Confronting pentaquark photoproduction with new LHCb observations

The newly measurement of production fractions of $P_c$ states by LHCb collaboration have put restriction on their branching ratios of $J/\psi p$ decay, thus constraining their photoproduction in $\gamma p\to J/\psi p$ reaction. We show the tension between LHCb results and the current experiments in search of $P_c$ photoproduction. We also find that the present information of branching ratios of $P_c\to J/\psi p$ has already confronted sharply with the models which study the nature of $P_c$

Kinetics and thermodynamics of electron transfer in Debye solvents: An analytical and nonperturbative reduced density matrix theory

A nonperturbative electron transfer rate theory is developed based on the reduced density matrix dynamics, which can be evaluated readily for the Debye solvent model without further approximation. Not only does it recover for reaction rates the celebrated Marcus' inversion and Kramers' turnover behaviors, the present theory also predicts for reaction thermodynamics, such as equilibrium Gibbs free-energy and entropy, some interesting solvent-dependent features that are calling for experimental verification. Moreover, a continued fraction Green's function formalism is also constructed, which can be used together with Dyson equation technique, for efficient evaluation of nonperturbative reduced density matrix dynamics.Comment: 8 pages, 5 figures. J. Phys. Chem. B, accepte

Data driven isospin analysis of timelike octet baryons electromagnetic form factors and charmonium decay into baryon-anti-baryon

Inspired by the recent precise data, we perform model-independently an isospin decomposition of the timelike octet baryons electromagnetic form factors. As noted in our previous work, the relative magnitude of isoscalar and isovector component is determined with the input of data on various isospin channels. Herein we further assert that {their relative phase can be constraint by the phase difference of oscillatory modulation of effective form factors} between isospin channels. The framework is extended to analyze the data of differential cross sections and applied to the form factors of nucleon and hyperons with detail and isospin non-conservation of charmonium decay into baryon-anti-baryon as well. We address that isospin analysis is meaningful when the isospin broken scale is compared to or smaller than the uncertainties of data.Comment: 11 pages, 7 figure