11,273 research outputs found
Probing the baryogenesis and dark matter relaxed in phase transition by gravitational waves and colliders
The cosmological phase transition with Q-balls production mechanism can
explain the baryogenesis and dark matter simultaneously, where constraints on
dark matter masses and reverse dilution are significantly relaxed. We study how
to probe this scenario by collider signals at QCD next-to-leading order and
gravitational wave signals.Comment: 22 pages,9 figures,4 tables, published in Phys.Rev.
Electroweak baryogenesis in the framework of the effective field theory
We study the electroweak baryogenesis in the framework of the effective field
theory. Our study shows that by introducing a light singlet scalar particle and
a dimension-5 operator, it can provide the strong first order phase transition
and the source of the CP-violation during the phase transition, and then
produce abundant particle phenomenology at zero temperature. We also show the
constraints on the new physics scale from the observed baryon-to-photon ratio,
the low-energy experiments, and the LHC data.Comment: 12 pages, 5 figures, 1 table; version published in Phys.Rev.
Three-terminal normal-superconductor junction as thermal transistor
We propose a thermal transistor based on a three-terminal
normal-superconductor (NS) junction with superconductor terminal acting as the
base. The emergence of heat amplification is due to the negative differential
thermal conductance (NDTC) effect for the NS diode in which the normal side
maintains a higher temperature. The temperature dependent superconducting
energy gap is responsible for the NDTC. By controlling quantum dot levels and
their coupling strengths to the terminals, a huge heat amplification factor can
be achieved. The setup offers an alternative tuning scheme of heat
amplification factor and may find use in cryogenic applications.Comment: 6 pages, 3 figure
SU(5) Symmetry of spdfg Interacting Boson Model
The extended interacting boson model with s-, p-, d-, f- and g-bosons being
included (spdfg IBM) are investigated. The algebraic structure including the
generators, the Casimir operators of the groups at the SU(5) dynamical symmetry
and the branching rules of the irreducible representation reductions along the
group chain are obtained. The typical energy spectrum of the Symmetry is given.Comment: 12 pages, 2 figure
Ultraviolet sources for advanced applications in the vacuum UV and near UV
This dissertation documents a systematic study consisting of experimental investigations and theoretical analyses of intense ultraviolet sources in VUV and near-UV. Some engineering issues regarding two prototypes of electrodeless lamps using rf and microwave are discussed.;Various excimers that produce intense UV light are investigated, including: (1) A benchmark Xe2 excimer which has been proven to be very efficient in our novel rf capacitively coupled discharge lamp; (2) A rarely studied excimer, KrI, which suffers from predissociation and was reported to be very weak or invisible by most of other studies; (3) XeI excimer whose emission dominates around 253 nm and is promising as a mercury-free lamp for antibacterial applications. In the above studies, discharge temperatures are estimated from the emission band width. An elaborate kinetic model is developed for KrI to account for the KrI* and I2* intensities as a function of pressure. It was found that Kr2* plays the rule for energy transfer instead of Kr* in the pressure of interest. The electromagnetic wave interaction with charge particles is studied in our 2D and 3D EM-PIC simulations for both the rf and microwave lamps. Important plasma parameters, such as the electron density and temperature are obtained for various pressures. The electron energy distribution function that is important to account for excimer excitation is obtained.;We also performed a high-level ab initio calculation in Gaussian to produce the ground state potential curve for KrI, which agrees with previous scattering experiments and is necessary for predicting spectral emissions. as a systematic study to account for the KrI emission spectra at high pressure, we use a semiclassical model to account for emissions between a bound excited state and an unbound ground state. An explicit expression is obtained to represent the observed spectral intensity. Important molecular constants are obtained for KrI and compared with previous results
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