7 research outputs found
On the electroweak phase transition in the Minimal Supersymmetric Standard Model
We study the finite-temperature effective potential of the Minimal
Supersymmetric Standard Model, in the limit of only one light Higgs boson.
Because of the large top Yukawa coupling, there can be significant differences
with respect to the Standard Model case: for given values of the Higgs and top
masses, little supersymmetry breaking in the stop sector can make the phase
transition more strongly first-order. After including the full structure of the
stop mass matrix, the most important experimental constraints and the leading
plasma effects, we find that the present limits on Higgs and squark masses are
still compatible with the scenario of electroweak baryogenesis, in a small
region of parameter space corresponding to m_h \simlt 70 \gev and \msba
\simlt 105 \gev.Comment: 10 A4 pages, 7 figures available upon request, CERN-TH.6833/93,
IEM-FT-69/93 (one paragraph expanded for clarity
The JANUS X-Ray Flash Monitor
JANUS is a NASA small explorer class mission which just completed phase A and
was intended for a 2013 launch date. The primary science goals of JANUS are to
use high redshift (6<z<12) gamma ray bursts and quasars to explore the
formation history of the first stars in the early universe and to study
contributions to reionization. The X-Ray Flash Monitor (XRFM) and the Near-IR
Telescope (NIRT) are the two primary instruments on JANUS. XRFM has been
designed to detect bright X-ray flashes (XRFs) and gamma ray bursts (GRBs) in
the 1-20 keV energy band over a wide field of view (4 steradians), thus
facilitating the detection of z>6 XRFs/GRBs, which can be further studied by
other instruments. XRFM would use a coded mask aperture design with hybrid CMOS
Si detectors. It would be sensitive to XRFs/GRBs with flux in excess of
approximately 240 mCrab. The spacecraft is designed to rapidly slew to source
positions following a GRB trigger from XRFM. XRFM instrument design parameters
and science goals are presented in this paper.Comment: submitted to Proc. SPIE, Vol. 7435 (2009), 7 pages, 8 figure