Neutrino Dark Energy and Baryon Asymmetry from Higgs Sector

We propose a new model to explain the neutrino masses, the dark energy and the baryon asymmetry altogether. In this model, neutrinos naturally acquire small Majorana masses via type-II seesaw mechanism, while the pseudo-Nambu-Goldstone bosons associated with the neutrino mass-generation mechanism provide attractive candidates for dark energy. The baryon asymmetry of the universe is produced from the Higgs triplets decay with CP-violation.Comment: 5 pages, 2 figures. Version accepted by PL

LHC Signatures of Two-Higgs-Doublets with Fourth Family

On-going Higgs searches in the light mass window are of vital importance for testing the Higgs mechanism and probing new physics beyond the standard model (SM). The latest ATLAS and CMS searches for the SM Higgs boson at the LHC (7TeV) found some intriguing excesses of events in the \gamma\gamma/VV^* channels (V=Z,W) around the mass-range of 124-126 GeV. We explore a possible explanation of the \gamma\gamma and VV^* signals from the light CP-odd Higgs A^0 or CP-even Higgs h^0 from the general two-Higgs-doublet model with fourth-family fermions. We demonstrate that by including invisible decays of the Higgs boson A^0 or h^0 to fourth-family neutrinos, the predicted \gamma\gamma and VV^* signals can explain the observed new signatures at the LHC, and will be further probed by the forthcoming LHC runs in 2012.Comment: 22pp, 10 Figs, JHEP published version, references adde

Probing Gravitational Dark Matter

So far all evidences of dark matter (DM) come from astrophysical and cosmological observations, due to gravitational interactions of the DM. It is possible that the true DM particle in the universe joins gravitational interactions only, but nothing else. Such a Gravitational DM (GDM) acts as a weakly interacting massive particle (WIMP), which is conceptually simple and attractive. In this work, we explore this direction by constructing the simplest scalar GDM particle $\chi_s$. It is a $Z_2$ odd singlet under the standard model (SM) gauge group, and naturally joins the unique dimension-4 interaction with Ricci curvature, $\xi_s \chi_s^2 R$, where $\xi_s$ is the dimensionless nonminimal coupling. We demonstrate that this gravitational interaction $\xi_s \chi_s^2 R$, together with Higgs-curvature nonminimal coupling term $\xi_h H^\dag H R$, induces effective couplings between $\chi_s^2$ and SM fields which can account for the observed DM thermal relic abundance. We analyze the annihilation cross sections of GDM particles and derive the viable parameter space for realizing the DM thermal relic density. We further study the direct/indirect detections and the collider signatures of such a scalar GDM. These turn out to be highly predictive and testable.Comment: 33pp, JCAP Final Version. Only minor rewordings, references adde

Estimating Chinese Interprovincial OutPut Spillovers with Provincial Input-Output Tables

This paper aims at estimating productivity improvement of Chinese 17 relatively backward provinces in manufactures through importing manufactured intermediates from advanced provinces on the basis of just published 2002 national and provincial input-output tables. As Chinese regional inequality remains large, North-South spillover models of trade are appropriate to guide this study. Applying reliable methods to approximate net interprovincial imports by province and sector and the allocation of imported manufactured inputs among sectors within each province, we use a Cob-Douglas production function incorporating Dixit-Stiglitz type increasing returns to variety to deal with the manufactured inputs, and treat the output spillovers as one part of total factor productivity. According to our estimations, as expected, interprovincial imports of manufactured inputs have significant impacts on industrial sectors as well on all sectors of these provinces.Chinese interprovincial trade;North-South spillovers;input-output tables;regional inequality;imported intermediates

Asymptotically Safe Higgs Inflation

We construct a new inflation model in which the standard model Higgs boson couples minimally to gravity and acts as the inflaton. Our construction of Higgs inflation incorporates the standard model with Einstein gravity which exhibits asymptotic safety in the ultraviolet region. The slow roll condition is satisfied at large field value due to the asymptotically safe behavior of Higgs self-coupling at high energies. We find that this minimal construction is highly predictive, and is consistent with both cosmological observations and collider experiments.Comment: 16pp, to match JCAP Final Version, only minor refinements, references adde

Single-Valued Hamiltonian via Legendre-Fenchel Transformation and Time Translation Symmetry

Under conventional Legendre transformation, systems with a non-convex Lagrangian will result in a multi-valued Hamiltonian as a function of conjugate momentum. This causes problems such as non-unitary time evolution of quantum state and non-determined motion of classical particles, and is physically unacceptable. In this work, we propose a new construction of single-valued Hamiltonian by applying Legendre-Fenchel transformation, which is a mathematically rigorous generalization of conventional Legendre transformation, valid for non-convex Lagrangian systems, but not yet widely known to the physics community. With the new single-valued Hamiltonian, we study spontaneous breaking of time translation symmetry and derive its vacuum state. Applications to theories of cosmology and gravitation are discussed.Comment: Journal Version, 16pp. All results + conclusions un-changed, only minor refinements to clarify the importance of our new LFT method and its physics applications; references adde