943 research outputs found
A split SUSY model from SUSY GUT
We propose to split the sparticle spectrum from the hierarchy between the GUT
scale and the Planck scale. A split supersymmetric model, which gives
non-universal gaugino masses, is built with proper high dimensional operators
in the framework of SO(10) GUT. Based on a calculation of two-loop beta
functions for gauge couplings (taking into account all weak scale threshold
corrections), we check the gauge coupling unification and dark matter
constraints (relic density and direct detections). We find that our scenario
can achieve the gauge coupling unification and satisfy the dark matter
constraints in some part of parameter space. We also examine the sensitivity of
the future XENON1T experiment and find that the currently allowed parameter
space in our scenario can be covered for a neutralino dark matter below about
1.0 TeV.Comment: 16 pages, 3 figure; minor changes, references adde
Heavy colored SUSY partners from deflected anomaly mediation
We propose a deflected anomaly mediation scenario from SUSY QCD which can
lead to both positive and negative deflection parameters (there is a smooth
transition between these two deflection parameter regions by adjusting certain
couplings). Such a scenario can naturally give a SUSY spectrum in which all the
colored sparticles are heavy while the sleptons are light. As a result, the
discrepancy between the Brookheaven experiment and LHC data can be
reconciled in this scenario. We also find that the parameter space for
explaining the anomaly at level can be fully covered by the
future LUX-ZEPLIN 7.2 Ton experiment.Comment: 16 pages, 6 figure
Probing GeV-scale MSSM neutralino dark matter in collider and direct detection experiments
Given the recent constraints from the dark matter (DM) direct detections, we
examine a light GeV-scale (2-30 GeV) neutralino DM in the alignment limit of
the Minimal Supersymmetric Standard Model (MSSM). In this limit without
decoupling, the heavy CP-even scalar plays the role of the Standard Model
(SM) Higgs boson while the other scalar can be rather light so that the DM
can annihilate through the resonance or into a pair of to achieve the
observed relic density. With the current collider and cosmological constraints,
we find that such a light neutralino DM above 6 GeV can be excluded by the
XENON-1T (2017) limits while the survivied parameter space below 6 GeV can be
fully covered by the future germanium-based light dark matter detections (such
as CDEX), by the Higgs coupling precison measurements or by the production
process at an electron-positron collider (Higgs factory).Comment: 15 pages, 5 figures. Discussions and references added, version
accepted by PL
Spatial Multizone Soundfield Reproduction Design
It is desirable for people sharing a physical space to access different multimedia information streams simultaneously. For a good user experience, the interference of the different streams should be held to a minimum. This is straightforward for the video component but currently difficult for the audio sound component. Spatial multizone soundfield reproduction, which aims to provide an individual sound environment to each of a set of listeners without the use of physical isolation or headphones, has drawn significant attention of researchers in recent years. The realization of multizone soundfield reproduction is a conceptually challenging problem as currently most of the soundfield reproduction techniques concentrate on a single zone.
This thesis considers the theory and design of a multizone soundfield reproduction system using arrays of loudspeakers in given complex environments. We first introduce a novel method for spatial multizone soundfield reproduction based on describing the desired multizone soundfield as an orthogonal expansion of formulated basis functions over the desired reproduction region. This provides the theoretical basis of both 2-D (height invariant) and 3-D soundfield reproduction for this work. We then extend the reproduction of the multizone soundfield over the desired region to reverberant environments, which is based on the identification of the acoustic transfer function (ATF) from the loudspeaker over the desired reproduction region using sparse methods. The simulation results confirm that the method leads to a significantly reduced number of required microphones for an accurate multizone sound reproduction compared with the state of the art, while it also facilitates the reproduction over a wide frequency range.
In addition, we focus on the improvements of the proposed multizone reproduction system with regard to practical implementation. The so-called 2.5D multizone oundfield reproduction is considered to accurately reproduce the desired multizone soundfield over a selected 2-D plane at the height approximately level with the listener’s ears using a single array of loudspeakers with 3-D reverberant settings. Then, we propose an adaptive reverberation cancelation method for the multizone soundfield reproduction within the desired region and simplify the prior soundfield measurement process. Simulation results suggest that the proposed method provides a faster convergence rate than the comparative approaches under the same hardware provision. Finally, we conduct the real-world implementation based on the proposed theoretical work. The experimental results show that we can achieve a very noticeable acoustic energy contrast between the signals recorded in the bright zone and the quiet zone, especially for the system implementation with reverberation equalization
- …