Scalar dark matter explanation of the DAMPE data in the minimal left-right symmetric model

Junjie Cao,Lei Zu,Peiwen Wu,Xiaofei Guo,Liangliang Shang,Fei Wang

doi:10.1103/physrevd.97.063016

Abstract

Left-Right symmetric model (LRSM) has been an attractive extension of the Standard Model (SM) which can address the origin of parity violation in the SM electroweak (EW) interactions, generate tiny neutrino masses, accommodate dark matter (DM) candidates and provide a natural framework for baryogenesis through leptogenesis. In this work we utilize the minimal LRSM to study the recently reported DAMPE results of cosmic $e^+e^-$ spectrum which exhibits a tentative peak around 1.4 TeV, while satisfying the current neutrino data. We propose to explain the DAMPE peak with a complex scalar DM $\chi$ in two scenarios: 1) $\chi\chi^* \to H_1^{++}H_1^{--} \to \ell_i^+\ell_i^+\ell_j^-\ell_j^-$; 2) $\chi\chi^* \to H_{k}^{++}H_{k}^{--} \to \ell_i^+\ell_i^+\ell_j^-\ell_j^-$ accompanied by $\chi\chi^* \to H_1^+ H_1^- \to \ell_i^+ \nu_{\ell_i} \ell_j^- \nu_{\ell_j}$ with $\ell_{i,j}=e,\mu,\tau$ and $k=1,2$. We fit the theoretical prediction on $e^+e^-$ spectrum to relevant experimental data to determine the scalar mass spectrum favored by the DAMPE excess. We also consider various constraints from theoretical principles, collider experiments as well as DM relic density and direct search experiments. We find that there are ample parameter space which can interpret the DAMPE data while passing the constraints. Our explanations, on the other hand, usually imply the existence of other new physics at the energy scale ranging from $10^7 {\rm GeV}$ to $10^{11} {\rm GeV}$. Collider tests of our explanations are also discussed.

Highlights

The discovery of the Higgs boson at the LHC indicates that the Standard Model (SM) of particle physics is a highly successful theory in describing a large amount of lowenergy phenomena [1,2]
We propose to explain the DArk Matter Particle Explorer (DAMPE) peak with a complex scalar dark matter (DM) χ in two scenarios: (1) χχÃ → Hþ1 þH−1 − → lþi lþi l−j l−j, and (2) χχÃ → Hþk þH−k − → lþi lþi l−j l−j accompanied by χχÃ → Hþ1 H−1 → lþi νli l−j νlj, with li;j 1⁄4 e, μ, τ and k 1⁄4 1, 2
We fit the theoretical prediction of the eþe− spectrum to relevant experimental data to determine the scalar mass spectrum favored by the DAMPE excess

Summary

INTRODUCTION

The discovery of the Higgs boson at the LHC indicates that the Standard Model (SM) of particle physics is a highly successful theory in describing a large amount of lowenergy phenomena [1,2]. We stress that DM candidates can automatically appear in LRSM with the DM stability guaranteed by either the nature of minimal dark matter or due to matter parity [13] In the former case, the DM particle can be identified as the neutral component within certain high-dimensional SUð2Þ representations that forbid the renormalizable couplings, leading to its decay. In the latter case, the residue ZB2 −L symmetry from the Uð1ÞB−L breaking by the scalar triplet Higgs ΔL;R can act as the DM parity, which could guarantee the stability of alternative fermionic (bosonic) DM candidates with even (odd) B − L charge [13,14].

BRIEF REVIEW OF THE MINIMAL LRSM

DAMPE EXPLANATION WITH SCALAR DM

IMPLICATION OF THE EXPLANATION

Findings

CONCLUSION