A new probe of dark sector dynamics at the LHC

We investigate the prospects for producing new, light, hidden states at a future e + e − collider in a Higgsed dark U(1) D model, which we call the Double Dark Portal model. The simultaneous presence of both vector and scalar portal couplings immediately modifies the Standard Model Higgsstrahlung channel, e + e − → Zh, at leading order in each coupling. In addition, each portal leads to complementary signals which can be probed at direct and indirect detection dark matter experiments. After accounting for current constraints from LEP and LHC, we demonstrate that a future e + e − Higgs factory will have unique and leading sensitivity to the two portal couplings by studying a host of new production, decay, and radiative return processes. Besides the possibility of exotic Higgs decays, we highlight the importance of direct dark vector and dark scalar production at e + e − machines, whose invisible decays can be tagged from the recoil mass method.

Section: Radiative Return Processes and Dark Matter Production At Thesupporting

confidence: 79%

A tale of two portals: testing light, hidden new physics at future e + e − colliders

Liu

Wang

2017

“…[27]). This allows us to study DM phenomenology in terms of a handful of masses and couplings [28][29][30][31][32][33][34][35][36][37][38][39][40][41][42][43][44][45] (with the further advantage of having the mediator in the spectrum) and allows us to combine mono-jet searches with complementary searches for resonances or mono-V events [46][47][48].…”

Section: Simplified Models For Vector Mediatorsmentioning

confidence: 99%

You can hide but you have to run: direct detection with vector mediators

DʼEramo

Kavanagh

Panci

2016

124

We study direct detection in simplified models of Dark Matter (DM) in which interactions with Standard Model (SM) fermions are mediated by a heavy vector boson. We consider fully general, gauge-invariant couplings between the SM, the mediator and both scalar and fermion DM. We account for the evolution of the couplings between the energy scale of the mediator mass and the nuclear energy scale. This running arises from virtual effects of SM particles and its inclusion is not optional. We compare bounds on the mediator mass from direct detection experiments with and without accounting for the running. In some cases the inclusion of these effects changes the bounds by several orders of magnitude, as a consequence of operator mixing which generates new interactions at low energy. We also highlight the importance of these effects when translating LHC limits on the mediator mass into bounds on the direct detection cross section. For an axial-vector mediator, the running can alter the derived bounds on the spin-dependent DM-nucleon cross section by a factor of two or more. Finally, we provide tools to facilitate the inclusion of these effects in future studies: general approximate expressions for the low energy couplings and a public code runDM to evolve the couplings between arbitrary energy scales.

“…For our case study in section 4, we will perform a detailed analysis of this novel signature. Initial studies of the dilepton resonance+ / E T , dijet resonance+ / E T , and charged tracks+ / E T signatures have also been presented in the literature [172][173][174].…”

Section: Signature Class 2: Resonances From S-channel Modelsmentioning

confidence: 99%

The coannihilation codex

Baker

Brod

Hedri

et al. 2015

121

We present a general classification of simplified models that lead to dark matter (DM) coannihilation processes of the form DM + X → SM 1 + SM 2 , where X is a coannihilation partner for the DM particle and SM 1 , SM 2 are Standard Model fields. Our classification also encompasses regular DM pair annihilation scenarios if DM and X are identical. Each coannhilation scenario motivates the introduction of a mediating particle M that can either belong to the Standard Model or be a new field, whereby the resulting interactions between the dark sector and the Standard Model are realized as tree-level and dimension-four couplings. We construct a basis of coannihilation models, classified by the SU(3) C × SU(2) L × U(1) Y quantum numbers of DM, X and M. Our main assumptions are that dark matter is an electrically neutral color singlet and that all new particles are either scalars, Dirac or Majorana fermions, or vectors. We illustrate how new scenarios arising from electroweak symmetry breaking effects can be connected to our electroweak symmetric simplified models. We offer a comprehensive discussion of the phenomenological features of our models, encompassing the physics of thermal freeze-out, direct and indirect detection constraints, and in particular searches at the Large Hadron Collider (LHC). Many novel signatures that are not covered in current LHC searches are emphasized, and new and improved LHC analyses tackling these signatures are proposed. We discuss how the coannihilation simplified models can be used to connect results from all classes of experiments in a straightforward and transparent way. This point is illustrated with a detailed discussion of the phenomenology of a particular simplified model featuring leptoquark-mediated dark matter coannihilation.