Precision calculations of dark matter relic abundance. (arXiv:1912.02870v2 [hep-ph] UPDATED)

<a href="http://arxiv.org/find/hep-ph/1/au:+Ala_Mattinen_K/0/1/0/all/0/1">Kalle Ala-Mattinen</a>, <a href="http://arxiv.org/find/hep-ph/1/au:+Kainulainen_K/0/1/0/all/0/1">Kimmo Kainulainen</a>

The dark matter annihilation channels sometimes involve sharp resonances. In

such cases the usual momentum averaged approximations for computing the DM

abundance may not be accurate. We develop an easily accessible momentum

dependent framework for computing the DM abundance accurately and efficiently

near such features. We apply the method to the case of a singlet scalar dark

matter $s$ interacting with SM through higgs portal $lambda_{rm hs}s^2 h^2$

and compare the results with different momentum averaged methods. The accuracy

of the latter depend strongly on the strength of the elastic interactions and

corrections are large if WIMP has negligible interactions beyond the main

annihilation channel. In the singlet scalar model however, the standard model

scatterings induce an efficient kinetic equilibrium that validates the momentum

averaged computation to 20 per cent accuracy. We update the current extent of

the allowed region in the light singlet scalar dark matter to $m_{rm S} in

[56,62.5]$ GeV.

The dark matter annihilation channels sometimes involve sharp resonances. In

such cases the usual momentum averaged approximations for computing the DM

abundance may not be accurate. We develop an easily accessible momentum

dependent framework for computing the DM abundance accurately and efficiently

near such features. We apply the method to the case of a singlet scalar dark

matter $s$ interacting with SM through higgs portal $lambda_{rm hs}s^2 h^2$

and compare the results with different momentum averaged methods. The accuracy

of the latter depend strongly on the strength of the elastic interactions and

corrections are large if WIMP has negligible interactions beyond the main

annihilation channel. In the singlet scalar model however, the standard model

scatterings induce an efficient kinetic equilibrium that validates the momentum

averaged computation to 20 per cent accuracy. We update the current extent of

the allowed region in the light singlet scalar dark matter to $m_{rm S} in

[56,62.5]$ GeV.

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