Neutrino Constraints on Inelastic Dark Matter after CDMS II

We discuss the neutrino constraints from solar and terrestrial dark matter (DM) annihilations in the inelastic dark matter (iDM) scenario after the recent CDMS II results. To reconcile the DAMA/LIBRA data with constraints from all other direct experiments, the iDM needs to be light ($m_\chi < 100$ GeV) and have a large DM-nucleon cross section ($\sigma_n \sim$ 10$^{-4}$ pb in the spin-independent (SI) scattering and $\sigma_n \sim$ 10 pb in the spin-dependent (SD) scattering). The dominant contribution to the iDM capture in the Sun is from scattering off Fe/Al in the SI/SD case. Current bounds from Super-Kamiokande exclude the hard DM annihilation channels, such as $W^+W^-$, $ZZ$, $t\bar{t}$ and $\tau^+ \tau^-$. For soft channels such as $b\bar{b}$ and $c \bar{c}$, the limits are loose, but could be tested or further constrained by future IceCube plus DeepCore. For neutrino constraints from the DM annihilation in the Earth, due to the weaker gravitational effect of the Earth and inelastic capture condition, the constraint exists only for small mass splitting $\delta <$ 40 keV and $m_\chi \sim (10, 50)$ GeV even in the $\tau^+ \tau^-$ channel.Comment: 11 pages, 8 figure

HRM Practices and Performance of Family-Run Workplaces: Evidence from the 2004 WERS

This paper analyses HRM practices of family-run workplaces using the 2004 WERS. Family-ownership and management within workplaces in the corporate sector is our focus. This family-run group represents nationally about 26% of workplaces and 14% of employment. We find that employees in this group have stronger feelings of job security and loyalty, which we relate to family companies' HRM practices such as stronger support for long-term employment – an "inclusivity" linked to long-term orientation. We also find that family-owned and managed workplaces have better financial and quality performance measures than non-family, to which family-related HRM practices contribute.job security, loyalty, family business, HRM practices, financial performance

Dissociable neural correlates of multisensory coherence and selective attention

Previous work has demonstrated that performance in an auditory selective attention task can be enhanced or impaired, depending on whether a task-irrelevant visual stimulus is temporally coherent with a target auditory stream or with a competing distractor. However, it remains unclear how audiovisual (AV) temporal coherence and auditory selective attention interact at the neurophysiological level. Here, we measured neural activity using electroencephalography (EEG) while human participants (men and women) performed an auditory selective attention task, detecting deviants in a target audio stream. The amplitude envelope of the two competing auditory streams changed independently, while the radius of a visual disc was manipulated to control the audiovisual coherence. Analysis of the neural responses to the sound envelope demonstrated that auditory responses were enhanced independently of the attentional condition: both target and masker stream responses were enhanced when temporally coherent with the visual stimulus. In contrast, attention enhanced the event-related response (ERP) evoked by the transient deviants, independently of AV coherence. Finally, in an exploratory analysis, we identified a spatiotemporal component of ERP, in which temporal coherence enhanced the deviant-evoked responses only in the unattended stream. These results provide evidence for dissociable neural signatures of bottom-up (coherence) and top-down (attention) effects in AV object formation.Significance StatementTemporal coherence between auditory stimuli and task-irrelevant visual stimuli can enhance behavioral performance in auditory selective attention tasks. However, how audiovisual temporal coherence and attention interact at the neural level has not been established. Here, we measured EEG during a behavioral task designed to independently manipulate AV coherence and auditory selective attention. While some auditory features (sound envelope) could be coherent with visual stimuli, other features (timbre) were independent of visual stimuli. We find that audiovisual integration can be observed independently of attention for sound envelopes temporally coherent with visual stimuli, while the neural responses to unexpected timbre changes are most strongly modulated by attention. Our results provide evidence for dissociable neural mechanisms of bottom-up (coherence) and top-down (attention) effects on AV object formation

Breit-Wigner Enhancement Considering the Dark Matter Kinetic Decoupling

In the paper we study the Breit-Wigner enhancement of dark matter (DM) annihilation considering the kinetic decoupling in the evolution of DM freeze-out at the early universe. Since the DM temperature decreases much faster (as $1/R^2$) after kinetic decoupling than that in kinetic equilibrium (as 1/R) we find the Breit-Wigner enhancement of DM annihilation rate after the kinetic decoupling will affect the DM relic density significantly. Focusing on the model parameters that trying to explain the anomalous cosmic positron/electron excesses observed by PAMELA/Fermi/ATIC we find the elastic scattering $Xf\to Xf$ is not efficient to keep dark matter in kinetic equilibrium, and the kinetic decoupling temperature $T_{kd}$ is comparable to the chemical decoupling temperature $T_f\sim O(10) GeV$. The reduction of the relic density after $T_{kd}$ is significant and leads to a limited enhancement factor $\sim O(10^2)$. Therefore it is difficult to explain the anomalous positron/electron excesses in cosmic rays by DM annihilation and give the correct DM relic density simultaneously in the minimal Breit-Wigner enhancement model

The Neural Basis of Independence Versus Interdependence Orientations:A Voxel-Based Morphometric Analysis of Brain Volume

Sociocultural research has established independence and interdependence as two fundamental ways of thinking about oneself and the social world. Recent neuroscience studies further demonstrate that these orientations modulate brain activity in various self- and socially related tasks. In the current study, we explored whether the traits of independence and interdependence are reflected in anatomical variations in brain structure. We carried out structural brain imaging on a large sample of healthy participants ( n = 265) who also completed self-report questionnaires of cultural orientations. Voxel-based morphometry analysis demonstrated that a relative focus of independence (vs. interdependence) was associated with increased gray-matter volume in a number of self-related regions, including ventromedial prefrontal cortex, right dorsolateral prefrontal cortex, and right rostrolateral prefrontal cortex. These results provide novel insights into the biological basis of sociocultural orientations. </jats:p

Merger Dynamics of the Pair of Galaxy Clusters -- A399 and A401

Convincing evidence of a past interaction between two rich clusters A399 and A401 was recently found by the X-ray imaging observations. In this paper we examine the structure and dynamics of this pair of galaxy clusters. A mixture-modeling algorithm has been applied to obtain a robust partition into two clusters, which allows us to discuss the virial mass and velocity distribution for each cluster. Assuming that these two clusters follow a linear orbit and they have once experienced a close encounter, we model the binary cluster as a two-body system. As a result, four gravitationally bound solutions are obtained. The recent X-ray observations seem to favor a scenario in which the two clusters with a true separation of $5.4h^{-1}$ Mpc are currently expanding at 583 km/s along the direction with a projection angle of 67.5 degree, and they will reach a maximum extent of $5.65h^{-1}$ Mpc in about $1.0h^{-1}$ Gyr.Comment: 11 pages, including 6 EPS figures and 4 tables, uses chjaa.cls, Accepted by the ChJA

On the Ground State of Two Flavor Color Superconductor

The diquark condensate susceptibility in neutral color superconductor at moderate baryon density is calculated in the frame of two flavor Nambu-Jona-Lasinio model. When color chemical potential is introduced to keep charge neutrality, the diquark condensate susceptibility is negative in the directions without diquark condensate in color space, which may be regarded as a signal of the instability of the conventional ground state with only diquark condensate in the color 3 direction.Comment: 4 pages, 2 figure

The newly observed open-charm states in quark model

Comparing the measured properties of the newly observed open-charm states D(2550), D(2600), D(2750), D(2760), D_{s1}(2710), D_{sJ}(2860), and D_{sJ}(3040) with our predicted spectroscopy and strong decays in a constituent quark model, we find that: (1) the D(2\,^1S_0) assignment to D(2550) remains open for its too broad width determined by experiment; (2) the D(2600) and $D_{s1}(2710)$ can be identified as the 2\,^3S_1-1\,^3D_1 mixtures; (3) if the D(2760) and D(2750) are indeed the same resonance, they would be the D(1\,^3D_3); otherwise, they could be assigned as the D(1\,^3D_3) and $D^\prime_2(1D)$, respectively; (4) the $D_{sJ}(2860)$ could be either the $D_{s1}(2710)$'s partner or the D_s(1\,^3D_3); and (5) both the $D_{s1}(2P)$ and $D^\prime_{s1}(2P)$ interpretations for the $D_{sJ}(3040)$ seem likely. The $E1$ and $M1$ radiative decays of these sates are also studied. Further experimental efforts are needed to test the present quarkonium assignments for these new open-charm states.Comment: 26 pages,7 figures, journal versio