Positivity bounds on Higgs-Portal dark matter

Abstract

We consider the positivity bounds for WIMP scalar dark matter with effective Higgs-portal couplings up to dimension-8 operators. Taking the superposed states for Standard Model Higgs and scalar dark matter, we show that the part of the parameter space for the effective couplings, otherwise unconstrained by phenomenological bounds, is ruled out by the positivity bounds on the dimension-8 derivative operators. We find that dark matter relic density, direct and indirect detection and LHC constraints are complementary to the positivity bounds in constraining the effective Higgs-portal couplings. In the effective theory obtained from massive graviton or radion, there appears a correlation between dimension-8 operators and other effective Higgs-portal couplings for which the strong constraint from direct detection can be evaded. Nailing down the parameter space mainly by relic density, direct detection and positivity bounds, we find that there are observable cosmic ray signals coming from the dark matter annihilations into a pair of Higgs bosons, WW or ZZ.

Hilbert series for ALP EFTs

“…With the full operator basis at dimension 8 one could study the implications of positivity on ALP EFTs, extending the analysis of ref. [83] in the scalar sector. Finally, with a complete basis one could extend the efforts of refs.…”

Positivity bounds on Higgs-portal freeze-in dark matter

“…complete model such as massive graviton or radion are crucial for identifying the safe Higgs-portal models from direct detection bounds [12].…”

“…In this article, we extend our analysis of the positivity bounds in ref. [12] to the case for freeze-in scalar dark matter with general Higgs-portal interactions. We assume that a sufficiently large reheating temperature is achieved after a slow-roll inflation and scalar dark matter is never in thermal equilibrium.…”

“…In particular, such consistency conditions give rise to positivity conditions in the forward limit of the scattering amplitudes at low energies [1][2][3]. Recently, positivity bounds have been applied to the SMEFTs [4][5][6][7][8][9][10][11] and the Higgs-portal derivative interactions for scalar dark matter [12]. In the latter work, it has been shown that the positivity bounds can constrain the parameter space further for explaining the relic density for Weakly Interacting Massive Particles [12].…”

“…Recently, positivity bounds have been applied to the SMEFTs [4][5][6][7][8][9][10][11] and the Higgs-portal derivative interactions for scalar dark matter [12]. In the latter work, it has been shown that the positivity bounds can constrain the parameter space further for explaining the relic density for Weakly Interacting Massive Particles [12]. As a by-product of looking for the origin of the dimension-8 derivative Higgs-portal couplings, it has been found that the correlations between dimension-4 and dimension-6 operators in a Ultra-Violet(UV)…”