Towards exotic hidden-charm pentaquarks in QCD

TLDR: A QCD sum rule investigation is performed, by which they can be identified as exotic hidden-charm pentaquarks composed of an anticharmed meson and a charmed baryon, and results suggest that P(c)(4380) and P (c)(4450) have quantum numbers J(P)=3/2(-) and 5/2 (+), respectively.

Abstract: Inspired by P(c)(4380) and P(c)(4450) recently observed by LHCb, a QCD sum rule investigation is performed, by which they can be identified as exotic hidden-charm pentaquarks composed of an anticharmed meson and a charmed baryon. Our results suggest that P(c)(4380) and P(c)(4450) have quantum numbers J(P)=3/2(-) and 5/2(+), respectively. Furthermore, two extra hidden-charm pentaqurks with configurations DΣ(c)(*) and D(*)Σ(c)(*) are predicted, which have spin-parity quantum numbers J(P)=3/2(-) and J(P)=5/2(+), respectively. As an important extension, the mass predictions of hidden-bottom pentaquarks are also given. Searches for these partners of P(c)(4380) and P(c)(4450) are especially accessible at future experiments like LHCb and BelleII.