Collider probes of axion-like particles
Martin Bauer, Matthias Neubert, Andrea Thamm
The Journal of High Energy Physics | Springer Science and Business Media LLC | Published : 2017
Axion-like particles (ALPs), which are gauge-singlets under the Standard Model (SM), appear in many well-motivated extensions of the SM. Describing the interactions of ALPs with SM fields by means of an effective Lagrangian, we discuss ALP decays into SM particles at one-loop order, including for the first time a calculation of the a → πππ decay rates for ALP masses below a few GeV. We argue that, if the ALP couples to at least some SM particles with couplings of order (0.01 − 1) TeV−1, its mass must be above 1 MeV. Taking into account the possibility of a macroscopic ALP decay length, we show that large regions of so far unconstrained parameter space can be explored by searches for the exot..View full abstract
Awarded by European Research Council (ERC)
Awarded by Cluster of Excellence Precision Physics, Fundamental Interactions and Structure of Matter
Awarded by German Federal Ministry for Education and Research (BMBF)
We are grateful to Thomas Becher, Konstantin Chetyrkin, David Curtin, Aneesh Manohar, Maxim Pospelov, Jorg Jackel, Joachim Kopp and Pedro Schwaller for useful discussions. M.N. thanks the Aspen Center for Physics, where this work has been completed, for hospitality and support. The research reported here has been supported by the Advanced Grant EFT4LHC of the European Research Council (ERC), the Cluster of Excellence Precision Physics, Fundamental Interactions and Structure of Matter (PRISMA - EXC 1098), and grant 05H12UME of the German Federal Ministry for Education and Research (BMBF).