Zheng-Mao Sheng

Classical Integrability of the O(N) Nonlinear Sigma Model on a Half-Line

The classical integrability of the O(N) nonlinear sigma model on a half-line is examined, and the existence of an infinity of conserved charges in involution is established for the free boundary condition. For the case N = 3 other possible boundary conditions are considered briefly.

High-energy monoenergetic protons from multistaged acceleration of thin double-layer target by circularly polarized laser

Multistaged acceleration of solid-density thin foils by ultraintense circularly polarized laser pulse is investigated. A stable radiation pressure acceleration (RPA) stage is first established. Higher dimensional effects such as transverse instabilities and enhanced electron heating then gradually make the initially opaque foil transparent to the laser light. Accordingly, the dominant acceleration mechanism changes smoothly from RPA to target normal sheath acceleration (TNSA). The transition can therefore enhance the maximum energy of the accelerated ions but broaden their energy spectrum. For a double-layer target, however, the light ions (protons) in the backlayer can be efficiently accelerated in the RPA and TNSA regimes nearly monoenergetically. Two-dimensional particle-in-cell simulations show that with this scheme a circularly polarized laser pulse of peak intensity 3.9x10{sup 22} W/cm{sup 2} can produce a collimated proton bunch that persists for many Rayleigh lengths and its peak energy can reach 4.2 GeV with FWHM of 200 MeV.

Higgs-strahlung and pair production in the e + e − collision in the noncommutative standard model

The Higgs-strahlung process

Bound on noncommutative standard model with hybrid gauge transformation via lepton flavor conserving

{e}^{+}{e}^{\ensuremath{-}}\ensuremath{\rightarrow}ZH

Z

and pair production process

decay

{e}^{+}{e}^{\ensuremath{-}}\ensuremath{\rightarrow}HH

Kinetic damping of Alfvén eigenmodes in general tokamak geometry

are studied in the framework of the minimal noncommutative (NC) standard model. In particular, the Feynman rules involving all orders of the noncommutative parameter

TeV Scale Phenomenology of

\ensuremath{\theta}

e^+e^- \to\mu^+ \mu^-

are derived using reclusive formation of the Seiberg-Witten map. It is shown that the total cross section and angular distribution can be significantly affected because of space-time noncommutativity when the collision energy exceeds to 1 TeV. It is found that in each process, there is an optimal collision energy (

Scattering in the Noncommutative Standard Model with Hybrid Gauge Transformation

{E}_{\mathrm{oc}}