https://doi.org/10.1140/epjc/s10052-018-5530-9
Regular Article - Theoretical Physics
Pentaquarks with hidden charm as hadroquarkonia
1
Department of Physics and Astronomy, University of Kentucky, Lexington, KY, 40506, USA
2
Petersburg Nuclear Physics Institute, Gatchina, St. Petersburg, 188300, Russia
3
Institut für Theoretische Physik II, Ruhr-Universität Bochum, Bochum, 44780, Germany
* e-mail: eides@pa.uky.edu
Received:
9
December
2017
Accepted:
6
January
2018
Published online:
17
January
2018
We consider hidden charm pentaquarks as hadroquarkonium states in a QCD inspired approach. Pentaquarks arise naturally as bound states of quarkonia excitations and ordinary baryons. The LHCb 
pentaquark is interpreted as a 
-nucleon bound state with spin-parity 
. The partial decay width 
MeV is calculated and turned out to be in agreement with the experimental data for . The pentaquark is predicted to be a member of one of the two almost degenerate hidden-charm baryon octets with spin-parities 
. The masses and decay widths of the octet pentaquarks are calculated. The widths are small and comparable with the width of the pentaquark, and the masses of the octet pentaquarks satisfy the Gell-Mann–Okubo relation. Interpretation of pentaquarks as loosely bound 
and 
deuteronlike states is also considered. We determine quantum numbers of these bound states and calculate their masses in the one-pion exchange scenario. The hadroquarkonium and molecular approaches to exotic hadrons are compared and the relative advantages and drawbacks of each approach are discussed.
© The Author(s), 2018
