The Generic Supersymmetric Standard Model as the Complete Theory of Supersymmetry without R-parity

The generic supersymmetric standard model is a model built from a supersymmetrized standard model field spectrum the gauge symmetries only. The popular minimal supersymmetric standard model differs from the generic version in having R-parity imposed by hand. We review an efficient formulation of the model in which all the admissible R-parity violating terms are incorporated without bias. The model gives many new interesting R-parity violating phenomenological features only started to be studied recently. Some of our recent results will be discussed, including newly identified 1-loop contributions to neutrino masses and electric dipole moments of neutron and electron. This is related to the largely overlooked R-parity violating contributions to squark and slepton mixings, which we also present in detail.Comment: 10 pages latex using espcrc2.sty (included) with a latex table and 3 eps- figure files incoporated, typos in a couple of expressions fixe

Golden Parachutes and the Limits of Shareholder Voting

With the passage of the Dodd-Frank Wall Street Reform and Consumer Protection Act in 2010, Congress attempted to constrain change-in-control payments (also known as “golden parachutes”) by giving shareholders the right to approve or disapprove such payments on an advisory basis. This Essay is the first to empirically examine the experience with the Say-on-Golden-Parachute (“SOGP”) vote. We find that unlike shareholder votes on proposed mergers, there is a significant amount of variation with respect to votes on golden parachutes. Notwithstanding the variation, however, the SOGP voting regime is likely ineffective in controlling golden parachute (“GP”) compensation. First, proxy advisors seem more likely to adopt a one-size-fits-all approach to recommendations on SOGP votes. Second, shareholders are more likely to adhere to advisor recommendations. Finally, the size of golden parachutes appears to be increasing in the years since the adoption of the Dodd-Frank Act in 2010, and the golden parachutes that are amended immediately prior to SOGP votes tend to grow rather than shrink. These findings contrast with the research that has examined Say on Pay (“SOP”), and we suggest that the differences between the two regimes lie in the absence of second-stage, marketbased discipline for SOGP votes. We offer potential avenues for improving SOGP’s ability to shape change-in-control compensation practices, such as making SOGP votes (partially) binding, and making the GP payment and SOGP voting information more readily available to shareholders of corporations where the target directors also serve as directors of acquiring corporations

Beam divergence measurements of InGaN/GaN micro-array light-emitting diodes using confocal microscopy

The recent development of high-density, two-dimensional arrays of micrometer-sized InGaN/GaN light-emitting diodes (micro-LEDs) with potential applications from scientific instrumentation to microdisplays has created an urgent need for controlled manipulation of the light output from these devices. With directed light output these devices can be used in situations where collimated beams or light focused onto several thousand matrix points is desired. In order to do this effectively, the emission characteristics of the devices must be fully understood and characterized. Here we utilize confocal microscopy to directly determine the emission characteristics and angular beam divergences from the individual micro-LED elements. The technique is applied to both top (into air) and bottom (through substrate) emission in arrays of green (540 nm), blue (470 nm), and UV (370 nm) micro-LED devices, at distances of up to 50 µm from the emission plane. The results are consistent with simple optical modeling of the expected beam profiles

Extended nonlocal chiral-quark model for the heavy-light quark systems

In this talk, we report the recent progress on constructing a phenomenological effective model for the heavy-light quark systems, which consist of (u,d,s,c,b) quarks, i.e. extended nonlocal chiral-quark model (ExNLChQM). We compute the heavy-meson weak-decay constants to verify the validity of the model. From the numerical results, it turns out that (f_D, f_B, f_{D_s}, f_{B_s})=(207.54,208.13,262.56,262.39) MeV. These values are in relatively good agreement with experimental data and various theoretical estimations.Comment: 3 pages, 4 figures, Talk given at the 20th International IUPAP Conference on Few-Body Problems in Physics (FB20), 20~25 August 2012, Fukuoka, Japa

Time and Amplitude of Afterpulse Measured with a Large Size Photomultiplier Tube

We have studied the afterpulse of a hemispherical photomultiplier tube for an upcoming reactor neutrino experiment. The timing, the amplitude, and the rate of the afterpulse for a 10 inch photomultiplier tube were measured with a 400 MHz FADC up to 16 \ms time window after the initial signal generated by an LED light pulse. The time and amplitude correlation of the afterpulse shows several distinctive groups. We describe the dependencies of the afterpulse on the applied high voltage and the amplitude of the main light pulse. The present data could shed light upon the general mechanism of the afterpulse.Comment: 11 figure

Reduced order models for control of fluids using the Eigensystem Realization Algorithm

In feedback flow control, one of the challenges is to develop mathematical models that describe the fluid physics relevant to the task at hand, while neglecting irrelevant details of the flow in order to remain computationally tractable. A number of techniques are presently used to develop such reduced-order models, such as proper orthogonal decomposition (POD), and approximate snapshot-based balanced truncation, also known as balanced POD. Each method has its strengths and weaknesses: for instance, POD models can behave unpredictably and perform poorly, but they can be computed directly from experimental data; approximate balanced truncation often produces vastly superior models to POD, but requires data from adjoint simulations, and thus cannot be applied to experimental data. In this paper, we show that using the Eigensystem Realization Algorithm (ERA) \citep{JuPa-85}, one can theoretically obtain exactly the same reduced order models as by balanced POD. Moreover, the models can be obtained directly from experimental data, without the use of adjoint information. The algorithm can also substantially improve computational efficiency when forming reduced-order models from simulation data. If adjoint information is available, then balanced POD has some advantages over ERA: for instance, it produces modes that are useful for multiple purposes, and the method has been generalized to unstable systems. We also present a modified ERA procedure that produces modes without adjoint information, but for this procedure, the resulting models are not balanced, and do not perform as well in examples. We present a detailed comparison of the methods, and illustrate them on an example of the flow past an inclined flat plate at a low Reynolds number.Comment: 22 pages, 7 figure

Vertex functions for d-wave mesons in the light-front approach

While the light-front quark model (LFQM) is employed to calculate hadronic transition matrix elements, the vertex functions must be pre-determined. In this work we derive the vertex functions for all d-wave states in this model. Especially, since both of $^3D_1$ and $^3S_1$ are $1^{--}$ mesons, the Lorentz structures of their vertex functions are the same. Thus when one needs to study the processes where $^3D_1$ is involved, all the corresponding formulas for $^3S_1$ states can be directly applied, only the coefficient of the vertex function should be replaced by that for $^3D_1$. The results would be useful for studying the newly observed resonances which are supposed to be d-wave mesons and furthermore the possible 2S-1D mixing in $\psi'$ with the LFQM.Comment: 12 pages, 2 figures, some typos corrected and more discussions added. Accepted by EPJ

Superconductivity in the C32 Intermetallic Compounds AAl(2-x)Si(x), with A=Ca and Sr, and 0.6<x<1.2

The intermetallic compounds AAl2-xSix, where A = Ca, Sr or Ba, crystallize in the C32 structure, same as the recently discovered MgB2 with a high superconducting transition temperature of 39 K. For x = 1, superconductivity has been observed in AAlSi with A = Ca and Sr, but not with A = Ba. The transition temperatures are 7.8 and 5.1 K, respectively for CaAlSi and SrAlSi. The CaAl2-xSix compound system display a Tc-peak at x = 1, a possible x-induced electronic transition at x ~ 0.75 and a possible miscibility gap near x ~ 1.1 which results in a very broad superconducting transition. The Seebeck coefficients of AAlSi indicate that their carriers are predominantly electrons in nature, in contrast to the holes in MgB2.Comment: 10 pages, 6 figure

Spectral Correlation in Incommensurate Multi-Walled Carbon Nanotubes

We investigate the energy spectra of clean incommensurate double-walled carbon nanotubes, and find that the overall spectral properties are described by the so-called critical statistics of Anderson metal-insulator transition. In the energy spectra, there exist three different regimes characterized by Wigner-Dyson, Poisson, and semi-Poisson distributions. This feature implies that the electron transport in incommensurate multi-walled nanotubes can be either diffusive, ballistic, or intermediate between them, depending on the position of the Fermi energy.Comment: final version to appear in Phys. Rev. Let