New analysis of neutron star constraints on asymmetric dark matter

Abstract

Due to their extreme density and low temperature, neutron stars (NS) are efficient probes to unveil interactions between standard model and dark matter (DM) particles. From elastic scatterings on NS material, DM can get gravitationally trapped by the star. The cooling of DM through further collisions may lead to the formation of a dense core which could collapse into a black hole, thus destroying the whole NS. From the observation of old NS, such a scenario leads to very stringent constraints on the parameter space of asymmetric DM. In this work we reexamine this possibility in detail. This includes: (a) a new detailed determination of the number of DM particles captured, properly taking into account the fact that neutrons form a highly degenerate Fermi material; (b) the determination of the time evolution of the DM density and energy profiles inside the NS, which allows us to understand how, as a function of time, DM thermalizes with NS material; (c) the determination of the corresponding constraints which hold on the DM-neutron cross section, including for the case where a large fraction of DM particles have not thermalized; (d) the first determination of the stringent constraints which also hold in a similar way on the DM-muon cross section, particularly relevant for leptophilic DM models; and (e) the use of realistic NS equations of state in determining these constraints. * Electronic address: rgaranir@ulb.ac.be † Electronic address: yoann.genolini@ulb.ac.be ‡ Electronic address: thambye@ulb.ac.be arXiv:1812.08773v1 [hep-ph] Note that small momentum dependence in the cross section has been ignored. For scalar interactions, i.e. L int ⊃the cross sections are dσ χ−f d cos θcm = G 2 S 8π m 2 f (mχ+m f ) 2 and dσ χ−f d cos θcm = G 2 S 2π m 2 χ m 2 f (mχ+m f ) 2 ,

Warming nuclear pasta with dark matter: kinetic and annihilation heating of neutron star crusts

“…Here we fix m DM = 1 TeV and (σv) 0 = 3×10 −26 cm 3 /s in Eq. (26), and assume a dark matter-nucleon cross section greater than 10 −40 cm 2 so that all transiting dark matter is captured by the crust (see Fig. 3).…”

“…× 10 10 , 3 × 10 11 ][17,26] Table I. Simplified model of the layers of the outer crust of a non-accreting neutron star used in this work. See Sec.…”

A supersymmetric theory of baryogenesis and sterile sneutrino dark matter from B mesons

“…DM that interacts with neutrons and electrons can upset this balance leading to destabilization of the star. Many studies have been conducted to investigate such effects and the constraints they imply [82][83][84][85][86][87][88]. As an example of an application, in Sec.…”

Dark matter interactions with muons in neutron stars

“…Dark matter capture: The maximal capture rate, i.e. the rate at which all DM particles χ with mass m χ that intercept the NS are captured, is given by the geometric rate [6] C 5.6 × 10 25 s…”

“…A typical old NS contains roughly 10 55 muons, compared to about 10 57 neutrons [1][2][3][4][5]. This lets NS interact with and potentially capture dark matter (DM) that couples mainly to muons, unique among astrophysical objects [6].…”