2016/05/31 by Xian-Jun Huang, Weihong Zhang, Wei-Hong Zhang +1
Physics and Astronomy · #Annihilation #Bar (unit) #Boson #Cosmology and Gravitation Theories #Dark Matter and Cosmic Phenomena #Dark matter #Geometry #Large Hadron Collider #Nuclear physics #Particle physics #Particle physics theoretical and experimental studies #Photon #Physics #Quantum mechanics #Scalar (mathematics) #Vector boson #hep-ph
paper · pdf · doi:10.1103/physrevd.94.035019
published as Phys. Rev. D 94, 035019 (2016) · 30 pages, 7 figures, references added
arxiv created 2016/06/04 · openalex publication_date 2016/08/22 · arxiv updated 2016/08/31 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
The recent LHC Run-2 data have shown a possible excess in diphoton events, suggesting the existence of a new resonance \ensuremathφ with mass M\ensuremath∼750 GeV. If \ensuremathφ plays the role of a portal particle connecting the Standard Model and the invisible dark sector, the diphoton excess should be correlated with another photon excess, namely, the excess in the diffuse gamma rays towards the Galactic Center, which can be interpreted by the annihilation of dark matter (DM). We investigate the necessary conditions for a consistent explanation for the two photon excesses, especially the requirement on the width-to-mass ratio \mathrm\ensuremathΓ/M and \ensuremathφ decay channels, in a collection of DM models where the DM particle can be scalar, fermionic, and vector, and \ensuremathφ can be generated through s-channel gg fusion or qq annihilation. We show that the minimally required \mathrm\ensuremathΓ/M is determined by a single parameter proportional to (m_\ensuremathχ/M)n, where the integer n depends on the nature of the DM particle. We find that for the scalar DM model with \ensuremathφ generated from qq annihilation, the minimally required \mathrm\ensuremathΓ/M can be as low as O(10^\ensuremath-3). For the scalar DM model with \ensuremathφ generated from gg fusion and fermionic DM model with \ensuremathφ from qq annihilation, the required \mathrm\ensuremathΓ/M are typically of O(10^\ensuremath-2). The vector DM models, however, require very large \mathrm\ensuremathΓ/M of order one. For the DM models which can consistently explain both the excesses, the predicted cross sections for gamma-ray line are typically of O(10^\ensuremath-31--10^\ensuremath-29) cm3 s^\ensuremath-1, which are close to the current limits from the Fermi-LAT experiment.