Neutrino oscillations as a probe of dark energy

We consider a class of theories in which neutrino masses depend significantly on environment, as a result of interactions with the dark sector. Such theories of mass varying neutrinos were recently introduced to explain the origin of the cosmological dark energy density and why its magnitude is apparently coincidental with that of neutrino mass splittings. In this Letter we argue that in such theories neutrinos can exhibit different masses in matter and in vacuum, dramatically affecting neutrino oscillations. As an example of modifications to the standard picture, we consider simple models that may simultaneously account for the LSND anomaly, KamLAND, K2K, and studies of solar and atmospheric neutrinos, while providing motivation to continue to search for neutrino oscillations in short baseline experiments such as BooNE.     

Dynamics of frequency and amplitude modulations in vocalizations produced by eastern towhees, Pipilo erythrophthalmus

Eastern towhees, Pipilo erythrophthalmus (Emberizidae, Passeriformes), appear to estimate source-SPL using spectral or temporal variables. Nevertheless, vocalizations are dynamic by nature and it remains unclear whether subjects pay attention to correlations between discrete variables or pay attention to the dynamics that these variables summarize. Sine functions are used to describe coarse (slow, < 10 Hz) frequency and amplitude modulations in towhee calls and correlations between variables are identified. Towhee calls are also finely (rapidly, > 400 Hz) modulated in both amplitude and frequency. Fine amplitude and frequency modulations correlate well (occur in phase) over relatively low fundamental frequencies (< approximately 3.5 kHz) and tend to have greater amplitudes and frequencies over these same frequencies. Modulations and correlations between modulations might exist due to stable dynamic interactions that occur within and between the physical forces that function to produce modulations in vocalizations. Results support the hypothesis that towhees communicate within separate sound frequency channels defined to each side of approximately 3.5 kHz.     

A comparative study of myo-inositol quantification using LCmodel at 1.5 T and 3.0 T with 3 D 1H proton spectroscopic imaging of the human brain

Myo-inositol is a strongly coupled system and resonates at four chemical shift positions. At 1.5 T, only the singlet component at 3.57 ppm is detected. However, at 3 T this resonance is resolved into its components at 3.55 ppm and 3.61 ppm. Due to the increased spectral resolution and signal-to-noise ratio, it is anticipated that the quantification of myo-inositol should improve at 3 T. Using data from normal controls and the LCmodel quantification procedure, we found that the quantification precision, reproducibility and detection sensitivity of myo-inositol is significantly better at 3 T relative to 1.5 T.     

Up quark mass in lattice QCD with three light dynamical quarks and implications for strong CP invariance

A standing mystery in the standard model is the unnatural smallness of the strong CP violating phase. A massless up quark has long been proposed as one potential solution. A lattice calculation of the constants of the chiral Lagrangian essential for the determination of the up quark mass, 2alpha(8)-alpha(5), is presented. We find 2alpha(8)-alpha(5)=0.29+/-0.18, which corresponds to m(u)/m(d)=0.410+/-0.036. This is the first such calculation using a physical number of dynamical light quarks, N(f)=3.     

Time-resolved measurements of self-focusing pulses in air

The spatial, spectral, and temporal properties of self-focusing 798-nm 100-fs pulses in air are experimentally measured with high-resolution, single-shot techniques at a set propagation distance of 10.91 m. The data, obtained with an initially collimated Gaussian beam, show significant evolution of spatial narrowing as well as temporal and spectral changes at intensities lower than those required for significant ionization of air.     

Ultrahigh-resolution optical coherence tomography by broadband continuum generation from a photonic crystal fiber

We have developed an ultrahigh-resolution optical coherence tomographic system in which broadband continuum generation from a photonic crystal fiber is used to produce high longitudinal resolution. Longitudinal resolution of 1.3-microm has been achieved in a biological tissue by use of continuum light from 800 to 1400 nm. The system employed a dynamic-focusing tracking method to maintain high lateral resolution over a large imaging depth. Subcellular imaging is demonstrated.     

Measurements of the Decay KL-->e+ e- mu+ mu-

The KTeV experiment at Fermilab has isolated a total of 132 events from the rare decay K(L)-->e+ e- mu+ mu-, with an estimated background of 0.8 events. The branching ratio of this mode is determined to be [2.69+/-0.24(stat)+/-0.12(syst)]x10(-9), with a radiative cutoff of M(2)(ee mu mu)/M(2)(K)>0.95. The first measurement using this mode of the parameter alpha from the D'Ambrosio-Isidori-Portolès (DIP) model of the K(L)gamma*gamma* vertex yields a result of -1.59+/-0.37, consistent with values obtained from other decay modes. Because of the limited statistics, no sensitivity is found to the DIP parameter beta. We use this decay mode to set limits on CP and lepton violation.     

Reliability of sound attenuation in Florida scrub habitat and behavioral implications

Attenuation over distance in natural habitat is often difficult to predict when measured without respect to sound frequency. The physical-acoustic structure of Florida scrub habitat is described and both attenuation and reliability of attenuation are measured as a function of sound frequency, over several distances, speaker elevations, and microphone elevations. The spatial context of sound propagation in Florida scrub habitat is discussed and a model designed to describe contributions to overall attenuation from individual factors is presented. Sound frequencies below approximately 3.5 kHz attenuate more reliably than higher sound frequencies, suggesting that animals should pay greatest attention to relatively low sound frequencies when they assess attenuation or estimate sound-pressure level.     

Field expulsion and reconfiguration in polaritonic photonic crystals

We uncover a rich set of optical phenomena stemming from the incorporation of polar materials exhibiting transverse phonon polariton excitations into a photonic crystal structure. We identify in the frequency spectrum two regimes in which the dielectric response of the polaritonic medium can induce extreme localization of the electromagnetic energy. Our analysis of the effect of polarization and the interaction between the polariton and photonic band gaps on the Bloch states leads to a pair of mechanisms for sensitive frequency-controlled relocation and/or reconfiguration of the fields.     

Quantum phase transition in quasi-one-dimensional BaRu6O12

We report the first systematic study of the electrical transport and magnetic properties of BaRu6O12, which has a quasi-one-dimensional (quasi-1D) hollandite structure. We show that BaRu6O12 is quasi-1D electronically as well. Its physical properties were found to be extremely sensitive to disorder. Furthermore, a transition from being metallic with a resistance drop around 2 K to being weakly insulating as the applied magnetic field was increased was also found. We propose that these two features are related to the possible presence of a quantum phase transition in this material system.