9,704 research outputs found
Cooperation through Coordination in Two Stages
This is the author accepted manuscript. The final version is available from Elsevier via the DOI in this recordEfficient cooperation often requires coordination, such that exactly one of two players takes
an available action. If the decisions whether to pursue the action are made simultaneously,
then neither or both may acquiesce leading to an inefficient outcome. However,
inefficiency may be reduced if players move sequentially. We test this experimentally by
introducing repeated two-stage versions of such a game where the action is individually
profitable. In one version, players may wait in the first stage to see what their partner did
and then coordinate in the second stage. In another version, sequential decision-making is
imposed by assigning one player to move in stage one and the other in stage two. Although
there are fewer cooperative decisions in the two-stage treatments, we show that overall
subjects coordinate better on efficient cooperation and on avoiding both acquiescing. Yet,
only some pairs actually achieve higher profits, while the least cooperative pairs do worse
in the two-stage games than their single-stage counterparts. For these, rather than
facilitating coordination, the additional stage invites unsuccessful attempts to disguise
uncooperative play, which are met with punishment
The GUT Scale and Superpartner Masses from Anomaly Mediated Supersymmetry Breaking
We consider models of anomaly-mediated supersymmetry breaking (AMSB) in which
the grand unification (GUT) scale is determined by the vacuum expectation value
of a chiral superfield. If the anomaly-mediated contributions to the potential
are balanced by gravitational-strength interactions, we find a
model-independent prediction for the GUT scale of order . The GUT threshold also affects superpartner masses, and can easily
give rise to realistic predictions if the GUT gauge group is asymptotically
free. We give an explicit example of a model with these features, in which the
doublet-triplet splitting problem is solved. The resulting superpartner
spectrum is very different from that of previously considered AMSB models, with
gaugino masses typically unifying at the GUT scale.Comment: 17 page
Simulations of magnetic and magnetoelastic properties of Tb2Ti2O7 in paramagnetic phase
Magnetic and magnetoelastic properties of terbium titanate pyrochlore in
paramagnetic phase are simulated. The magnetic field and temperature
dependences of magnetization and forced magnetostriction in Tb2Ti2O7 single
crystals and polycrystalline samples are calculated in the framework of
exchange charge model of crystal field theory and a mean field approximation.
The set of electron-deformation coupling constants has been determined.
Variations of elastic constants with temperature and applied magnetic field are
discussed. Additional strong softening of the crystal lattice at liquid helium
temperatures in the magnetic field directed along the rhombic symmetry axis is
predicted.Comment: 13 pages, 4 figures, 2 table
Paid stomatologic services as the tool of increase social medical and economic efficiency of public services
The Material stated in given article, is dedicated to rendering the pay medical services that allows to provide social protection medical workman and earn, which can be directed on social development of the group and increasing quality turned out to be medical-preventive stomatology help
The legal person in stomatoligic sector of business
The Material given article help to do the right choice of the market niche that allows to provide efficient operating the juridical person and warns the adduction of the organizing structure, management and data ware, systems of preparing the personnel in accordance with confirmed standard
Fermion Masses and Mixing and CP-Violation in SO(10) Models with Family Symmetries
Several ideas for solving the problem of fermion mass hierarchy and mixing
and specific supersymmetric models that realize it are reviewed. In particular,
we discuss many models based on SO(10) in four dimensions combined with a
family symmetry to accommodate fermion mass hierarchy and mixing, including the
case of neutrinos. These models are compared and various tests that can be used
to distinguish these models are suggested. We also include a discussion of a
few SO(10) models in higher space-time dimensions.Comment: 66 pages; 5 figures; Submitted to International Journal of Modern
Physics A; v2: a few references added; some changes in tex
Natural Little Hierarchy from a Partially Goldstone Twin Higgs
We construct a simple theory in which the fine-tuning of the standard model
is significantly reduced. Radiative corrections to the quadratic part of the
scalar potential are constrained to be symmetric under a global U(4) x U(4)'
symmetry due to a discrete Z_2 "twin" parity, while the quartic part does not
possess this symmetry. As a consequence, when the global symmetry is broken the
Higgs fields emerge as light pseudo-Goldstone bosons, but with sizable quartic
self-interactions. This structure allows the cutoff scale, \Lambda, to be
raised to the multi-TeV region without significant fine-tuning. In the minimal
version of the theory, the amount of fine-tuning is about 15% for \Lambda = 5
TeV, while it is about 30% in an extended model. This provides a solution to
the little hierarchy problem. In the minimal model, the "visible" particle
content is exactly that of the two Higgs doublet standard model, while the
extended model also contains extra vector-like fermions with masses ~(1-2)TeV.
At the LHC, our minimal model may appear exactly as the two Higgs doublet
standard model, and new physics responsible for cutting off the divergences of
the Higgs mass-squared parameter may not be discovered. Several possible
processes that may be used to discriminate our model from the simple two Higgs
doublet model are discussed for the LHC and for a linear collider.Comment: 22 page
On identifying the neutron star that was born in the supernova that placed 60Fe onto the Earth
Recently, 60Fe was found in the Earth crust formed in a nearby recent
supernova (SN). If the distance to the SN and mass of the progenitor of that SN
was known, then one could constrain SN models. Knowing the positions, proper
motions, and distances of dozens of young nearby neutron stars, we can
determine their past flight paths and possible kinematic origin. Once the birth
place of a neutron star in a SN is found, we would have determined the distance
of the SN and the mass of the SN progenitor star.Comment: refereed NPA5 conference proceedings, in pres
Anomaly mediated supersymmetry breaking and its test in linear colliders
Signatures of anomaly mediated supersymmetry breaking in linear colliders are
briefly reviewed after presenting an outline of the theoretical framework. A
unique and distinct feature of a large class of models of this type is a
winolike chargino which is very closely degenerate in mass with the lightest
neutralino. The very slow decay of this chargino results in a heavily ionizing
charged track and one soft charged pion with a characteristic momentum
distribution, leading to unique signals in linear colliders which are
essentially free of background. The determination of chargino and slepton
masses from such events is a distinctly interesting possibility.Comment: 15 pages, LaTex, 4 PS figures, ws-mpla.cls file included. One
reference added. To appear as a Brief Review in Modern Physics Letters
Effects of prenatal exposure to diclofenac sodium and saline on the optic nerve of 4- and 20-week-old male rats: A stereological and histological study
- …