45,948 research outputs found
Engineering knowledge requirements for sand and dust on Mars
The successful landing of human beings on Mars and the establishment of a permanent outpost there will require an understanding of the Martian environment by the engineers. A key feature of the Martian environment is the nearly ubiquitous presence of sand and dust. The process which the engineering community will undertake to determine the sensitivities of their designs to the current level of knowledge about Mars sand and dust is emphasized. The interaction of the engineering community with the space exploration initiative (SEI) mission planners and management is described
Physics of An Ultrahigh-Statistics Charm Experiment
We review the physics goals of an ultrahigh-statistics charm experiment and
place them in the broader context of the community's efforts to study the
Standard Model and to search for physics beyond the Standard Model, and we
point out some of the experimental difficulties which must be overcome if these
goals are to be met.Comment: 9 pages, no figure
Gaugino-Assisted Anomaly Mediation
We present a model of supersymmetry breaking mediated through a small extra
dimension. Standard model matter multiplets and a supersymmetry-breaking (or
``hidden'') sector are confined to opposite four-dimensional boundaries while
gauge multiplets live in the bulk. The hidden sector does not contain a singlet
and the dominant contribution to gaugino masses is via anomaly-mediated
supersymmetry breaking. Scalar masses get contributions from both anomaly
mediation and a tiny hard breaking of supersymmetry by operators on the
hidden-sector boundary. These operators contribute to scalar masses at one loop
and in most of parameter space, their contribution dominates. Thus it is easy
to make all squared scalar masses positive. As no additional fields or
symmetries are required below the Planck scale, we consider this the simplest
working model of anomaly mediation. The gaugino spectrum is left untouched and
the phenomenology of the model is roughly similar to anomaly mediated
supersymmetry breaking with a universal scalar mass added. We identify the main
differences in the spectrum between this model and other approaches. We also
discuss mechanisms for generating the mu term and constraints on additional
bulk fields.Comment: LaTeX, 26 pages, 8 eps figure
Status of MICE
Muon ionization cooling is the only practical method for preparing
high-brilliance beams needed for a neutrino factory or muon collider. The muon
ionization cooling experiment (MICE) under development at the Rutherford
Appleton Laboratory comprises a dedicated beamline to generate a range of input
emittance and momentum, with time-of-flight and Cherenkov detectors to ensure a
pure muon beam. A first measurement of emittance is performed in the upstream
magnetic spectrometer with a scintillating-fiber tracker. A cooling cell will
then follow, alternating energy loss in liquid hydrogen with RF acceleration. A
second spectrometer identical to the first and a particle identification system
will measure the outgoing emittance. Plans for measurements of emittance and
cooling are described.Comment: Poster presented at ICHEP08 Conference, Philadelphia, USA, July 2008.
3 pages, 3 figure
- …