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Pran Nath

2012

Positron excess

Articles 1 - 2 of 2

Full-Text Articles in Physical Sciences and Mathematics

Pamela Positron Excess As A Signal From The Hidden Sector, Daniel Feldman, Zuowei Liu, Pran Nath Apr 2012

Pamela Positron Excess As A Signal From The Hidden Sector, Daniel Feldman, Zuowei Liu, Pran Nath

Pran Nath

The recent positron excess observed in the PAMELA satellite experiment strengthens previous experimental findings. We give here an analysis of this excess in the framework of the Stueckelberg extension of the standard model which includes an extra U(1)ₓ gauge field and matter in the hidden sector. Such matter can produce the right amount of dark matter consistent with the Wilkinson Microwave Anisotropy Probe (WMAP) constraints. Assuming the hidden sector matter to be Dirac fermions it is shown that their annihilation can produce the positron excess with the right positron energy dependence seen in the HEAT, AMS, and the PAMELA experiments. …


Explaining Pamela And Wmap Data Through Coannihilations In Extended Sugra With Collider Implications, Daniel Feldman, Zuowei Liu, Pran Nath, Brent D. Nelson Apr 2012

Explaining Pamela And Wmap Data Through Coannihilations In Extended Sugra With Collider Implications, Daniel Feldman, Zuowei Liu, Pran Nath, Brent D. Nelson

Pran Nath

The PAMELA positron excess is analyzed within the framework of nonuniversal supergravity (SUGRA) models with an extended U(1)n gauge symmetry in the hidden sector leading to neutralino dark matter with either a mixed Higgsino-wino lightest R-parity odd supersymmetric particle (LSP) or an essentially pure wino-dominated LSP. The Higgsino-wino LSP can produce the observed PAMELA positron excess and satisfy relic density constraints in the extended class of models due to a near degeneracy of the mass spectrum of the extended neutralino sector with the LSP mass. The simultaneous satisfaction of the WMAP relic density data and the PAMELA data is accomplished …