328 research outputs found
Preliminary geophysical interpretation of the McKeand River area, southern Baffin Island, Nunavut: insights from gravity, magnetic and geological data
The recently completed McKeand River and Amittok Lake aeromagnetic surveys on southern Baffin Island, Nunavut pro-
vide a new high-resolution magnetic dataset over an area with no previous coverage. Complemented by regional gravity
data, newly acquired rock-property information and geological-mapping products, the aeromagnetic dataset yields qualita-
tive and quantitative information on the structure and geology of the underlying bedrock. This paper presents a preliminary
interpretation of these datasets that delineates three gravimetric and five magnetic domains. The gravity data outline a broad
negative anomaly associated with a plutonic-intrusive suite, as well as several isolated gravity highs associated with
metasedimentary strata. Magnetic domains are defined on the basis of anomaly amplitude, wavelength and texture, and are
correlated to the mapped geology and magnetic properties. Associations between potential-field anomalies, physical prop-
erties and mineral occurrences help define the regional distribution of economically significant horizons
Project X functional requirements specification
Project X is a multi-megawatt proton facility being developed to support
intensity frontier research in elementary particle physics, with possible
applications to nuclear physics and nuclear energy research, at Fermilab. A
Functional Requirements Specification has been developed in order to establish
performance criteria for the Project X complex in support of these multiple
missions. This paper will describe the Functional Requirements for the Project
X facility and the rationale for these requirements.Comment: 3 pp. Particle Accelerator, 24th Conference (PAC'11) 28 Mar - 1 Apr
2011: New York, US
Completing the bedrock mapping of southern Baffin Island, Nunavut; plutonic suites and regional stratigraphy
This paper summarizes the field observations and initial interpretations following eight weeks of regional and targeted bed-
rock mapping on south-central Baffin Island, Nunavut. The 2015 field campaign completes a two-decade mission to update
the geoscience knowledge for the whole of Baffin Island south of latitude 70°N. The bedrock in the area is dominated by a
Paleoproterozoic metaplutonic suite, ranging in composition from gabbro to syenogranite, with crosscutting relations indi-
cating a progression from mafic to silicic magmatism. Phase-equilibria modelling reveals that the prevailing upper-amphi-
bolite– to lower-granulite–facies metamorphic conditions overlap the stability limits of magnetite and orthopyroxene for a
typical granitoid bulk composition, which is consistent with field observations of the discontinuous presence of both phases
throughout the map area. This result is also consistent with regional aeromagnetic data that show complex structures within
relatively homogeneous map units, which are primarily attributed to variations in the abundance of magnetite. The granitoid
rocks are interpreted as part of the middle Paleoproterozoic Cumberland Batholith.
Metasedimentary rocks, including quartzite, pelite, marble and metagreywacke, are present as enclaves and screens within
and between plutonic bodies. An examination of the ‘ghost’stratigraphy suggests that the metasedimentary rocks through-
out most of the map area can be correlated with the middle Paleoproterozoic Lake Harbour Group, except in the northeast,
where the unique presence of greywacke suggests a middle Paleoproterozoic Piling Group affinity. This transition in strata
is consistent with the proposal that a middle Paleoproterozoic tectonic suture (the Baffin suture) associated with the Trans-
Hudson Orogen runs through Cumberland Sound. Completion of the bedrock mapping in southern Baffin Island indicates
that the region offers a world-class exposure of a reworked Paleoproterozoic convergent margin, which affords valuable in-
sight into a variety of magmatic and tectonic processes that can be applied to younger collisional belt
Note on the pseudo-Nambu-Goldstone Boson of Meta-stable SUSY Violation
Many models of meta-stable supersymmetry (SUSY) breaking lead to a very light
scalar pseudo-Nambu Goldstone boson (PNGB), P, associated with spontaneous
breakdown of a baryon number like symmetry in the hidden sector. Current
particle physics data provide no useful constraints on the existence of P. For
example, the predicted decay rates for both K --> pi + P, b--> s + P and
Upsilon --> photon + P are many orders of magnitude below the present
experimental bounds. We also consider astrophysical implications of the PNGB
and find a significant constraint from its effect on the evolution of red
giants. This constraint either rules out models with a hidden sector gauge
group larger than SU(4), or requires a new intermediate scale, of order at most
10^{10} GeV, at which the hidden sector baryon number is explicitly broken.Comment: 17 pages, 3 figures. Version 2: minor typographical errors fixed.
Version 3: a more reliable estimate for the decay rate of K-->pi+PNGB is
provided, and the predicted rate for b-->s+PNGB is now include
Rare Decays with a Light CP-Odd Higgs Boson in the NMSSM
We have previously proposed a light pseudoscalar Higgs boson in the
next-to-minimal supersymmetric standard model (NMSSM), the A_1^0, as a
candidate to explain the HyperCP observations in Sigma^+ -> p mu^+ mu^-. In
this paper we calculate the rates for several other rare decay modes that can
help confirm or refute this hypothesis. The first modes we evaluate are K_L ->
pi pi A_1^0, which are interesting because they are under study by the KTeV
Collaboration. We next turn to eta -> pi pi A_1^0, which are interesting
because they are independent of the details of the flavor-changing sector of
the NMSSM and may be accessible at DAPhNE. For completeness, we also evaluate
Omega^- -> Xi^- A_1^0.Comment: 17 pages, 11 figure
- …