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Gaps in topological magnon spectra; Intrinsic versus extrinsic effects

Do, S.-H.*; Paddison, J. A. M.*; Sala, G.*; Williams, T. J.*; 金子 耕士; 桑原 慶太郎*; May, A. F.*; Yan, J.*; McGuire, M. A.*; Stone, M. B.*; et al.

Physical Review Letters, 106(6), p.L060408_1 - L060408_6, 2022/08

 被引用回数:1 パーセンタイル:65.64(Materials Science, Multidisciplinary)

For topological magnon spectra, determining and explaining the presence or absence of a gap at a magnon crossing point is a central issue. An inelastic neutron scattering study of a single crystals is a powerful experimental technique to investigate the spin dynamics and hence is widely employed to probe the the magnetic excitation spectra of topological materials. However, when the neutron intensity rapidly disperses, such as near a crossing point for a Dirac magnon, the apparent spectrum is extremely sensitive to experimental conditions including sample mosaic, resolution, and integration range. Here we study a gapless Dirac magnon candidate CrCl$$_{3}$$ to show how the quantification of a gapless or gaped spectrum at the Dirac point is extremely sensitive to the integration range of data. Our work calls for a careful examination of reports of gaps in inelastic neutron scattering spectra to ensure that topological gaps are not misdiagnosed or overestimated due to experimental factors.


Electric monopole transition from the superdeformed band in $$^{40}$$Ca

井手口 栄治*; Kib$'e$di, T.*; Dowie, J. T. H.*; Hoang, T. H.*; Kumar Raju, M.*; 青井 考*; Mitchell, A. J.*; Stuchbery, A. E.*; 清水 則孝*; 宇都野 穣; et al.

Physical Review Letters, 128(25), p.252501_1 - 252501_6, 2022/06

 被引用回数:1 パーセンタイル:68.58(Physics, Multidisciplinary)



Theory of Emergent Inductance with Spin-Orbit Coupling Effects

山根 結太*; 深見 俊輔*; 家田 淳一

Physical Review Letters, 128(14), p.147201_1 - 147201_6, 2022/04

 被引用回数:0 パーセンタイル:0(Physics, Multidisciplinary)



Novel coupled channel framework connecting the quark model and lattice QCD for the near-threshold $$D_s$$ states

Yang, Z.*; Wang, G.-J.*; Wu, J.-J.*; 岡 眞; Zhu, S.-L.*

Physical Review Letters, 128(11), p.112001_1 - 112001_6, 2022/03

 被引用回数:1 パーセンタイル:68.58(Physics, Multidisciplinary)



Measurements of strong-interaction effects in kaonic-helium isotopes at sub-eV precision with X-ray microcalorimeters

橋本 直; 谷田 聖; 他68名*

Physical Review Letters, 128(11), p.112503_1 - 112503_6, 2022/03

 被引用回数:0 パーセンタイル:0(Physics, Multidisciplinary)

We have measured the $$3d to 2p$$ transition X-rays of kaonic $$^3$$He and $$^4$$He atoms using superconducting transition-edge-sensor microcalorimeters with an energy resolution better than 6 eV (FWHM). We determined the energies to be $$6224.5 pm 0.4$$ (stat) $$pm 0.2$$ (syst) eV and $$6463.7pm 0.3$$ (stat) $$pm 0.1$$ (syst) eV, and widths to be $$2.5pm 1.0$$ (stat) $$pm 0.4$$ (syst) eV and $$1.0 pm 0.6$$ (stat) $$pm 0.3$$ (stat) eV, for kaonic $$^3$$He and $$^4$$He, respectively. These values are nearly 10 times more precise than in previous measurements. Our results exclude the large strong-interaction shifts and widths that are suggested by a coupled-channel approach, and agree with calculations based on optical-potential models.


Intrinsic torques emerging from anomalous velocity in magnetic textures

荒木 康史; 家田 淳一

Physical Review Letters, 127(21), p.277205_1 - 277205_7, 2021/12

 被引用回数:1 パーセンタイル:30.66(Physics, Multidisciplinary)



Measurement of differential branching fractions of inclusive $${B to X_u , ell^+, nu_{ell}}$$ decays

Cao, L.*; 谷田 聖; Belle Collaboration*; 他199名*

Physical Review Letters, 127(26), p.261801_1 - 261801_8, 2021/12

 被引用回数:0 パーセンタイル:0(Physics, Multidisciplinary)

The first measurements of differential branching fractions of inclusive semileptonic $${B to X_u , ell^+, nu_{ell}}$$ decays are performed using the full Belle data set of 711 fb$$^{-1}$$ of integrated luminosity at the $$Upsilon(4S)$$ resonance and for $$ell = e, mu$$. Differential branching fractions are reported as a function of the lepton momentum, the four-momentum-transfer squared, light-cone momenta, the hadronic mass, and the hadronic mass squared. They are obtained by subtracting the backgrounds from semileptonic $${B to X_c , ell^+, nu_{ell}}$$ decays and other processes, and corrected for resolution and acceptance effects. The measured distributions are compared to predictions from inclusive and hybrid $${B to X_u , ell^+, nu_{ell}}$$ calculations.


Hybridization of Bogoliubov quasiparticles between adjacent CuO$$_2$$ layers in the triple-layer cuprate Bi$$_2$$Sr$$_2$$Ca$$_2$$Cu$$_3$$O$$_{10+delta}$$ studied by angle-resolved photoemission spectroscopy

出田 真一郎*; Johnston, S.*; 吉田 鉄平*; 田中 清尚*; 森 道康; 安齋 太陽*; 井野 明洋*; 有田 将司*; 生天目 博文*; 谷口 雅樹*; et al.

Physical Review Letters, 127(21), p.217004_1 - 217004_6, 2021/11

 被引用回数:0 パーセンタイル:0(Physics, Multidisciplinary)

Hybridization of Bogoliubov quasiparticles (BQPs) between the CuO$$_2$$ layers in the triple-layer cuprate high-temperature superconductor Bi$$_2$$Sr$$_2$$Ca$$_2$$Cu$$_3$$O$$_{10+delta}$$ is studied by angle-resolved photoemission spectroscopy (ARPES). In the superconducting state, an anti-crossing gap opens between the outer- and inner-BQP bands, which we attribute primarily to interlayer single-particle hopping with possible contributions from interlayer Cooper pairing. We find that the $$d$$-wave superconducting gap of both BQP bands smoothly develops with momentum without abrupt jump in contrast to a previous ARPES study. Hybridization between the BQPs also gradually increases in going from the off-nodal to the anti-nodal region, which is explained by the momentum-dependence of the interlayer single-particle hopping. As possible mechanisms for the enhancement of the superconducting transition temperature, the hybridization between the BQPs, as well as the combination of phonon modes of the triple CuO$$_2$$ layers and spin fluctuations are discussed.


Precise measurement of the $$D^0$$ and $$D^+$$ lifetimes at Belle II

Abudin$'e$n, F.*; 谷田 聖; Belle II Collaboration*; 他385名*

Physical Review Letters, 127(21), p.211801_1 - 211801_9, 2021/11

 被引用回数:0 パーセンタイル:0(Physics, Multidisciplinary)

We report a measurement of the $$D^0$$ and $$D^+$$ lifetimes using $$D^0to K^-pi^+$$ and $$D^+to K^-pi^+pi^+$$ decays reconstructed in $$e^+e^-to cbar{c}$$ data recorded by the Belle II experiment at the SuperKEKB asymmetric-energy $$e^+e^-$$ collider. The data, collected at center-of-mass energies at or near the $$Upsilon(4S)$$ resonance, correspond to an integrated luminosity of $$72,{rm fb}^{-1}$$. The results, $$tau(D^0) = 410.5pm1.1,{rm(stat)}pm0.8,{rm(syst.)},{rm fs}$$ and $$tau(D^+) = 1030.4pm4.7,{rm(stat)}pm3.1,{rm(syst.)},{rm fs}$$, are the most precise to date and are consistent with previous determinations.


Large shape staggering in neutron-deficient Bi isotopes

Barzakh, A.*; Andreyev, A. N.; Raison, C.*; Cubiss, J. G.*; 他53名*

Physical Review Letters, 127(19), p.192501_1 - 192501_7, 2021/11

 被引用回数:5 パーセンタイル:75.62(Physics, Multidisciplinary)

The changes in the mean-square charge radius (relative to $$^{209}$$Bi, magnetic moments and quadrupole moments of the neutron-deficient bismuth isotopes $$^{187,188,189,190}$$Bi were measured at ISOLDE (CERN). In the experiment, the in-source resonance-ionization spectroscopy technique was employed, which permits to study isotopes produced with rates as low as 0.1/sec. The radii of $$^{187.188.189}$$Bi manifest a large staggering, corresponding to a sudden increase of the radius of $$^{188}$$Bi relative to its $$^{187,189}$$Bi neighbors. This staggering effect occurs at neutron number $$N$$=105, where shape staggering was also observed in the mercury isotopes. Experimental results were compared with state-of-the-art mean-field calculations, which permit to identify the quasiparticle configurations compatible with the observed spin, parity and magnetic moment of the newly observed states.


Solving the puzzles of the decay of the heaviest known proton-emitting nucleus $$^{185}$$Bi

Doherty, D. T.*; Andreyev, A. N.; Seweryniak, D.*; Woods, P. J.*; Carpenter, M. P.*; Auranen, K.*; Ayangeakaa, A. D.*; Back, B. B.*; Bottoni, S.*; Canete, L.*; et al.

Physical Review Letters, 127(20), p.202501_1 - 202501_6, 2021/11

 被引用回数:4 パーセンタイル:69.65(Physics, Multidisciplinary)

$$^{185}$$Bi is the heaviest known proton emitting isotope. Its decay had been observed, but the assumed ground-state lifetime ($$sim$$$$60~mu$$s) was incorrect, leading to unexplained hindrance. With two new experiments at Argonne National Laboratory, two states were clearly identified. One is the proton-emitting ground-state (spin 1/2$$^+$$, half-life: 2.8$$^{+2.3}_{-1.0}$$ $$mu$$s), the second is a 58(2) $$mu$$s $$gamma$$-decaying isomer. The new data show the inversion of the ground and isomeric states compared to neighboring Bi isotopes. This is the only known example of a ground-state proton decay to a daughter nucleus ($$^{184}$$Pb) with a major shell closure.


Probing gluon spin-momentum correlations in transversely polarized protons through midrapidity isolated direct photons in $$p^uparrow+p$$ collisions at $$sqrt{s}$$=200 GeV

Acharya, U. A.*; 長谷川 勝一; 今井 憲一*; 佐甲 博之; 佐藤 進; 谷田 聖; PHENIX Collaboration*; 他306名*

Physical Review Letters, 127(16), p.162001_1 - 162001_8, 2021/10

 被引用回数:1 パーセンタイル:30.66(Physics, Multidisciplinary)

Studying spin-momentum correlations in hadronic collisions offers a glimpse into a three-dimensional picture of proton structure. The transverse single-spin asymmetry for midrapidity isolated direct photons in $$p^uparrow+p$$ collisions at $$sqrt{s}$$=200 GeV is measured with the PHENIX detector at the Relativistic Heavy Ion Collider (RHIC). Because direct photons in particular are produced from the hard scattering and do not interact via the strong force, this measurement is a clean probe of initial-state spin-momentum correlations inside the proton and is in particular sensitive to gluon interference effects within the proton. This is the first time direct photons have been used as a probe of spin-momentum correlations at RHIC. The uncertainties on the results are a fifty-fold improvement with respect to those of the one prior measurement for the same observable, from the Fermilab E704 experiment. These results constrain gluon spin-momentum correlations in transversely polarized protons.


Measurements of the branching fractions of the semileptonic decays $$Xi_{c}^{0} to Xi^{-} ell^{+} nu_{ell}$$ and the asymmetry parameter of $$Xi_{c}^{0} to Xi^{-} pi^{+}$$

Li, Y. B.*; 谷田 聖; Belle Collaboration*; 他182名*

Physical Review Letters, 127(12), p.121803_1 - 121803_8, 2021/09

 被引用回数:11 パーセンタイル:87.76(Physics, Multidisciplinary)

Using data samples of 89.5 and 711 fb$$^{-1}$$ recorded at energies of $$sqrt{s}=10.52$$ and $$10.58$$ GeV, respectively, with the Belle detector at the KEKB $$e^+e^-$$ collider, we report measurements of branching fractions of semileptonic decays $$Xi_{c}^{0} to Xi^{-} ell^{+} nu_{ell}$$ ($$ell=e$$ or $$mu$$) and the $$CP$$-asymmetry parameter of $$Xi_{c}^{0} to Xi^{-} pi^{+}$$ decay. The branching fractions are measured to be $${cal B}(Xi_{c}^{0} to Xi^{-} e^{+} nu_{e}$$)=($$1.31 pm 0.04 pm 0.07 pm 0.38$$)% and $${cal B}(Xi_{c}^{0} to Xi^{-} mu^{+} nu_{mu}$$)=($$1.27 pm 0.06 pm 0.10 pm 0.37$$)%, and the decay parameter $$alpha_{Xipi}$$ is measured to be $$0.63 pm 0.03 pm 0.01$$ with much improved precision compared to the current world average. The corresponding ratio $${cal B}(Xi_{c}^{0} to Xi^{-} e^{+} nu_{e})$$/$${cal B}(Xi_{c}^{0} to Xi^{-} mu^{+} nu_{mu})$$ is 1.03 $$pm$$ 0.05 $$pm$$ 0.07, which is consistent with the expectation of lepton flavor universality. The first measured asymmetry parameter $${cal A}_{CP} = (alpha_{Xi^{-}pi^{+}} + alpha_{bar{Xi}^{+}pi^{-}})/(alpha_{Xi^{-}pi^{+}} - alpha_{bar{Xi}^{+}pi^{-}}) = 0.024 pm 0.052 pm 0.014$$ is found to be consistent with zero. The first and the second uncertainties above are statistical and systematic, respectively, while the third ones arise due to the uncertainty of the $$Xi_{c}^{0} to Xi^{-} pi^+$$ branching fraction.


Deexcitation dynamics of muonic atoms revealed by high-precision spectroscopy of electronic $$K$$ X rays

奥村 拓馬*; 東 俊行*; Bennet, D. A.*; Caradonna, P.*; Chiu, I. H.*; Doriese, W. B.*; Durkin, M. S.*; Fowler, J. W.*; Gard, J. D.*; 橋本 直; et al.

Physical Review Letters, 127(5), p.053001_1 - 053001_7, 2021/07

 被引用回数:2 パーセンタイル:49.19(Physics, Multidisciplinary)



Pairing forces govern population of doubly magic $$^{54}$$Ca from direct reactions

Browne, F.*; Chen, S.*; Doornenbal, P.*; Obertelli, A.*; 緒方 一介*; 宇都野 穣; 吉田 数貴; Achouri, N. L.*; 馬場 秀忠*; Calvet, D.*; et al.

Physical Review Letters, 126(25), p.252501_1 - 252501_7, 2021/06

 被引用回数:1 パーセンタイル:30.66(Physics, Multidisciplinary)



Experimental evidence for common driving effects in low-energy fission from sublead to actinides

Schmitt, C.*; Lemasson, A.*; Schmidt, K.-H.*; Jhingan, A.*; Biswas, S.*; Kim, Y. H.*; Ramos, D.*; Andreyev, A. N.; Curien, D.*; Ciemala, M.*; et al.

Physical Review Letters, 126(13), p.132502_1 - 132502_6, 2021/04

 被引用回数:6 パーセンタイル:79.85(Physics, Multidisciplinary)

Isotopic distributions of fragments from fission of the neutron-deficient $$^{178}$$Hg nuclide are reported. This experimental observable is obtained for the first time in the region around lead using an innovative approach based on inverse kinematics and the coincidence between the large acceptance magnetic spectrometer VAMOS++ and a new detection arm close to the target. The average fragment $$N/Z$$ ratio and prompt neutron $$Mn$$ multiplicity are derived and compared with current knowledge from actinide fission. A striking consistency emerges, revealing the unexpected dominant role of the proton subsystem with atomic number between the $$Z$$ = 28 and 50 magic numbers. The origin of nuclear charge polarization in fission and fragment deformation at scission are discussed.


New $$alpha$$-emitting isotope $$^{214}$$U and abnormal enhancement of $$alpha$$-particle clustering in lightest uranium isotopes

Zhang, Z. Y.*; Yang, H. B.*; Andreyev, A. N.; Liu, M. L.*; Ma, L.*; 他37名*

Physical Review Letters, 126(15), p.152502_1 - 152502_6, 2021/04

 被引用回数:22 パーセンタイル:96.76(Physics, Multidisciplinary)

A new $$alpha$$-emitting isotope $$^{214}$$U, produced by the fusion-evaporation reaction $$^{182}$$W($$^{36}$$Ar,4n)$$^{214}$$U, was identified by employing the gas-filled recoil separator SHANS and the recoil-$$alpha$$ correlation technique. More precise $$alpha$$-decay properties of even-even nuclei $$^{216,218}$$U were also measured in the reactions of $$^{40}$$Ar, $$^{40}$$Ca beams with $$^{180,182,184}$$W targets. By combining the experimental data, improved $$alpha$$-decay reduced widths $$delta$$$$^{2}$$ for the even-even Po-Pu nuclei in the vicinity of the magic neutron number ${it N}$ = 126 are deduced. Their systematic trends are discussed in terms of the ${it N}$ $$_{it p}$$ ${it N}$ $$_{it n}$$ scheme in order to study the influence of proton-neutron interaction on $$alpha$$ decay in this region of nuclei. It is strikingly found that the reduced widths of $$^{214,216}$$U are significantly enhanced by a factor of two as compared with the ${it N}$ $$_{it p}$$ ${it N}$ $$_{it n}$$ systematics for the 84 $$leq$$ ${it Z}$ $$leq$$ 90 and ${it N}$ $$<$$ 126 even-even nuclei. The abnormal enhancement is interpreted by the strong monopole interaction between the valence protons and neutrons occupying the $$pi$$1${it f}$ $$_{7/2}$$ and $$nu$$1${it f}$ $$_{5/2}$$ spin-orbit partner orbits, which is supported by the large-scale shell model calculation.


Test of lepton-flavor universality in $${Bto K^astell^+ell^-}$$ decays at Belle

Wehle, S.*; 谷田 聖; Belle Collaboration*; 他179名*

Physical Review Letters, 126(16), p.161801_1 - 161801_8, 2021/04

 被引用回数:7 パーセンタイル:83.09(Physics, Multidisciplinary)

We present a measurement of $$R_{K^{ast}}$$, the branching fraction ratio $${{cal B}(Bto K^ast mu^+ mu^-)}$$/ $${{cal B}(Bto K^ast e^+ e^-)}$$, for both charged and neutral $$B$$ mesons. The ratio for the charged case, $$R_{K{^{ast +}}}$$, is the first measurement ever performed. In addition, we report absolute branching fractions for the individual modes in bins of the squared dilepton invariant mass, $$q^2$$. The analysis is based on a data sample of $$711~mathrm{fb}^{-1}$$, containing $$772times 10^{6}$$ $$Bbar B$$ events, recorded at the $$Upsilon(4S)$$ resonance with the Belle detector at the KEKB asymmetric-energy $$e^+e^-$$ collider. The obtained results are consistent with Standard Model expectations.


Chirality memory stored in magnetic domain walls in the ferromagnetic state of MnP

Jiang, N.*; 新居 陽一*; 有沢 洋希*; 齊藤 英治; 大江 純一郎*; 小野瀬 佳文*

Physical Review Letters, 126(17), p.177205_1 - 177205_5, 2021/04

 被引用回数:2 パーセンタイル:49.19(Physics, Multidisciplinary)

Chirality in a helimagnetic structure is determined by the sense of magnetic moment rotation. We found that the chiral information did not disappear even after the phase transition to the high-temperature ferromagnetic phase in a helimagnet MnP. The 2nd harmonic resistivity $$rho^{2mathrm{f}}$$, which reflects the breaking down of mirror symmetry, was found to be almost unchanged after heating the sample above the ferromagnetic transition temperature and cooling it back to the helimagnetic state. The application of a magnetic field along the easy axis in the ferromagnetic state quenched the chirality-induced $$rho^{2mathrm{f}}$$. This indicates that the chirality memory effect originated from the ferromagnetic domain walls.


Quasifree neutron knockout reaction reveals a small $$s$$-Orbital component in the Borromean nucleus $$^{17}$$B

Yang, Z. H.*; 久保田 悠樹*; Corsi, A.*; 吉田 数貴; Sun, X.-X.*; Li, J. G.*; 木村 真明*; Michel, N.*; 緒方 一介*; Yuan, C. X.*; et al.

Physical Review Letters, 126(8), p.082501_1 - 082501_8, 2021/02


 被引用回数:23 パーセンタイル:96.99(Physics, Multidisciplinary)

ボロミアン核であり中性子ハロー構造が期待される$$^{17}$$Bに対する($$p$$,$$pn$$)反応実験を行った。断面積の運動量分布を分析することで、$$1s_{1/2}$$$$0d_{5/2}$$軌道の分光学的因子を決定した。驚くべきことに、$$1s_{1/2}$$の分光学的因子は9(2)%と小さいことが明らかになった。この結果は、連続状態を含むdeformed relativistic Hartree-Bogoliubov理論によってよく説明された。本研究の結果によると、現在知られているハロー構造を持つとされる原子核の中で$$^{17}$$Bは$$s$$および$$p$$軌道の成分が最も小さく、$$s$$または$$p$$軌道成分が支配的であることが必ずしもハロー構造の前提条件ではない可能性を示唆している。

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