231,509 research outputs found
DIS Prospects at the Future Muon Collider Facility
We discuss prospects of deep inelastic scattering physics capabilities at the
future muon collider facility. In addition to mu^+ mu^- collider itself, the
facility provides other possibilities. Among the possibilities, we present
muon-proton collider and neutrino fixed target programs at the muon collider
facility. This mu-p collider program extends kinematic reach and luminosity by
an order of magnitude, increasing the possibility of search for new exotic
particles. Perhaps most intriguing DIS prospects come from utilizing high
intensity neutrino beam resulting from continuous decays of muons in various
sections of the muon collider facility. One of the most interesting findings is
a precision measurement of electroweak mixing angle, sin^2theta_W, which can be
achieved to the precision equivalent to delta M_W ~ 30 MeV.Comment: 8 pages, 4 figures, To be published in the proceedings of the 6th
international workshop on Deep Inelastic Scattering, Brussel, Belgium (1998
Alternative Derivation of the Hu-Paz-Zhang Master Equation for Quantum Brownian Motion
Hu, Paz and Zhang [ B.L. Hu, J.P. Paz and Y. Zhang, Phys. Rev. D {\bf 45}
(1992) 2843] have derived an exact master equation for quantum Brownian motion
in a general environment via path integral techniques. Their master equation
provides a very useful tool to study the decoherence of a quantum system due to
the interaction with its environment. In this paper, we give an alternative and
elementary derivation of the Hu-Paz-Zhang master equation, which involves
tracing the evolution equation for the Wigner function. We also discuss the
master equation in some special cases.Comment: 17 pages, Revte
Assessment criteria for 2D shape transformations in animation
The assessment of 2D shape transformations (or morphing) for animation is a difficult task because it is a multi-dimensional problem. Existing morphing techniques pay most attention to shape information interactive control and mathematical simplicity. This paper shows that it is not enough to use shape information alone, and we should consider other factors such as structure, dynamics, timing, etc. The paper also shows that an overall objective assessment of morphing is impossible because factors such as timing are related to subjective judgement, yet local objective assessment criteria, e.g. based on shape, are available. We propose using “area preservation” as the shape criterion for the 2D case as an acceptable approximation to “volume preservation” in reality, and use it to establish cases in which a number of existing techniques give clearly incorrect results. The possibility of deriving objective assessment criteria for dynamics simulations and timing under certain conditions is discussed
Bayesian analysis of a Tobit quantile regression model
This paper develops a Bayesian framework for Tobit quantile regression. Our approach
is organized around a likelihood function that is based on the asymmetric Laplace dis-
tribution, a choice that turns out to be natural in this context. We discuss families
of prior distribution on the quantile regression vector that lead to proper posterior
distributions with ¯nite moments. We show how the posterior distribution can be
sampled and summarized by Markov chain Monte Carlo methods. A method for com-
paring alternative quantile regression models is also developed and illustrated. The
techniques are illustrated with both simulated and real data. In particular, in an em-
pirical comparison, our approach out-performed two other common classical estimators
Hamiltonian Reduction of -theories at the Level of Correlators
Since the work of Bershadsky and Ooguri and Feigin and Frenkel it is well
known that correlators of current algebra for admissible
representations should reduce to correlators for conformal minimal models. A
precise proposal for this relation has been given at the level of correlators:
When primary fields are expressed as with being
a variable to keep track of the representation multiplet (possibly
infinitely dimensional for admissible representations), then the minimal model
correlator is supposed to be obtained simply by putting all . Although
strong support for this has been presented, to the best of our understanding a
direct, simple proof seems to be missing so in this paper we present one based
on the free field Wakimoto construction and our previous study of that in the
present context. We further verify that the explicit correlators we
have published in a recent preprint reduce in the above way, up to a constant
which we also calculate. We further discuss the relation to more standard
formulations of hamiltonian reduction.Comment: 13 pages, LaTe
Generalized linear isotherm regularity equation of state applied to metals
A three-parameter equation of state (EOS) without physically incorrect
oscillations is proposed based on the generalized Lennard-Jones (GLJ) potential
and the approach in developing linear isotherm regularity (LIR) EOS of Parsafar
and Mason [J. Phys. Chem., 1994, 49, 3049]. The proposed (GLIR) EOS can include
the LIR EOS therein as a special case. The three-parameter GLIR, Parsafar and
Mason (PM) [Phys. Rev. B, 1994, 49, 3049], Shanker, Singh and Kushwah (SSK)
[Physica B, 1997, 229, 419], Parsafar, Spohr and Patey (PSP) [J. Phys. Chem. B,
2009, 113, 11980], and reformulated PM and SSK EOSs are applied to 30 metallic
solids within wide pressure ranges. It is shown that the PM, PMR and PSP EOSs
for most solids, and the SSK and SSKR EOSs for several solids, have physically
incorrect turning points, and pressure becomes negative at high enough
pressure. The GLIR EOS is capable not only of overcoming the problem existing
in other five EOSs where the pressure becomes negative at high pressure, but
also gives results superior to other EOSs.Comment: 9 pages, 3 figure
Giant enhanced optical nonlinearity of colloidal nanocrystals with a graded-index host
The effective linear and third-order nonlinear optical properties of metallic
colloidal crystal immersed in a graded-index host fluid are investigated
theoretically. The local electric fields are extracted self-consistently based
on the layer-to-layer interactions, which are readily given by the Lekner
summation method. The resultant optical absorption and nonlinearity enhancement
show a series of sharp peaks, which merge in a broadened resonant band. The
sharp peaks become a continuous band for increasing packing density and number
of layers. We believe that the sharp peaks arise from the in-plane dipolar
interactions and the surface plasmon resonance, whereas the continuous band is
due to the presence of the gradient in the host refractive index. These results
have not been observed in homogeneous and randomly-dispersed colloids, and thus
would be of great interest in optical nanomaterial engineering.Comment: Submitted to Applied Physics Letter
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