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Journal Articles

Strong decays of singly heavy baryons from a chiral effective theory of diquarks

Kim, Y.*; Oka, Makoto; Suenaga, Daiki*; Suzuki, Kei

Physical Review D, 107(7), p.074015_1 - 074015_15, 2023/04

 Times Cited Count:0

A chiral effective theory of scalar and vector diquarks is formulated, which is based on $$SU(3)_Rtimes SU(3)_L$$ chiral symmetry and includes interactions between scalar and vector diquarks with one or two mesons. We find that the diquark interaction term with two mesons breaks the $$U(1)_A$$ and flavor $$SU(3)$$ symmetries. To determine the coupling constants of the interaction Lagrangians, we investigate one-pion emission decays of singly heavy baryons $$Qqq$$ ($$Q = c$$, $$b$$ and $$q = u$$, $$d$$, $$s$$), where baryons are regarded as diquark-heavy-quark two-body systems. Using this model, we present predictions of the unobserved decay widths of singly heavy baryons. We also study the change of masses and strong decay widths of singly heavy baryons under partial restoration of chiral symmetry.

Journal Articles

The Investigations of the $$P$$-wave $$B_s$$ states combining quark model and lattice QCD in the coupled channel framework

Yang, Z.*; Wang, G.-J.*; Wu, J.-J.*; Oka, Makoto; Zhu, S.-L.*

Journal of High Energy Physics (Internet), 2023(1), p.058_1 - 058_19, 2023/01

 Times Cited Count:0 Percentile:0.04(Physics, Particles & Fields)

Combining the quark model, the quark-pair-creation mechanism and $$B^{(*)}bar K$$ interaction, we have investigated the near-threshold $$P$$-wave $$B_s$$ states in the framework of the Hamiltonian effective field theory. With the heavy quark flavor symmetry, all the parameters are determined in the $$D_s$$ sector by fitting the lattice data. The masses of the bottom-strange partners of the $$D^{*}_{s0}(2317)$$ and $$D^{*}_{s1}(2460)$$ are predicted, which are well consistent with the lattice QCD simulation. The two $$P$$-wave $$B_s$$ states are the mixtures of the bare $$bar b s$$ core and $$B^{(*)}bar K$$ component. Moreover, we find a crossing point between the energy levels with and without the interaction Hamiltonian in the finite volume spectrum in the $$0^+$$ case, which corresponds to a CDD (Castillejo-Dalitz-Dyson) zero in the $$T$$-matrix of the $$Bbar K$$ scattering. This CDD zero will help deepen the insights of the near-threshold states and can be examined by future lattice calculation.

Journal Articles

$$S$$-wave fully charmed tetraquark resonant states

Wang, G.-J.*; Meng, Q.*; Oka, Makoto

Physical Review D, 106(9), p.096005_1 - 096005_9, 2022/11

$$S$$-wave resonances in the fully charmed tetraquark system are studied in the quark model. The complex scaling method allows us to get the complex eigen-energies of the tetraquark system above the fall-apart decay thresholds. We found two resonances in each of the $$J^{PC}=0^{++}$$, $$1^{+-}$$ and $$2^{++}$$ sectors, respectively. The obtained resonances are about 100 MeV higher than the recently found resonance, $$X(6900)$$.

Journal Articles

Weinberg operator contribution to the $$CP$$-odd nuclear force in the quark model

Yamanaka, Nodoka*; Oka, Makoto

Physical Review D, 106(7), p.075021_1 - 075021_15, 2022/10

 Times Cited Count:0 Percentile:0.01(Astronomy & Astrophysics)

The contribution of the $$CP$$ violating three-gluon interaction, proposed by Weinberg, to the short-range $$CP$$-odd nuclear force is evaluated in the nonrelativistic quark model. We first show that the naive leading contribution generated by the quark exchange process vanishes at sufficiently short distance within the resonating group method, by considering the one-loop level gluon exchange $$CP$$-odd interquark potential induced by the Weinberg operator with massive quarks and gluons. We then estimate the true leading contribution by evaluating the gluonic correction to the $$CP$$-odd interquark potential in the closure approximation. It is found that the resulting irreducible $$CP$$-odd nuclear force is comparable to that generated by the chiral rotation of the $$CP$$-even short-range nuclear force, where the $$CP$$-odd mass calculated with QCD sum rules is used as input. The explicit calculation of the electric dipole moment (EDM) of the $$^3$$He nucleus yields $$d^{(irr)}_{3He}(w) = -1.5 w e$$ MeV. The total $$^3He$$ EDM, accounting for the intrinsic nucleon EDM, the pion-exchange and the short- range $$CP$$-odd nuclear force, is $$d_{(tot)}(w) = 20(+14-11) we$$ MeV, with the dominant effect coming from the intrinsic nucleon EDM.

Journal Articles

Doubly heavy tetraquarks in a chiral-diquark picture

Kim, Y.*; Oka, Makoto; Suzuki, Kei

Physical Review D, 105(7), p.074021_1 - 074021_17, 2022/04

 Times Cited Count:10 Percentile:94.91(Astronomy & Astrophysics)

Energy spectrum of doubly heavy tetraquarks, $$T_{QQ}$$ ($$QQ bar{q} bar{q}$$ with $$Q = c, b$$ and $$q = u, d, s$$), is studied in the potential chiral-diquark model. Using the chiral effective theory of diquarks and the quark-diquark-based potential model, the $$T_{bb}$$, $$T_{cc}$$, and $$T_{cb}$$ tetraquarks are described as a three-body system composed of two heavy quarks and an antidiquark. We find several $$T_{bb}$$ bound states, while no $$T_{cc}$$ and $$T_{cb}$$ (deep) bound state is seen. We also study the change of the $$T_{QQ}$$ tetraquark masses under restoration of chiral symmetry.

Journal Articles

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.*; Oka, Makoto; Zhu, S.-L.*

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

 Times Cited Count:13 Percentile:97.96(Physics, Multidisciplinary)

A novel framework is proposed to extract near-threshold resonant states from finite-volume energy levels of lattice QCD and is applied to elucidate structures of the positive parity $$D_s$$. The quark model, the quark-pair-creation mechanism and $$D^{(*)}K$$ interaction are incorporated into the Hamiltonian effective field theory. The bare $$1^+$$ $$cbar s$$ states are almost purely given by the states with heavy-quark spin bases. The physical $$D^*_{s0}(2317)$$ and $$D^*_{s1}(2460)$$ are the mixtures of bare $$cbar s$$ core and $$D^{(*)}K$$ component, while the $$D^*_{s1}(2536)$$ and $$D^*_{s2}(2573)$$ are almost dominated by bare $$cbar{s}$$. Furthermore, our model well reproduce the clear level crossing of the $$D^*_{s1}(2536)$$ with the scattering state at a finite volume.

Journal Articles

Dynamic accommodation of internal stress and selection of crystallographic orientation relationship in pearlite

Amemiya, Yutaro*; Nakada, Nobuo*; Morooka, Satoshi; Kosaka, Makoto*; Kato, Masaharu*

ISIJ International, 62(2), p.282 - 290, 2022/02

 Times Cited Count:1 Percentile:44.11(Metallurgy & Metallurgical Engineering)

Journal Articles

Doubly heavy tetraquark resonant states

Meng, Q.*; Harada, Masayasu*; Hiyama, Emiko; Hosaka, Atsushi; Oka, Makoto

Physics Letters B, 824, p.136800_1 - 136800_5, 2022/01

 Times Cited Count:9 Percentile:97.15(Astronomy & Astrophysics)

Spectrum of the doubly heavy tetraquarks, $$bbbar q bar q$$, is studied in a constituent quark model. Four-body problem is solved in a variational method where the real scaling technique is used to identify resonant states above the fall-apart decay thresholds. In addition to the two bound states that were reported in the previous study we have found several narrow resonant states above the $$BB^*$$ and $$B^*B^*$$ thresholds. Their structures are studied and are interpreted by the quark dynamics. A narrow resonance with spin-parity $$J^P=1^+$$ is found to be a mixed state of a compact tetraquark and a $$B^*B^*$$ scattering state. This is driven by a strong color Coulombic attraction between the $$bb$$ quarks. Negative-parity excited resonances with $$J^P=0^-$$, $$1^-$$ and $$2^-$$ form a triplet under the heavy-quark spin symmetry. It turns out that they share a similar structure to the $$lambda$$-mode of a singly heavy baryon as a result of the strongly attractive correlation for the doubly heavy diquark.

JAEA Reports

Examination of exposure management method for the eye lens at Oarai Research and Development Institute

Matsuoka, Amane; Yasumune, Takashi; Kojima, Nobuhiro; Miyauchi, Hideaki; Takasaki, Koji; Hashimoto, Makoto

JAEA-Review 2021-055, 11 Pages, 2021/12


The dose limit for the eye lens was lowered on April 1 2021, and a 3 mm dose equivalent was added to the calculation. The guidelines require that lens dosimeters be worn and managed when there is a risk of exceeding control standards. In this report, in order to examine future management methods, we investigated whether work that might exceed the equivalent dose limit was performed in the past. As a result of the investigation, the exposure dose for all works after fiscal year 2008 was sufficiently low compared to the equivalent dose limit. For this reason, it is considered that there is no need for additional management of wearing a personal dosimeter near the eyes for the work that is normally performed. In the future, as in the past, the basic management method will be to wear a dosimeter only on the basic part of the trunk under uniform exposure conditions, and to wear a dosimeter on the basic part of the trunk and the maximum dose part under nonuniform exposure conditions. When performing work with a high exposure dose to the eye lens, a dosimeter should be worn near the eye to measure the 3 mm dose equivalent.

Journal Articles

Prediction of Double-heavy Tetraquarks Bound States in Quark Model

Meng, Q.*; Hiyama, Emiko; Hosaka, Atsushi; Oka, Makoto; Gubler, P.; Can, K. U.*; Takahashi, Toru*; Zong, H. S.*

Few-Body Systems, 62(4), p.79_1 - 79_5, 2021/12

 Times Cited Count:0 Percentile:0(Physics, Multidisciplinary)

Journal Articles

Heavy baryon spectrum with chiral multiplets of scalar and vector diquarks

Kim, Y.*; Liu, Y.-R.*; Oka, Makoto; Suzuki, Kei

Physical Review D, 104(5), p.054012_1 - 054012_18, 2021/09

 Times Cited Count:6 Percentile:58.46(Astronomy & Astrophysics)

Chiral effective theory of scalar and vector diquarks is formulated according to the linear sigma model. The main application is to describe the ground and excited states of singly heavy baryons with a charm or bottom quark. Applying the potential quark model between the diquark and the heavy quark ($$Q=c, b$$), we construct a heavy-quark-diquark model. The spectra of the positive- and negative-parity states of $$Lambda_Q$$, $$Sigma_Q$$, $$Xi^{(')}_Q$$ and $$Omega_Q$$ are obtained. The masses and interaction parameters of the effective theory are fixed partly from the lattice QCD data and also from fitting low-lying heavy baryon masses. We find that the negative parity excited states of $$Xi_Q$$ (flavor $$bar{bf 3}$$) are different from those of $$Lambda_Q$$, because of the inverse hierarchy of the pseudoscalar diquark. On the other hand, $$Sigma_Q, Xi'_Q$$ and $$Omega_Q$$ (flavor $${bf 6}$$) baryons have similar spectra. We compare our results of the heavy-quark-diquark model with experimental data as well as the quark model.

Journal Articles

The Negative-parity spin-1/2 $$Lambda$$ baryon spectrum from lattice QCD and effective theory

Pavao, R.*; Gubler, P.; Fernandez-Soler, P.*; Nieves, J.*; Oka, Makoto; Takahashi, Toru*

Physics Letters B, 820, p.136473_1 - 136473_8, 2021/09

 Times Cited Count:3 Percentile:61.99(Astronomy & Astrophysics)

Journal Articles

Survival probabilities of charmonia as a clue to measure transient magnetic fields

Iwasaki, Sachio*; Jido, Daisuke*; Oka, Makoto; Suzuki, Kei

Physics Letters B, 820, p.136498_1 - 136498_6, 2021/09

 Times Cited Count:0 Percentile:0.02(Astronomy & Astrophysics)

We investigate time evolution of $$S$$-wave charmonium populations under a time-dependent homogeneous magnetic field and evaluate survival probabilities of the low-lying charmonia to the goal of estimating the magnetic field strength at heavy-ion collisions. Our approach implements mixing between different spin eigenstates and transitions to radially excited states. We show that the survival probabilities can change even by an extremely short magnetic field. Furthermore, we find that the survival probabilities depend on the initial spin states. We propose the sum of the survival probabilities over spin partners as an observable insensitive to the initial states. We also find that the sum can be approximately given as a function of $$sigma B_0^2$$ with a duration time $$sigma$$ and the maximum strength of the magnetic field $$B_0$$.

Journal Articles

Rapid analysis of $$^{90}$$Sr in cattle bone and tooth samples by inductively coupled plasma mass spectrometry

Koarai, Kazuma; Matsueda, Makoto; Aoki, Jo; Yanagisawa, Kayo*; Terashima, Motoki; Fujiwara, Kenso; Kino, Yasushi*; Oka, Toshitaka; Takahashi, Atsushi*; Suzuki, Toshihiko*; et al.

Journal of Analytical Atomic Spectrometry, 36(8), p.1678 - 1682, 2021/08

 Times Cited Count:2 Percentile:38.85(Chemistry, Analytical)

Rapid analysis of $$^{90}$$Sr in bone and tooth samples of cattle were achieved by an inductively coupled plasma mass spectrometry (ICP-MS) coupled with mass shift and solid phase extraction techniques. Limit of detection (LOD) in the ICP-MS measurement of 0.1 g samples was lower than that of the radioactivity measurement. Analytical time of the ICP-MS method was reduced from 20 days to 11 hours, compared with the radiometric method. Therefore, the ICP-MS method can be rapid and useful procedure of $$^{90}$$Sr in small bone and tooth samples derived from terrestrial animals.

Journal Articles

Higher fully charmed tetraquarks; Radial excitations and $$P$$-wave states

Wang, G.-J.*; Meng, L.*; Oka, Makoto; Zhu, S.-L.*

Physical Review D, 104(3), p.036016_1 - 036016_15, 2021/08

 Times Cited Count:13 Percentile:83.08(Astronomy & Astrophysics)

Radial excited states and $$P$$-wave excited states of the fully charmed tetraquark spectrum was studied in the quark model. In the standard model settings, we find that several states may correspond to the observed X(6900) region. The possible quantum numbers are $$0^{++}$$, $$2^{++}$$, $$1^{+-}$$, and $$2^{-+}$$ states.

Journal Articles

A Review of quarkonia under strong magnetic fields

Iwasaki, Sachio*; Oka, Makoto; Suzuki, Kei

European Physical Journal A, 57(7), p.222_1 - 222_14, 2021/07

 Times Cited Count:11 Percentile:70.22(Physics, Nuclear)

We review the properties of quarkonia under strong magnetic fields. The main phenomena are (i) mixing between different spin eigenstates, (ii) quark Landau levels and deformation of wave function, (iii) modification of $$bar{Q}Q$$ potential, and (iv) the motional Stark effect. For theoretical approaches, we review (i) constituent quark models, (ii) effective Lagrangians, (iii) QCD sum rules, and (iv) holographic approaches.

Journal Articles

Radioactivity and radionuclides in deciduous teeth formed before the Fukushima-Daiichi Nuclear Power Plant accident

Takahashi, Atsushi*; Chiba, Mirei*; Tanahara, Akira*; Aida, Jun*; Shimizu, Yoshinaka*; Suzuki, Toshihiko*; Murakami, Shinobu*; Koarai, Kazuma; Ono, Takumi*; Oka, Toshitaka; et al.

Scientific Reports (Internet), 11(1), p.10355_1 - 10355_11, 2021/05

 Times Cited Count:5 Percentile:51.81(Multidisciplinary Sciences)

Journal Articles

Electromagnetic transitions of the singly charmed baryons with spin 3/2

Kim, J.-Y.*; Kim, H.-C.*; Yang, G.-S.*; Oka, Makoto

Physical Review D, 103(7), p.074025_1 - 074025_21, 2021/04


 Times Cited Count:8 Percentile:73.98(Astronomy & Astrophysics)

We investigate the electromagnetic transitions of the singly charmed baryons with spin 3/2, based on a pion mean-field approach, also known as the chiral quark-soliton model, taking into account the rotational $$1/N_c$$ corrections and the effects of flavor SU(3) symmetry breaking. We examine the valence- and sea-quark contributions to the electromagnetic transition form factors and find that the quadrupole form factors of the sea-quark contributions dominate over those of the valence-quark ones in the smaller $$Q^2$$ region, whereas the sea quarks only provide marginal contributions to the magnetic dipole transition form factors of the baryon sextet with spin 3/2. The effects of the flavor SU(3) symmetry breaking are in general very small except for the forbidden transition $$Xi_c^0 gamma to Xi^{* 0}_c$$ by $$U$$-spin symmetry. We also discuss the widths of the radiative decays for the baryon sextet with spin 3/2, comparing the present results with those from other works.

Journal Articles

Thermally altered subsurface material of asteroid (162173) Ryugu

Kitazato, Kohei*; Milliken, R. E.*; Iwata, Takahiro*; Abe, Masanao*; Otake, Makiko*; Matsuura, Shuji*; Takagi, Yasuhiko*; Nakamura, Tomoki*; Hiroi, Takahiro*; Matsuoka, Moe*; et al.

Nature Astronomy (Internet), 5(3), p.246 - 250, 2021/03

 Times Cited Count:27 Percentile:97(Astronomy & Astrophysics)

Here we report observations of Ryugu's subsurface material by the Near-Infrared Spectrometer (NIRS3) on the Hayabusa2 spacecraft. Reflectance spectra of excavated material exhibit a hydroxyl (OH) absorption feature that is slightly stronger and peak-shifted compared with that observed for the surface, indicating that space weathering and/or radiative heating have caused subtle spectral changes in the uppermost surface. However, the strength and shape of the OH feature still suggests that the subsurface material experienced heating above 300 $$^{circ}$$C, similar to the surface. In contrast, thermophysical modeling indicates that radiative heating does not increase the temperature above 200 $$^{circ}$$C at the estimated excavation depth of 1 m, even if the semimajor axis is reduced to 0.344 au. This supports the hypothesis that primary thermal alteration occurred due to radiogenic and/or impact heating on Ryugu's parent body.

Journal Articles

Stable double-heavy tetraquarks; Spectrum and structure

Meng, Q.*; Hiyama, Emiko*; Hosaka, Atsushi; Oka, Makoto; Gubler, P.; Can, K. U.*; Takahashi, Toru*; Zong, H. S.*

Physics Letters B, 814, p.136095_1 - 136095_6, 2021/03

 Times Cited Count:28 Percentile:99.14(Astronomy & Astrophysics)

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