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.
118113543
Dynamically broken supergauge symmetries
The dynamical breaking of the supergauge symmetries in the massless supergauge Wess-Zumino 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 and the gauge symmetry breaking can be realized dynamically. It is also shown that the dynamical breaking moves the vacuum expectation values of two scalar fields away from zero. In order to restore the symmetry of the vacuum, one of the two scalar fields is translated and at the same time the mass spectrum is changed too.
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.
121108397
Soliton Solution of SU(3) Gauge Fields at Finite Temperature
Starting from a soliton model of SU(3) gauge fields, we investigate the behaviour of the model at finite temperature. it is found that colour confinement at zero temperature can be melted away under high temperatures.
119693019
Dynamical Symmetry Breaking of Maximally Generalized Yang–Mills Model and Its Restoration at Finite Temperatures
In terms of the Nambu–Jona-Lasinio mechanism, dynamical breaking of gauge symmetry for the maximally generalized Yang–Mills model is investigated. The gauge symmetry behavior at finite temperature is also investigated and it is shown that the gauge symmetry broken dynamically at zero temperature can be restored at finite temperatures.
116939187
Dynamical CP violation of the generalized Yang-Mills model
Starting from the generalized Yang-Mills model which contains, besides the vector part Vμ, also a scalar part S and a pseudoscalar part P. It is shown, in terms of the Nambu-Jona-Lasinio (NJL) mechanism, that CP violation can be realized dynamically. The combination of the generalized Yang-Mills model and the NJL mechanism provides a new way to explain CP violation.
17295428
Influences of the magnetic coupling process on the spectrum of a disk covered by the corona
Context. Recently, much attention has been paid to the magnetic coupling (MC) process, which is supported by the very high emissivity indexes observed in Seyfert 1 galaxy MCG-6-30-15 and GBHC XTE J1650-500. But the rotational energy transferred from a black hole is simply assumed to be radiated away from the surrounding accretion disk in the black-body spectrum, which is obviously not consistent with the observed hard power-law X-ray spectra. Aims. We introduce a corona into the MC model to make it more compatible with observations. Methods. We describe the model and the procedure of a simplified Monte Carlo simulation, compare the output spectra in the cases with and without the MC effects, and discuss the influences of the three parameters involved in the MC process on the output spectra. Results. It is shown that the MC process augments radiation fluxes in the UV or X-ray band. The emergent spectrum is affected by the BH spin and magnetic field strength at the BH horizon, while it is almost unaffected by the radial profile of the magnetic field at the disk. Conclusions. Introducing corona into the MC model will improve the fitting of the output spectra from AGNs and GBHCs.
123177398
FERMI@Elettra: A Seeded Harmonic Cascade FEL for EUV and Soft X-Rays
We describe the machine layout and major performance parameters for the FERMI FEL project funded for construction at Sincrotrone Trieste, Italy, within the next five years. The project will be the first user facility based on seeded harmonic cascade FEL's, providing controlled, high peak-power pulses. With a high-brightness rf photocathode gun, and using the existing 1.2 GeV S-band linac, the facility will provide tunable output over a range from {approx}100 nm to {approx}10 nm, with pulse duration from 40 fs to {approx} 1ps, peak power {approx}GW, and with fully variable output polarization. Initially, two FEL cascades are planned; a single-stage harmonic generation to operate > 40 nm, and a two-stage cascade operating from {approx}40 nm to {approx}10 nm or shorter wavelength. The output is spatially and temporally coherent, with peak power in the GW range. Lasers provide modulation to the electron beam, as well as driving the photocathode and other systems, and the facility will integrate laser systems with the accelerator infrastructure, including a state-of-the-art optical timing system providing synchronization of rf signals, lasers, and x-ray pulses. Major systems and overall facility layout are described, and key performance parameters summarized.
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
119212313
FEL Polarization Control Studies on Dalian Coherent Light Source
The polarization switch of a free-electron laser (FEL) is of great importance to the user scientific community. In this paper, we investigate the generation of controllable polarization FEL from two well-known approaches for Dalian coherent light source, i.e., crossed planar undulator and elliptical permanent undulator. In order to perform a fair comparative study, a one-dimensional time-dependent FEL code has been developed, in which the imperfection effects of an elliptical permanent undulator are taken into account. Comprehensive simulation results indicate that the residual beam energy chirp and the intrinsic FEL gain may contribute to the degradation of the polarization performance for the crossed planar undulator. And the elliptical permanent undulator is not very sensitive to the undulator errors and beam imperfections. Meanwhile, with proper configurations of the main planar undulators and additional elliptical permanent undulator section, circular polarized FEL with pulse energy exceeds 100 μJ could be achieved at Dalian coherent light source.
44445173
Beam-Beam Effects in the Ring-Ring Version of eRHIC
Beam-beam effects in the ring-ring version of eRHIC was studied with a self-consistent beam-beam simulation by using the particle-in-cell method. Beam-beam limits of the two beams were examined as the thresholds of the onset of the coherent beam-beam instability. For the proposed luminosity, the bunch intensities optimized in consideration of the beam-beam effect were discussed. As the beam-beam interaction in the eRHIC is traditionally considered as a strong-weak case, this represents an example of the coherent beam-beam effect in the strong-weak case of beam-beam interactions.