2,740 research outputs found
Global fits of the scalar singlet model using GAMBIT
The extension of the standard model (SM) by a Higgs portal scalar field is
one the simplest dark matter theories. We present here the first results for a
global fit to this model using the global and beyond the SM inference tool
(GAMBIT). This software enables the combination of dark matter constraints in a
statistically consistent manner. In total 15 parameters are varied and the
parameter space explored using four different scanning algorithms. The viable
parameter space is reduced from previous studies of this model due to the
inclusion of the latest direct detection constraints.Comment: 7 pages, 2 figures. Contribution to proceedings of EPS-HEP 201
CFB Goose Bay and Operation âDesert Shieldâ
Canada committed forces to the American-led Coalition in the 1990â1991 campaign to liberate Kuwait (Operation DESERT SHIELD and Operation DESERT STORM). The Navy played an important role in the naval portion in this campaign known as Operation DESERT STORM. Canadian CF-18s provided defensive combat air patrols over the Persian Gulf region (less Kuwait and Iraq). Canadian soldiers helped guard prisoners of war, defend airfields and provide security for the 1st Canadian Field Hospital that provided additional health service support. While all of these were important contributions, Canada also provided assistance for Operation DESERT SHIELD. A number of states deployed forces to Saudi Arabia to aid in that Kingdomâs defence should Iraqi forces have attacked. Some Canadian contributions to this operation remain unacknowledged. The massive victory in DESERT STORM was a direct result of the efforts expended in DESERT SHIELD. The two operations comprise the 1991 Gulf Campaign. Canadian Forces Base (CFB) Goose Bay played a little known but remarkable role in Operation DESERT SHIELD in August 1990. It was, in fact, the first unit of the Canadian Forces to support the 1990â1991 Gulf Campaign by acting as a transit station for the US Air Forceâs Military Airlift Command (MAC) as well as other US Air Force formations during Operation DESERT SHIELD
Two-loop mass splittings in electroweak multiplets: winos and minimal dark matter
The radiatively-induced splitting of masses in electroweak multiplets is
relevant for both collider phenomenology and dark matter. Precision two-loop
corrections of (MeV) to the triplet mass splitting in the wino
limit of the minimal supersymmetric standard model can affect particle
lifetimes by up to . We improve on previous two-loop self-energy
calculations for the wino model by obtaining consistent input parameters to the
calculation via two-loop renormalisation-group running, and including the
effect of finite light quark masses. We also present the first two-loop
calculation of the mass splitting in an electroweak fermionic quintuplet,
corresponding to the viable form of minimal dark matter (MDM). We place
significant constraints on the lifetimes of the charged and doubly-charged
fermions in this model. We find that the two-loop mass splittings in the MDM
quintuplet are not constant in the large-mass limit, as might naively be
expected from the triplet calculation. This is due to the influence of the
additional heavy fermions in loop corrections to the gauge boson propagators.Comment: 31 pages, 10 figures, 2 Table
Defining the frame of minimum nonlinear Hubble expansion variation
We characterize a cosmic rest frame in which the monopole variation of the
spherically averaged nonlinear Hubble expansion is most uniform, under
arbitrary local Lorentz boosts of the central observer. Using the COMPOSITE
sample of 4534 galaxies, we identify a degenerate set of candidate minimum
nonlinear variation frames, which includes the rest frame of the Local Group
(LG) of galaxies, but excludes the standard Cosmic Microwave Background (CMB)
frame. Candidate rest frames defined by a boost from the LG frame close to the
plane of the galaxy have a statistical likelihood similar to the LG frame. This
may result from a lack of constraining data in the Zone of Avoidance. We extend
our analysis to the Cosmicflows-2 (CF2) sample of 8162 galaxies. While the
signature of a systematic boost offset between the CMB and LG frame averages is
still detected, the spherically averaged nonlinear expansion variation in all
rest frames is significantly larger in the CF2 sample than would be reasonably
expected. We trace this to the CF2 distances being reported without a
correction for inhomogeneous distribution Malmquist bias. Systematic
differences in the inclusion of the large SFI++ subsample into the COMPOSITE
and CF2 catalogues are analysed. Our results highlight the importance of a
careful treatment of Malmquist biases for future peculiar velocities studies,
including tests of the hypothesis of Wiltshire et al [Phys. Rev. D 88 (2013)
083529; arXiv:1201.5371] that a significant fraction of the CMB temperature
dipole may be nonkinematic in origin.Comment: 25 pages, 19 figures; v4 erratum added: small corrections, no change
in conclusion
Multilayer Resist Imaging Methods
A trilayer imaging system, using DuPont Pyralin polyimide as a planarizing layer, an Allied Chemical Accuglass Spin On Glass barrier layer, and an imaging layer of Kodak 820 positive photoresist, has been previously investigated at RIT. This system failed to perform as expected when the polyimide coating lifted off the metal layer it was designed to mask. This project investigates the process previously used and makes an attempt to qualify it. Along with this, a process is proposed which uses the polyirnide as a lift-off material in a reversal process using the same materials and equipment
Cretaceous Carabidae (Coleoptera) from Orapa, Botswana
Thesis (Ph.D.)--University of the Witwatersrand, Faculty of Science, 1990.A fauna of mid-Cretaceous Carabidae (Coleoptera), recovered
from Orapa Diamond mine, Botswana is described. The
carabids are similar to extant forms and include: the first
record of a fossil of the subfamily Promecognathinae,
Palaeoaxinidium orapensis (gen. et sp. n o v . ); the earliest
record of a member of the Scaritinae; and ten specimens
which are placed tentatively in the subfamilies Siagoninae
(two specimens), Pterostichinae (three specimens),
Anchomeninae (one specimen), and Harpalinae (four specimens);
in addition two specimens cannot be placed in any
particular subfamily.
The manner of preservation of the fossils is described, and
a taphonomic analysis of the site is attempted. The exact
age of the sediments is discussed, and a palaeoenvironment
is inferred from a study of the carabids, the rest of the
fossil fauna, and the sediments.
This fauna of carabids lived in a well-wooded crater formed
by the eruption of a kimberlite. The climate of the time
was seasonal, warm, and intermediate between tropical and
temperate extremes.
The morphological conservatism of the promecogna thine, and
the apparent conservatism of the way of life of members of
this group, provides support for the punctuated equilibrium
pattern of evolution
âStructured agencyâ, normalising power, and third space workers: higher education professional services staff as regulatory policy actors
As the English Higher Education (HE) system becomes characterised by centralised regulation, many professional services staff increasingly occupy significant positions sitting between traditional administrative roles, academia and management with responsibility for interpreting and implementing key policies. This study presents findings from a nested institutional case study, in a research-intensive institution, of the experiences of professional services staff implementing the Teaching Excellence Framework (TEF). Examining how policy âlandedâ in two academic schools, the findings present staff acting as both operational and strategic drivers: experiencing the regulatory policy cycle as opportunities, subjugation and threat. On the one hand, the high-stakes nature of the TEF led to the development of policy-specific, third space-type roles with enhanced employment contracts, prestige, and agency and the reformulation of working relationships. On the other, the TEF, as but one feature of the regulatory burden on institutions, provided only a limited kind of agency â a term referred to here as âstructured agencyâ to staff. Through analysis of the diversity of roles, experiences and skills within the professional services workforce, this paper highlights the critical importance of professional services staff in a complex regulatory policy process, and the ways in which policy enactment in this space both constrains some individuals while, given adequate resource, enables others to carve out new career spaces and career trajectories. As the Office for Students (OfS) continues to normalise its power in institutions, these insights have important implications for labour force management, in turn allowing for the meaningful enactment of central policy within universities
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