Speaker
Description
Search and study of multiquark XYZ states is one of the urgent tasks of modern high energy physics. Calculations obtained using Lattice QCD cannot fully describe spectrum of that states and predict parameters currently unopened states. Studying the properties of exotic hadrons can bring us to a better understanding of the strong interaction. In this report, results of the amplitude analysis of $B^{0} \to J/\psi K \pi$, $B_{s} \to J/\psi K K$ decays at the ATLAS experiment at the LHC are presented. The analysis is based on a sample of $pp$ collision data at the center of mass energies $\sqrt{s}$ = 13 TeV corresponding to integrated luminosity of 139 $fb^{-1}$. Contributions from the exotic states $Z_{c}^{\pm}(4200)$, $Z_{c}^{\pm}(4430)$, $Z_{c}^{\pm}(3900)$, $Z_{cs}^{\pm}(4000)$, $Z_{cs}^{\pm}(4220)$ to the above mentioned decays are observed with a total significance above 10$\sigma$. The report also contains study of various spin-parity options of $Z_{c}^{\pm}(4200)$ state.
