We have investigated the electromagnetic decays of the antitriplet and sextet charmed baryon systems with $J^P= frac{1}{2}^+, frac{3}{2}^+$ in the framework of the heavy baryon chiral perturbation theory. We first construct the chiral Lagrangians at
$O(p^2)$ and $O(p^3)$. Then we calculate the electromagnetic (EM) decay amplitudes of the charmed baryon systems up to $O(p^3)$. With the help of the quark model, we estimate the low energy constants. The numerical results of the EM decay widths show good convergence of the chiral expansion. We notice that the two neutral EM decay processes $Xi_c^0rightarrowgamma+Xi_c^0$ and ${Xi_c^*}^0rightarrowgamma+Xi_c^0$ are strongly suppressed by the SU(3) U-spin flavor symmetry. With the same formalism, we also estimate the EM decay widths of the bottomed baryons. The EM decay widths of the heavy baryons may be measured at facilities such as LHCb and JPARC. The explicit chiral structures of the heavy baryon decay amplitudes derived in this work may be useful to the possible chiral extrapolations of the future lattice simulations of these EM decay amplitudes.
Gutman and Wagner proposed the concept of matching energy (ME) and pointed out that the chemical applications of ME go back to the 1970s. Let $G$ be a simple graph of order $n$ and $mu_1,mu_2,ldots,mu_n$ be the roots of its matching polynomial. The m
atching energy of $G$ is defined to be the sum of the absolute values of $mu_{i} (i=1,2,ldots,n)$. In this paper, we characterize the graphs with minimal matching energy among all unicyclic and bicyclic graphs with a given diameter $d$.
Evolutionary game theory is employed to study topological conditions of scale-free networks for the evolution of cooperation. We show that Apollonian Networks (ANs) are perfect scale-free networks, on which cooperation can spread to all individuals,
even though there are initially only 3 or 4 hubs occupied by cooperators and all the others by defectors. Local topological features such as degree, clustering coefficient, gradient as well as topology potential are adopted to analyze the advantages of ANs in cooperation enhancement. Furthermore, a degree-skeleton underlying ANs is uncovered for understanding the cooperation diffusion. Constructing this kind degree-skeleton for random scale-free networks promotes cooperation level close to that of Barabasi-Albert networks, which gives deeper insights into the origin of the latter on organization and further promotion of cooperation.
We consider the mixed three-qubit bound entangled state defined as the normalized projector on the subspace that is complementary to an Unextendible Product Basis [C. H. Bennett et. al., Phys. Rev. Lett. 82, 5385 (1999)]. Using the fact that no produ
ct state lies in the support of that state, we compute its entanglement by providing a basis of its subspace formed by minimally-entangled states. The approach is in principle applicable to any entanglement measure; here we provide explicit values for both the geometric measure of entanglement and a generalized concurrence.
We conducted the observational tests of a phase correction scheme for the Atacama Compact Array (ACA) of the Atacama Large Millimeter and submillimeter Array (ALMA) using the Submillimeter Array (SMA). Interferometers at millimeter- and submillimeter
-wave are highly affected by the refraction induced by water vapor in the troposphere, which results as phase fluctuations. The ACA is planning to compensate the atmospheric phase fluctuations using the phase information of the outermost antennas with interpolating to the inner antennas by creating a phase screen. The interpolation and extrapolation phase correction schemes using phase screens are tested with the SMA to study how effective these schemes are. We produce a plane of a wavefront (phase screen) from the phase information of three antennas for each integration, and this phase screen is used for the interpolation and extrapolation of the phases of inner and outer antennas, respectively. The interpolation scheme obtains apparently improved results, suggesting that the ACA phase correction scheme will work well. On the other hand, the extrapolation scheme often does not improve the results. After the extrapolation, unexpectedly large phase fluctuations show up to the antennas at the distance of ~140 m away from the center of the three reference antennas. These direction vectors are almost perpendicular to the wind direction, suggesting that the phase fluctuations can be well explained by the frozen phase screen.
We prove that the bipartite entangled state of rank three is distillable. So there is no rank three bipartite bound entangled state. By using this fact, We present some families of rank four states that are distillable. We also analyze the relation between the low rank state and the Werner state.
We present a new method of analytically deriving the entanglement of formation of the bipartite mixed state. The method realizes the optimal decomposition families of states. Our method can lead to many new results concerning entanglement of formatio
n, its additivity and entanglement cost. We illustrate it by investigating the two-qubit state, the separable state, the maximally correlated state, the isotropic state and the Werner state.
This paper has been withdrawn.
We introduce a feasible method of constructing the entanglement witness that detects the genuine entanglement of a given pure multiqubit state. We illustrate our method in the scenario of constructing the witnesses for the multiqubit states that are
broadly theoretically and experimentally investigated. It is shown that our method can construct the effective witnesses for experiments. We also investigate the entanglement detection of symmetric states and mixed states.
There has been important experimental progress in the sector of heavy baryons in the past several years. We study the strong decays of the S-wave, P-wave, D-wave and radially excited charmed baryons using the $^3P_0$ model. After comparing the calcul
ated decay pattern and total width with the available data, we discuss the possible internal structure and quantum numbers of those charmed baryons observed recently.
