Zb tetraquark channel and $B\bar B^*$ interaction from lattice QCD
| Autor: | Prelovsek, S., Bahtiyar, H., Petkovic, J. |
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| Rok vydání: | 2019 |
| Předmět: | |
| Druh dokumentu: | Working Paper |
| Popis: | Two tetraquark candidates $Z_b(10610)$ and $Z_b(10650)$ with flavor structure $\bar bb\bar du$ were discovered by Belle experiment in 2011. We present a preliminary $N_f=2$ lattice study of the $\bar bb\bar du$ system in the approximation of static $b$ quarks, where the total spin of heavy quarks is fixed to one. The ground and the excited eigen-energies are determined as a function of separation $r$ between $b$ and $\bar b$. The lower eigenstates are related to a bottomonium and a pion. One of the higher eigenstates is dominated by $B\bar B^*$: its energy is significantly below $m_B+m_{B*}$ for r=[0.1,0.4] fm, which suggests sizable attraction. The attractive potential $V(r)$ between $B$ and $\bar B^*$ is extracted assuming that this eigenstate is related exclusively to $B\bar B^*$. Assuming a certain form of the potential and solving non-relativistic Schrodinger equation, we find a bound state pole below $B\bar B^*$ threshold. For certain parametrizations, the bound state is very close to the $B\bar B^*$ threshold - this feature could be related to $Z_b(10610)$ in the experiment. Comment: 7 pages, 4 figures, Proceedings of Lattice2019, 16-22 June 2019, Wuhan, China; v2 reflects changes in 1912.02656v4 which discusses the same study |
| Databáze: | arXiv |
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