Speaker
Description
Exotic scalars and vectors coupled to nucleons and muons can be copiously produced in cold isolated neutron stars (NSs). In these environments, the milder temperature dependence of their emissivity compared to neutrinos magnifies significantly the effect of these novel exotic particles on the cooling process of such stars. The absence of traces of exotic cooling for a well-measured sample of NSs with ages around $10^5$ years can be exploited to set stringent constraints on the coupling strength of bosons with masses $m_\phi$<1 MeV, superseding by many orders of magnitude the corresponding SN 1987A cooling bound in the given mass range. Equivalently, I will discuss how the same constraints can be also derived following a simple argument based on analytic behavior of the NS cooling process. These arguments induce the most stringent bounds on the strength of fifth forces between nucleons and muons and acting on micro- to picometer length scales.