Article
Astronomy & Astrophysics
Qi Meng, Masayasu Harada, Emiko Hiyama, Atsushi Hosaka, Makoto Oka
Summary: The spectrum of the doubly heavy tetraquarks, bb (q) over bar(q) over bar, is investigated in a constituent quark model. Several narrow resonant states are found, including a mixed state of a compact tetraquark and a B* B* scattering state driven by a strong color Coulombic attraction between the bb quarks. In addition, negative-parity excited resonances exhibit similar structures to the lambda-mode of a singly heavy baryon due to the attractive correlation for the doubly heavy diquark.
Article
Multidisciplinary Sciences
Rudolf N. N. Faustov, Vladimir O. O. Galkin, Elena M. M. Savchenko
Summary: This study calculates the masses of fully heavy tetraquarks' ground and excited states (namely 1P, 2S, 1D, 2P, 3S) comprising charm and bottom quarks and antiquarks. The calculations are based on the diquark-antidiquark picture within the relativistic quark model and employ the quasipotential approach and quantum chromodynamics. The findings demonstrate that most investigated states of tetraquarks exist as broad resonances above the decay thresholds.
Article
Physics, Particles & Fields
Guo-Liang Yu, Zhen-Yu Li, Zhi-Gang Wang, Lu Jie, Yan Meng
Summary: Inspired by recent progresses in observations of the fully charmed tetraquark states by LHCb, CMS, and ATLAS collaborations, a systematic study is performed on the ground states and first radial excitations of the S- and P-wave cc (c) over bar(c) over bar system. The results from calculations using the relativized quark model show that there are no stable bound states for the fully charmed tetraquark states and their sizes are smaller than 1 fm. The X(6600) structure is suggested to be one of the 0(++)(1S) and 2(++)(1S) states or their mixtures, while X(6900) and X(7200) are proposed to be the corresponding states with different quantum numbers.
EUROPEAN PHYSICAL JOURNAL C
(2023)
Article
Astronomy & Astrophysics
Zheng Zhao, Kai Xu, Attaphon Kaewsnod, Xuyang Liu, Ayut Limphirat, Yupeng Yan
Summary: This study calculates the masses of qq(Q) over bar(Q) over bar tetraquark states using a constituent quark model and compares the theoretical predictions with experimental results, suggesting possible assignments.
Article
Physics, Particles & Fields
Guang-Juan Wang, Lu Meng, Li-Ye Xiao, Makoto Oka, Shi-Lin Zhu
Summary: The mass spectrum and strong decays of S-wave csqq states in the compact tetraquark scenario were systematically studied. The recently observed X0(2900) might be a good candidate for a tetraquark state, while future experimental search for X(2649) will be helpful.
EUROPEAN PHYSICAL JOURNAL C
(2021)
Article
Physics, Nuclear
Jian-Bo Cheng, Shi-Yuan Li, Yan-Rui Liu, Zong-Guo Si, Tao Yao
Summary: In this study, the masses of QQ (q) over bar(q) over bar tetraquark states are calculated using the HDAS and CMI model. The results indicate that double-charm tetraquarks are unstable, while stable double-bottom tetraquarks have specific mass ranges.
Article
Astronomy & Astrophysics
Zhongkui Kuang, Kamil Serafin, Xingbo Zhao, James P. Vary
Summary: This study examines all-charm tetraquarks using basis light-front quantization in Hamiltonian dynamics, focusing on mass calculations and meson-meson breakup threshold estimates. Results indicate that the lowest two-charm-two-anticharm state is not a tightly bound tetraquark.
Article
Physics, Particles & Fields
Xuejie Liu, Hongxia Huang, Jialun Ping, Dianyong Chen, Xinmei Zhu
Summary: This study systematically investigates different structures and channel couplings of tetraquark systems, proposing hypotheses to explain exotic resonance states. Experimental tests are expected to verify these hypotheses.
EUROPEAN PHYSICAL JOURNAL C
(2021)
Article
Physics, Particles & Fields
Jie Zhang, Jin-Bao Wang, Gang Li, Chun-Sheng An, Cheng-Rong Deng, Ju-Jun Xie
Summary: This study systematically investigates the fully heavy tetraquark states using a nonrelativistic constituent quark model, taking into account the instanton-induced and one-gluon exchange interactions. The results show the existence of specific states at certain energy ranges. It suggests that the newly observed X(6900) state by LHCb may be an excited state, while the reported X(6600) state by CMS and ATLAS may be a ground state tetraquark.
EUROPEAN PHYSICAL JOURNAL C
(2022)
Article
Astronomy & Astrophysics
Yue Tan, Xuejie Liu, Xiaoyun Chen, Hongxia Huang, Jialun Ping
Summary: This study investigates the resonance ωχbJ discovered in e+e- collisions and explores its potential identification with the previously reported T(10753). The study finds that the mass of T(5S), T(4S), and T(3D) as potential two-quark state candidates are inconsistent with the experimentally observed T(10753). The study also discovers several resonant states, one of which is a promising candidate for T(10753). These findings suggest the need for future experiments to search for additional resonant states in this energy range.
Article
Astronomy & Astrophysics
H. Garcia-Tecocoatzi, A. Giachino, J. Li, A. Ramirez-Morales, E. Santopinto
Summary: The total decay widths of the charmed baryons are calculated using the 3P0 model. Both the charmed baryon-(vector/pseudoscalar) meson pairs and the (octet/decuplet) baryon-(pseudoscalar/vector) charmed meson pairs are considered, within a constituent quark model. The masses of the charmed baryon ground states and their excitations up to the D-wave are also calculated using a Hamiltonian model, with parameters fitted to experimental data.
Article
Physics, Particles & Fields
Rui-Rui Dong, Niu Su, Hua-Xing Chen
Summary: This study investigates the exotic hadrons with quantum numbers J(PC) = 4(+-), which cannot be reached by traditional (q) over barq mesons and qqq baryons. The researchers systematically construct various diquark antidiquark interpolating currents and use QCD sum rules to calculate correlation functions. The obtained results suggest the existence of a purely exotic hadron, a fully-strange tetraquark state of J(PC) = 4(+-), with a possible decay mode into the P-wave phi (1020)f(2)'(1525) channel.
EUROPEAN PHYSICAL JOURNAL C
(2022)
Article
Astronomy & Astrophysics
Niu Su, Rui-Rui Dong, Hua-Xing Chen, Wei Chen, Er-Liang Cui
Summary: In this study, the QCD sum rules method was used to examine tetraquark states with exotic quantum numbers. The analysis revealed the decay characteristics of these states into different channels, providing insights into the construction of relevant tetraquark currents.
Article
Physics, Nuclear
Zahra Ghalenovi, Masoumeh Moazzen Sorkhi
Summary: In this study, the static properties and semileptonic decays of ground-state doubly heavy baryons were investigated using a non-relativistic quark model. Ground state masses and magnetic moments of doubly heavy omega and Xi baryons were calculated using a phenomenological potential model. In the heavy quark limit, a simple form of the universal Isgur-Wise function was introduced and used as the transition form factor to investigate the exclusive b -> c semileptonic decay widths and branching fractions for 1/2 -> 1/2 baryon transitions. The obtained results are consistent with other theoretical predictions.
Article
Astronomy & Astrophysics
Guang-Juan Wang, Qi Meng, Makoto Oka
Summary: In this study, we calculate the mass spectrum of the S-wave fully-charmed tetraquark resonant states using the nonrelativistic quark model and identify the genuine resonances with the complex scaling technique. The results show the existence of two resonances in each J(PC) sector, and the higher resonances may be good candidates for the X(7200) state.
Article
Astronomy & Astrophysics
Qi Meng, Masayasu Harada, Emiko Hiyama, Atsushi Hosaka, Makoto Oka
Summary: The spectrum of the doubly heavy tetraquarks, bb (q) over bar(q) over bar, is investigated in a constituent quark model. Several narrow resonant states are found, including a mixed state of a compact tetraquark and a B* B* scattering state driven by a strong color Coulombic attraction between the bb quarks. In addition, negative-parity excited resonances exhibit similar structures to the lambda-mode of a singly heavy baryon due to the attractive correlation for the doubly heavy diquark.
Article
Physics, Multidisciplinary
Zhi Yang, Guang-Juan Wang, Jia-Jun Wu, Makoto Oka, Shi-Lin Zhu
Summary: A novel framework is proposed to extract near-threshold resonant states from lattice QCD energy levels and is applied to study the structures of positive parity D-s mesons. The quark model, quark-pair-creation mechanism, and D-(*K-) interaction are incorporated into the effective field theory to analyze the composition of the D-s mesons. The results show that the physical D-s0* (2317) and D-s1* (2460) are mixtures of bare c (s) over bar core and D-(*K-) component, while the D-s1* (2536) and D-s2* (2573) are dominated by the bare CS%.
PHYSICAL REVIEW LETTERS
(2022)
Article
Physics, Particles & Fields
Naohiro Osamura, Philipp Gubler, Nodoka Yamanaka
Summary: The contribution of the CP violating three-gluon Weinberg operator to atomic and nuclear EDMs is estimated using QCD sum rules. By calculating transition matrix elements and determining the isovector CP-odd pion-nucleon vertex using chiral perturbation theory, the long-range CP-odd nuclear force is obtained. The upper limit on the Weinberg operator magnitude is derived from experimental data on the Hg-199 atomic EDM if it is considered the only source of CP violation at a scale of 1 TeV.
JOURNAL OF HIGH ENERGY PHYSICS
(2022)
Article
Astronomy & Astrophysics
Philipp Gubler, Naoki Yamamoto, Di-Lun Yang
Summary: We investigate the polarized gravitational waves generated by chiral fermions in the early Universe, with a focus on the contribution from left-handed neutrinos in thermal equilibrium. The correlation functions of gravitational fields related to the circular polarization of gravitational waves are computed. It is found that thermalized neutrinos induce a non-vanishing circular polarization in the long wavelength region, linearly dependent on the neutrino degeneracy parameter and wavenumber of gravitational waves. Although the magnitude of these gravitational waves is currently undetectable, future detectors in ultra-high frequency regimes may provide information on the neutrino degeneracy parameter.
JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS
(2022)
Article
Physics, Particles & Fields
Zhi Yang, Guang-Juan Wang, Jia-Jun Wu, Makoto Oka, Shi-Lin Zhu
Summary: In this study, we investigated the near-threshold P-wave B-s states using the Hamiltonian effective field theory, combining the quark model, the quark-pair-creation mechanism and B-(*)(K) over bar interaction. By fitting the lattice data and applying the heavy quark flavor symmetry, we determined all the parameters in the D-s sector. The predicted masses of the bottom-strange partners of the D-30*(2317) and D-31*(2460) are consistent with lattice QCD simulation. We also observed a crossing point in the finite volume spectrum, which corresponds to a CDD zero in the B(K) over bar scattering T-matrix, providing further insights into the near-threshold states.
JOURNAL OF HIGH ENERGY PHYSICS
(2023)
Article
Astronomy & Astrophysics
Qi Meng, Emiko Hiyama, Makoto Oka, Atsushi Hosaka, Chang Xu
Summary: The spectrum of doubly heavy tetraquarks is studied in a quark model, showing that the compact bound states are shifted up due to the repulsive central force between quarks and antiquarks. This effect may explain the small binding energy in Tcc. Additionally, a resonant state is reported.
Article
Astronomy & Astrophysics
In Woo Park, Hiroyuki Sako, Kazuya Aoki, Philipp Gubler, Su Houng Lee
Summary: Angular distributions of 0 meson decay amplitudes in e+e- and K+K- channels were computed using specific interaction Lagrangians and arguments based on angular momentum conservation. The obtained results were used to assess methods for experimentally distinguishing the longitudinal and transverse polarization modes of the 0 meson, and advantages and disadvantages of using either leptonic or hadronic decay modes were discussed.
Article
Astronomy & Astrophysics
Yonghee Kim, Makoto Oka, Daiki Suenaga, Kei Suzuki
Summary: We formulate a chiral effective theory of scalar and vector diquarks based on SU(3)R x SU(3)L chiral symmetry, including interactions between scalar and vector diquarks with one or two mesons. The interaction term with two mesons breaks the U(1)A and flavor SU(3) symmetries. By investigating one-pion emission decays of singly heavy baryons, we determine the coupling constants of the interaction Lagrangians and make 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.
Article
Astronomy & Astrophysics
Guang-Juan Wang, Qi Meng, Makoto Oka
Summary: In this study, we calculate the mass spectrum of the S-wave fully-charmed tetraquark resonant states using the nonrelativistic quark model and identify the genuine resonances with the complex scaling technique. The results show the existence of two resonances in each J(PC) sector, and the higher resonances may be good candidates for the X(7200) state.
Article
Astronomy & Astrophysics
Nodoka Yamanaka, Makoto Oka
Summary: This study evaluates the contribution of the CP-violating three-gluon interaction proposed by Weinberg to the short-range CP-odd nuclear force. The results show that this contribution is comparable to the CP-even short-range nuclear force and has a significant impact, especially in the calculation of the electric dipole moment of the 3He nucleus.
Article
Astronomy & Astrophysics
Jisu Kim, Philipp Gubler, Su Houng Lee
Summary: This study investigates the modification of the ?? meson spectrum in nuclear matter using an updated QCD sum rule analysis. It takes into account recent improvements in properly treating the chiral invariant and breaking components of four-quark condensates. The study finds that the mass shift of the ?? meson in nuclear matter is particularly sensitive to the strange sigma term ??sN, which determines the decrease of the strange quark condensate in nuclear matter.
Article
Astronomy & Astrophysics
Yonghee Kim, Makoto Oka, Kei Suzuki
Summary: The energy spectrum of doubly heavy tetraquarks, TQQ (QQq??q?? with Q = c, b and q = u, d, s), is investigated in the potential chiral-diquark model. The Tbb, Tcc, and Tcb tetraquarks are described as a three-body system composed of two heavy quarks and an antidiquark. Several Tbb bound states are found, and the change of TQQ tetraquark masses under restoration of chiral symmetry is also studied.
Correction
Astronomy & Astrophysics
Kiyoshi Sasaki, Naruhito Ishizuka, Makoto Oka, Takeshi Yamazaki
Article
Astronomy & Astrophysics
Nelson R. F. Braga, Octavio C. Junqueira
Summary: This study investigates the influence of rotation on the transition temperature of strongly interacting matter produced in non-central heavy ion collisions. By using a holographic description of an AdS black hole, the authors extend the analysis to the more realistic case where the matter spreads over a region around the rotational axis. The results show the coexistence of confined and deconfined phases and are consistent with the concept of local temperature in rotating frames developed by Tolman and Ehrenfest.
Article
Astronomy & Astrophysics
Bing Sun, Jiachen An, Zhoujian Cao
Summary: This paper investigates the effect of gravitational constant variation on the propagation of gravitational waves. By employing two analytical methods, the study finds that variations in the gravitational constant result in amplitude and phase corrections for gravitational waves, and the time variation of the gravitational constant can be constrained through the propagation of gravitational waves.
Article
Astronomy & Astrophysics
Abdellah Touati, Zaim Slimane
Summary: This letter presents the first study of Hawking radiation as a tunneling process within the framework of non-commutative gauge theory of gravity. The non-commutative Schwarzschild black hole is reconstructed using the Seiberg-Witten map and the star product. The emission spectrum of outgoing massless particles is computed using the quantum tunneling mechanism. The results reveal pure thermal radiation in the low-frequency scenario, but a deviation from pure thermal radiation in the high-frequency scenario due to energy conservation. It is also found that noncommutativity enhances the correlations between successively emitted particles.
Article
Astronomy & Astrophysics
Shahar Hod
Summary: The travel times of light signals between two antipodal points on a compact star's surface are calculated for two different trajectories. It is shown that, for highly dense stars, the longer trajectory along the surface may have a shorter travel time as measured by asymptotic observers. A critical value of the dimensionless density-area parameter is determined for constant density stars to distinguish cases where crossing through the star's center or following a semi-circular trajectory on the surface has a shorter travel time as measured by asymptotic observers.
