Global fit of pseudo-Nambu-Goldstone Dark Matter

Abstract

We perform a global fit within the pseudo-Nambu-Goldstone dark matter (DM) model emerging from an additional complex scalar singlet with a softly broken global U (1) symmetry. Leading to a momentum-suppressed DM-nucleon cross section at tree level, the model provides a natural explanation for the null results from direct detection experiments. Our global fit combines constraints from perturbative unitarity, DM relic abundance, Higgs invisible decay, electroweak precision observables and latest Higgs searches at colliders. The results are presented in both frequentist and Bayesian statistical frameworks. Furthermore, post-processing our samples, we include the likelihood from gamma-ray observations of Fermi-LAT dwarf spheroidal galaxies and compute the one-loop DM-nucleon cross section. We find two favoured regions characterised by their dominant annihilation channel: the Higgs funnel and annihilation into Higgs pairs. Both are compatible with current Fermi-LAT observations, and furthermore, can fit the slight excess observed in four dwarfs in a mass range between about 30-300 GeV. While the former region is hard to probe experimentally, the latter can partly be tested by current observations of cosmic-ray antiprotons as well as future gamma-ray observations. [15,16]. More commonly, however, particle DM models with a pseudoscalar mediator [17][18][19][20][21][22] leads to a momentum-suppressed DM-nucleon cross section. Thus, this class of models can naturally evade the strong limits from direct detection experiments.A popular example in this regards is the pseudo-Nambu-Goldstone (pNG) DM. It is realised by adding a complex scalar singlet with a softly broken global U (1) symmetry [23-25] to the Standard Model (SM) particle content. Due to the soft symmetry breaking, the resulting Goldstone becomes massive, i.e., a pNG boson. An additional CP symmetry ensures the stability of the pNG boson, which serves as a viable DM candidate. The Goldstone nature of the DM particle implies that the pNG DM-nucleon cross section is momentum-suppressed at tree-level. 1 Thus, a pNG DM model offers a natural way of evading the strong direct detection limits. A leading-order contribution to the pNG DM-nucleon cross section in the zero-momentum limit appears at the one-loop level [27,28]. For typical DM velocities in our galaxy, v χ ∼ 10 −3 , it can easily dominate over the tree-level contribution. The one-loop cross section can vary by several orders of magnitude in the allowed model parameter space. It has been shown that for parameter points which satisfy the relic density constraint, the one-loop cross section is typically below ∼ 10 −50 cm 2 [27] and thus beyond the expected reach of future direct detection experiments, e.g., LUX-ZEPLIN (LZ) [29] and DARWIN [30].More recently, the pNG DM model was confronted against the constraints from perturbative unitarity, DM relic density, Higgs invisible decay, XENON1T, Fermi-LAT dwarf spheroidal (dSph) galaxies [31] and LHC searches at √ s = 13 TeV [25,[32][33][34]. Projected limits from DA...

Pseudo-Goldstone dark matter: gravitational waves and direct-detection blind spots

“…yielding the following effective coupling for direct detection, where p 1 and k 1 are the momenta of the incoming and outgoing χ-particles, resp., 10) which explicitly shows that the direct-detection cross section vanishes in the t → 0 limit. Let us now study how the cubics µ 3 and µ 3 affect the cross section and pseudo-Goldstone mass.…”

“…characterising the strength of the transition, and in terms of 10) which gives approximately the inverse duration of the transition [63]. Here, S is the Euclidean action of the bubble solution.…”

“…In the minimal pseudo-Goldstone DM model [4][5][6][7][8][9][10] (see also refs. [11,12]), the global U(1) symmetry is explicitly broken down to a Z 2 symmetry by the DM mass term.…”

Neutrino and Z′ phenomenology in an anomaly-free U(1) extension: role of higher-dimensional operators

“…Free from restrictions (such as those imposed by X-ray or Lyman-α observations), this could, again, play a significant role in the evolution of galaxy clusters etc. [111]. A detailed examination of such effects is beyond the scope of this paper and is postponed for a future study.…”

A minimal model for neutral naturalness and pseudo-Nambu-Goldstone dark matter

“…In refs. [94,95] the AMS-02 antiproton flux data was used to put stringent constraints on DM with masses in range [150,1000] GeV, see also [96] for a recent global fit analysis of pNGB DM. The AMS-02 95% C.L.…”