50,867 research outputs found
Directional Detection of Dark Matter with MIMAC
Directional detection is a promising search strategy to discover galactic
Dark Matter. We present a Bayesian analysis framework dedicated to Dark Matter
phenomenology using directional detection. The interest of directional
detection as a powerful tool to set exclusion limits, to authentify a Dark
Matter detection or to constrain the Dark Matter properties, both from particle
physics and galactic halo physics, will be demonstrated. However, such results
need highly accurate track reconstruction which should be reachable by the
MIMAC detector using a dedicated readout combined with a likelihood analysis of
recoiling nuclei.Comment: 4 pages, 2 figures, to appear in the proceedings of the TAUP 2011
conference held in Munich (5 - 9 September, 2011
Identification of Dark Matter with directional detection
Directional detection is a promising search strategy to discover galactic
Dark Matter. Taking advantage on the rotation of the Solar system around the
Galactic center through the Dark Matter halo, it allows to show a direction
dependence of WIMP events. Data of directional detectors are composed of energy
and a 3D track for each recoiling nuclei. Here, we present a Bayesian analysis
method dedicated to data from upcoming directional detectors. However, we focus
only on the angular part of the event distribution, arguing that the energy
part of the background distribution is unknown. Two different cases are
considered: a positive or a null detection of Dark Matter. In the first
scenario, we will present a map-based likelihood method allowing to recover the
main incoming direction of the signal and its significance, thus proving its
Galactic origin. In the second scenario, a new statistical method is proposed.
It is based on an extended likelihood in order to set robust and competitive
exclusion limits. This method has been compared to two other methods and has
been shown to be optimal in any detector configurations. Eventually, prospects
for the MIMAC project are presented in the case of a 10 kg CF4 detector with an
exposition time of 3 years.Comment: Proceeding of the 8th International Workshop on the Identification of
Dark Matter (IDM 2010), July 2010, Montpellier, France. To appear in
Proceedings of Science (PoS
Directional detection of galactic dark matter
Directional detection is a promising Dark Matter search strategy. Taking
advantage on the rotation of the Solar system around the galactic center
through the Dark Matter halo, it allows to show a direction dependence of WIMP
events that may be a powerful tool to identify genuine WIMP events as such.
Directional detection strategy requires the simultaneous measurement of the
energy and the 3D track of low energy recoils, which is a common challenge for
all current projects of directional detectors.Comment: Proceedings of UCLA Dark Matter 2012, 10th Symposium on Sources and
Detection of Dark Matter and Dark Energy in the Universe, Marina del Rey
Marriott, CA, USA, February 22-24, 201
Supersymmetric dark matter search via spin-dependent interaction with He3
The potentialities of MIMAC-He3, a MIcro-tpc MAtrix of Chambers of Helium 3,
for supersymmetric dark matter search are discussed within the framework of
effective MSSM models without gaugino mass unification at the GUT scale. A
phenomenological study has been done to investigate the sensitivity of the
MIMAC-He3 detector to neutralinos (m > 6 GeV/c2) via spin-dependent interaction
with He3 as well as its complementarity to direct and indirect detection
experiments. Comparison with other direct dark matter searches will be
presented in a WIMP model-independent framework.Comment: 13 pages, 5 figure
MIMAC-He3 : A Micro-TPC Matrix of Chambers of He3 for direct detection of Wimps
The project of a micro-TPC matrix of chambers of \hetrois for direct
detection of non-baryonic dark matter is presented. The privileged properties
of He3 are highlighted. The double detection (ionization - projection of
tracks) is explained and its rejection evaluated. The potentialities of
MIMAC-He3 for supersymmetric dark matter search are discussed.Comment: to appear in Proc. of the 9th International Conference on Topics in
Astroparticle and Underground Physics (TAUP 2005), Zaragoza, Sept. 200
Elodie metallicity-biased search for transiting Hot Jupiters I. Two Hot Jupiters orbiting the slightly evolved stars HD118203 and HD149143
We report the discovery of a new planet candidate orbiting the subgiant star
HD118203 with a period of P=6.1335 days. The best Keplerian solution yields an
eccentricity e=0.31 and a minimum mass m2sin(i)=2.1MJup for the planet. This
star has been observed with the ELODIE fiber-fed spectrograph as one of the
targets in our planet-search programme biased toward high-metallicity stars,
on-going since March 2004 at the Haute-Provence Observatory. An analysis of the
spectroscopic line profiles using line bisectors revealed no correlation
between the radial velocities and the line-bisector orientations, indicating
that the periodic radial-velocity signal is best explained by the presence of a
planet-mass companion. A linear trend is observed in the residuals around the
orbital solution that could be explained by the presence of a second companion
in a longer-period orbit. We also present here our orbital solution for another
slightly evolved star in our metal-rich sample, HD149143, recently proposed to
host a 4-d period Hot Jupiter by the N2K consortium. Our solution yields a
period P=4.09 days, a marginally significant eccentricity e=0.08 and a
planetary minimum mass of 1.36MJup. We checked that the shape of the spectral
lines does not vary for this star as well.Comment: Accepted in A&A (6 pages, 6 figures
Relativistic deuteron structure function at large Q^2
The deuteron deep inelastic unpolarized structure function F_2^D is
calculated using the Wilson operator product expansion method. The long
distance behaviour, related to the deuteron bound state properties, is
evaluated using the Bethe-Salpeter equation with one particle on mass shell.
The calculation of the ratio F_2^D/F_2^N is compared with other convolution
models showing important deviations in the region of large x. The implications
in the evaluation of the neutron structure function from combined data on
deuterons and protons are discussed.Comment: 7 pages, 1 ps figure, RevTeX source, 1 tar.gz file. Submited to
Physical Letter
- …