107 research outputs found
Searching for an invisible A' vector boson with DarkLight
High-luminosity experiments are able to search for new physics at low
energies, which could have evaded detection thus far due to very weak couplings
to the Standard Model. The DarkLight experiment at Jefferson Lab is designed to
search for a new U(1) vector boson A' in the mass range 10-100 MeV through its
decay A' -> e+ e-. In this paper, we demonstrate that DarkLight is also
sensitive to an A' decaying to invisible final states. We analyze the DarkLight
reach for invisible A' bosons assuming a nominal two month running time,
including the possibility of augmenting the DarkLight design to include photon
detection. We also propose two new analysis techniques that might prove useful
for other high-luminosity searches: a cut on missing energy to improve the
invariant mass resolution, and a cut on the sign of the missing invariant
mass-squared to mitigate pileup. We compare the DarkLight reach to existing
experimental proposals, including a complementary search using the VEPP-3
positron beam.Comment: 18 pages, 22 figures, 4 tables; v2: references and clarifications
added; v3: version published in PRD, discussion of constraints from rare kaon
decays adde
The goldstone and goldstino of supersymmetric inflation
We construct the minimal effective field theory (EFT) of supersymmetric
inflation, whose field content is a real scalar, the goldstone for
time-translation breaking, and a Weyl fermion, the goldstino for supersymmetry
(SUSY) breaking. The inflating background can be viewed as a single
SUSY-breaking sector, and the degrees of freedom can be efficiently
parameterized using constrained superfields. Our EFT is comprised of a chiral
superfield X_NL containing the goldstino and satisfying X_NL^2 = 0, and a real
superfield B_NL containing both the goldstino and the goldstone, satisfying
X_NL B_NL = B_NL^3 = 0. We match results from our EFT formalism to existing
results for SUSY broken by a fluid background, showing that the goldstino
propagates with subluminal velocities. The same effect can also be derived from
the unitary gauge gravitino action after embedding our EFT in supergravity. If
the gravitino mass is comparable to the Hubble scale during inflation, we
identify a new parameter in the EFT related to a time-dependent phase of the
gravitino mass parameter. We briefly comment on the leading contributions of
goldstino loops to inflationary observables.Comment: 32 pages, 2 figures. v3: clarifications and references added. Matches
JHEP version. v2: typos fixed, footnote and references adde
Halo-Independent Direct Detection Analyses Without Mass Assumptions
Results from direct detection experiments are typically interpreted by
employing an assumption about the dark matter velocity distribution, with
results presented in the plane. Recently methods which are
independent of the DM halo velocity distribution have been developed which
present results in the plane, but these in turn require an
assumption on the dark matter mass. Here we present an extension of these
halo-independent methods for dark matter direct detection which does not
require a fiducial choice of the dark matter mass. With a change of variables
from to nuclear recoil momentum (), the full halo-independent
content of an experimental result for any dark matter mass can be condensed
into a single plot as a function of a new halo integral variable, which we call
. The entire family of conventional halo-independent
plots for all DM masses are directly found from the single
plot through a simple rescaling of axes. By considering
results in space, one can determine if two experiments are
inconsistent for all masses and all physically possible halos, or for what
range of dark matter masses the results are inconsistent for all halos, without
the necessity of multiple plots for different DM masses.
We conduct a sample analysis comparing the CDMS II Si events to the null
results from LUX, XENON10, and SuperCDMS using our method and discuss how the
mass-independent limits can be strengthened by imposing the physically
reasonable requirement of a finite halo escape velocity.Comment: 23 pages, 8 figures. v2: footnote and references adde
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