Collider Signatures of Goldstone Bosons

Abstract

Recently Weinberg suggested that Goldstone bosons arising from the spontaneous breakdown of some global hidden symmetries can interact weakly in the early Universe and account for a fraction of the effective number of neutrino species N_eff, which has been reported persistently 1 σaway from its expected value of three. In this work, we study in some details a number of experimental constraints on this interesting idea based on the simplest possibility of a global U(1), as studied by Weinberg. We work out the decay branching ratios of the associated light scalar field $\sigma$ and suggest a possible collider signature at the Large Hadron Collider (LHC). In some corners of the parameter space, the scalar field σcan decay into a pair of pions with a branching ratio of order O(1)% while the rest is mostly a pair of Goldstone bosons. The collider signature would be gluon fusion into the standard model Higgs boson gg -> H or associated production with a W gauge boson q q'-bar -> H W, followed by H -> σσ-> (ππ) (αα), where αis the Goldstone boson.

14pages, 2 figures; corrected the formula for Higgs decay into pions; references added; accepted for PRD

References in corpus (4)

• Goldstone Bosons as Fractional Cosmic Neutrinos
• Search for Production of Invisible Final States in Single-Photon Decays of Upsilon(1S)
• W-WIMP Annihilation as a Source of the Fermi Bubbles
• Searching for Nambu-Goldstone Bosons at the LHC

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• Three Loop Neutrino Model with Isolated $k^{\pm \pm }$
• Dark matter production from Goldstone boson interactions and implications for direct searches and dark radiation
• Electroweak baryogenesis in the framework of the effective field theory
• Detecting multimuon jets from the Higgs exotic decays in the Higgs portal framework
• Weinberg's Higgs portal confronting recent LUX and LHC results together with upper limits on B^+ and K^+ decay into invisibles
• Supernovae and Weinberg's Higgs Portal Dark Radiation and Dark Matter
• Cosmological and astrophysical signatures of dark matter annihilations into pseudo-Goldstone bosons
• Supernova Bounds on Weinberg's Goldstone Bosons
• Majorana dark matter through the Higgs portal under the vacuum stability lamppost
• Dark Photon as Fractional Cosmic Neutrino Masquerader
• Neutrinophilic two Higgs doublet model with $U(1)$ global symmetry