Journal of High Energy Physics

We study the stability of extreme Reissner-Nordström-AdS black hole under massless scalar perturbations. We show that the perturbation on the horizon of the extreme Reissner-Nordström-AdS black hole experiences a power-law decay, instead of an exponential decay as observed in the nonextreme AdS black hole. On the horizon of the extreme Reissner-Nordström-AdS black hole, the blow up happens at lower order derivative of the scalar field compared with that of the extreme Reissner-Nordström black hole, which shows that extreme AdS black holes tend to instability in comparison to black holes in asymptotic flat space-times.

Dotsenko-Fateev and Chern-Simons matrix models, which describe Nekrasov functions for SYM theories in different dimensions, are all incorporated into network matrix models with the hidden Ding-Iohara-Miki (DIM) symmetry. This lifting is especially simple for what we call balanced networks. Then, the Ward identities (known under the names of Virasoro/ $$ \mathcal{W} $$ -constraints or loop equations or regularity condition for qq-characters) are also promoted to the DIM level, where they all become corollaries of a single identity.

We explore different branches of the fermion doublers with Wilson fermion in perturbation theory, in the context of additive mass renormalization and chiral anomaly, and show that by appropriately averaging over suitably chosen branches one can reduce cut-off artifacts. Comparing the central branch with all other branches, we find that the central branch, among all the avatars of the Wilson fermion, is the most suitable candidate for exploring near conformal lattice field theories.

A popular regime in the NMSSM parameter space involves a light CP-odd Higgs A 1. This scenario has consequences for e.g. light singlino Dark Matter annihilating in the A 1-funnel. In order to confront the pseudoscalar to experimental limits such as flavour observables, Upsilon decays or Beam-Dump experiments, it is necessary to control the interactions of this particle with hadronic matter and derive the corresponding decays. The partonic description cannot be relied upon for masses close to $$ {m_A}_{{}_1} $$ ∼ 1GeV and we employ a chiral lagrangian, then extended to a spectator model for somewhat larger masses, to describe the interplay of the CP-odd Higgs with hadrons. Interestingly, a mixing can develop between A 1 and neutral pseudoscalar mesons, leading to substantial hadronic decays and a coupling of A 1 to the chiral anomaly. Additionally, quartic A 1-meson couplings induce tri-meson decays of the Higgs pseudoscalar. We investigate these effects and propose an estimate of the Higgs widths for masses below $$ {m_A}_{{}_1} $$ ≲ 3 GeV. While we focus on the case of the NMSSM, our results are applicable to a large class of models.