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The Φp bound state in the unitary coupled-channel approximation

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Communications in Theoretical Physics 2023年第5期75卷 142-148页

作者： Bao-Xi Sun Ying-Ying Fan Qin-Qin Cao Faculty of Science Beijing University of TechnologyBeijing 100124China

The strong attractive interaction of the φ meson and the proton has recently been reported by the ALICE Collaboration.The corresponding scattering length f_(0) is given as Re(f_(0))=0.85±0.34(stat)±0.14(syst)and Im(f_(0))=0.16±0.10(stat)±0.09(syst)fm.The fact that the real part is significant in contrast to the imaginary part indicates a dominant role of elastic scattering,whereas the inelastic process is less important.In this work,such scattering processes are inspected based on a unitary coupled-channel approach inspired by the Bethe-Salpeter equation.The φp scattering length is calculated based on this approach,and it is found that the experimental value of the φp scattering length can be obtained only if the attractive interaction of the φ meson and the proton is taken into account.A significant outcome of such attractive interaction is a two-pole structure in the φp scattering amplitude.One of the poles,located at(1969−i283)MeV might correspond to N(1895)1/2^(−)or N(1875)3/2^(−)as listed in the review of the Particle Data Group(PDG).The other one,located at 1949−i3 MeV should be a φN bound state,which has no counterpart in the PDG data.

关键词： hadronic structure hadronic resonance Bethe-Salpeter equation chiral effective theory unitary coupled-channel approach vector meson-baryon octet interaction

unitary Scattering Protected by Pseudo-Hermiticity

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Chinese Physics Letters 2022年第3期39卷 82-88页

作者：金亮 School of Physics Nankai UniversityTianjin 300071China

Hermitian systems possess unitary scattering.However,the Hermiticity is unnecessary for a unitary scattering although the scattering under the influence of non-Hermiticity is mostly non-unitary.Here we prove that the unitary scattering is protected by certain type of pseudo-Hermiticity and unaffected by the degree of non-Hermiticity.The energy conservation is violated in the scattering process and recovers after scattering.The subsystem of the pseudo-Hermitian scattering center including only the connection sites is Hermitian.These findings provide fundamental insights on the unitary scattering,pseudo-Hermiticity,and energy conservation,and are promising for light propagation,mesoscopic electron transport,and quantum interference in non-Hermitian systems.

关键词： scattering unitary protected

The unitary connections on the complex Grassmann manifold

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Science China Mathematics 1998年第12期41卷 1248-1254页

作者：陆启铿 Institute of Mathematics Chinese Academy of Sciences Beijing China Institute of Mathematics Shantou University Shantou China

In the complex Grassmann manifold F(m,n), the space of complex \%n\%\|planes passes through the origin of C \%m+n\% ; the local coordinate of the space can be arranged into an \%m×n\% matrix \%Z.\% It is proved thatK=K(Z,\%d\%Z)=(I+ZZ  ) -12 (I+ZZ  ) 12 -(I+ZZ  ) 12 ·(I+ZZ  ) -12 is a \%U(m)\%\|connection of F\%(m,n)\% and its curvature formΩ\-1= d K+K∧Ksatisfies the Yang\|Mills equation. Moreover,B=B(Z, d Z)=K(Z, d Z)- tr (K(Z, d Z))mI (m) is an SU(m) \|connection and its curvature formΩ\-2= d B+B∧Bsatisfies the Yang\|Mills equation.

关键词： unitary connection Grassmann manifold.

Average fidelity estimation of twirled noisy quantum channel using unitary 2t-design

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Chinese Physics B 2019年第1期28卷 223-231页

作者：张林曦朱畅华裴昌幸 State Key Laboratory of Integrated Services Networks Xidian UniversityXi’an 710071China Science and Technology on Communication Networks Laboratory Shijiazhuang 050081China

We propose a method to estimate the average fidelity using the unitary 2t-design of a twirled noisy channel, which is suitable for large-scale quantum circuits. Compared with the unitary 2-design in randomized benchmarking, the unitary2t-design for the twirling of noisy channels is more flexible in construction and can provide more information. In addition,we prove that the proposed method provides an efficient and reliable estimation of the average fidelity in benchmarking multistage quantum gates and estimating the weakly gate-and time-dependent noise. For time-dependent noise, we provide a scheme of moment superoperator to analyze the noise in different experiments. In particular, we give a lower bound on the average fidelity of a channel with imperfect implementation of benchmarking and state preparation and measurement errors(SPAM).

关键词： quantum channel average fidelity unitary 2t-design

How tightly is the nuclear symmetry energy constrained by a unitary Fermi gas?

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Nuclear Science and Techniques 2017年第12期28卷 248-254页

作者： Nai-Bo Zhang Bao-Jun Cai Bao-An Li William G.Newton Jun Xu Department of Physics and Astronomy Texas A&M University-Commerce Shandong Provincial Key Laboratory of Optical Astronomy and Solar-Terrestrial Environment Institute of Space Sciences Shandong University Department of Physics Shanghai University Department of Physics and Astronomy Shanghai Key Laboratory for Particle Physics and Cosmology Shanghai Jiao Tong University Shanghai Institute of Applied Physics Chinese Academy of Sciences

We examine critically how tightly the density dependence of nuclear symmetry energy E_(sym)(q) is constrained by the universal equation of state of the unitary Fermi gas EUG(q) considering currently known uncertainties of higher order parameters describing the density dependence of the equation of state of isospin asymmetric nuclear matter. We found that E_(UG)(q) does provide a useful lower boundary for the E_(sym)(q). However, it doesnot tightly constrain the correlation between the magnitude E_(sym)(q_0) and slope L unless the curvature K_(sym)of the symmetry energy at saturation density q_0 is more precisely known. The large uncertainty in the skewness parameters affects the E_(sym)(q_0) versus L correlation by the same almost as significantly as the uncertainty in K_(sym).

关键词： Symmetry energy unitary gas Equation of state Nuclear matter

Solving Generalized Non-degenerate Two-Mode Two-Photon Jaynes-Cummings Model by Supersymmetric unitary Transformation

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Communications in Theoretical Physics 2002年第7期38卷 85-88页

作者： SONG Tong-Qiang ZHU Yue-Jin Department of Physics Ningbo University Ningbo 315211 China Department of Physics Ningbo University Ningbo 315211 China

Based on supersymmetric quantum mechanics theory, we introduced a supersymmetric unitary transfor mation to diagonalize the Hamiltonian of non-degenerate two-mode two-photon Jaynes-Cummings models which include any forms of intensity-dependent coupling, field-dependent detuning, and field nonlinearity. Its eigenvalue, eigenstates,and time evolution of state vector are obtained.

关键词： supersymmetric unitary transformation, Jaynes-Cumnings model

Pure quantitative characterization of finite projective special unitary groups

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Science China Mathematics 2002年第6期45卷 761-772页

作者：曹洪平施武杰 Department of Mathematics Sichuan University Chengdu 610064 China Department of Mathematics Southwest Normal University Chongqing 400715 China Department of Mathematics Soochow University Suzhou 215006 China Institute of Mathematics Southwest Normal University Chongqing 400715 China

We prove that each projective special unitary group G can be characterized using; only the set of element orders of G and the order of G.

关键词： projective special unitary group, finite simple group, set of element orders, classifica tion theorem.

Entanglement capacity of two-qubit unitary operator for rank two mixed states

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Science China(Physics,Mechanics & Astronomy) 2007年第6期50卷 691-697页

作者： DI YaoMin & LIU Li Department of Physics,Xuzhou Normal University,Xuzhou 221116,China Department of Physics Xuzhou Normal University Xuzhou China

The entanglement capacity of two-qubit unitary operator acting on rank two mixed states in concurrence is discussed. The condition of perfect entangler is the same as that acting on pure states and the entanglement capacity is the mixing parameter v1. For non-perfect entangler,the upper and lower bound of the entanglement ca-pacity are given.

关键词： two-qubit, unitary operator, mixed states, concurrence, entanglement capacity The entanglement capacity of two-qubit unitary operator acting on rank two mixed states in concurrence is discussed. The condition of perfect entangler is the same as that acting on pure states and the entanglement capacity is the mixing parameter v1. For non-perfect entangler, the upper and lower bound of the entanglement capacity are given.……

Effect of Preparation Technology Parameters on the Restriction Performances of unitary Titanium Porous Restrictor

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稀有金属材料与工程 2011年第S3期40卷 301-305页

作者： Tan Ping1, Pang Guangqing2, Tang Huiping1, Chen Jinmei1, Ge Yuan1, Wang Qiangbin1, Kang Xinting1 1State Key Laboratory of Porous Metal Materials, Northwest Institute for Nonferrous Metal Research, Xi’an 710016, China 2Xi’an Baoder Powder Metallurgy CO.LTD, Xi’an 710016, China NW Inst Nonferrous Met Res State Key Lab Porous Met Mat Xian 710016 Peoples R China Xian Baoder Powder Met CO LTD Xian 710016 Peoples R China

unitary titanium porous restrictor was prepared by a sintering welding technique. The results indicated that the restriction performance of unitary Ti porous restrictor was not only dependent on the morphology and particle size of the original powder, but also influenced by the molding pressure, sintering temperature and sintering pressure. The restrictor obtained from titanium powder with large particle size or spherical morphology possesses big porosity, large pore size and high permeability but low restriction. Instead, the restrictor derived from fine powder with irregular morphology had small porosity, narrow pore size but high restriction performance. In addition, the restriction ability of the titanium porous restrictor metals increased by increasing of molding and sintering pressure and the sintering temperature. However, a much higher sintering temperature induced a bad welding status, which ascribed to excessive sintering shrinkage of the porous restrictor, and the cracks between the porous body and the compact shell easily occurred. Finally, the strength of the dense Ti shell would decrease due to the flaws caused by the grain growth during sintering process. It was an ideal method to avoid the grain growth at high temperature through increasing the molding and sintering pressure and decreasing the sintering temperature, which could obtain a good sinter behavior and air tightness between the porous body and the Ti shell, thus, which satisfied the requirements in the applications.

关键词： unitary titanium porous metal restrictor sinter diffusion welding