2009/02/28 by Bumseok Kyae · 3 citations
Computer Science · Physics and Astronomy · #Anomaly (physics) #Computational Physics and Python Applications #Dark Matter and Cosmic Phenomena #Dark matter #Extra dimensions #Fermion #Lepton #Lepton number #Particle physics theoretical and experimental studies #Standard Model (mathematical formulation) #Supersymmetry #Yukawa potential #astro-ph.CO #astro-ph.HE #hep-ph #hep-th
paper · pdf · doi:10.1088/1475-7516/2009/07/028
published as JCAP 0907:028,2009 · 12 pages, published version
openalex publication_date 2009/07/20 · arxiv created 2009/08/01 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
We present a supersymmetric model with two dark matter (DM) components explaining the galactic positron excess observed by PAMELA/HEAT and ATIC/PPB-BETS: One is the conventional (bino-like) lightest supersymmetric particle (LSP) χ, and the other is a TeV scale meta-stable neutral singlet N D , which is a Dirac fermion ( N , N c ). In this model, N D decays dominantly into χ e + e − through an R parity preserving dimension 6 operator with the life time τ N ∼ 10 26 sec. We introduce a pair of vector-like superheavy SU(2) lepton doublets ( L , L c ) and lepton singlets ( E , E c ). The dimension 6 operator leading to the N D decay is generated from the leptophilic Yukawa interactions by W ⊃ Ne c E + Lh d E c + m 3/2 l 1 L c with the dimensionless couplings of order unity, and the gauge interaction by ⊃ (2) 1/2 g ' c * e c χ+h.c. The superheavy masses of the vector-like leptons ( M L , M E ∼ 10 16 GeV) are responsible for the longevity of N D . The low energy field spectrum in this model is just the MSSM fields and N D . Even for the case that the portion of N D is much smaller than that of χ in the total DM density [ (10 −10 ) ≲ n N D / n χ ], the observed positron excess can be explained by adopting relatively lighter masses of the vector-like leptons (10 13 GeV ≲ M L , E ≲ 10 16 GeV). The smallness of the electron mass is also explained. This model is easily embedded in the flipped SU(5) grand unification, which is a leptophilic unified theory.