4,636 research outputs found
Optimal Jet Finder
We describe a FORTRAN 77 implementation of the optimal jet definition for
identification of jets in hadronic final states of particle collisions. We
discuss details of the implementation, explain interface subroutines and
provide a usage example. The source code is available from
http://www.inr.ac.ru/~ftkachov/projects/jets/Comment: version to appear in Comp. Phys. Commun., 36 page
Uniformizing higher-spin equations
Vasiliev's higher-spin theories in various dimensions are uniformly
represented as a simple system of equations. These equations and their gauge
invariances are based on two superalgebras and have a transparent algebraic
meaning. For a given higher-spin theory these algebras can be inferred from the
vacuum higher-spin symmetries. The proposed system of equations admits a
concise AKSZ formulation. We also discuss novel higher-spin systems including
partially-massless and massive fields in AdS, as well as conformal and massless
off-shell fields.Comment: 29 pages, references added, final versio
A Monte Carlo Test of the Optimal Jet Definition
We summarize the Optimal Jet Definition and present the result of a benchmark
Monte Carlo test based on the W-boson mass extraction from fully hadronic
decays of pairs of W's.Comment: 7 pages, talk given at Lake Louise Winter Institute: "Particles and
the Universe", Lake Louise, Canada, February 16-22, 2003, to be published in
the proceeding
On semiring complexity of Schur polynomials
Semiring complexity is the version of arithmetic circuit complexity that allows only two operations: addition and multiplication. We show that semiring complexity of a Schur polynomial {s_\lambda(x_1,\dots,x_k)} labeled by a partition {\lambda=(\lambda_1\ge\lambda_2\ge\cdots)} is bounded by {O(\log(\lambda_1))} provided the number of variables is fixed
Multiple Factorizations of Bivariate Linear Partial Differential Operators
We study the case when a bivariate Linear Partial Differential Operator
(LPDO) of orders three or four has several different factorizations.
We prove that a third-order bivariate LPDO has a first-order left and right
factors such that their symbols are co-prime if and only if the operator has a
factorization into three factors, the left one of which is exactly the initial
left factor and the right one is exactly the initial right factor. We show that
the condition that the symbols of the initial left and right factors are
co-prime is essential, and that the analogous statement "as it is" is not true
for LPDOs of order four.
Then we consider completely reducible LPDOs, which are defined as an
intersection of principal ideals. Such operators may also be required to have
several different factorizations. Considering all possible cases, we ruled out
some of them from the consideration due to the first result of the paper. The
explicit formulae for the sufficient conditions for the complete reducibility
of an LPDO were found also
Electron mobility on a surface of dielectric media: influence of surface level atoms
We calculate the contribution to the electron scattering rate from the
surface level atoms (SLA), proposed in [A.M. Dyugaev, P.D. Grigoriev, JETP
Lett. 78, 466 (2003)]. The inclusion of these states into account was
sufficient to explain the long-standing puzzles in the temperature dependence
of the surface tension of both He isotopes and to reach a very good agreement
between theory and experiment. We calculate the contribution from these SLA to
the surface electron scattering rate and explain some features in the
temperature dependence of the surface electron mobility. This contribution is
essential at low temperature when the He vapor concentration is
exponentially small. For an accurate calculation of the electron mobility one
also needs to consider the influence of the clamping electric field on the
surface electron wave function and the temperature dependence of the He3
chemical potential.Comment: 6 pages, 1 figur
Controlling Physical Systems with Symmetries
Symmetry properties of the evolution equation and the state to be controlled
are shown to determine the basic features of the linear control of unstable
orbits. In particular, the selection of control parameters and their minimal
number are determined by the irreducible representations of the symmetry group
of the linearization about the orbit to be controlled. We use the general
results to demonstrate the effect of symmetry on the control of two sample
physical systems: a coupled map lattice and a particle in a symmetric
potential.Comment: 6 page
Hierarchy of general invariants for bivariate LPDOs
We study invariants under gauge transformations of linear partial
differential operators on two variables. Using results of BK-factorization, we
construct hierarchy of general invariants for operators of an arbitrary order.
Properties of general invariants are studied and some examples are presented.
We also show that classical Laplace invariants correspond to some particular
cases of general invariants.Comment: to appear in J. "Theor.Math.Phys." in May 200
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