(Astronomy & Astrophysics)

磁場と結合させたカイラルラグランジアンにおけるスカーミオンの性質の変化を調べた。強い磁場のもとでスカーミオンが変形し、質量が増大することが明らかになり、そのメカニズムを考察した。さらにスカーミオンから導かれる核子と$$Delta$$バリオンの性質を調べた。

論文

Further signatures to support the tetraquark mixing framework for the two light-meson nonets

Kim, H.*; Kim, K. S.*; Cheoun, M.-K.*; 慈道 大介*; 岡 眞

Physical Review D, 99(1), p.014005_1 - 014005_15, 2019/01

https://doi.org/10.1103/PhysRevD.99.014005
 パーセンタイル：100(Astronomy & Astrophysics)

前回の論文で指摘した、軽いスカラー中間子8重項のテトラクォーク描像に基づく状態混合について、さらなる証拠となる現象の解析を行った。

論文

Radiative transitions of doubly charmed baryons in lattice QCD

Bartiyar, H.*; Can, K. U.*; Erkol, G.*; 岡 眞; 高橋 徹*

Physical Review D, 98(11), p.114505_1 - 114505_14, 2018/12

https://doi.org/10.1103/PhysRevD.98.114505
 被引用回数：2 パーセンタイル：64.74(Astronomy & Astrophysics)

スピン3/2の2重チャームバリオンからスピン1/2の基底状態への光遷移振幅を格子QCDによる第一原理計算を用いて求めた。

論文

Measurement of the branching fraction and time-dependent $$CP$$ asymmetry for $$B^0to J/psipi^0$$ decays

Pal, B.*; 谷田 聖; Belle Collaboration*; 他158名*

Physical Review D, 98(11), p.112008_1 - 112008_8, 2018/12

https://doi.org/10.1103/PhysRevD.98.112008
 パーセンタイル：100(Astronomy & Astrophysics)

We measure the branching fraction and time-dependent $$CP$$-violating asymmetry for $$B^0to J/psipi^0$$ decays using a data sample of 711 $${rm fb^{-1}}$$ collected on the $$Upsilon(4S)$$ resonance by the Belle experiment running at the KEKB $$e^+e^-$$ collider. The branching fraction is measured to be $$mathcal{B}(B^0to J/psipi^0) = [1.62,pm 0.11~({rm stat}) pm0.07~({rm syst})]times 10^{-5}$$, which is the most precise measurement to date. The measured $$CP$$ asymmetry parameters are $$mathcal{S} = -0.59,pm 0.19~({rm stat}) pm 0.03~({rm syst})$$ and $$mathcal{A} = -0.15,pm 0.14~({rm stat}),^{+0.04}_{-0.03}~({rm syst})$$. The mixing-induced $$CP$$ asymmetry ($$mathcal{S}$$) differs from the case of no $$CP$$ violation by 3.0 standard deviations, and the direct $$CP$$ asymmetry ($$mathcal{A}$$) is consistent with zero.

論文

Measurement of the decays $$Lambda_cto Sigmapipi$$ at Belle

Berger, M.*; 谷田 聖; Belle Collaboration*; 他197名*

Physical Review D, 98(11), p.112006_1 - 112006_10, 2018/12

https://doi.org/10.1103/PhysRevD.98.112006
 被引用回数：2 パーセンタイル：64.74(Astronomy & Astrophysics)

We report measurements of the branching fractions of the decays $$Lambda^+_ctoSigma^+pi^-pi^+$$, $$Lambda^+_ctoSigma^0pi^+pi^0$$ and $$Lambda^+_ctoSigma^+pi^0pi^0$$ relative to the reference channel $$Lambda^+_cto pK^-pi^+$$. The analysis is based on the full data sample collected at and close to $$Upsilon(4S)$$ resonance by the Belle detector at the KEKB asymmetric-energy $$e^+e^-$$ collider corresponding to the integrated luminosity of 711 fb$$^{-1}$$. We measure $${cal B}(Lambda^+_crightarrowSigma^+pi^-pi^+)/{cal B}(Lambda^+_cto pK^-pi^+) = 0.706~pm 0.003~pm 0.029$$, $${cal B}(Lambda^+_crightarrowSigma^0pi^+pi^0)/{cal B}(Lambda^+_cto pK^-pi^+) = 0.491~pm 0.005~pm 0.028$$ and $${cal B}(Lambda^+_crightarrowSigma^+pi^0pi^0)/{cal B}(Lambda^+_cto pK^-pi^+) = 0.198~pm 0.006~pm 0.016$$. The listed uncertainties are statistical and systematic, respectively.

論文

Search for the rare decay of $$B^+ to ell^{,+} nu_{ell} gamma$$ with improved hadronic tagging

Gelb, M.*; 谷田 聖; Belle Collaboration*; 他185名*

Physical Review D, 98(11), p.112016_1 - 112016_13, 2018/12

https://doi.org/10.1103/PhysRevD.98.112016
 パーセンタイル：100(Astronomy & Astrophysics)

We present the result of the search for the rare $$B$$ meson decay of $$B^+ to ell^{,+} nu_{ell} gamma$$ with $$ell =e,mu$$. For the search the full data set recorded by the Belle experiment of $$711 , mathrm{fb}^{-1}$$ integrated luminosity near the $$Upsilon (4S)$$ resonance is used. Signal candidates are reconstructed for photon energies $$E_{gamma}$$ larger than $$1 , mathrm{GeV}$$ using a novel multivariate tagging algorithm. The novel algorithm fully reconstructs the second $$B$$ meson produced in the collision using hadronic modes and was specifically trained to recognize the signal signature in combination with hadronic tag-side $$B$$ meson decays. This approach greatly enhances the performance. Background processes that can mimic this signature, mainly charmless semileptonic decays and continuum processes, are suppressed using multivariate methods. The number of signal candidates is determined by analyzing the missing mass squared distribution as inferred from the signal side particles and the kinematic properties of the tag-side $$B$$ meson. No significant excess over the background-only hypothesis is observed and upper limits on the partial branching fraction $$ Delta mathcal{B} $$ with $$E_{gamma} > 1 , mathrm{GeV}$$ individually for electron and muon final states as well as for the average branching fraction of both lepton final states are reported. We find a Bayesian upper limit of $$Delta mathcal{B}( B^{+} to ell^{, +} nu_{ell} gamma) < 3.0 times 10^{-6}$$ at 90% CL and also report an upper limit on the first inverse moment of the light-cone distribution amplitude of the $$B$$ meson of $$lambda_B$$ at 90% CL.

論文

Measurement of $$phi$$-meson production at forward rapidity in $$p+p$$ collisions at $$sqrt{s}=510$$ GeV and its energy dependence from $$sqrt{s}=200$$ GeV to 7 TeV

Adare, A.*; 長谷川 勝一; 今井 憲一; 永宮 正治*; 佐甲 博之; 佐藤 進; 谷田 聖; PHENIX Collaboration*; 他351名*

Physical Review D, 98(9), p.092006_1 - 092006_13, 2018/11

https://doi.org/10.1103/PhysRevD.98.092006
 パーセンタイル：100(Astronomy & Astrophysics)

The PHENIX experiment at the Relativistic Heavy Ion Collider has measured the differential cross section of $$phi$$(1020) meson production at forward rapidity in $$p$$$$+$$$$p$$ collisions at $$sqrt{s}=$$510 GeV via the dimuon decay channel. The integrated cross section in the rapidity and $$p_T$$ ranges $$1.2 < |y| < 2.2$$ and $$2 < p_T < 7$$ GeV/$$c$$ is $$sigma_phi=2.79 pm 0.20,{rm (stat)} pm 0.17,{rm (syst)} pm 0.34, {rm (norm)} times 10^{-2}$$~mb. The energy dependence of $$sigma_phi$$ ($$1.2 < |y|<2.2$$; $$2<p_T<5$$ GeV/$$c$$) is studied using the PHENIX measurements at $$sqrt{s}=$$200 and 510 GeV and the Large-Hadron-Collider measurements at $$sqrt{s}=$$2.76 and 7 TeV. The experimental results are compared to various event generator predictions (pythia6, pythia8, phojet, ampt, epos3, and epos-lhc).

論文

Measurement of $$cos{2beta}$$ in $$B^{0} to D^{(*)} h^{0}$$ with $$D to K_{S}^{0} pi^{+} pi^{-}$$ decays by a combined time-dependent Dalitz plot analysis of $$B_{A}B_{AR}$$ and Belle data

足立 一郎*; 谷田 聖; Belle Collaboration*; 他406名*

Physical Review D, 98(11), p.112012_1 - 112012_29, 2018/11

https://doi.org/10.1103/PhysRevD.98.112012
 被引用回数：1 パーセンタイル：64.74(Astronomy & Astrophysics)

We report measurements of $$sin{2beta}$$ and $$cos{2beta}$$ from a time-dependent Dalitz plot analysis of $$B^{0} to D^{(*)} h^{0}$$ with $$D to K_{S}^{0} pi^{+} pi^{-}$$ decays, where the light unflavored and neutral hadron $$h^{0}$$ is a $$pi^{0}$$, $$eta$$, or $$omega$$ meson. The analysis is performed with a combination of the final data sets of the BABAR and Belle experiments containing $$471 times 10^{6}$$ and $$772 times 10^{6}$$ $$Bbar{B}$$ pairs collected at the $$Upsilonleft(4Sright)$$ resonance at the asymmetric-energy B factories PEP-II at SLAC and KEKB at KEK, respectively. We measure $$sin{2beta} = 0.80 pm 0.14 ,(rm{stat.}) pm 0.06 ,(rm{syst.}) pm 0.03 ,(rm{model})$$ and $$cos{2beta} = 0.91 pm 0.22 ,(rm{stat.}) pm 0.09 ,(rm{syst.}) pm 0.07 ,(rm{model})$$. The result for the direct measurement of the angle is $$beta = left( 22.5 pm 4.4 ,(rm{stat.}) pm 1.2 ,(rm{syst.}) pm 0.6 ,(rm{model}) right)^{circ}$$. The last quoted uncertainties are due to the composition of the $$D^{0} to K_{S}^{0} pi^{+} pi^{-}$$ decay amplitude model, which is newly established by a Dalitz plot amplitude analysis of a high-statistics $$e^{+}e^{-} to cbar{c}$$ data sample as part of this analysis. We find the first evidence for $$cos2beta>0$$ at the level of $$3.7$$ standard deviations. The measurement excludes the trigonometric multifold solution $$pi/2 - beta = (68.1 pm 0.7)^{circ}$$ at the level of $$7.3$$ standard deviations and therefore resolves an ambiguity in the determination of the apex of the CKM Unitarity Triangle. The hypothesis of $$beta = 0^{circ}$$ is ruled out at the level of $$5.1$$ standard deviations, and thus $$CP$$ violation is observed in $$B^{0} to D^{(*)} h^{0}$$ decays.

論文

Observation of $$e^+e^-topi^+pi^-pi^0chi_{b1,2}(1P)$$ and search for $$e^+e^-tophichi_{b1,2}(1P)$$ at $$sqrt{s}$$ = 10.96 - 11.05 GeV

Yin, J. H.*; 谷田 聖; Belle Collaboration*; 他189名*

Physical Review D, 98(9), p.091102_1 - 091102_9, 2018/11

https://doi.org/10.1103/PhysRevD.98.091102
 パーセンタイル：100(Astronomy & Astrophysics)

We report searches for the processes $$e^+e^-topi^+pi^-pi^0chi_{bJ}$$ and $$e^+e^-tophichi_{bJ}$$ (J=1,2) in the vicinity of the $$Upsilon(11020)$$ resonance using energy scan data collected by the Belle experiment at the KEKB collider. We observe $$e^+e^-to pi^+pi^-pi^0chi_{b1}$$ and find evidence for $$e^+e^-to omegachi_{b2}$$ processes for data with center-of-mass energies from 10.96 to 11.05~GeV for the first time. The statistical significance for $$pi^+pi^-pi^0chi_{b1}$$ and $$omegachi_{b2}$$ are $$6.1sigma$$ and $$4.0sigma$$, respectively. We investigate energy dependence of the $$e^+e^-topi^+pi^-pi^0chi_{bJ}$$ cross section and find that it is consistent with production of $$Upsilon(10860)$$ and $$Upsilon(11020)$$ resonances without significant non-resonant contribution. Assuming $$e^+e^-to pi^+pi^-pi^0chi_{bJ}$$ proceeds via $$Upsilon(10860)$$ and $$Upsilon(11020)$$, the branching fraction $$mathcal{B}(Upsilon(11020)topi^+pi^-pi^0chi_{bJ})=(8.6pm4.1pm6.1^{+4.5}_{-2.5})times10^{-3}$$ is measured for the first time, where the first error is statistical, the second is systematic, and the third from the branching fraction of $$Upsilon(11020)to e^+e^-$$. The signals for $$e^+e^-to phichi_{bJ}$$ are not significant, and the upper limits of the Born cross sections at the 90% confidence level are $$0.6$$ and $$1.0$$~pb for $$e^+e^-to phichi_{b1}$$ and $$phichi_{b2}$$, respectively, for center-of-mass energies from 10.96 to 11.05 GeV.

論文

Observation of $$e^+e^- to gamma chi_{c1}$$ and search for $$e^+e^- to gamma chi_{c0}, gamma chi_{c2}$$, and $$gammaeta_c$$ at $$sqrt{s}$$ near 10.6 GeV at Belle

Jia, S.*; 谷田 聖; Belle Collaboration*; 他191名*

Physical Review D, 98(9), p.092015_1 - 092015_8, 2018/11

https://doi.org/10.1103/PhysRevD.98.092015
 パーセンタイル：100(Astronomy & Astrophysics)

Using data samples of 89.5~fb$$^{-1}$$, 711.0~fb$$^{-1}$$, and 121.4~fb$$^{-1}$$ collected with the Belle detector at the KEKB asymmetric-energy $$e^+e^-$$ collider at center-of-mass energies 10.52 GeV, 10.58 GeV, and 10.867 GeV, respectively, we study the exclusive reactions $$e^+e^-togammachi_{cJ}$$ ($$J = 0,~1,~2$$) and $$e^+e^-togammaeta_c$$. A significant $$gamma chi_{c1}$$ signal is observed for the first time at $$sqrt{s}=10.58$$ GeV with a significance of $$5.1sigma$$ including systematic uncertainties. No significant excesses for $$gamma chi_{c0}$$, $$gamma chi_{c2}$$, and $$gamma eta_c$$ final states are found, and we set 90% credibility level upper limits on the Born cross sections ($$sigma_{rm B}$$) at 10.52 GeV, 10.58 GeV, and 10.867~GeV. Together with cross sections measured by BESIII at lower center-of-mass energies, the energy dependency of $$sigma_{rm B}(e^+e^-togammachi_{c1})$$ is obtained.

論文

Search for the lepton-flavor-violating decay $$B^{0}to K^{ast 0} mu^{pm} e^{mp}$$

Sandilya, S.*; 谷田 聖; Belle Collaboration*; 他211名*

Physical Review D, 98(7), p.071101_1 - 071101_8, 2018/10

https://doi.org/10.1103/PhysRevD.98.071101
 被引用回数：1 パーセンタイル：64.74(Astronomy & Astrophysics)

We have searched for the lepton-flavor-violating decay $$B^{0}to K^{ast 0} mu^{pm} e^{mp}$$ using a data sample of 711 fb$$^{-1}$$ that contains $$772 times 10^{6}$$ $$Bbar{B}$$ pairs. The data were collected near the $$Upsilon (4S)$$ resonance with the Belle detector at the KEKB asymmetric-energy $$e^{+}e^{-}$$ collider. No signals were observed, and we set 90% confidence level upper limits on the branching fractions of $${cal B}(B^{0}to K^{ast 0} mu^{+} e^{-}) < 1.2times 10^{-7}$$, $${cal B}(B^{0}to K^{ast 0} mu^{-} e^{+}) < 1.6times 10^{-7}$$, and, for both decays combined, $${cal B}(B^{0}to K^{ast 0} mu^{pm} e^{mp}) < 1.8times 10^{-7}$$. These are the most stringent limits on these decays to date.

論文

Measurement of $$eta_c(1S)$$, $$eta_c(2S)$$, and nonresonant $$eta' pi^+ pi^-$$ production via two-photon collisions

Xu, Q. N.*; 谷田 聖; Belle Collaboration*; 他176名*

Physical Review D, 98(7), p.072001_1 - 072001_17, 2018/10

https://doi.org/10.1103/PhysRevD.98.072001
 パーセンタイル：100(Astronomy & Astrophysics)

We report the measurement of $$gamma gamma to eta_c(1S)$$, $$eta_c(2S) to eta' pi^+ pi^-$$ with $$eta'$$ decays to $$gamma rho$$ and $$eta pi^+ pi^-$$ using 941 fb$$^{-1}$$ of data collected with the Belle detector at the KEKB asymmetric-energy $$e^+e^-$$ collider. The $$eta_c(1S)$$ mass and width are measured to be $$M = [2984.6pm0.7 (stat.)pm2.2 (syst.)]$$ MeV/$$c^{2}$$ and $$Gamma = [30.8^{+2.3}_{-2.2}~(stat.) pm 2.5~(syst.)]$$ MeV, respectively. First observation of $$eta_c(2S) to eta' pi^+ pi^-$$ with a significance of $$5.5sigma$$ including systematic error is obtained, and the $$eta_c(2S)$$ mass is measured to be $$M = [3635.1pm3.7~(stat.)pm2.9~(syst.)]$$ MeV/$$c^{2}$$. The products of the two-photon decay width and branching fraction $$(B)$$ of decays to $$eta'pi^+ pi^-$$ are determined to be $$Gamma_{gamma gamma}B = [65.4pm2.6~(stat.)pm6.9~(syst.)]$$ eV for $$eta_c(1S)$$ and $$[5.6^{+1.2}_{-1.1}~(stat.)pm1.1~(syst.)]$$ eV for $$eta_c(2S)$$. A new decay mode for the $$eta_c(1S)$$ to $$eta'f_0(2080)$$ with $$f_0(2080) to pi^+ pi^-$$ is observed with a statistical significance of $$20sigma$$. The $$f_0(2080)$$ mass and width are determined to be $$M = [2083^{+63}_{-66}~(stat.)pm 32~(syst.)]$$ MeV/$$c^{2}$$ and $$Gamma = [178^{+60}_{-178}~(stat.) pm 55~(syst.)]$$ MeV. The cross sections for $$gamma gamma to eta' pi^+ pi^-$$ and $$eta'f_{2}(1270)$$ are measured for the first time.

論文

Nonperturbative transverse-momentum-dependent effects in dihadron and direct photon-hadron angular correlations in $$p+p$$ collisions at $$sqrt{s}=200$$ GeV

Aidala, C.*; 長谷川 勝一; 今井 憲一; 佐甲 博之; 佐藤 進; 谷田 聖; PHENIX Collaboration*; 他287名*

Physical Review D, 98(7), p.072004_1 - 072004_13, 2018/10

https://doi.org/10.1103/PhysRevD.98.072004
 被引用回数：1 パーセンタイル：64.74(Astronomy & Astrophysics)

Dihadron and isolated direct photon-hadron angular correlations are measured in $$p$$$$+$$$$p$$ collisions at $$sqrt{s}=200$$ GeV. The correlations are sensitive to nonperturbative initial-state and final-state transverse momentum $$k_T$$ and $$j_T$$ in the azimuthal nearly back-to-back region $$Deltaphisimpi$$. In this region, transverse-momentum-dependent evolution can be studied when several different hard scales are measured. To have sensitivity to small transverse momentum scales, nonperturbative momentum widths of $$p_{rm out}$$, the out-of-plane transverse momentum component perpendicular to the trigger particle, are measured. These widths are used to investigate possible effects from transverse-momentum-dependent factorization breaking. When accounting for the longitudinal momentum fraction of the away-side hadron with respect to the near-side trigger particle, the widths are found to increase with the hard scale; this is qualitatively similar to the observed behavior in Drell-Yan and semi-inclusive deep-inelastic scattering interactions. The momentum widths are also studied as a function of center-of-mass energy by comparing to previous measurements at $$sqrt{s}=510$$ GeV. The nonperturbative jet widths also appear to increase with $$sqrt{s}$$ at a similar $$x_T$$, which is qualitatively consistent to similar measurements in Drell-Yan interactions.

論文

Cross section and longitudinal single-spin asymmetry $$A_L$$ for forward $$W^{pm}rightarrowmu^{pm}nu$$ production in polarized $$p$$$$+$$$$p$$ collisions at $$sqrt{s}=510$$ GeV

Adare, A.*; 長谷川 勝一; 今井 憲一; 永宮 正治; 佐甲 博之; 佐藤 進; 谷田 聖; PHENIX Collaboration*; 他423名*

Physical Review D, 98(3), p.032007_1 - 032007_14, 2018/08

https://doi.org/10.1103/PhysRevD.98.032007

We have measured the cross section and single spin asymmetries from forward $$W^{pm}rightarrowmu^{pm}nu$$ production in longitudinally polarized $$p$$$$+$$$$p$$ collisions at $$sqrt{s}=510$$ GeV using the PHENIX detector at the Relativistic Heavy Ion Collider. The cross sections are consistent with previous measurements at this collision energy, while the most forward and backward longitudinal single spin asymmetries provide new insights into the sea quark helicities in the proton. The charge of the $$W$$ bosons provides a natural flavor separation of the participating partons.

論文

Single-spin asymmetry of $$J/psi$$ production in $$p$$$$+$$$$p$$, $$p$$$$+$$Al, and $$p$$$$+$$Au collisions with transversely polarized proton beams at $$sqrt{s_{_{NN}}}=200$$ GeV

Aidala, C.*; 長谷川 勝一; 今井 憲一; 佐甲 博之; 佐藤 進; 谷田 聖; PHENIX Collaboration*; 他286名*

Physical Review D, 98(1), p.012006_1 - 012006_11, 2018/07

https://doi.org/10.1103/PhysRevD.98.012006
 被引用回数：2 パーセンタイル：44.38(Astronomy & Astrophysics)

We report the transverse single-spin asymmetries of $$J/psi$$ production at forward and backward rapidity, $$1.2<|y|<2.2$$, as a function of $$J/psi$$ transverse momentum ($$p_T$$) and Feynman-$$x$$ ($$x_F$$). The data analyzed were recorded by the PHENIX experiment at the Relativistic Heavy Ion Collider in 2015 from $$p$$$$+$$$$p$$, $$p$$$$+$$Al, and $$p$$$$+$$Au collisions with transversely polarized proton beams at $$sqrt{s_{_{NN}}}=200$$ GeV. At this collision energy, single-spin asymmetries for heavy-flavor particle production of $$p$$$$+$$$$p$$ collisions provide access to the spin-dependent gluon distribution and higher-twist correlation functions inside the nucleon, such as the gluon Qiu-Sterman and trigluon correlation functions. Proton + nucleus collisions offer an excellent opportunity to study nuclear effects on the correlation functions. The data indicate negative asymmetries at the two-standard-deviation level in the $$p$$$$+$$Au data for $$p_T<2$$ GeV/$$c$$ at both forward and backward rapidity, while in $$p$$$$+$$$$p$$ and $$p$$$$+$$Al collisions the asymmetries are consistent with zero within the range of experimental uncertainties.

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

https://doi.org/10.1103/PhysRevD.98.012005
 パーセンタイル：100(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

Nonperturbative evaluation for anomalous dimension in 2-dimensional $$O$$(3) sigma model

Jimmenez, S.*; 岡 眞; 佐々木 潔*

Physical Review D, 97(11), p.114506_1 - 114506_28, 2018/06

https://doi.org/10.1103/PhysRevD.97.114506
 パーセンタイル：100(Astronomy & Astrophysics)

2次元$$O$$(3)シグマ模型における異常次元を有限体積中で非摂動的に計算し、摂動的な計算結果と比較検討した。

論文

Search for $$Upsilon(1S,2S) to Z^{+}_{c}Z^{(prime) -}_{c}$$ and $$e^{+}e^{-} to Z^{+}_{c}Z^{(prime) -}_{c}$$ at $$sqrt{s}$$ = 10.52, 10.58, and 10.867 GeV

Jia, S.*; 谷田 聖; Belle Collaboration*; 他181名*

Physical Review D, 97(11), p.112004_1 - 112004_16, 2018/06

https://doi.org/10.1103/PhysRevD.97.112004
 パーセンタイル：100(Astronomy & Astrophysics)

The first search for $$Z_{c}$$ pair production in $$Upsilon(1S)$$ and $$Upsilon(2S)$$ decays and in $$e^{+}e^{-}$$ annihilation at $$sqrt{s}$$ = 10.52, 10.58, and 10.867 GeV is conducted using data collected with the Belle detector at the KEKB asymmetric energy electron-positron collider. No significant signals are observed in any of the studied modes, and the 90% credibility level upper limits on their product branching fractions in $$Upsilon(1S)$$ and $$Upsilon(2S)$$ decays ($${cal B}(Upsilon(1S,2S)to Z^{+}_{c}Z^{(prime) -}_{c})times{cal B}(Z^{+}_{c}topi^{+}+cbar c)$$ ($$cbar c=J/psi$$, $$chi_{c1}(1P)$$, $$psi(2S)$$)) and the product of Born cross section and branching fraction for $$e^{+}e^{-} to Z^{+}_{c}Z^{(prime) -}_{c}$$ ($$sigma(e^+e^- to Z^{+}_{c}Z^{(prime) -}_{c})times {cal B}(Z^{+}_{c} to pi^+ +cbar c)$$) at $$sqrt{s}$$ = 10.52, 10.58, and 10.867 GeV are determined. Here, $$Z_{c}$$ refers to the $$Z_{c}(3900)$$ and $$Z_{c}(4200)$$ observed in the $$pi J/psi$$ final state, the $$Z_{c1}(4050)$$ and $$Z_{c2}(4250)$$ in the $$pichi_{c1}(1P)$$ state, and the $$Z_{c}(4050)$$ and $$Z_{c}(4430)$$ in the $$pipsi(2S)$$ state.

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