15,095 research outputs found

    Explaining the DAMPE data with scalar dark matter and gauged U(1)Leβˆ’LΞΌU(1)_{L_e-L_\mu} interaction

    Full text link
    Inspired by the peak structure observed by recent DAMPE experiment in e+eβˆ’e^+e^- cosmic-ray spectrum, we consider a scalar dark matter (DM) model with gauged U(1)Leβˆ’LΞΌU(1)_{L_e-L_\mu} symmetry, which is the most economical anomaly-free theory to potentially explain the peak by DM annihilation in nearby subhalo. We utilize the process χχ→Zβ€²Zβ€²β†’llΛ‰lβ€²lΛ‰β€²\chi \chi \to Z^\prime Z^\prime \to l \bar{l} l^\prime \bar{l}^\prime, where Ο‡\chi, Zβ€²Z^\prime, l(β€²)l^{(\prime)} denote the scalar DM, the new gauge boson and l(β€²)=e,ΞΌl^{(\prime)} =e, \mu, respectively, to generate the e+eβˆ’e^+e^- spectrum. By fitting the predicted spectrum to the experimental data, we obtain the favored DM mass range mχ≃3060βˆ’100+80 GeVm_\chi \simeq 3060^{+80}_{-100} \, {\rm GeV} and Ξ”m≑mΟ‡βˆ’mZ′≲14 GeV\Delta m \equiv m_\chi - m_{Z^\prime} \lesssim 14 \, {\rm GeV} at 68%68\% Confidence Level (C.L.). Furthermore, we determine the parameter space of the model which can explain the peak and meanwhile satisfy the constraints from DM relic abundance, DM direct detection and the collider bounds. We conclude that the model we consider can account for the peak, although there exists a tension with the constraints from the LEP-II bound on mZβ€²m_{Z^\prime} arising from the cross section measurement of e+eβˆ’β†’Zβ€²βˆ—β†’e+eβˆ’e^+e^- \to Z^{\prime\ast} \to e^+ e^-.Comment: 15 pages, 4 figure

    Simplified TeV leptophilic dark matter in light of DAMPE data

    Full text link
    Using a simplified framework, we attempt to explain the recent DAMPE cosmic e++eβˆ’e^+ + e^- flux excess by leptophilic Dirac fermion dark matter (LDM). The scalar (Ξ¦0\Phi_0) and vector (Ξ¦1\Phi_1) mediator fields connecting LDM and Standard Model particles are discussed. Under constraints of DM relic density, gamma-rays, cosmic-rays and Cosmic Microwave Background (CMB), we find that the couplings PβŠ—SP \otimes S, PβŠ—PP \otimes P, VβŠ—AV \otimes A and VβŠ—VV \otimes V can produce the right bump in e++eβˆ’e^+ + e^- flux for a DM mass around 1.5 TeV with a natural thermal annihilation cross-section ∼3Γ—10βˆ’26cm3/s \sim 3 \times 10^{-26} cm^3/s today. Among them, VβŠ—VV \otimes V coupling is tightly constrained by PandaX-II data (although LDM-nucleus scattering appears at one-loop level) and the surviving samples appear in the resonant region, mΞ¦1≃2mΟ‡m_{\Phi_1} \simeq 2m_{\chi}. We also study the related collider signatures, such as dilepton production ppβ†’Ξ¦1β†’β„“+β„“βˆ’pp \to \Phi_1 \to \ell^+\ell^-, and muon gβˆ’2g-2 anomaly. Finally, we present a possible U(1)XU(1)_X realization for such leptophilic dark matter.Comment: discussions added, version accepted by JHE
    • …
    corecore