Analysis of the heavy tensor mesons strong decay with QCD sum rules

In this article, the tensor-vector-pseudoscalar type of vertex is analyzed with the QCD sum rules and the local-QCD sum rules. Correspondingly, the hadronic coupling constants of D2*(2460), Ds2*(2573), B2*(5747) and Bs2*(5840), and their decay widths are calculated. The results indicate that the QCD sum rules and the local-QCD sum rules give the consistent descriptions. Finally, the full widths of these 4 tensor mesons are discussed in detail.

General Reynolds Analogy for Blunt-nosed Bodies in Hypersonic Flows

In this paper, the relation between skin friction and heat transfer along windward sides of blunt-nosed bodies in hypersonic flows is investigated. The self-similar boundary layer analysis is accepted to figure out the distribution of the ratio of skin friction to heat transfer coefficients along the wall. It is theoretically obtained that the ratio depends linearly on the local slope angle of the wall surface, and an explicit analogy expression is presented for circular cylinders, although the linear distribution is also found for other nose shapes and even in gas flows with chemical reactions. Furthermore, based on the theoretical modelling of the second order shear and heat transfer terms in Burnett equations, a modified analogy is derived in the near continuum regime by considering the rarefied gas effects. And a bridge function is also constructed to describe the nonlinear analogy in the transition flow regime. At last, the direct simulation Monte Carlo method is used to validate the theoretical results. The general analogy, beyond the classical Reynolds analogy, is applicable to both flat plates and blunt-nosed bodies, in either continuous or rarefied hypersonic flows.

Systematic analysis of the $D_{J}(2580)$, $D_{J}^{*}(2650)$, $D_{J}(2740)$, $D_{J}^{*}(2760)$, $D_{J}(3000)$ and $D_{J}^{*}(3000)$ in $D$ meson family

In this work, we tentatively assign the charmed mesons $D_{J}(2580)$, $D_{J}^{*}(2650)$, $D_{J}(2740)$, $D_{J}^{*}(2760)$, $D_{J}(3000)$ and $D_{J}^{*}(3000)$ observed by the LHCb collaboration according to their spin-parity and masses, then study their strong decays to the ground state charmed mesons plus light pseudoscalar mesons with the $^{3}P_{0}$ model. According to these study, we assigned the $D_{J}^{*}(2760)$ as the $1Dfrac{5}{2}3^{-}$ state, the $D_{J}^{*}(3000)$ as the $1Ffrac{5}{2}2^{+}$ or $1Ffrac{7}{2}4^{+}$ state, the $D_{J}(3000)$ as the $1Ffrac{7}{2}3^{+}$ or $2Pfrac{1}{2}1^{+}$ state in the $D$ meson family. As a byproduct, we also study the strong decays of $2Pfrac{1}{2}0^{+}$,$2Pfrac{3}{2}2^{+}$, $3Sfrac{1}{2}1^{-}$, $3Sfrac{1}{2}0^{-}$ etc, states, which will be helpful to further experimentally study mixings of these $D$ mesons.