We perform a constituent quark model analysis for the masses of the doubly heavy tetraquark states TQQ after we fix the parameters to fit the masses of the newly observed Ξcc ++ and hadrons involving heavy quarks relevant to the stability of these states. We investigate in detail how the relative distances between quark pairs vary as we change the quark content and how they affect the various contributions to the total tetraquark masses. We also find that our full calculations give in general less binding compared to simplified quark model calculations that treat quark dynamics inside the tetraquark the same as that inside a baryon. We trace the main origin to be the differences in the number of relative kinetic energies which increases as one goes from meson, baryon and tetraquarks. We also compare our new results with previous works using less constrained parameters and find that the tetraquark state Tbb(udb¯b¯) and Tbb(usb¯b¯) are bound by 121 MeV and 7 MeV, respectively.
Bibliographical noteFunding Information:
This work was supported by the Korea National Research Foundation (NRF) under the grant number 2016R1D1A1B03930089 and 2017R1D1A1B03028419 .
© 2018 Elsevier B.V.
All Science Journal Classification (ASJC) codes
- Nuclear and High Energy Physics