5,476 research outputs found
Solitaire Clobber
Clobber is a new two-player board game. In this paper, we introduce the
one-player variant Solitaire Clobber where the goal is to remove as many stones
as possible from the board by alternating white and black moves. We show that a
checkerboard configuration on a single row (or single column) can be reduced to
about n/4 stones. For boards with at least two rows and two columns, we show
that a checkerboard configuration can be reduced to a single stone if and only
if the number of stones is not a multiple of three, and otherwise it can be
reduced to two stones. We also show that in general it is NP-complete to decide
whether an arbitrary Clobber configuration can be reduced to a single stone.Comment: 14 pages. v2 fixes small typ
The Differential equation method: calculation of vertex-type diagrams with one non-zero mass
The differential equation method is applied to evaluate analytically two-loop
vertex Feynman diagrams. Three on-shell infrared divergent planar two-loop
diagrams with zero thresholds contributing to the processes Z --> bb bar (for
zero b mass) and/or H --> gg are calculated in order to demonstrate a new
application of this method.Comment: 12 pages, LATEX, uses axodray.st
Towards Automatic Analytic Evaluation of Diagrams with Masses
A method to calculate two-loop self-energy diagrams of the Standard Model is
demonstrated. A direct physical application is the calculation of the two-loop
electroweak contribution to the anomalous magnetic moment of the muon
. Presently, we confine ourselves to a ``toy'' model with
only , and a heavy neutral scalar particle (Higgs). The algorithm
is implemented as a FORM-based program package. For generating and
automatically evaluating any number of two-loop self-energy diagrams, a special
C-program has been written. This program creates the initial FORM-expression
for every diagram generated by QGRAF, executes the corresponding subroutines
and sums up the final results.Comment: LaTeX, 20 pages, 7 eps-figures included; extended version of talk
given at AIHEN96, Lausanne, 1-6 Sept. 1996; detailed description of C-program
is given; accepted for publication in Comp.Phys.Com
Controlling Molecular Scattering by Laser-Induced Field-Free Alignment
We consider deflection of polarizable molecules by inhomogeneous optical
fields, and analyze the role of molecular orientation and rotation in the
scattering process. It is shown that molecular rotation induces spectacular
rainbow-like features in the distribution of the scattering angle. Moreover, by
preshaping molecular angular distribution with the help of short and strong
femtosecond laser pulses, one may efficiently control the scattering process,
manipulate the average deflection angle and its distribution, and reduce
substantially the angular dispersion of the deflected molecules. We provide
quantum and classical treatment of the deflection process. The effects of
strong deflecting field on the scattering of rotating molecules are considered
by the means of the adiabatic invariants formalism. This new control scheme
opens new ways for many applications involving molecular focusing, guiding and
trapping by optical and static fields
Apollo helmet dosimetry experiments Final report
Procedure for measuring heavy cosmic ray particles directly incident on spacecrew
Project {\tt SANC} (former {\tt CalcPHEP}): Support of Analytic and Numeric calculations for experiments at Colliders
The project, aimed at the theoretical support of experiments at modern and
future accelerators -- TEVATRON, LHC, electron Linear Colliders (TESLA, NLC,
CLIC) and muon factories, is presented. Within this project a four-level
computer system is being created, which must automatically calculate, at the
one-loop precision level the pseudo- and realistic observables (decay rates and
event distributions) for more and more complicated processes of elementary
particle interaction, using the principle of knowledge storing.
It was already used for a recalculation of the EW radiative corrections for
Atomic Parity Violation [1] and complete one-loop corrections for the process
[2-4]; for the latter an, agreement up to 11 digits with
FeynArts and the other results is found. The version of {\tt SANC} that we
describe here is capable of automatically computing the decay rates and the
distributions for the decays in the one-loop
approximation.Comment: 3 Latex, Presented at ICHEP2002, Amsterdam, July 24-30, 2000;
Submitted to Proceeding
Fast-Converging Tatonnement Algorithms for the Market Problem
Why might markets tend toward and remain near equilibrium prices? In an effort to shed light on this question from an algorithmic perspective, this paper defines and analyzes two simple tatonnement algorithms that differ from previous algorithms that have been subject to asymptotic analysis in three significant respects: the price update for a good depends only on the price, demand, and supply for that good, and on no other information; the price update for each good occurs distributively and asynchronously; the algorithms work (and the analyses hold) from an arbitrary starting point. Our algorithm introduces a new and natural update rule. We show that this update rule leads to fast convergence toward equilibrium prices in a broad class of markets that satisfy the weak gross substitutes property. These are the first analyses for computationally and informationally distributed algorithms that demonstrate polynomial convergence. Our analysis identifies three parameters characterizing the markets, which govern the rate of convergence of our protocols. These parameters are, broadly speaking: 1. A bound on the fractional rate of change of demand for each good with respect to fractional changes in its price. 2. A bound on the fractional rate of change of demand for each good with respect to fractional changes in wealth. 3. The relative demand for money at equilibrium prices. We give two protocols. The first assumes global knowledge of only the first parameter. For this protocol, we also provide a matching lower bound in terms of these parameters. Our second protocol assumes no global knowledge whatsoever
Soliton control in modulated optically-induced photonic lattices
We discuss soliton control in reconfigurable optically-induced photonic
lattices created by three interfering beams. We reveal novel dynamical regimes
for strongly localized solitons, including binary switching and soliton
revivals through resonant wave mixing.Comment: 7 pages, 5 figures. Content modifie
B Physics - A Theoretical Review
This overview of what we can hope to learn from high-statistics experiments
in B physics in the next few years includes: (a) a review of parameters of the
Cabibbo-Kobayashi-Maskawa (CKM) Matrix; (b) direct determination of magnitudes
of CKM elements; (c) forthcoming information from studies of kaons; (d) CP
violation in B decays; (e) aspects of rate measurements; (f) the role of
charm-anticharm annihilation; (g) remarks on tagging; and (h) effects beyond
the standard model.Comment: 23 pages, latex, 4 figures, further corrections to reference
Using B_s^0 Decays to Determine the CP Angles \alpha and \gamma
Dighe, Gronau and Rosner have shown that, by assuming SU(3) flavor symmetry
and first-order SU(3) breaking, it is possible to extract the CP angles \alpha
and \gamma from measurements of the decay rates of B_d^0(t) --> \pi^+\pi^-,
B_d^0 --> \pi^- K^+ and B^+ --> \pi^+ K^0, along with their charge-conjugate
processes. We extend their analysis to include the SU(3)-related decays B_s^0
--> \pi^+ K^-, B_s^0(t) --> K^+ K^- and B_s^0 --> K^0 {\bar K^0}. There are
several advantages to this extension: discrete ambiguities are removed, fewer
assumptions are necessary, and the method works even if all strong phases
vanish. In addition, we show that \gamma can be obtained cleanly, with no
penguin contamination, by using the two decays B_s^0(t) --> K^+ K^- and B_s^0
--> K^0 {\bar K^0}.Comment: 28 pages, LaTe
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