124156903
Dynamical Symmetry Breaking for Weinberg–Salam Model and Restoration at Finite Temperature
In this paper, we utilize Nambu-Jona-Lasinio (NJL) mechanism to discuss the dynamical symmetry breaking for Weinberg-Salam model. In the NJL mechanism the symmetry breaking not only is determined by the potential of scalar field but also has important relation with condensate of the fermion pair . We find that the coefficient of quadric term of scalar field can still cause symmetry breaking by virtue of , and the vacuum expected value of scalar field obeys , i.e., the order parameter which causes phase transition is the condensate of fermion pair . We also discuss the restoration problem of gauge symmetry breaking by the NJL mechanism at high temperatures.
125862664
Dynamical Breaking of Supersymmetry and Its Restoration at High Temperatures
The dynamical breaking of the supersymmetric Higgs model is discussed without adding the Fayet—Iliopoulos term to the Lagrangian. It is shown, in terms of the Nambu—Jona-Lasinio mechanism, that the supersymmetry breaking can be realized dynamically in the supersymmetric Higgs model. The supersymmetry behavior at finite temperatures is also investigated and it is shown that the supersymmetry broken dynamically at zero temperature can be restored at finite temperatures.
123979917
A QCD Model Using Generalized Yang–Mills Theory
Generalized Yang–Mills theory has a covariant derivative, which contains both vector and scalar gauge bosons. Based on this theory, we construct a strong interaction model by using the group U(4). By using this U(4) generalized Yang–Mills model, we also obtain a gauge potential solution, which can be used to explain the asymptotic behavior and color confinement.
115467192
Dynamical breaking of supergauge symmetry and its restoration at high temperatures
The dynamical breaking of the supersymmetric Higgs model is discussed without adding the Fayet—Iliopoulos term to the Lagrangian. It is shown, in terms of the Nambu—Jona-Lasinio mechanism, that the supersymmetry breaking can be realized dynamically in the supersymmetric Higgs model. The supersymmetry behavior at finite temperatures is also investigated and it is shown that the supersymmetry broken dynamically at zero temperature can be restored at finite temperatures.
120248097
Maximally Generalized Yang?Mills Model and Dynamical Breaking of Gauge Symmetry
A maximally generalized Yang–Mills model, which contains, besides the vector part Vμ, also an axial-vector part Aμ, a scalar part S, a pseudoscalar part P, and a tensor part Tμν, is constructed and the dynamical breaking of gauge symmetry in the model is also discussed. It is shown, in terms of the Nambu–Jona-Lasinio mechanism, that the gauge symmetry breaking can be realized dynamically in the maximally generalized Yang–Mills model. The combination of the maximally generalized Yang–Mills model and the NJL mechanism provides a way to overcome the difficulties related to the Higgs field and the Higgs mechanism in the usual spontaneous symmetry breaking theory.
119770868
Layout and optics for the RHIC electron cooler
As part of a luminosity upgrade it is planned to add an electron cooling section to the RHIC accelerator. Existing electron coolers operate at low beam energies and use a continuous electron stream. The ion energy of 100 GeV/u in RHIC requires an electron energy of 55 MeV. Therefore the RHIC cooler uses a linac with energy recovery for the electron acceleration. Short bunches exiting the linac section are stretched longitudinally to reduce the momentum charge and space charge effects in the cooling section, and compressed afterwards for deceleration and energy recovery in the linac. This report describes the design of the electron beam transport and simulation results.
117050867
Bunch Length Measurement System at Jefferson Lab Using Coherent Synchrotron Radiation
322774
INFLUENCE OF THE MAGNETIC COUPLING PROCESS ON ADVECTION-DOMINATED ACCRETION FLOWS AROUND BLACK HOLES
A large-scale closed magnetic field can transfer angular momentum and energy between a black hole (BH) and its surrounding accretion flow. We investigate the effects of this magnetic coupling (MC) process on the dynamics of a hot accretion flow (e. g., an advection-dominated accretion flow). The energy and angular momentum fluxes transported by the magnetic field are derived with an equivalent-circuit approach. For a rapidly rotating BH, it is found that the radial velocity and the electron temperature of the accretion flow decrease, whereas the ion temperature and the surface density increase. The significance of the MC effects depends on the value of the viscosity parameter alpha. The effects are obvious for alpha = 0.3 but nearly ignorable for alpha = 0.1. For a BH with specific angular momentum a(*) = 0.9 and alpha = 0.3, we find that for reasonable parameters the radiative efficiency of a hot accretion flow can be increased by similar to 30%.
55642268
Simulation of magnetized beams
The angular momentums of particles in a bunch of beam are of importance in many applications. Usually the angular momentums are related to the end field of solenoids. In electron cooling facilities the solenoid fields are widely used as they are found very helpful not only in focusing and guiding the charge particle beams but also in enhancing the cooling rates. The RHIC electron cooler is a challenging project because it requires a high performance facility including a solenoid with high quality strong field (1 tesla). Issues caused by the end fields of the solenoid have been studied to minimize the extra temperature and coherent motions. In this paper we report recent results in simulating the angular momentums of the electron beam and its application on the RHIC electron cooler
120250349
Momentum space Z2 number, quantized Berry phase and the quantum phase transitions in spin chain systems
We characterize the quantum phase transitions of gapped time-reversal invariant spin chain systems by nontrivial Z2 numbers derived from a quantized Berry phase in a (1?+?1)-dimensional Bloch momentum space. We study this approach analytically in a general two-band model and give a concrete example in a transverse field XY spin chain system. In our scheme, an extra local gauge transformation is performed to the spin system by a time-dependent twist operator, which endows the Hamiltonian of the system with the topology of a torus without changing its energy spectrum. The Z2 number is obtained by a loop integral of the Berry gauge potential along a quarter of the Brillouin zone. We show that the different phases of the XY spin chain system are distinguished by the Z2 topological order in momentum space.