Responsibility modulates neural mechanisms of outcome processing : an ERP study

The role of personal responsibility in decision-making and its influence on the outcome evaluation process have been investigated relatively rarely in cognitive neuroscience. The present event-related brain potential (ERP) study manipulated the subjective sense of responsibility by modifying outcome controllability in a gambling task. Participants reported a higher sense of responsibility and produced a larger fERN when they were told that the game was 'controllable' compared with when they were told that the game was 'uncontrollable.' In addition, fERN amplitude was correlatedwith individual self-reports of personal responsibility over the outcomes. These results indicate that self-attribution of responsibility associated with different degrees of controllability affects the outcome evaluation process and fERN amplitude

Radiative Neutrino Mass with Z3Z_3 Dark matter: From Relic Density to LHC Signatures

In this work we give a comprehensive analysis on the phenomenology of a specific $\mathbb{Z}_3$ dark matter (DM) model in which neutrino mass is induced at two loops by interactions with a DM particle that can be a complex scalar or a Dirac fermion. Both the DM properties in relic density and direct detection and the LHC signatures are examined in great detail, and indirect detection for gamma-ray excess from the Galactic Center is also discussed briefly. On the DM side, both semi-annihilation and co-annihilation processes play a crucial role in alleviating the tension of parameter space between relic density and direct detection. On the collider side, new decay channels resulting from $\mathbb{Z}_3$ particles lead to distinct signals at LHC. Currently the trilepton signal is expected to give the most stringent bound for both scalar and fermion DM candidates, and the signatures of fermion DM are very similar to those of electroweakinos in simplified supersymmetric models.Comment: 40 pages, 24 figure

Melting of Multilayer Colloidal Crystals Confined Between Two Walls

Video microscopy is employed to study the melting behaviors of multilayer colloidal crystals composed of diameter-tunable microgel spheres confined between two walls.We systematically explore film thickness effects on the melting process and on the phase behaviors of single crystal and polycrystalline films. Thick films (\u3e4 layers) are observed to melt heterogeneously, while thin films ( ≤ 4 layers) melt homogeneously, even for polycrystalline films. Grain-boundary melting dominates other types of melting processes in polycrystalline films thicker than 12 layers. The heterogeneous melting from dislocations is found to coexist with grain-boundary melting in films between 5- and 12-layers. In dislocation melting, liquid nucleates at dislocations and forms lakelike domains embedded in the larger crystalline matrix; the “lakes” are observed to diffuse, interact, merge with each other, and eventually merge with large strips of liquid melted from grain boundaries. Thin film melting is qualitatively different: thin films homogeneously melt by generating many small defects which need not nucleate at grain boundaries or dislocations. For three- and four-layer thin films, different layers are observed to have the same melting point, but surface layers melt faster than bulk layers. Within our resolution, two- to four-layer films appear to melt in one step, while monolayers melt in two steps with an intermediate hexatic phase