Microlensing Detections of Moons of Exoplanets

We investigate the characteristic of microlensing signals of Earth-like moons orbiting ice-giant planets. From this, we find that non-negligible satellite signals occur when the planet-moon separation is similar to or greater than the Einstein radius of the planet. We find that the satellite signal does not diminish with the increase of the planet-moon separation beyond the Einstein radius of the planet unlike the planetary signal which vanishes when the planet is located well beyond the Einstein radius of the star. We also find that the satellite signal tends to have the same sign as that of the planetary signal. These tendencies are caused by the lensing effect of the star on the moon in addition to the effect of the planet. We determine the range of satellite separations where the microlensing technique is optimized for the detections of moons. By setting an upper limit as the angle-average of the projected Hill radius and a lower limit as the half of the Einstein radius of the planet, we find that the microlensing method would be sensitive to moons with projected separations from the planet of $0.05 {\rm AU} \lesssim d_{\rm p} \lesssim 0.24 {\rm AU}$ for a Jupiter-mass planet, $0.03 {\rm AU}\lesssim d_{\rm p} \lesssim 0.17 {\rm AU}$ for a Saturn-mass planet, and $0.01 {\rm AU} \lesssim d_{\rm p} \lesssim 0.08 {\rm AU}$ for a Uranus-mass planet. We compare the characteristics of the moons to be detected by the microlensing and transit techniquesComment: 6pages, 6 figure

Grid computing in image analysis

Diagnostic surgical pathology or tissue–based diagnosis still remains the most reliable and specific diagnostic medical procedure. The development of whole slide scanners permits the creation of virtual slides and to work on so-called virtual microscopes. In addition to interactive work on virtual slides approaches have been reported that introduce automated virtual microscopy, which is composed of several tools focusing on quite different tasks. These include evaluation of image quality and image standardization, analysis of potential useful thresholds for object detection and identification (segmentation), dynamic segmentation procedures, adjustable magnification to optimize feature extraction, and texture analysis including image transformation and evaluation of elementary primitives

A Morphological Assessment of Bovine Chondrocytes Cultured on Poly(Ethyl Methacrylate)/Tetrahydrofurfuryl Methacrylate

A heterocyclic methacrylate polymer system, PEMA/THFMA, has shown potential as a biomaterial for cartilage repair in a rabbit model and has properties making it suitable for use clinically. The ability of the polymer system, PEMA/THFMA, and a related system, PEMA/HEMA, to support chondrocytes in vitro was assessed by scanning electron microscopy. Chondrocytes adhered to the surface of the PEMA/THFMA by day one, having a rounded morphology and clustered appearance opposed to the Thermanox® control, where the cells had spread out and become fibroblastic in appearance. The chondrocytes divided rapidly on the PEMA/ THFMA system by day three and had completely covered the surface by day seven. In contrast, chondrocytes did not adhere well to the more hydrophilic PEMA/ HEMA system. A few cells were seen on the surface by day one and by days three and seven, there was no evidence of cell growth or spreading across the surface. In conclusion, the PEMA/THFMA system can support chondrocytes in vitro, whereas the PEMA/HEMA system does not

Neutrino wave function and oscillation suppression

We consider a thought experiment, in which a neutrino is produced by an electron on a nucleus in a crystal. The wave function of the oscillating neutrino is calculated assuming that the electron is described by a wave packet. If the electron is relativistic and the spatial size of its wave packet is much larger than the size of the crystal cell, then the wave packet of the produced neutrino has essentially the same size as the wave packet of the electron. We investigate the suppression of neutrino oscillations at large distances caused by two mechanisms: 1) spatial separation of wave packets corresponding to different neutrino masses; 2) neutrino energy dispersion for given neutrino mass eigenstates. We resolve contributions of these two mechanisms.Comment: 7 page

Remarks upon the mass oscillation formulas

The standard formula for mass oscillations is often based upon the approximation $t \approx L$ and the hypotheses that neutrinos have been produced with a definite momentum $p$ or, alternatively, with definite energy $E$. This represents an inconsistent scenario and gives an unjustified reduction by a factor of two in the mass oscillation formulas. Such an ambiguity has been a matter of speculations and mistakes in discussing flavour oscillations. We present a series of results and show how the problem of the factor two in the oscillation length is not a consequence of gedanken experiments, i.e. oscillations in time. The common velocity scenario yields the maximum simplicity.Comment: 9 pages, AMS-Te

Neutrino oscillations and the effect of the finite lifetime of the neutrino source

We consider a neutrino source at rest and discuss a condition for the existence of neutrino oscillations which derives from the finite lifetime $\tau_S$ of the neutrino source particle. This condition is present if the neutrino source is a free particle such that its wave function is non-stationary. For a Gaussian wave function and with some simplifying assumptions, we study the modification of the usual oscillation probability stemming from $\tau_S$. In the present accelerator experiments the effect of $\tau_S$ can be neglected. We discuss some experimental situations where the source lifetime becomes relevant in the oscillation formula.Comment: 13 pages latex file with 2 figure

Neutralino Pair Production and 3-Body Decays at e+e−e^+e^- Linear Colliders as Probes of CP Violation in the Neutralino System

In the CP-invariant supersymmetric theories, the steep S-wave (slow P-wave) rise of the cross section for any non-diagonal neutralino pair production in $e^+ e^-$ annihilation, $e^+e^- \to \tilde{\chi}^0_i \tilde{\chi}^0_j$ ($i \neq j$), near threshold is accompanied by the slow P-wave (steep S-wave) decrease of the fermion invariant mass distribution of the 3-body neutralino decay, $\tilde{\chi}^0_i \to \tilde{\chi}^0_j f\bar{f}$ ($f=l$ or $q$), near the end point. These selection rules, unique to the neutralino system due to its Majorana nature, guarantee that the observation of simultaneous sharp S-wave excitations of the production cross section near threshold and the lepton and quark invariant mass distribution near the end point is a qualitative, unambiguous evidence for CP violation in the neutralino system.Comment: 11 pages, 1 eps figure, a reference adde

Neutrino oscillations from the splitting of Fermi points

As was shown previously, oscillations of massless neutrinos may be due to the splitting of multiply degenerate Fermi points. In this Letter, we give the details and propose a three-flavor model of Fermi point splittings and neutrino mixings with only two free parameters. The model may explain recent experimental results from the K2K and KamLAND collaborations. There is also rough agreement with the data on atmospheric neutrinos (SuperK) and solar neutrinos (SNO), but further analysis is required. Most importantly, the Ansatz allows for relatively strong T-violating (CP-nonconserving) effects in the neutrino sector.Comment: 6 pages with jetplFRK.cls, v4: published versio

Upper Bounds on Lepton-number Violating Processes

We consider four lepton-number violating (\lv) processes: (a) neutrinoless double-beta decay (0\nu\beta\beta), (b) Delta L = 2 tau decays, (c) Delta L = 2 rare meson decays and (d) nuclear muon-positron conversion. In the absence of exotic \lv interactions, the rates for these processes are determined by effective neutrino masses _{\ell_1\ell_2}, which can be related to the sum of light neutrino masses, the neutrino mass-squared differences, the neutrino mixing angles, a Dirac phase and two Majorana phases. We sample the experimentally allowed ranges of _{\ell_1\ell_2} based on neutrino oscillation experiments as well as cosmological observations, and obtain a stringent upper bound _{\ell_1\ell_2} \lsim 0.14 eV. We then calculate the allowed ranges for _{\ell_1\ell_2} from the experimental rates of direct searches for the above Delta L = 2 processes. Comparing our calculated rates with the currently or soon available data, we find that only the $0\nu\beta\beta$ experiment may be able to probe _{ee} with a sensitivity comparable to the current bound. Muon-positron conversion is next in sensitivity, while the limits of direct searches for the other Delta L = 2 processes are several orders of magnitude weaker than the current bounds on _{\ell_1\ell_2}. Any positive signal in those direct searches would indicate new contributions to the \lv interactions beyond those from three light Majorana neutrinos.Comment: 20 pages, revtex4, 2 figures (5 files), Version published in Physical Review