2,425 research outputs found
Temporal distortion of annual modulation at low recoil energies
We show that the main features of the annual modulation of the signal
expected in a WIMP direct detection experiment, i.e. its sinusoidal dependence
with time, the occurrence of its maxima and minima during the year and (under
some circumstances) even the one-year period, may be affected by relaxing the
isothermal sphere hypothesis in the description of the WIMP velocity phase
space. The most relevant effect is a distortion of the time-behaviour at low
recoil energies for anisotropic galactic halos. While some of these effects
turn out to be relevant at recoil energies below the current detector
thresholds, some others could already be measurable, although some degree of
tuning between the WIMP mass and the experimental parameters would be required.
Either the observation or non-observation of these effects could provide clues
on the phase space distribution of our galactic halo.Comment: 4 pages, 4 figures, typeset with ReVTeX4. The paper may also be found
at http://www.to.infn.it/~fornengo/papers/distortion.ps.g
New results from DAMA/LIBRA
DAMA/LIBRA is running at the Gran Sasso National Laboratory of the I.N.F.N..
Here the results obtained with a further exposure of 0.34 ton x yr are
presented. They refer to two further annual cycles collected one before and one
after the first DAMA/LIBRA upgrade occurred on September/October 2008. The
cumulative exposure with those previously released by the former DAMA/NaI and
by DAMA/LIBRA is now 1.17 ton x yr, corresponding to 13 annual cycles. The data
further confirm the model independent evidence of the presence of Dark Matter
(DM) particles in the galactic halo on the basis of the DM annual modulation
signature (8.9 sigma C.L. for the cumulative exposure). In particular, with the
cumulative exposure the modulation amplitude of the single-hit events in the (2
-- 6) keV energy interval measured in NaI(Tl) target is (0.0116 +- 0.0013)
cpd/kg/keV; the measured phase is (146 +- 7) days and the measured period is
(0.999 +- 0.002) yr, values well in agreement with those expected for the DM
particles.Comment: presented at the Int. Conf. Beyond the Standard Models of Particle
Physics, Cosmology and Astrophysics (BEYOND 2010), 1-6 February 2010, Cape
Town, South Afric
Results on Dark Matter and beta beta decay modes by DAMA at Gran Sasso
DAMA is an observatory for rare processes and it is operative deep
underground at the Gran Sasso National Laboratory of the I.N.F.N. (LNGS). Here
some arguments will be presented on the investigation on dark matter particles
by annual modulation signature and on some of the realized double beta decay
searches.Comment: Contributed paper to Neutrinoless Double Beta Decay (NDBD07),
Ahmedabad (India), February 200
A CoGeNT confirmation of the DAMA signal
The CoGeNT collaboration has recently reported a rising low energy spectrum
in their ultra low noise germanium detector. This is particularly interesting
as the energy range probed by CoGeNT overlaps with the energy region in which
DAMA has observed their annual modulation signal. We show that the mirror dark
matter candidate can simultaneously explain both the DAMA annual modulation
signal and the rising low energy spectrum observed by CoGeNT. This constitutes
a model dependent confirmation of the DAMA signal and adds weight to the mirror
dark matter paradigm.Comment: About 8 pages, expanded and update
WIMPless dark matter and the excess gamma rays from the Galactic center
In this paper we discuss the excess gamma rays from the Galactic center, the
WMAP haze and the CoGeNT and DAMA results in WIMPless models. At the same time
we also investigate the low energy constraints from the anomalous magnetic
moment of leptons and from some lepton flavor violating decays. It is found
that, for scalar or vector WIMPless dark matter, neither the WMAP haze nor the
CoGeNT and DAMA observations could be explained simultaneously with the excess
gamma rays from the Galactic center. As to fermion WIMPless dark matter, it is
only marginally possible to accommodate the CoGeNT and DAMA results with the
excess gamma rays from the Galactic center with vector connector fields. On the
other hand, only scalar connector fields could interpret the WMAP haze
concerning the constraints of anomalous magnetic moment of leptons.
Furthermore, if there is only one connector field for all the charged leptons,
some lepton flavor violating decays could happen with too large branching
ratios severely violating the experimental bounds.Comment: 15 pages, 3 figures, accepted for publication in Phys. Rev.
Tests of Pauli Exclusion Principle Violations from Non-commutative quantum gravity
We review the main recent progresses in non-commutative space-time
phenomenology in underground experiments. A popular model of non-commutative
space-time is -Poincar\'e model, based on the Groenewold-Moyal plane
algebra. This model predicts a violation of the Spin-statistic theorem, in turn
implying an energy and angular dependent violation of the Pauli Exclusion
principle. Pauli Exclusion Principle Violating transitions in nuclear and
atomic systems can be tested with very high accuracy in underground laboratory
experiments such as DAMA/LIBRA and VIP(2). In this paper we derive that the
-Poincar\'e model can be already ruled-out until the Planck scale, from
nuclear transitions tests by DAMA/LIBRA experiment.Comment: version submitted to the journal. arXiv admin note: text overlap with
arXiv:1811.0642
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