Threshold-cusp explanation for $X$ and $Z_{cs}$ in $B^{+}\to J/\psi \varphi K^{+}$

S. X. Nakamura, X. Luo

Several $X$ and $Z_{cs}$ exotic hadrons were claimed in the LHCb's amplitude analysis on $B^{+}\to J/\psi \varphi K^{+}$. The data shows that all the peaks and also dips in the spectra are locate…