arXiv subjects
Publications and source records attributed to Alfred Tang.
Radiations produced by neutrino-antineutrino annihilation at the Z0 pole can be used to heat up the primary stage of a thermonuclear warhead and can in principle detonate the device remotely. Neutrino-antineutrino annihilation can also be used as a tactical assault weapon to target hideouts that are unreachable by conventional means.
Muon backgrounds at Super-Kamiokande, KamLAND and CHOOZ are calculated using MUSIC. A modified version of the Gaisser sea level muon distribution and a well-tested Monte Carlo integration method are introduced. Average muon energy, flux and rate are tabulated. Plots of average energy and angular distributions are given. Implications on muon tracker design for future experiments are discussed.
One of the most important and surprising discoveries in cosmology in recent years is the realization that our Universe is dominated by a mysterious dark energy, which leads to an accelerating expansion of space-time. A simple generalization of the standard Friedmann-Robertson-Walker equations based on General Relativity and the Cosmological Principles with the inclusion of a number of closed extra dimensions reproduces the currently observed data on dark energy, without the introduction of any cosmological constant or new particles. In particular, with a few extra dimensions, we obtain the redshift dependence of the deceleration parameter, the dark energy equation of state, as well as the age of the Universe in agreement with data, with essentially no free parameter. This model predicts that the extra dimensions have been compactified throughout the cosmic history, and it therefore suggests that signals from early Universe may give promising signatures of extra dimensions.
Non-supersymmetric Yang-Mill gauge theory in 4-dimension is shown to be dual to 4-dimensional non-supersymmetric string theory in a twisted AdS2(n)xT2 spacetime background. The partition function of a generic hadron is calculated to illustrate the mathematical structure of the twisted QCD topology. The physical implications of the twisted QCD topology are discussed.
We describe a calculation using quenched lattice QCD of the connected part of the neutron electric form factor for momentum transfers in the range $0.3 {\rm GeV^2} \stackrel{<}{\sim} -q^2 \stackrel{<}{\sim} 1.0 {\rm GeV^2}$. We extract the implied charge radius using a Galster parameterization and consider various ways of extrapolating the neutron charge radius value to the chiral limit. We find that the measured charge radii may be reconciled to experiment by standard phenomenology and lowest or next to lowest order contributions from chiral perturbation theory.
A new geometrical interpretation of chiral perturbation theory based on topological QCD is presented in picture format. This work is a written summary of a talk given at NAPP 2003 in Dubrovnik, Croatia.
The Lund string fragmentation model is applied in a non-perturbative calculation of the invariant production cross section of pions from proton-proton collisions in the soft pT region. Invariant production cross sections of pions and kaons from proton-proton collisions in the hard pT region are calculated from the Feynman-Field perturbative QCD parton model. Parameterizations of these production invariant cross sections are described.
This work is a pedagogical introduction to the Lund string fragmentation model and the Feynman-Field hadron production model. Derivations of important formulas are worked out in details whenever possible. An example is given to show how to evaluate the invariant meson production cross section using the Monte Carlo integration technique.
A new method is presented for solving the momentum-space Schrodinger equation with a linear potential. The Lande-subtracted momentum space integral equation can be transformed into a matrix equation by the Nystrom method. The method produces only approximate eigenvalues in the cases of singular potentials such as the linear potential. The eigenvalues generated by the Nystrom method can be improved by calculating the numerical errors and adding the appropriate corrections. The end results are more accurate eigenvalues than those generated by the basis function method. The method is also shown to work for a relativistic equation such as the Thompson equation.
This paper derives most of the formulas in the MKN (Maung-Kahana-Norbury) Theory of bound states which incorporates the Lande Subtraction method to remove the singularities of the Cornell potential.
The non-relativistic Schrodinger equation with the linear and Coulomb potentials is solved numerically in configuration space using the relaxation method. The numerical method presented in this paper is a plain explicit Schrodinger solver which is conceptually simple and is suitable for advanced undergraduate research.
Early Chew-Frautschi plots show that meson and baryon Regge trajectoies are approximately linear and non-intersecting. In this paper, we reconstruct all Regge trajectories from the most recent data. Our plots show that meson trajectories are non-linear and intersecting. We also show that all current meson Regge trajectories models are ruled out by data.