119275511
Gravitational Field Equations and Theory of Dark Matter and Dark Energy
The main objective of this article is to derive new gravitational field equations and to establish a unified theory for dark energy and dark matter. The gravitational field equations with a scalar potential $\varphi$ function are derived using the Einstein-Hilbert functional, and the scalar potential $\varphi$ is a natural outcome of the divergence-free constraint of the variational elements. 
Gravitation is now described by the Riemannian metric 
$g_{\mu\nu}$, the scalar potential $\varphi$ and their interactions, unified by the new field equations. 
From quantum field theoretic point of view, the vector field $\Phi_\mu=D_\mu \varphi$, the gradient of the scalar function $\varphi$, is a spin-1 massless bosonic particle field. The field equations induce a natural duality between the graviton (spin-2 massless bosonic particle) and this spin-1 massless bosonic particle. Both particles can be considered as gravitational force carriers, and as they are massless, the induced forces are long-range forces. The (nonlinear) interaction between these bosonic particle fields leads to a unified theory for dark energy and dark matter. Also, associated with the scalar potential $\varphi$ is the scalar potential energy density $\frac{c^4}{8\pi G} \Phi=\frac{c^4}{8\pi G} g^{\mu\nu}D_\mu D_\nu \varphi$, which represents a new type of energy caused by the non-uniform distribution of matter in the universe. 
The negative part of this potential energy density produces attraction, and the positive part produces repelling force. This potential energy density is conserved with mean zero: $\int_M \Phi dM=0$. 
The sum of this potential energy density 
$\frac{c^4}{8\pi G} \Phi$ and the coupling energy 
 between the energy-momentum tensor $T_{\mu\nu}$ and the scalar potential field $\varphi$ gives rise to a unified theory for dark matter and dark energy: 
The negative part of 
this sum represents the dark matter, which produces attraction, 
and the positive part represents the dark energy, which drives the acceleration of expanding galaxies. 
In addition, the scalar curvature of space-time obeys $R=\frac{8\pi G}{c^4} T + \Phi$. 
Furthermore, the proposed field equations resolve a few difficulties encountered by the classical Einstein field equations.
51818165
Unified field equations coupling four forces and principle of interaction dynamics
The main objective of this article is to postulate a principle of interaction dynamics (PID) and to derive field equations coupling the four fundamental interactions based on first principles. PID is a least action principle subject to div$_A$-free constraints for the variational element with $A$ being gauge potentials. The Lagrangian action is uniquely determined by 1) the principle of general relativity, 2) the $U(1)$, $SU(2)$ and $SU(3)$ gauge invariances, 3) the Lorentz invariance, and 4) the principle of representation invariance (PRI), introduced in [11]. The unified field equations are then derived using PID. The field model spontaneously breaks the gauge symmetries, and gives rise to a new mass generation mechanism. 
The unified field model introduces a natural duality between the mediators and their dual mediators, and can be easily decoupled to study each individual interaction when other interactions are negligible. The unified field model, together with PRI and PID applied to individual interactions, provides clear explanations and solutions to a number of outstanding challenges in physics and cosmology, including e.g. the dark energy and dark matter phenomena, the quark confinement, asymptotic freedom, short-range nature of both strong and weak interactions, decay mechanism of sub-atomic particles, baryon asymmetry, and the solar neutrino problem.
118453039
Holographic dark energy in a universe with spatial curvature and massive neutrinos: a full Markov Chain Monte Carlo exploration
In this paper, we report the results of constraining the holographic dark energy model with spatial curvature and massive neutrinos, based on a Markov Chain Monte Carlo global fit technique. The cosmic observational data include the full WMAP 7-yr temperature and polarization data, the type Ia supernova data from Union2.1 sample, the baryon acoustic oscillation data from SDSS DR7 and WiggleZ Dark Energy Survey, and the latest measurements of H-0 from HST. To deal with the pertubations of dark energy, we adopt the parameterized post-Friedmann method. We find that, for the simplest holographic dark energy model without spatial curvature and massive neutrinos, the phenomenological parameter c < 1 at more than 4 sigma confidence level. The inclusion of spatial curvature enlarges the errors bars and leads to c < 1 only in about 2.5 sigma range; in contrast, the inclusion of massive neutrinos does not have significant influence on c. We also find that, for the holographic dark energy model with spatial curvature but without massive neutrinos, the 3 sigma errors bars of the current fractional curvature density Omega k(0) are still in order 10(-2); for the model with massive neutrinos but without spatial curvature, the 2 sigma upper bound of the total mass of neutrinos is Sigma m(v) < 0.48eV. Moreover, there exists clear degeneracy between spatial curvature and massive neutrinos in the holographic dark energy model, which enlarges the upper bound of Sigma m(v) by more than 2 times. In addition, we demonstrate that, making use of the full WMAP data can give better constraints on the holographic dark energy model, compared with the case using the WMAP "distance priors".
119188783
Probing interaction and spatial curvature in the holographic dark energy model
In this paper we place observational constraints on the interaction and spatial curvature in the holographic dark energy model. We consider three kinds of phenomenological interactions between holographic dark energy and matter, i.e., the interaction term Q is proportional to the energy densities of dark energy (rho(A)), matter (p(m)), and matter plus dark energy (p(m) + p(A)). For probing the interaction and spatial curvature in the holographic dark energy model, we use the latest observational data including the type la supernovae (SNIa) Constitution data, the shift parameter of the cosmic microwave background (CMB) given by the five-year Wilkinson Microwave Anisotropy Probe (WMAP5) observations, and the baryon acoustic oscillation (BAO) measurement, from the Sloan Digital Sky Survey (SDSS). Our results show that, the interaction and spatial curvature in the holographic dark energy model are both rather small. Besides, it is interesting to find that there exists significant degeneracy between the phenomenological interaction and the spatial curvature in the holographic dark energy model.
118060536
Measurement of $\chi_{cJ}$ decaying into $p\bar{n}\pi^{-}$ and $p\bar{n}\pi^{-}\pi^{0}$
Using a data sample of $1.06 \times 10^{8}$ $\psip$ events collected with the BESIII detector in 2009, the branching fractions of $\chi_{cJ}\to p\bar{n}\pi^{-}$ and $\chi_{cJ}\to p\bar{n}\pi^{-}\pi^{0}$ ($J$=0,1,2) are measured{Throughout the text, inclusion of charge conjugate modes is implied if not stated otherwise.}. The results for $\chi_{c0}\to p\bar{n}\pi^{-}$ and $\chi_{c2}\to p\bar{n}\pi^{-}$ are consistent with, but much more precise than those of previous measurements. The decays of $\chi_{c1}\to p\bar{n}\pi^{-}$ and $\chi_{cJ}\to p\bar{n}\pi^{-}\pi^{0}$ are observed for the first time.
118632632
Heavy fragment radioactivity of Pu-238: Si and Mg emission
In addition to its two known hadronic decay modes\char22{}alpha decay (half-life 88 yr) and spontaneous fission (5\ifmmode\times\else\texttimes\fi{}${10}^{10}$ yr)\char22{}we have found that $^{238}\mathrm{Pu}$ also decays by emission of a Mg nucleus (\ensuremath{\sim}2\ifmmode\times\else\texttimes\fi{}${10}^{18}$ yr) and by emission of a Si nucleus (\ensuremath{\sim}6\ifmmode\times\else\texttimes\fi{}${10}^{17}$ yr). This extends to four (the other two being $^{14}\mathrm{C}$ emission and Ne emission) the number of known modes of decay by emission of a fragment of mass between that of an alpha particle and that resulting from fission. The branching ratios relative to alpha decay are the lowest yet observed: \ensuremath{\sim}6\ifmmode\times\else\texttimes\fi{}${10}^{\mathrm{\ensuremath{-}}17}$ for Mg emission and 1.4\ifmmode\times\else\texttimes\fi{}${10}^{\mathrm{\ensuremath{-}}16}$ for Si emission.
119087832
Candidate chiral doublet bands in the odd-odd nucleus Cs 126
The candidate chiral doublet bands recently observed in $^{126}$Cs have been extended to higher spins, several new linking transitions between the two partner members of the chiral doublet bands are observed, and $\gamma$$-$intensities related to the chiral doublet bands are presented by analyzing the $\gamma$$-$$\gamma$ coincidence data collected earlier at the NORDBALL through the $^{116}$Cd$($$^{14}$N, 4n$)$$^{126}$Cs reaction at a beam energy of 65 MeV. The intraband $B(M1)/B(E2)$ and interband $B(M1)_{in}/B(M1)_{out}$ ratios and the energy staggering parameter, S(I), have been deduced for these doublet bands. The results are found to be consistent with the chiral interpretation for the two structures. Furthermore, the observation of chiral doublet bands in $^{126}$Cs together with those in $^{124}$Cs, $^{128}$Cs, $^{130}$Cs and $^{132}$Cs also indicates that the chiral conditions do not change rapidly with decreasing neutron number in these odd-odd Cesium isotopes.