7 research outputs found
Phenomenology of General Gauge Mediation in light of a 125 GeV Higgs
We explore the phenomenology of the full General Gauge Mediation parameter
space in the MSSM focusing on the consequences of having a fundamental Higgs
around 125 GeV. Assuming GUT-complete structure of the hidden sector, we allow
for deviations from the strict definition of gauge mediated SUSY-breaking
coming from mild violations of messenger-parity and from extra couplings
between the Higgs multiplets and the hidden sector. Relaxing the GUT
assumption, our parameter space is defined by the property of having vanishing
A-terms at the messenger scale. In this extended setup we focus on the
possibility of splitting the SU(3) mass parameters of GGM. In all these
scenarios we investigate the possible spectra, discussing to what extent having
an Higgs mass around 125 GeV is constraining the GGM parameter space and what
are the possible signatures at LHC.Comment: 83 pages, 29 figures; v2: minor corrections, references adde
Neutralino Dark Matter from Indirect Detection Revisited
We revisit indirect detection possibilities for neutralino dark matter,
emphasizing the complementary roles of different approaches. While thermally
produced dark matter often requires large astrophysical "boost factors" to
observe antimatter signals, the physically motivated alternative of non-thermal
dark matter can naturally provide interesting signals, for example from light
wino or Higgsino dark matter. After a brief review of cosmic ray propagation,
we discuss signals for positrons, antiprotons, synchrotron radiation and gamma
rays from wino annihilation in the galactic halo, and examine their
phenomenology. For pure wino dark matter relevant to the LHC, PAMELA and GLAST
should report signals.Comment: 23 pages, 9 figures: v2. Corrected typos, fixed synchrotron bounds in
light of bugs in progra
Is the PAMELA Positron Excess Winos?
Recently the PAMELA satellite-based experiment reported an excess of galactic
positrons that could be a signal of annihilating dark matter. The PAMELA data
may admit an interpretation as a signal from a wino-like LSP of mass about 200
GeV, normalized to the local relic density, and annihilating mainly into
W-bosons. This possibility requires the current conventional estimate for the
energy loss rate of positrons be too large by roughly a factor of five. Data
from anti-protons and gamma rays also provide tension with this interpretation,
but there are significant astrophysical uncertainties associated with their
propagation. It is not unreasonable to take this well-motivated candidate
seriously, at present, in part because it can be tested in several ways soon.
The forthcoming PAMELA data on higher energy positrons and the FGST (formerly
GLAST) data, should provide important clues as to whether this scenario is
correct. If correct, the wino interpretation implies a cosmological history in
which the dark matter does not originate in thermal equilibrium.Comment: 7 pages, 4 figue