19,986 research outputs found
The Brutal Murder of George J. Bushman
In the fall of 1918 there occurred in Adams County a singularly brutal murder that brought the County and the town of Gettysburg to a shocked standstill. The tentacles of this event would reach into four Pennsylvania counties: Adams, Cumberland, Dauphin, and Philadelphia, and eventually the Pennsylvania Supreme Court. The investigation of the crime and the trial of the perpetrators involved so many public officials and families, as well as the extended judicial system and geographical locations within and without the County, that we have included a Cast of Characters and Locations to assist the reader in following this convoluted tale
Constraining the Natural MSSM through tunneling to color-breaking vacua at zero and non-zero temperature
We re-evaluate the constraints on the parameter space of the minimal
supersymmetric standard model from tunneling to charge- and/or color-breaking
minima, taking into account thermal corrections. We pay particular attention to
the region known as the Natural MSSM, where the masses of the scalar partners
of the top quarks are within an order of magnitude or so of the electroweak
scale. These constraints arise from the interaction between these scalar tops
and the Higgs fields, which allows the possibility of parameter points having
deep charge- and color-breaking true vacua. In addition to requiring that our
electro-weak-symmetry-breaking, yet QCD- and electromagnetism-preserving vacuum
has a sufficiently long lifetime at zero temperature, also demanding stability
against thermal tunneling further restricts the allowed parameter space.Comment: 7 pages, 2 figures, software available from
http://vevacious.hepforge.org/ - version 2 matches that accepted for
publication in Phys. Lett.
Length-dependent oscillations of the conductance through atomic chains: The importance of electronic correlations
We calculate the conductance of atomic chains as a function of their length.
Using the Density Matrix Renormalization Group algorithm for a many-body model
which takes into account electron-electron interactions and the shape of the
contacts between the chain and the leads, we show that length-dependent
oscillations of the conductance whose period depends on the electron density in
the chain can result from electron-electron scattering alone. The amplitude of
these oscillations can increase with the length of the chain, in contrast to
the result from approaches which neglect the interactions.Comment: 7 pages, 4 figure
Vevacious: A Tool For Finding The Global Minima Of One-Loop Effective Potentials With Many Scalars
Several extensions of the Standard Model of particle physics contain
additional scalars implying a more complex scalar potential compared to that of
the Standard Model. In general these potentials allow for charge and/or color
breaking minima besides the desired one with correctly broken SU(2)_L times
U(1)_Y . Even if one assumes that a metastable local minimum is realized, one
has to ensure that its lifetime exceeds that of our universe. We introduce a
new program called Vevacious which takes a generic expression for a one-loop
effective potential energy function and finds all the tree-level extrema, which
are then used as the starting points for gradient-based minimization of the
one-loop effective potential. The tunneling time from a given input vacuum to
the deepest minimum, if different from the input vacuum, can be calculated. The
parameter points are given as files in the SLHA format (though is not
restricted to supersymmetric models), and new model files can be easily
generated automatically by the Mathematica package SARAH. This code uses
HOM4PS2 to find all the minima of the tree-level potential, PyMinuit to follow
gradients to the minima of the one-loop potential, and CosmoTransitions to
calculate tunneling times.Comment: 44 pages, 1 figure, manual for publicly available software, v2
corresponds to version accepted for publication in EPJC [clearer explanation
of scale dependence and region of validity, explicit mention that SLHA files
should have blocks matching those expected by model files, updated
references
Prediction of narrow and resonances with hidden charm above 4 GeV
The interaction between various charmed mesons and charmed baryons are
studied within the framework of the coupled channel unitary approach with the
local hidden gauge formalism. Several meson-baryon dynamically generated narrow
and resonances with hidden charm are predicted with mass
above 4 GeV and width smaller than 100 MeV. The predicted new resonances
definitely cannot be accommodated by quark models with three constituent quarks
and can be looked for at the forthcoming PANDA/FAIR experiments.Comment: 4 pages, 3 figure
A high-performance data structure for mobile information systems
Mobile information systems can now be provided on small form-factor computers. Dictionary-based data compression extends the capabilities of systems with limited processing and memory to enable data intensive applications to be supported in such environments. The nature of judicial sentencing decisions requires that a support system provides accurate and up-to-date data and is compatible with the professional working experience of a judge. The difficulties caused by mobility and the data dependence of the decision-making process are addressed by an Internet-based architecture for collecting and distributing system data.We describe an approach to dictionary-based data compression and the structure of an information system that makes use of this technology
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