Gauge and Lorentz Covariant Quark Propagator in an Arbitrary Gluon Field

The quark propagator in presence of an arbitrary gluon field is calculated gauge and Lorentz covariantly order by order in terms of powers of gluon field and its derivatives. The result is independent of path connecting ends of propagator and leading order result coincides with the exact propagator in the trivial case of vanishing gluon field.Comment: 9 page

Time-domain response of nabla discrete fractional order systems

This paper investigates the time--domain response of nabla discrete fractional order systems by exploring several useful properties of the nabla discrete Laplace transform and the discrete Mittag--Leffler function. In particular, we establish two fundamental properties of a nabla discrete fractional order system with nonzero initial instant: i) the existence and uniqueness of the system time--domain response; and ii) the dynamic behavior of the zero input response. Finally, one numerical example is provided to show the validity of the theoretical results.Comment: 13 pages, 6 figure

Searching for X0(2900) X_{0}(2900) and X1(2900) X_{1}(2900) through the kaon induced reactions

The productions of the exotic states $X_0(2900)$ and $X_1(2900)$ in $K^{+}p \to \Sigma_{c}^{++}X_{0}(2900)$ and $K^{+}p \to \Sigma_{c}^{++}X_{1}(2900)$ reactions are studied within an effective Lagrangian approach. The $t-$channel Born term is included to calculate the production cross sections. The numerical results show that the total cross section may reach up to about 0.5 nb and 25 nb for the production of $X_0(2900)$ and $X_1(2900)$, respectively. The predicted differential cross sections are sensitive to the scattering angles and have strong forward enhancements. The cross sections for the $K^{+}n \to \Lambda_{c}^{+}X_{0,1}$ are also calculated and found to be larger than that in $K^{+}p$ collisions by more than one order of magnitude. The results are helpful to the possible experiments at J-PARC and COMPASS.Comment: 5 pages, 5 figure

Empirical comparison of diffusion kurtosis imaging and diffusion basis spectrum imaging using the same acquisition in healthy young adults

As diffusion tensor imaging gains widespread use, many researchers have been motivated to go beyond the tensor model and fit more complex diffusion models, to gain a more complete description of white matter microstructure and associated pathology. Two such models are diffusion kurtosis imaging (DKI) and diffusion basis spectrum imaging (DBSI). It is not clear which DKI parameters are most closely related to DBSI parameters, so in the interest of enabling comparisons between DKI and DBSI studies, we conducted an empirical survey of the interrelation of these models in 12 healthy volunteers using the same diffusion acquisition. We found that mean kurtosis is positively associated with the DBSI fiber ratio and negatively associated with the hindered ratio. This was primarily driven by the radial component of kurtosis. The axial component of kurtosis was strongly and specifically correlated with the restricted ratio. The joint spatial distributions of DBSI and DKI parameters are tissue-dependent and stable across healthy individuals. Our contribution is a better understanding of the biological interpretability of the parameters generated by the two models in healthy individuals