arXiv subjects
Publications and source records attributed to Ji-ho Jang.
We studied the transverse beam dynamics including aberration effects of sextupole and octupole perturbations in a thermal wave model. A functional integration method was used to calculate the first-order perturbation effects. We found that the model successfully explains a PARMILA simulation results for proton beams without space-charge effects in a FODO lattice.
When charged particles collide with a vacuum bubble, they can radiate strong electromagnetic waves due to rapid deceleration. Owing to the energy loss of the particles by this bremsstrahlung radiation, there is a non-negligible damping pressure acting on the bubble wall even when thermal equilibrium is maintained. In the non-relativistic region, this pressure is proportional to the velocity of the wall and could have influenced the bubble dynamics in the early universe.
We investigated the transverse beam dynamics in a thermal wave model by using a functional method. It can describe the beam optical elements separately with a kernel for a component. The method can be applied to general quadrupole magnets beyond a thin lens approximation as well as drift spaces. We found that the model can successfully describe the PARMILA simulation result through an FODO lattice structure for the Gaussian input beam without space charge effects.
We explore the possible enhancement of direct CP violating parameter epsilon'/epsilon in the general left-right model based on the SU(2)_L times SU(2)_R times U(1) gauge group. The mixing matrix of right-handed quarks, V_{CKM}^R is observable in the left-right model, and provides new source of CP violating phase. We calculate the parameter epsilon'/epsilon in the left-right model and show that the new phases from V_{CKM}^R can yield the sizable contribution to the direct CP violation enough to satisfy the recent measurements of Re(epsilon'/epsilon) from Fermilab KTeV and CERN NA48 experiments.
The first order phase transition proceeds via nucleation and growth of true vacuum bubbles. When charged particles collide with the bubble they could radiate electromagnetic wave. We show that, due to an energy loss of the particles by the radiation, the damping pressure acting on the bubble wall depends on the velocity of the wall even in a thermal equilibrium state.