In this paper, we present some inequalities for the Co-PI index involving the some topological indices, the number of vertices and edges, and the maximum degree. After that, we give a result for trees. In addition, we give some inequalities for the largest eigenvalue of the Co-PI matrix of G.

Triangle mechanisms for $B^0\to (J/\psi\pi^+\pi^-) K^+\pi^-$ are studied. Experimentally, an $X(3872)$ peak has been observed in this process. When the final $(J/\psi\pi^+\pi^-)\pi$ invariant mass is around $D^*\bar D^*$ threshold, one of triangle causes a singularity and generates sharp $X(3872)$-like $J/\psi\pi^+\pi^-$ distribution. The Breit-Wigner width fitted to spectrum 3871.68 MeV (a few...

Abstract We study the $$D^+ \rightarrow \pi ^+ \eta $$ D+→π+ηη and ^0 xmlns:mml="http://www.w3.org/1998/Math/MathML">D<...