One Loop Renormalization of Spontaneously Broken U(2) Gauge Theory on Noncommutative Spacetime

We examine the renormalizability problem of spontaneously broken non-Abelian gauge theory on noncommutative spacetime. We show by an explicit analysis of the U(2) case that ultraviolet divergences can be removed at one loop level with the same limited number of renormalization constants as required on commutative spacetime. We thus push forward the efforts towards constructing realistic models of gauge interactions on noncommutative spacetime.Comment: 35 pages, figures using axodraw; v2: expanded discussion in the final section, additional refs added and typos fixe

Unique Neutrino Mass Operator at any Mass Dimension

When the standard model is viewed as a low energy effective theory, the neutrinos can obtain mass from higher dimensional operators. It has been known for long that such an operator first appears at mass dimension five and that it is unique. Here we show that the effective neutrino mass operator at every higher dimension is unique. This general claim is established using Young tableau, and illustrated by exhausting all potentially different operators at dimension seven. The result is relevant to the search of new physics effects beyond neutrino mass that can arise at a relatively low energy scale.Comment: 6 pages, 1 figure; v2: modified/added a few sentences, more acknowledgement, added a ref to [7] and a new [8], typos fixed, proofread version for Phys Lett

Bounds on Unparticles Couplings to Electrons: from Electron g-2 to Positronium Decays

Unparticles as suggested recently by Georgi have surprising phenomenological implications, distinctive from any other new physics that we know of. But they must interact very feebly with ordinary matter to have avoided detection thus far. We determine how feebly they can interact with the electron, using the precisely measured quantities in QED: the electron g-2 and the bounds on invisible and exotic positronium decays. The most stringent bound comes from invisible ortho-positronium decays: the effective energy scale entering the vector unparticle-electron interaction must exceed 4 x 10^5 TeV for a scaling dimension 3/2 of the vector unparticle. The lower bounds on scales for other unparticles range from a few tens to a few hundreds TeV. This makes the detection of unparticles challenging in low energy electron systems.Comment: v1: 8 pages, 1 figure; v2: proofread version for PRD. (1) Added '(see also [4])' just before eq. (5). (2) Update ref list and change its format, change one PACS number. (3) Minor changes during the course of copyediting, like adding punctuation to eqs, changing hyphenation, et

Hydrodynamics with chiral anomaly and charge separation in relativistic heavy ion collisions

Matter with chiral fermions is microscopically described by theory with quantum anomaly and macroscopically described (at low energy) by anomalous hydrodynamics. For such systems in the presence of external magnetic field and chirality imbalance, a charge current is generated along the magnetic field direction --- a phenomenon known as the Chiral Magnetic Effect (CME). The quark-gluon plasma created in relativistic heavy ion collisions provides an (approximate) example, for which the CME predicts a charge separation perpendicular to the collisional reaction plane. Charge correlation measurements designed for the search of such signal have been done at RHIC and the LHC for which the interpretations, however, remain unclear due to contamination by background effects that are collective flow driven, theoretically poorly constrained, and experimentally hard to separate. Using anomalous (and viscous) hydrodynamic simulations, we make a first attempt at quantifying contributions to observed charge correlations from both CME and background effects in one and same framework. The implications for the search of CME are discussed.Comment: 5 pages, 3 figures, Published version in Phys. Lett.

Spin 3/2 Particle as a Dark Matter Candidate: an Effective Field Theory Approach

There is no indication so far on the spin of dark matter particles. We consider the possibility in this work that a spin-3/2 particle acts as dark matter. Employing the approach of effective field theory, we list all possible 4-fermion effective interactions between a pair of such fields and a pair of ordinary fermion fields. We investigate the implications of the proposal on the relic density, the antiproton to proton flux ratio in cosmic rays, and the elastic scattering off nuclei in direct detection. While the relic density and flux ratio are sensitive to all interactions albeit at different levels, the direct detection is only sensitive to a few of them. Using the observed data and experimental bounds, we set constraints on the relation of couplings and dark particle mass. In particular, we find that some mass ranges can already be excluded by jointly applying the observed relic density on the one side and the measured antiproton to proton flux ratio or the upper bounds from direct detection on the other.Comment: v1: 18 pages including 6 figs; v2: 19 pages including 6 figs, added more refs, fixed wrong labels (to experiments) in figs. 3 and 4, corrected typos; v3: 19 pages, slight clarifications in response to referee's comments, added more refs, identical to the proofread version for jhep except for the format of ref

Spatially-Rotated Paintings: A Reply to Markosian’s "Sideways Music"

In “Sideways Music”, Ned Markosian uses aesthetic intuitions about temporally-rotated music to argue that the metaphysics of time is different from the metaphysics of space. In response, I use aesthetic intuitions about spatially-rotated paintings to pose a dilemma for Markosian’s argument: either he accepts the intuitions about spatially-rotated paintings, in which case he must give up on some assumptions in his argument, or he rejects intuitions about spatially-rotated paintings, in which case an analogous response can be given regarding intuitions about temporally-rotated music. That is, if Markosian wants to hold on to the assumptions that underwrite his argument, then he thereby offers his opponent the resources with which to resist his conclusion. As such, Markosian’s argument cannot offer a new independent consideration for adjudicating the metaphysical debate between the Dynamic Theorist and the Spacetime Theorist. [Unpublishable 2019

Immersion is Attention / Becoming Immersed

Children sometimes lose themselves in make-believe games. Actors sometimes lose themselves in their roles. Readers sometimes lose themselves in their books. From people's introspective self-reports and phenomenological experiences, these immersive experiences appear to differ from ordinary experiences of simply playing a game, simply acting out a role, and simply reading a book. What explains the difference? My answer: attention. [Unpublishable 2007-2017. This paper was referenced in Liao and Doggett (2014).

Genre Moderates Morality’s Influence on Aesthetics

The present studies investigate morality’s influence on aesthetics and one potential moderator of that influence: genre. Study 1 finds that people’s moral evaluation positively influence their aesthetic evaluation of an artwork. Study 2 and 3 finds that this influence can be moderated by the contextual factor of genre. These results broaden our understanding of the relationship between morality and aesthetics, and suggest that models of art appreciation should take into account morality and its interaction with context. [Unpublishable 2010-2017.