Optical properties of a suspension of hard spheres

The optical properties of suspensions are studied in a wide range of concentrations. An expression for the polarization operator is obtained taking into account the contributions of two-and three-particle correlations. The extinction length l and the transport length l* are calculated in terms of a model of hard spheres. A detailed comparison of the results of calculations with experimental data is performed. In calculations, the structure factor is determined in the Percus-Yevick approximation, while the form factor is taken into account in the Rayleigh-Gans approximation and in terms of the Mie theory. It is shown that taking into account the contribution of three-particle correlations improves the agreement of the theory with experiment. It is found that, in the range of high suspension concentrations, the optical parameters are more sensitive to the choice of the model for the structure factor than for the form factor.     

On the structure of the three-particle operator in generalized kinetic equations for inhomogeneous gases

It is shown that the three-particle kinetic operator for inhomogeneous gases obtained using Prigogine's method and the matrix representation of the Liouville equation introduced by Balescu is equivalent to the corresponding expression derived by Choh and Uhlenbeck using Bogolubov's method. Both theories take into account the space and time delocalization associated with finite collision time, and the resulting corrections to the asymptotic collision operator are equivalent.     

Relativistic addition of interactions in constraint Hamiltonian mechanics

The problem of constructing separable N-particle interactions for given two-body forces in the constraint Hamiltonian approach to relativistic classical mechanics is tackled in two different ways. A formal expression for the N-particle constraints is given in terms of a classical wave operator. An (independent) iterative scheme for these constraints is carried out. Explicit formulas for the three-particle interactions are written down, accurate up to second order in the two-body coupling constants and symmetric with respect to particle permutations.     

利用单个三粒子最大GHZ态或两个EPR态隐形传送任意三粒子GHZ态

提出利用单个三粒子最大Greenberger-Horne-Zeilinger (GHZ)态或两个Einstein-Podolsky-Rosen (EPR)态作为量子信道确定性隐形传送任意三粒子GHZ态的两个方案，并将方案推广至隐形传送任意n(n≥4)粒子GHZ态的情况.讨论了量子信道受噪声影响时隐形传态的保真度.研究发现，当作为量子信道的单个三粒子最大GHZ态受到噪声影响时，隐形传态的保真度仅与量子信道的纠缠度有关，而当作为量子信道的两个EPR态受到噪声影响时，隐形传态的保真度不仅与量子信道的纠缠度有关，还与待传送态的纠缠度有关.所提出的方案具有节省量子信道纠缠资源的特点. 关键词： 隐形传态 三粒子Greenberger-Horne-Zeilinger态 量子逻辑门 保真度     

A Proposal of Telecloning for a Three-Particle Entangled?W?State

A 1→2 telecloning solution for an arbitrary three-particle entangled W state is proposed in which two four-particle entangled states are used as quantum channels. It is proposed that the three-particle W state can be telecloned based on the quantum teleportation and the local copying of entanglement, and the fidelity of each clone depends on the input state. This scheme can be generalized into the case of 1→N (N>2) telecloning of an arbitrary three-particle W state. Furthermore, another scheme for 1→N (N≥2) telecloning of an arbitrary n-particle (n≥4) W state is proposed, the multi-bit controlled-NOT (CNOT) gates and additional particles are needed in this case. Project 10574060 supported by the National Natural Science Foundation of China.     

Calculation of partition function by the method of coherent states

The method of coherent states on Lie groups in the case of a three-particle interaction Hamiltonian is used to derive a differential equation that determines the matrix elements of the canonical statistical operator taken between coherent states. An example for which this equation can be solved in a closed form is given. The temperature dependence of the partition function of a pair of fermions interacting with an oscillator is obtained explicitly.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 10, pp. 64–69, October, 1976.     

Quantum Entanglement in Relativistic Three-Particle Systems

The relativistic three-particle systems are studied within the framework of Relativistic Schrödinger Theory (RST), with emphasis on the determination of the energy functional for the stationary bound states. The phenomenon of entanglement shows up here in form of the exchange energy which is a significant part of the relativistic field energy. The electromagnetic interactions become unified with the exchange interactions into a relativistic U(N) gauge theory, which has the Hartree–Fock equations as its non-relativistic limit. This yields a general framework for treating entangled states of relativistic many-particle systems, e.g., the N-electron atoms.     

Elimination of Rotational Degrees of Freedom in Expansion Methods for Three Nucleons

 Euler angles determining rotations of a system as a whole are conveniently separated in three-particle basis functions. Analytic integration of matrix elements over Euler angles is done in a general form. Results for the Euler angle integrated matrix elements of a realistic NN interaction are listed. The partial wave decomposition of correlated three-body states is considered. E-mail address: efros@mbslab.kiae.ru Received May 4, 2002; accepted July 26, 2002     

Structure of the <Superscript>6</Superscript>He nucleus in the three-particle model

The properties of the ⁶He nucleus were investigated in a three-particle approximation (a alpha-particle cluster plus two neutrons) on the basis of the variational approach by using a Gaussian basis. For nn and nα interactions, potentials that make it possible to describe S-wave phase shifts for elastic scattering and, simultaneously, to reproduce faithfully the energy and the size of the ⁶He nucleus were proposed. Characteristic structural features of this nucleus that are manifested in the density distributions, elastic form factor, pair correlation functions, and momentum distributions of particles constituting the ⁶He nucleus in the three-particle model were revealed.     

利用一个三粒子W态隐形传送N粒子GHZ态

杨洪钦等提出一个用两个三粒子W态作为量子信道将N粒子GHZ态从发送者传送给两个接收者中任意一个的量子隐形传送方案. 给出其理论分析,并提出了一个仅用一个三粒子W态作为量子信道将N粒子GHZ态传送给两个接收者之一的量子隐形传送的方案. 关键词： 隐形传态 GHZ态 W态量子信道     

Influence of <Emphasis Type="Italic">CP</Emphasis> and <Emphasis Type="Italic">CPT</Emphasis> on production and decay of Dirac and Majorana fermions

The consequences of CP and CPT invariance for production and subsequent decay of Dirac and Majorana fermions in polarized fermion-antifermion annihilation are analytically studied. We derive general symmetry relations for the production spin density matrix and for the three-particle decay matrices and obtain constraints for the polarization and the spin-spin correlations of Dirac and Majorana fermions. We prove that only for Majorana fermions the energy and opening angle distribution factorizes exactly into contributions from production and decay if CP is conserved. Received: 6 November 2001 / Revised version: 23 April 2002 / Published online: 12 July 2002     

Correlated complex exponential wave functions for atomic-molecular systems

The application of flexible correlated complex exponential basis functions depending on all inter-particle distances in precision variational computations of atomic-molecular systems is considered. In contrast to three-particle systems, the application of such functions for four-particle systems is hindered by the cumber-some nature of the multistep algorithm of evaluation of the integrals determining the matrix elements of the energy operator. Transformations reducing the number of integrals to be evaluated are carried out. As a result, the computation volume is reduced by a factor of six: instead of 43 integrals, it is sufficient to take 6 integrals of the Coulomb interaction of pairs of particles and the overlap integral. The method of direct construction of formulas for many-particle integrals is discussed.     

Resonance effects in the binding of a nucleon to an unbound core

The theory of the single-particle form factor for a nucleon bound to an unbound core presented recently is implemented as a concrete three-particle model for ⁶Li. It is shown that for reasonable assumptions concerning the interactions involved one can reproduce the experimental binding energy and size of this nucleus.     

Remote Operation on Quantum State Among Multiparty

In this paper, a scheme is proposed for performing remote operation on quantum state among multiparty. We use three-particle GHZ state as quantum channels to prepare a state operator, which describes quantum correlation between states and operations. Based on the special characteristic of the state operator, observers can perform unitary operation on a system that is away from observers. Our studies show this process is deterministic. We further consider remote operation among N spatially distributed observers, and the results show the successful realization of remote operation needs collective participation of N parties, that is, there exists strong correlation among multiparty. In addition, we investigate the case in which observers share a three-particle W state as quantum channels to perform remote operation and studies find this process is probabilistic.     

A Hilbert space approach to the Lippmann-Schwinger equation in momentum representation

We study the Lippmann-Schwinger equation for the quantum mechanical two-body scattering problem. We propose a Hilbert space approach in momentum-angular momentum representation. Imposing a Hölder integrability condition on the potential, the kernel of the integral equation becomes a compact operator in an adequate Hilbert space H⁰. We show that expansion into orthogonal polynomials becomes very simple, and we give an application to the three-particle problem.     

利用三粒子纠缠态建立量子隐形传态网络的探讨

利用W态纠缠源可以产生三纠缠粒子，用这些相互纠缠的粒子作为量子信道，再辅以经典信道传送Bell基联合测量信息和von Neumann测量信息，便可实现量子隐形传态网络.基于上述思想，研究了三纠缠粒子量子隐形传态网络的物理基础，得到了基于三粒子W 关键词： 量子通信 量子隐形传态 W态')" href="#">W态     

Green's functions of three-particle subresolvents containing separable potentials

Analytic expressions for Green's functions of three-particle subresolvents (including one spectator particle) are given, i.e. the configuration space representation of the operator-valued functionG _α (z)=(z?K?V _α )^?1 whereK is the total kinetic energy of the three-particle system andV _α is the interaction of the pairΒγ. A sum of separable potentials is well suited to exhibit the structure of the corresponding Riemann surface such that from these results also some conclusions may be drawn about the full Green's operator of the three-particle system.     

Threshold behaviour of the three-particle scattering amplitude and gas approximation in the many-body problem

It is established by investigation of the gas approximation for the ground state energy in many-body problem how the low energy parameters of the two-particle and essentially three-particle scattering amplitude determine the dominant terms of the energy expansion in series of gas parameter. The correspondence to the gas approximation in the Faddeev integral equations in the form of the three-particle amplitude low energy behaviour near the threshold E → 0 is obtained.     

<Emphasis Type="Italic">B</Emphasis>→<Emphasis Type="Italic">D</Emphasis><Superscript>(*)</Superscript> form factors from QCD light-cone sum rules

We derive new QCD sum rules for B→D and B→D ^* form factors. The underlying correlation functions are expanded near the light-cone in terms of B-meson distribution amplitudes defined in HQET, whereas the c-quark mass is kept finite. The leading-order contributions of two- and three-particle distribution amplitudes are taken into account. From the resulting light-cone sum rules we calculate all B→D ^(*) form factors in the region of small momentum transfer (maximal recoil). In the infinite heavy-quark mass limit the sum rules reduce to a single expression for the Isgur–Wise function. We compare our predictions with the form factors extracted from experimental B→^(*) l ν _l decay rates fitted to dispersive parameterizations.