Limits on heavy neutral leptons, Z′ bosons and majorons from high-energy supernova neutrinos
Kensuke Akita, Sang Hui Im, Mehedi Masud, Seokhoon Yun
Abstract
A bstract Light hypothetical particles with masses up to $$ \mathcal{O}(100) $$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mi>O</mml:mi> <mml:mfenced> <mml:mn>100</mml:mn> </mml:mfenced> </mml:math> MeV can be produced in the core of supernovae. Their subsequent decays to neutrinos can produce a flux component with higher energies than the standard flux. We study the impact of heavy neutral leptons, Z ′ bosons, in particular $$ \textrm{U}{(1)}_{L_{\mu }-{L}_{\tau }} $$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mi>U</mml:mi> <mml:msub> <mml:mfenced> <mml:mn>1</mml:mn> </mml:mfenced> <mml:mrow> <mml:msub> <mml:mi>L</mml:mi> <mml:mi>μ</mml:mi> </mml:msub> <mml:mo>−</mml:mo> <mml:msub> <mml:mi>L</mml:mi> <mml:mi>τ</mml:mi> </mml:msub> </mml:mrow> </mml:msub> </mml:math> and U(1) B−L gauge bosons, and majorons coupled to neutrinos flavor-dependently. We obtain new strong limits on these particles from no events of high-energy SN 1987A neutrinos and their future sensitivities from observations of galactic supernova neutrinos.