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1.
We consider the motion of an impurity in a Bose-Einstein condensate system at T = 0 K with the contact interaztions for boson-boson and boson-impurity. Under the forward-scattering approximation, we obtain a Fr6hlich-like Hamiltonian for this system, which means that a polaron can be formed. The effective mass, the phonon number and the energy to form a polaron are obtained. We also discuss the validity of the forwardscattering approximation for this system. 相似文献
2.
A generalized Collins formula derived by virtue of the displacement-squeezing related squeezed coherent state representation 下载免费PDF全文
Based on the displacement-squeezing related squeezed
coherent state representation ≤ft\vert z\right\rangle _{g} and
using the technique of integration within an ordered product of
operators, this paper finds a generalized Fresnel operator, whose
matrix element in the coordinate representation leads to a
generalized Collins formula (Huygens--Fresnel integration
transformation describing optical diffraction). The generalized
Fresnel operator is
derived by a quantum mechanical mapping from z to sz-rz^{\ast } in the %
≤ft\vert z\right\rangle _{g} representation, while ≤ft\vert
z\right\rangle _{g} in phase space is graphically denoted by an
ellipse. 相似文献
3.
The kaon meson electromagnetic form factor is calculated in the framework of coupled Schwinger-Dyson and Bethe-Salpeter formulation in simplified impulse approximation (dressed vertex) with modified flat-bottom potential, which is a combination of the flat-bottom potential taking into consideration the infrared and ultraviolet asymptotic behaviours of the effective quark-gluon coupling. All the numerical results give a good fit to experimental values. 相似文献
4.
An effective action for Bose-Hubbard model with two-and three-body on-site interaction in a square optical lattice is derived in the frame of a strong-coupling approach developed by Sengupta and Dupuis.From this effective action,superfluid-Mott insulator(MI) phase transition,excitation spectrum and momentum distribution for two phases are calculated by taking into account Gaussian fluctuation about the saddle-point approximation.In addition the effects of three-body interaction are also discussed. 相似文献
5.
An Electromagnetic Form Factor of a Charged Scalar Meson with Schwinger-Dyson and Bethe-Salpeter Equations 下载免费PDF全文
The wave functions and electromagnetic form factor of charged scalar mesons are studied with a modified vectorvector fiat-bottom potential model under the framework of the Schwinger-Dyson and Bethe-Salpeter equations. The obtained results agree well with other theories. 相似文献
6.
First and second sound modes in a uniform fermionic atom gas with Feshbaeh resonance are investigated in the frame of a two-fluid model at finite temperature. All thermodynamic quantities axe calculated for a given thermodynamic potential. The analytical results for thermodynamic quantities and sound velocities in BCS and BEC limits are obtained. The numerical results show that there exists a continuous interpolation for sound velocities of the first and second sound modes at fixed T/Tc between BCS and BEC limits. The existence of the second sound mode indicates the existence of superfluidity. 相似文献
7.
When the fourth generation of quarks have sufficiently small mixing with ordinary standard-model quarks, the hadrons made up from these quarks can be long-lived enough. We analyze the (1/2)+ baryon states containing fourth-generation quarks and standard-model quarks, i.e. the charm or bottom quarks, in the QCD sum rules approach. Considering the perturbative and two gluon condensate contributions in the calculation, we give the numerical results of the masses and pole residues. 相似文献
8.
Behaviour of a simple model polariton system is restudied.The distribution of phonons in polartion never is sub-Poisson given by computation of the thermal counterpart of the Q parameter and the matrix m^(3).The polariton complex as a whole shows non-classical behaviour below a threshold temperature,which depends on the photon-phonon coupling strength,when the distribution of phonons is always classical at any temperature. 相似文献
9.
10.
The light vector mesons are studied within the framework of the Beth-Salpeter equation with the vector vectortype flat-bottom potential. The Bethe-Salpeter wavefunetions and the decay constants of the vector mesons are obtained. All the obtained results, fp, f φ, and fK*, are in agreement with the experimental values, respectively. 相似文献