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Anatomy of Bs → P P decays and effects of the next-to-leading order contributions in the perturbative QCD approach

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arXiv 2019年

作者： Yan, Da-Cheng Liu, Xin Xiao, Zhen-Jun Department of Physics Institute of Theoretical Physics Nanjing Normal University Nanjing Jiangsu210023 China School of Physics and Electronic Engineering Jiangsu Normal University Xuzhou221116 China Jiangsu Key Laboratory for Numerical Simulation of Large Scale Complex Systems Nanjing Normal University Nanjing Jiangsu210023 China

By employing the perturbative QCD (PQCD) factorization approach, we made a systematic investigation for the CP-averaged branching ratios and the CP-violating asymmetries of the thirteen B¯s0 → P P decays (here P = (π, K, η, η′)) with the inclusion of all currently known next-to-leading order (NLO) contributions, and compared our results with the measured values or the theoretical predictions from other different approaches. We focused on the examination of the effects of the NLO contributions and found the following points: (a) for B¯s0 → (K0K¯ 0, K+K−, η′η′, π−K+) decays, the NLO contributions can provide a (40 − 150)% enhancement or a 20% reduction to the corresponding leading order (LO) PQCD predictions for their decay rates and result in a much better agreement between the PQCD predictions and the experimental measurements;(b) for the pure annihilation decay B¯s0 → π+π−, the PQCD prediction still remain consistent with the data after the inclusion of the small NLO reduction;(c) the PQCD predictions for the ratio (fs/fd) · B(Bs0 → π+π−)/B(B0 → K+π−) and (fs/fd) · B(Bs0 → π+K−)/B(B0 → K+π−) become agree very well with the measured ones after the inclusion of a 40% NLO reduction;(d) for B¯s0 → K+K− and B¯s0 → π−K+ decays, the NLO PQCD predictions for their CP-violating asymmetries do agree very well with the measured values in both the sign and the magnitude;and (e) for all B¯s0 → P P decays, we also compared our results with those obtained in the QCD factorization approach and soft-collinear effective theory and discussed their similarities and differences. Copyright © 2019, The Authors. All rights reserved.

关键词： Forecasting

S-wave resonance contributions to the B(0s) → ηc(2S)π+π− in the perturbative QCD factorization approach

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arXiv 2017年

作者： Ma, Ai-Jun Li, Ya Wang, Wen-Fei Xiao, Zhen-Jun Department of Physics Institute of Theoretical Physics Nanjing Normal University Nanjing Jiangsu210023 China Institute of Theoretical Physics Shanxi University Taiyuan Shanxi030006 China Jiangsu Key Laboratory for Numerical Simulation of Large Scale Complex Systems Nanjing Normal University Nanjing Jiangsu210023 China

By employing the perturbative QCD (PQCD) factorization approach, we study the quasi-two-body B(0s) → ηc(2S)π+π− decays, where the pion pair comes from the S-wave resonance f0(X). The Breit−Wigner formula for the f0(500) and f0(1500) resonances, and the Flatté model for the f0(980) resonance are adopted to parameterize the time-like scalar form factors in the two-pion distribution amplitudes. As a comparison, Bugg's model is also used for the wide f0(500) in this work. For decay rates, we found the following PQCD predictions: (a) B(Bs0 → ηc(2S)f0(X)[π+π−]s) = (2.67+1−1..7808 ) × 10−5 when the contributions from f0(980) and f0(1500) are all taken into account;(b) B(B0 → ηc(2S)f0(500)[π+π−]s) = (1.40+0−0..9256 ) × 10−6 in the Breit-Wigner model and (1.53+0−0..9761) × 10−6 in the Bugg's model. Copyright © 2017, The Authors. All rights reserved.

关键词： Hadrons

Quasi-two-body decays B(s) → D(ρ(1450), ρ(1700)) → Dππ in the perturbative QCD factorization approach

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arXiv 2017年

By employing a framework for the quasi-two-body decays in the perturbative QCD (PQCD) factorization approach, we calculate the branching ratios of the decays B(s) → D(ρ(1450), ρ(1700)) → Dππ with D = (D(s), D¯(s)). The pion vector form factor Fπ, acquired from a BABAR Collaboration analysis of e+e− → π+π−(γ) data, is involved in the two-pion distribution amplitudes ΦIππ=1. The PQCD predictions for the branching ratios of the considered quasi-two-body decays are in the range of 10−10 ∼ 10−4. The PQCD predictions for B(B0 → D¯ 0(ρ0(1450), ρ0(1700)) → D¯ 0π+π−) agree well with the measured values as reported by LHCb if one takes still large theoretical errors into account. Unlike the traditional way of the PQCD approach, one can extract the decay rates for the two-body decays B(s) → D(ρ(1450), ρ(1700)) from the results of the corresponding quasi-two-body decays. The PQCD predictions for B(B(s) → Dρ(1450)) and B(B(s) → Dρ(770)) are similar in magnitude: an interesting relation to be tested by future experimental measurements. Copyright © 2017, The Authors. All rights reserved.

关键词： Hadrons

Quasi-two-body decays B → ηc(1S, 2S) [ρ(770), ρ(1450), ρ(1700) →] ππ in the perturbative QCD approach

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arXiv 2017年

作者： Li, Ya Ma, Ai-Jun Rui, Zhou Xiao, Zhen-Jun Department of Physics Institute of Theoretical Physics Nanjing Normal University Nanjing Jiangsu210023 China College of Sciences North China University of Science and Technology Tangshan063009 China Jiangsu Key Laboratory for Numerical Simulation of Large Scale Complex Systems Nanjing Normal University Nanjing Jiangsu210023 China

In this paper, we calculated the branching ratios of the quasi-two-body decays B → ηc(1S, 2S) [ρ(770), ρ(1450), ρ(1700) →]ππ by employing the perturbative QCD (PQCD) approach. The contributions from the P -wave resonances ρ(770), ρ(1450) and ρ(1700) were taken into account. The two-pion distribution amplitude ΦPππ is parameterized by the vector current time-like form factor Fπ to study the considered decay modes. We found that (a) the PQCD predictions for the branching ratios of the considered quasi-two-body decays are in the order of 10−7 ∼ 10−6, while the two-body decay rates B(B → ηc(1S, 2S)(ρ(1450), ρ(1700))) are extracted from those for the corresponding quasi-two-body decays;(b) the whole pattern of the pion form factor-squared |Fπ|2 measured by the BABAR Collaboration could be understood based on our theoretical results;(c) the general expectation based on the similarity between B → ηcππ and B → J/ψππ decays are confirmed: R2(ηc) ≈ 0.45 is consistent with the measured R2(J/ψ) ≈ 0.56 ± 0.09 within errors;and (d) new ratios R3(ηc(1S)) and R4(ηc(2S)) among the branching ratios of the considered decay modes are defined and could be tested by future experiments. Copyright © 2017, The Authors. All rights reserved.

关键词： Hadrons

Spontaneous PT-symmetry breaking in non-Hermitian Kitaev and extended Kitaev models

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Physical Review A 2015年第1期92卷 012116-012116页

作者： Xiaohui Wang Tingting Liu Ye Xiong Peiqing Tong Department of Physics and Institute of Theoretical Physics Nanjing Normal University Nanjing 210023 People's Republic of China Jiangsu Key Laboratory for Numerical Simulation of Large Scale Complex Systems Nanjing Normal University Nanjing 210023 People's Republic of China and Kavli Institute for Theoretical Physics China CAS Beijing 100190 People's Republic of China

The spontaneous parity-time (PT) symmetry breaking is discussed in non-Hermitian PT-symmetric Kitaev and extended Kitaev models whose Hermiticity is broken by the presence of two conjugated imaginary potentials ±iγ at two end sites. In the case of the non-Hermitian Kitaev model, a spontaneous PT-symmetry breaking transition (SPTBT) occurs at a certain γc in the topologically trivial phase (TTP) region, similar to that of the Su-Schrieffer-Heeger (SSH) model. However, unlike the SSH model, the system also undergoes such a transition in the topologically nontrivial phase (TNP) region. We study an extended Kitaev model by combining the superconducting pairing in the Kitaev model and the staggered hopping in the SSH model. This model contains three different topological phases: the TTP, the Kitaev-like TNP, and the SSH-like TNP. For the non-Hermitian extended Kitaev model, a SPTBT occurs in the Kitaev-like TNP region, as well as in part of the TTP and SSH-like TNP regions, whereas the PT symmetry is broken for an arbitrary nonzero γ in the rest of the TTP and SSH-like TNP regions. Therefore, we can conclude that there is no universal correlation between topological properties and the SPTBT.

关键词： TANTALUM compounds QUADRUPOLE moments ELECTRON-nucleus scattering HYPERFINE structure QUANTUM chromodynamics

Work done and irreversible entropy production in a suddenly quenched quantum spin chain with asymmetrical excitation spectra

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Physical Review E 2015年第3期91卷 032137-032137页

作者： Ming Zhong Peiqing Tong Department of Physics and Institute of Theoretical Physics Nanjing Normal University Nanjing 210023 People's Republic of China Jiangsu Key Laboratory for Numerical Simulation of Large Scale Complex Systems Nanjing Normal University Nanjing 210023 People's Republic of China and Kavli Institute for Theoretical Physics China CAS Beijing 100190 People's Republic of China

In this paper, we extend the studies on the emergent thermodynamics in a quenched quantum Ising chain (QIC) [R. Dorner, J. Goold, C. Cormick, M. Paternostro, and V. Vedral, Phys. Rev. Lett. 109, 160601 (2012)] to a more general quantum spin chain with asymmetrical excitation spectra. We verify that the Jarzynski and Tasaki-Crooks relations are still tenable in this system. As an example, we discuss the behaviors of the work done and irreversible entropy production induced by a sudden quenching in the anisotropic XY chain in a transverse field with the XZY-YZX type of three-site interactions. Different from the QIC, this system has the phase transitions not only between two gapped phases, but also between gapped (or gapless) and gapless phases at zero temperature. We discuss the effects of quantum phase transitions on the work done and irreversible entropy production at low temperature.

关键词： ISING model THERMODYNAMICS QUANTUM systems QUANTUM phase transitions LOW temperature physics

The next-to-leading order corrections to B →-transition in the kTfactorization

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arXiv 2018年

作者： Hua, Jun Zhang, Ya-Lan Xiao, Zhen-Jun Department of Physics Institute of Theoretical Physics Nanjing Normal University Nanjing Jiangsu210023 China Department of Faculty of Mathematics and Physics Huaiyin Institute of Technology Huaian Jiangsu223001 China Jiangsu Key Laboratory for Numerical Simulation of Large Scale Complex Systems Nanjing Normal University Nanjing210023 China

In this paper, we investigate the factorization hypothesis step by step for the exclusive process B → ρ at next-to-leading order (NLO) with the collinear factorization approach, and then we extend our results to the kTfactorization frame. We show that the soft divergence from the specific NLO diagrams will cancel each other at the quark level, while the remaining collinear divergence can be absorbed into the NLO wave functions. The full NLO amplitudes can be factorized into two parts: The NLO B and ρ meson wave functions containing the collinear divergence and the leading order (LO) finite hard kernels. We give the general form of the nonlocal hadron matrix for the NLO B and ρ meson wave functions and all results of factorization for different twists' combinations. Copyright © 2018, The Authors. All rights reserved.

关键词： Factorization

Directed momentum current induced by the PT-symmetric driving

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Physical Review E 2019年第4期99卷 042201-042201页

作者： Wen-Lei Zhao Jiaozi Wang Xiaohui Wang Peiqing Tong School of Science Jiangxi University of Science and Technology Ganzhou 341000 China Department of Modern Physics University of Science and Technology of China Hefei 230026 China School of Information Engineering Jiangxi University of Science and Technology Ganzhou 341000 China Department of Physics and Institute of Theoretical Physics Nanjing Normal University Nanjing 210023 China Jiangsu Provincial Key Laboratory for Numerical Simulation of Large Scale Complex Systems Nanjing Normal University Nanjing Jiangsu 210023 China

We investigate the directed momentum current in the quantum kicked rotor model with PT-symmetric deriving potential. For the quantum nonresonance case, the values of quasienergy become complex when the strength of the imaginary part of the kicking potential exceeds a threshold value, which demonstrates the appearance of the spontaneous PT symmetry breaking. In the vicinity of the transition point, the momentum current exhibits a staircase growth with time. Each platform of the momentum current corresponds to the mean momentum of some eigenstates of the Floquet operator whose imaginary parts of the quasienergy are significantly large. Above the transition point, the momentum current increases linearly with time. Interestingly, its acceleration rate exhibits a kind of “quantized” increment with the kicking strength. We propose a modified classical acceleration mode of the kicked rotor model to explain such an intriguing phenomenon. Our theoretical prediction is in good agreement with numerical results.

关键词： Coherent control Cold atoms & matter waves Light-matter interaction Wave chaos

Summation of Divergent Series and Quantum Phase Transitions in Kitaev Chains with Long-Range Hopping

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arXiv 2023年

作者： Fu, Hao Tong, Peiqing School of Mathematical Sciences Nanjing Normal University Nanjing210023 China School of Physics and Technology Nanjing Normal University Nanjing210023 China Jiangsu Key Laboratory for Numerical Simulation of Large Scale Complex Systems Nanjing Normal University Nanjing210023 China

We study the quantum phase transitions (QPTs) in extended Kitaev chains with long-range (1/rα) hopping. Formally, there are two QPT points at µ = µ0(α) and µπ(α) (µ is the chemical potential) which correspond to the summations of (formula presented) and (formula presented), respectively. When α ≤ 0, both the series are divergent and it is usually believed that no QPTs exist. However, we find that there are two QPTs at µ = µ0(0) and µπ(0) for α = 0 and one QPT at µ = µπ(α) for α 0 and induces topological phases with the winding number ω := ±1/2. At the same time, the von Neumann entropy are power law of the subchain length L no matter in the gapped region or not. In addition, we also study the QPTs, topological properties, and von Neumann entropy of the systems with α > 0. Copyright © 2023, The Authors. All rights reserved.

关键词： Topology