Vibrational Modes in LiBC: Theory Compared with Experiment

The search for other superconductors in the MgB2 class currently is focussed on Li{1-x}BC, which when hole-doped (concentration x) should be a metal with the potential to be a better superconductor than MgB2. Here we present the calculated phonon spectrum of the parent semiconductor LiBC. The calculated Raman-active modes are in excellent agreement with a recent observation, and comparison of calculated IR-active modes with a recent report provides a prediction of the LO--TO splitting for these four modes, which is small for the B-C bond stretching mode at ~1200 cm^{-1}, but large for clearly resolved modes at 540 cm^{-1} and 620 cm^{-1}.Comment: 4 pages, two embedded figures. Physica B (in press

A Revised Effective Temperature Scale for the Kepler Input Catalog

We present a catalog of revised effective temperatures for stars observed in long-cadence mode in the Kepler Input Catalog (KIC). We use SDSS griz filters tied to the fundamental temperature scale. Polynomials for griz color-temperature relations are presented, along with correction terms for surface gravity effects, metallicity, and statistical corrections for binary companions or blending. We compare our temperature scale to the published infrared flux method (IRFM) scale for VJKs in both open clusters and the Kepler fields. We find good agreement overall, with some deviations between (J - Ks)-based temperatures from the IRFM and both SDSS filter and other diagnostic IRFM color-temperature relationships above 6000 K. For field dwarfs we find a mean shift towards hotter temperatures relative to the KIC, of order 215 K, in the regime where the IRFM scale is well-defined (4000 K to 6500 K). This change is of comparable magnitude in both color systems and in spectroscopy for stars with Teff below 6000 K. Systematic differences between temperature estimators appear for hotter stars, and we define corrections to put the SDSS temperatures on the IRFM scale for them. When the theoretical dependence on gravity is accounted for we find a similar temperature scale offset between the fundamental and KIC scales for giants. We demonstrate that statistical corrections to color-based temperatures from binaries are significant. Typical errors, mostly from uncertainties in extinction, are of order 100 K. Implications for other applications of the KIC are discussed.Comment: Corrected for sign flip errors in the gravity corrections. Erratum to this paper is attached in Appendix. Full version of revised Table 7 can be found at http://home.ewha.ac.kr/~deokkeun/kic/sdssteff_v2.dat.g

Acoustically evoked potentials in two cephalopods inferred using the auditory brainstem response (ABR) approach

It is still a matter of debate whether cephalopods can detect sound frequencies above 400 Hz. So far there is no proof for the detection of underwater sound above 400 Hz via a physiological approach. The controversy of whether cephalopods have a sound detection ability above 400 Hz was tested using the auditory brainstem response (ABR) approach, which has been successfully applied in fish, crustaceans, amphibians, reptiles and birds. Using ABR we found that auditory evoked potentials can be obtained in the frequency range 400 to 1500 Hz (Sepiotheutis lessoniana) and 400 to 1000 Hz (Octopus vulgaris), respectively. The thresholds of S. lessoniana were generally lower than those of O. vulgaris

The radio structure of 3C 316, a galaxy with double-peaked narrow optical emission lines

The galaxy 3C\,316 is the brightest in the radio band among the optically-selected candidates exhibiting double-peaked narrow optical emission lines. Observations with the Very Large Array (VLA), Multi-Element Remotely Linked Interferometer Network (e-MERLIN), and the European VLBI Network (EVN) at 5\,GHz have been used to study the radio structure of the source in order to determine the nature of the nuclear components and to determine the presence of radio cores. The e-MERLIN image of 3C 316 reveals a collimated coherent east-west emission structure with a total extent of about 3 kpc. The EVN image shows seven discrete compact knots on an S-shaped line. However, none of these knots could be unambiguously identified as an AGN core. The observations suggest that the majority of the radio structure belongs to a powerful radio AGN, whose physical size and radio spectrum classify it as a compact steep-spectrum source. Given the complex radio structure with radio blobs and knots, the possibility of a kpc-separation dual AGN cannot be excluded if the secondary is either a naked core or radio quiet.Comment: 12 pages, 3 figures, 2 tables. Accepted for publication in the MNRA

Muon anomalous magnetic moment and lepton flavor violation in MSSM

We give a thorough analysis of the correlation between the muon anomalous magnetic moment and the radiative lepton flavor violating (LFV) processes within the minimal supersymmetric standard model. We find that in the case when the slepton mass eigenstates are nearly degenerate, $\delta a_\mu$, coming from SUSY contributions, hardly depends on the lepton flavor mixing and, thus, there is no direct relation between $\delta a_\mu$ and the LFV processes. On the contrary, if the first two generations' sleptons are much heavier than the 3rd one, i.e., in the effective SUSY scenario, the two quantities are closely related. In the latter scenario, the SUSY parameter space to account for the experimental $\delta a_\mu$ is quite different from the case of no lepton flavor mixing. Especially, the Higgsino mass parameter $\mu$ can be either positive or negative.Comment: 22 pages, 9 figures; Some discussions are modifie