The rare decay B0 → φφ can occur only via penguin annihilation topology in the standard model. We calculate this channel in the perturbative QCD approach. The predicted branching ratio is very small at (10−8). We also give the polarization fractions, which shows that the transverse polarization contribution is comparable to the longitudinal one, due to a big transverse contribution from factori...

A broadband wavelength-parallel polarimeter has been designed or polarization measurements of multiple Dense WDM channels in parallel, which is based on a 2-D spectral disperser via a diffraction grating and a virtually-imaged phased-array (VIPA). At a hyperfine 2.8 GHz sub-channel spacing, we have demonstrated spectral polarization measurements of ~1500 sub-channels (~32 nm spectral range), wi...

Quantum Cryptography, or more accurately, Quantum Key Distribution (QKD) is based on using an unconditionally secure “quantum channel” to share a secret key among two users. A manufacturer of QKD devices could, intentionally or not, use a (semi-)classical channel instead of the quantum channel, which would remove the supposedly unconditional security. One example is the BB84 protocol, where the...

This report presents experimental results on a Multi-User MultiInput Multi-Output (MU-MIMO) channel of an antenna with orthogonal patterns and polarizations in an outdoor urban area. The antenna configuration employing orthogonal patterns and polarizations is useful in achieving a small terminal antenna since many antennas can be placed in the same location. The properties of this antenna are c...

Ion permeation through the gramicidin channel is studied using a model that circumvents two major difficulties inherent to standard simulational methods. It exploits the timescale separation between electronic and structural contributions to dielectric stabilization, accounting for the influence of electronic polarization by embedding the channel in a dielectric milieu that describes this polar...

A transcranial channel is an interface between the skull and brain; it consists of a biocompatible and highly conductive material that helps convey the current induced by transcranial direct current stimulation (tDCS) to the target area. However, it has been proposed only conceptually, and there has been no concrete study of its efficacy. In this work, we conducted a computational investigation...