Luo Xiangqian

Bound states and critical behavior of the Yukawa potential

We investigate the bound states of the Yukawa potential V (r)=−λexp(−αr)/r, using different algorithms: solving the Schrödinger equation numerically and our Monte Carlo Hamiltonian approach. There is a critical α = αC, above which no bound state exists. We study the relation between αC and λ for various angular momentum quantum number l, and find in atomic units, αC(l) = λ[A1 exp(−l/B1) + A2 exp(−l/B2)], with A1 = 1.020(18), B1 = 0.443(14), A2 = 0.170(17), and B2 = 2.490(180).

(3+1)-Dimensional Quantum Mechanics from Monte Carlo Hamiltonian: Harmonic Oscillator*

In Lagrangian formulation, it is extremely difficult to compute the excited spectrum and wavefunctions of a quantum theory via Monte Carlo methods. Recently, we developed a Monte Carlo Hamiltonian method for investigating this hard problem and tested the algorithm in quantum-mechanical systems in 1+1 and 2+1 dimensions. In this paper we apply it to the study of the low-energy quantum physics of the (3+1)-dimensional harmonic oscillator.

Hamiltonian Monte Carlo Application to (2+1)-Dimensional Quantum Mechanics*

Using a recently developed Hamiltonian Monte Carlo method, we compute the lowlying energy spectrum and wavefunctions as well as thermodynamical observables in (2+1)-dimensional quantum mechanics, and give an estimate of the statistical errors. Our numerical results are in good agreement with the exact ones.

Monte Carlo Hamiltonian: Linear Potentials*

We further study the validity of the Monte Carlo Hamiltonian method. The advantage of the method, in comparison with the standard Monte Carlo Lagrangian approach, is its capability to study the excited states. We consider two quantum mechanical models: a symmetric one ; and an asymmetric one , for and , for . The results for the spectrum, wave functions and thermodynamical observables are in agreement with the analytical or Runge–Kutta calculations.We further study the validity of the Monte Carlo Hamiltonian method. The advantage of the method, in comparison with the standard Monte Carlo Lagrangian approach, is its capability to study the excited states. We consider two quantum mechanical models: a symmetric one

Calculation of Vacuum Wavefunction and Mass .Gap from Improved (2+l)-Dimensional SU(2) Lattice Gauge Field Hamiltonian*

V(x) = |x|/2

Monte Carlo Hamiltonian: Inverse Potential

; and an asymmetric one

Light Hadron Masses in Quantum Chromodynamics with Valence Wilson Quarks at β=6.25 from a Parallel PC Cluster

V(x)=\infty

Glueball masses from Hamiltonian lattice QCD

, for

Spontaneous chiral-symmetry breaking of lattice QCD with massless dynamical quarks

x<0

Parallel Supercomputing PC Cluster and Some Physical Results in Lattice QCD

and