Beyond the soft photon approximation in radiative production and decay of charged vector mesons

We study the effects of model-dependent contributions and the electric quadrupole moment of vector mesons in the decays $V^- \to P^-P^0\gamma$ and $\tau^- \to \nu V^-\gamma$. Their interference with the amplitude originating from the radiation due to electric charges vanishes for photons emitted collinearly to the charged particle in the final state. This brings further support to our claim in previous works, that measurements of the photon energy spectrum for nearly collinear photons in those decays are suitable for a first measurement of the magnetic dipole moment of charged vector mesons.Comment: 13 pages, 2 eps figures, Latex. Accepted for publication in Journal of Physics G: Nuclear and Particle Physics(2001

CP violation in semileptonic tau lepton decays

The leading order contribution to the direct CP asymmetry in tau^{+/-} -> K^{+/-} pi^0 nu_{tau} decay rates is evaluated within the Standard Model. The weak phase required for CP violation is introduced through an interesting mechanism involving second order weak interactions, which is also responsible for tiny violations of the Delta S= Delta Q rule in K_{l3} decays. The calculated CP asymmetry turns out to be of order 10^{-12}, leaving a large window for studying effects of non-standard sources of CP violation in this observable.Comment: 5 pages, 3 figures, version published in Phys.Rev.

Electron-Electron Interactions in the Vacuum Polarization of Graphene

We discuss the effect of electron-electron interactions on the static polarization properties of graphene beyond RPA. Divergent self-energy corrections are naturally absorbed into the renormalized coupling constant $\alpha$. We find that the lowest order vertex correction, which is the first non-trivial correlation contribution, is finite, and about 30% of the RPA result at strong coupling $\alpha \sim 1$. The vertex correction leads to further reduction of the effective charge. Finite contributions to dielectric screening are expected in all orders of perturbation theory.Comment: 5 pages, 2 figures; published versio

Raman spectroscopy study of the interface structure in (CaCuO2)n/(SrTiO3)m superlattices

Raman spectra of CaCuO2/SrTiO3 superlattices show clear spectroscopic marker of two structures formed in CaCuO2 at the interface with SrTiO3. For non-superconducting superlattices, grown in low oxidizing atmosphere, the 425 cm-1 frequency of oxygen vibration in CuO2 planes is the same as for CCO films with infinite layer structure (planar Cu-O coordination). For superconducting superlattices grown in highly oxidizing atmosphere, a 60 cm-1 frequency shift to lower energy occurs. This is ascribed to a change from planar to pyramidal Cu-O coordination because of oxygen incorporation at the interface. Raman spectroscopy proves to be a powerful tool for interface structure investigation

Electronic compressibility of a graphene bilayer

We calculate the electronic compressibility arising from electron-electron interactions for a graphene bilayer within the Hartree-Fock approximation. We show that, due to the chiral nature of the particles in this system, the compressibility is rather different from those of either the two-dimensional electron gas or ordinary semiconductors. We find that an inherent competition between the contributions coming from intra-band exchange interactions (dominant at low densities) and inter-band interactions (dominant at moderate densities) leads to a non-monotonic behavior of the compressibility as a function of carrier density.Comment: 4 pages, 4 figures. Final versio

Not White Enough, Not Black Enough: Reimagining Affirmative Action Jurisprudence in Law School Admissions Through a Filipino-American Paradigm

Writing the majority opinion upholding the use of racial preferences in law school admissions in 2003, Justice Sandra Day O’Connor anticipated that racial preferences would no longer be necessary in twenty-five years. On the contrary, 2021 has seen the astronomic rise of critical race theory, the popularity of race-driven “diversity” initiatives in higher education, and the continued surge of identity politics in the mainstream. So much has been written on affirmative action—what else could this Comment add to the conversation? Analyzing the Court’s application of strict scrutiny through a Filipino- American paradigm, this Comment ultimately concludes that affirmative action in law school admissions is unconstitutional under the Fourteenth Amendment’s Equal Protection Clause. However, this Comment also concludes that affirmative action is not only necessary to but also consistent with the repeatedly upheld anti-subordination aspect and redistributive rubric of the Reconstruction Amendments. Navigating the tension between these two tenets, this Comment cautiously proposes a race-neutral alternative to current affirmative action policy toward building a more perfect union

Energy harvesting from vehicular traffic over speed bumps: A review

Energy used by vehicles to slow down in areas of limited speed is wasted. A traffic energy-harvesting device (TEHD) is capable of harvesting vehicle energy when passing over a speed bump. This paper presents a classification of the different technologies used in the existing TEHDs. Moreover, an estimation of the energy that could be harvested with the different technologies and their cost has been elaborated. The energy recovered with these devices could be used for marking and lighting of roads in urban areas, making transportation infrastructures more sustainable and environmentally friendly

Dynamical Renormalization Group Study for a Class of Non-local Interface Equations

We provide a detailed Dynamic Renormalization Group study for a class of stochastic equations that describe non-conserved interface growth mediated by non-local interactions. We consider explicitly both the morphologically stable case, and the less studied case in which pattern formation occurs, for which flat surfaces are linearly unstable to periodic perturbations. We show that the latter leads to non-trivial scaling behavior in an appropriate parameter range when combined with the Kardar-Parisi-Zhang (KPZ) non-linearity, that nevertheless does not correspond to the KPZ universality class. This novel asymptotic behavior is characterized by two scaling laws that fix the critical exponents to dimension-independent values, that agree with previous reports from numerical simulations and experimental systems. We show that the precise form of the linear stabilizing terms does not modify the hydrodynamic behavior of these equations. One of the scaling laws, usually associated with Galilean invariance, is shown to derive from a vertex cancellation that occurs (at least to one loop order) for any choice of linear terms in the equation of motion and is independent on the morphological stability of the surface, hence generalizing this well-known property of the KPZ equation. Moreover, the argument carries over to other systems like the Lai-Das Sarma-Villain equation, in which vertex cancellation is known {\em not to} imply an associated symmetry of the equation.Comment: 34 pages, 9 figures. Journal of Statistical Mechanics: Theory and Experiments (in press