XENON1T solar axion and the Higgs boson emerging from the dark

Abstract

In a recent letter we proposed a new non-thermal mechanism of Dark Matter production based on vacuum misalignment, where both the Higgs boson and a very light pseudo-scalar η emerge from the Dark sector. In this letter, we identify the parameter space in a composite scenario where the light pseudo-scalar can be produced in the sun and explain the XENON1T excess in electron recoil data. The model's Dark Matter candidate has a mass around 50 TeV and out of range for Direct Detection. Testable predictions include Gravitational waves at frequencies in the Hz range from a cosmological phase transition, an exotic decay Z → γ + inv. with rates 4 ÷ 16 • 10 −12 testable at a future Tera-Z collider, and an enhancement by 17 ÷ 40% of the branching ratio KL → π 0 + inv., not enough to explain the KOTO anomaly. All these predictions may be confirmed by future experiments.

Loop-generated neutrino masses in composite Higgs models

“…The XENON1T excess: in our paper [89], we identified the parameter space in a composite scenario where the light pseudo-scalar η, identical to the χ state in table 2, can be produced in the sun and explain the XENON1T excess in electron recoil data [90]. We considered the SU(6)/Sp(6) template model as here, where the misalignment angle may be in the range 0.004 < s θ < 0.007 to explain this excess.…”

“…[33] and, as presented in ref. [89], an explaination of the recent XENON1T excess in electron recoil data [90]. contribution with a Re η 0 loop is…”

“…Finally, according to ref. [89], this model with such small s θ gives rise to additional testable predictions include gravitation waves at frequencies in the Hz range from a cosmological phase transition, an exotic decay Z → γ + inv. with rates 4 ÷ 16 • 10 −12 testable at a future Tera-Z collider, and an enhancement by 17 ÷ 40% of the branching ratio K L → π 0 + inv., not enough to explain the KOTO anomaly [91].…”

Exploring new possibilities to discover a light pseudo-scalar at LHCb

“…10 (top) we show the central prediction for the signal cross section σ ( pp → a) × B(a → c c) of the benchmark models M1, M4, M9, and M11 with v/ f = 1 Table 4 Cumulative efficiencies (in %) for both signal and background. The background fragmentation fraction f B c c→D + D − and acceptance f B Acc are independent on the mass points and are given in (9).…”

“…One example is provided by electrically neutral, colorless, scalars with a mass below the Z pole and above the heavy meson mass scales [6]. Rare meson decays, in fact, provide an additional class of strong bounds [7][8][9][10]. At the LHC, low masses are mainly constrained by di-muon [11][12][13][14][15] and di-photon searches [16][17][18][19][20][21].…”