2025/08/18 by Brambilla, Nora, Mohapatra, Abhishek, Vairo, Antonio · 2 citations
#FOS: Physical sciences #High Energy Physics - Experiment (hep-ex) #High Energy Physics - Lattice (hep-lat) #High Energy Physics - Phenomenology (hep-ph)
paper · doi:10.48550/arxiv.2508.13050
The hidden-charm pentaquark states P_cc(4312)+, P_cc(4380)+, P_cc(4440)+, and P_cc(4457)+, all with isospin I = 1/2, were discovered by the LHCb collaboration in the decay process Λb0 → J/ψp K-. Although their quantum numbers remain undetermined, these states have generated significant theoretical interest. We analyze their spectrum and decay patterns-including those of their spin partners-within the Born--Oppenheimer effective field theory (BOEFT), a framework grounded in QCD. At leading order in BOEFT, we identify these pentaquark states as bound states in BO potentials that exhibit at short-distance a repulsive octet behavior and a nonperturbative shift due to the adjoint baryons masses, while asymptotically approaching the ΣcD threshold. We further incorporate \cal O(1/mQ) spin-dependent corrections to compute pentaquark multiplet spin splittings. Based on the spectrum, semi-inclusive decay widths to J/ψ and ηc, and the decay width ratios to ΛcD and ΛcD^*, we provide the first theoretical predictions for the adjoint baryon masses, which can be confirmed by future lattice QCD studies. Moreover, our analysis supports the quantum number assignments: JP = (1/2)- for P_cc(4312)+, (3/2)- for P_cc(4380)+, (1/2)- for P_cc(4457)+, and (3/2)- for P_cc(4440)+. We also present results for the lowest bottom pentaquarks.