A broad pseudovector glueball from holographic QCD

We study the decay of a pseudovector glueball with quantum numbers J(PC) = 1(+-) , the lightest glueball with spin different from zero or two, in the top-down holographic Witten-Sakai-Sugimoto model. This glueball is dual to the string-theoretic Kalb-Ramond tensor field, which completely fixes all its couplings by gauge invariance and D-brane anomaly inflow. The dominant decay channels are determined by a Chern-Simons-like action for the flavor branes; couplings from the Dirac-Born-Infeld action turn out to be subdominant. While the resulting width is parametrically of order N-c(-2)lambda(-1) for N-c colors and 't Hooft coupling lambda, when extrapolated to N-c = 3 and with X matched to experimental data, the prediction is that the pseudovector glueball is an extremely broad resonance. (C) 2018 The Authors. Published by Elsevier B.V.