Collider and astrophysical signatures of light scalars with enhanced $\tau$ couplings

Abstract

Beyond Standard Model scenarios addressing the flavor puzzle and the hierarchy problem generally predict dominant new physics couplings with fermions of the third generation. In this Letter, we explore the collider and astrophysical signatures of new light scalar and pseudoscalar particles dominantly coupled to the $\tau$-lepton. The best experimental prospects are expected at Belle II through the $e^{+}{e}^{-}\to {\tau }^{+}{\tau }^{-}\gamma \gamma$, ${\tau }^{+}{\tau }^{-}\gamma$, $3\gamma$, mono-$\gamma$ processes, and the $\tau$ anomalous magnetic moment. The correlated effects in these searches can unambiguously point toward the underlying new physics dynamics. Moreover, we study astrophysics bounds - especially from core-collapse supernovae and neutron star mergers - finding them particularly effective and complementary to collider bounds. We carry out this program in the well-motivated context of axion-like particles as well as generic CP-even and CP-odd particles, highlighting possible ways to discriminate among them.

9 pages, 6 figures, v2: matches published version

References in corpus (23)

• The $g-2$ of charged leptons, $\alpha (M_Z^2)$ and the hyperfine splitting of muonium
• Collider Probes of Axion-Like Particles
• Dielectric Haloscopes: A New Way to Detect Axion Dark Matter
• Revised constraints and Belle II sensitivity for visible and invisible axion-like particles
• Resonant detection of axion mediated forces with Nuclear Magnetic Resonance
• The Low-Energy Effective Theory of Axions and ALPs
• Flavor probes of axion-like particles
• Contributions of axion-like particles to lepton dipole moments
• Heavy axion-like particles and core-collapse supernovae: constraints and impact on the explosion mechanism
• Updated constraints on axion-like particles from temporal information in supernova SN1987A gamma-ray data
• Axion-sourced fireballs from supernovae
• Invisible and displaced dark matter signatures at Belle II
• Tau anomalous magnetic moment form factor at Super B/Flavor factories
• Flavor hierarchies, flavor anomalies, and Higgs mass from a warped extra dimension
• Multimessenger Constraints on Radiatively Decaying Axions from GW170817
• 3D template-based $Fermi$-LAT constraints on the diffuse supernova axion-like particle background
• Non-universal gauge interactions addressing the inescapable link between Higgs and Flavour
• On Flavour and Naturalness of Composite Higgs Models
• Revisiting the production of ALPs at B-factories
• Investigating the gamma-ray burst from decaying MeV-scale axion-like particles produced in supernova explosions
• Towards testing the magnetic moment of the tau at one part per million
• Observation of $\gamma \gamma$ $\to$ $\tau \tau$ in proton-proton collisions and limits on the anomalous electromagnetic moments of the $\tau$ lepton
• Tau spin correlations and the anomalous magnetic moment

Cited by in corpus (3)

• Anomalous Dimension of a General Effective Gauge Theory I: Bosonic Sector
• Light new physics and the $\tau$ lepton dipole moments: prospects at Belle II
• Small Progenitors, Large Couplings: Type Ic Supernova Constraints on Radiatively Decaying Particles