A new anomalous contribution to the central charge of the N=2 monopole

We calculate the one-loop corrections to the mass and central charge of the BPS monopole in N=2 super-Yang-Mills theory in 3+1 dimensions using a supersymmetry-preserving version of dimensional regularization adapted to solitons. In the renormalization scheme where previous studies have indicated vanishing quantum corrections, we find nontrivial corrections that we identify as the 3+1 dimensional analogue of the anomaly in the conformal central charge of the N=1 supersymmetric kink in 1+1 dimensions. As in the latter case, the associated contribution to the ordinary central charge has exactly the required magnitude to preserve BPS saturation at the one-loop level. It also restores consistency of calculations involving sums over zero-point energies with the low-energy effective action of Seiberg and Witten.Comment: 1+10 pages. v3: version to appear in Physics Letters B (more precise title and abstract, additional explanations in the text concerning the nature of the anomaly involved

Nonchiral enhancement of scalar glueball decay in the Witten-Sakai-Sugimoto model

We estimate the consequences of finite masses of pseudoscalar mesons on the decay rates of scalar glueballs in the Witten-Sakai-Sugimoto model, a top-down holographic model of low-energy QCD, by extrapolating from the calculable vertex of glueball fields and the eta' meson which follows from the Witten-Veneziano mechanism for giving mass to the latter. Evaluating the effect on the recently calculated decay rates of glueballs in the Witten-Sakai-Sugimoto model, we find a strong enhancement of the decay of scalar glueballs into kaons and eta mesons, in fairly close agreement with experimental data on the glueball candidate f0(1710).Comment: 6 pages, 2 tables; v3: minor modifications and references adde

Constraints on the ηη′\eta \eta' decay rate of a scalar glueball from gauge/gravity duality

Predictions of glueball decay rates in the holographic Witten-Sakai-Sugimoto model for low-energy QCD can be uniquely extended to include finite quark masses up to an as yet undetermined parameter in the coupling of glueballs to the nonanomalous part of the pseudoscalar mass terms. The assumption of a universal coupling of glueballs to mass terms of the full nonet of pseudoscalar mesons leads to flavor asymmetries in the decay rates of scalar glueballs that agree well with experimental data for the glueball candidate $f_0(1710)$ and implies a vanishing decay rate into $\eta\eta'$ pairs, for which only upper bounds for the $f_0(1710)$ meson are known at present from experiment. Relaxing this assumption, the holographic model gives a tight correlation between the decay rates into pairs of pseudo-Goldstone bosons of same type and $\eta\eta'$ pairs. If $\Gamma(G\to KK)/\Gamma(G\to\pi\pi)$ is kept within the range reported currently by the Particle Data Group for the $f_0(1710)$ meson, the rate $\Gamma(G\to\eta\eta')/\Gamma(G\to\pi\pi)$ is predicted to be $\lesssim 0.04$. The corresponding situation for $f_0(1500)$ is also discussed, which however is found to be much less compatible with the interpretation of a largely unmixed glueball.Comment: 7 pages, 3 figures; v2: minor corrections, version to appear in Phys. Rev.