Light Non-Abelian Vector Dark Matter Produced Through Vector Misalignment

In this paper, we examine the evolution of light, feebly interacting non-abelian dark gauge bosons dark matter in the early universe. In the region of the parameter space where the dark gauge coupling is too small for the gauge bosons to be produced efficiently via the freeze-in mechanism, the observed relic density of dark matter can be obtained via the vector misalignment mechanism. Vector misalignment has already been discussed in the case of dark photon dark matter. In this study, we extend the arguments to non-abelian gauge bosons. We specifically work on a dark sector scenario with a $SU(2)_R$ gauge symmetry, spontaneously broken by a scalar $\phi$. For sufficiently light $\lesssim O( MeV)$ and feebly interacting $g_R \lesssim 10^{-10}$ gauge boson, $W_R$ become the dark matter candidates. The portal between the dark sector and the Standard Model (SM) sector, in this study, is provided by the right-handed electron charged under $SU(2)_R$. After discussing the evolution of $W_R$ in the early universe, we study the constraints on the model and show the allowed region of the parameter space. Furthermore, the benchmark that can explain the XENON1T excess is demonstrated.Comment: 16 pages, 5 figure

Catching sparks from well-forged neutralinos

In this paper we present a new search technique for electroweakinos, the superpartners of electroweak gauge and Higgs bosons, based on final states with missing transverse energy, a photon, and a dilepton pair, $\ell^+\,\ell^- + \gamma + \displaystyle{\not} E_T$. Unlike traditional electroweakino searches, which perform best when $m_{\widetilde{\chi}^0_{2,3}} - m_{\widetilde{\chi}^0_1}, m_{\widetilde{\chi}^{\pm}} - m_{\widetilde{\chi}^0_1} > m_Z$, our search favors nearly degenerate spectra; degenerate electroweakinos typically have a larger branching ratio to photons, and the cut $m_{\ell\ell} \ll m_Z$ effectively removes on-shell Z boson backgrounds while retaining the signal. This feature makes our technique optimal for `well-tempered' scenarios, where the dark matter relic abundance is achieved with inter-electroweakino splittings of $\sim 20 - 70\,\text{GeV}$. Additionally, our strategy applies to a wider range of scenarios where the lightest neutralinos are almost degenerate, but only make up a subdominant component of the dark matter -- a spectrum we dub `well-forged'. Focusing on bino-Higgsino admixtures, we present optimal cuts and expected efficiencies for several benchmark scenarios. We find bino-Higgsino mixtures with $m_{\widetilde{\chi}^0_{2,3}} \lesssim 190\,\text{GeV}$ and $m_{\widetilde{\chi}^0_{2,3}} - m_{\widetilde{\chi}^0_1} \cong 30\,\text{GeV}$ can be uncovered after roughly $600\,\text{fb}^{-1}$ of luminosity at the 14 TeV LHC. Scenarios with lighter states require less data for discovery, while scenarios with heavier states or larger mass splittings are harder to discriminate from the background and require more data. Unlike many searches for supersymmetry, electroweakino searches are one area where the high luminosity of the next LHC run, rather than the increased energy, is crucial for discovery.Comment: Updated to published version. Reference adde, discussion of other models expanded, and typos fixed. revtex4-1, 29 pages, 9 figures, and 3 table