1,701 research outputs found
Calculation of Second Topological Moment <m^2> of Two Entangled Polymers
We set up a Chern-Simons theory for the entanglement of two polymers P_1 and
P_2, and calculate the second topological moment , where m is the linking
number. The result applies approximately to a polymer in an ensemble of many
others, if these are considered as a single very long effective polymer.Comment: Author Information under
http://www.physik.fu-berlin.de/~kleinert/institution.html Latest update of
paper also at http://www.physik.fu-berlin.de/~kleinert/30
Founding a mathematical diffusion model in linguistics. The case study of German syntactic features in the North-Eastern Italian dialects
We take as a case study the spread of Germanic syntactic features into
Romance dialects of North-Eastern Italy, which occurred after the immigration
of German people in the Tyrol during the High Middle Ages.
An interactive map is produced using tools of what is called Geographic Data
Science. A smooth two-dimensional surface expresses locally which
fraction of territory uses a given German language feature: it is obtained by
interpolating a discrete function that says if at any surveyed locality that
feature is used or not.\newline
This surface is thought of as the value at the present time of
a function describing a diffusion-convection phenomenon in two dimensions (here
said \emph{tidal} mode), which is subjected in a very natural way to the same
equation, suitably contextualized, used in physics for a number of
phenomenological facts like the heat diffusion. It is shown that solutions of
this equation, evaluated at the present time, fit well with the data as
interpolated by , thus providing convincing pictures of
diffusion-convection of the linguistic features of the case study, albeit
simplifications and approximations.\newline
Very importantly, it is shown that Schmidt's 'waves' can be counted among the
solutions of the diffusion equation: superimposing Schmidt 'waves' to a 'tidal
flooding' can reproduce complexities of real linguistic diffusion events
Totem: a case study in HEP
It is being proved that the neurochip \Totem{} is a viable solution for high
quality and real time computational tasks in HEP, including event
classification, triggering and signal processing. The architecture of the chip
is based on a "derivative free" algorithm called Reactive Tabu Search (RTS),
highly performing even for low precision weights. ISA, VME or PCI boards
integrate the chip as a coprocessor in a host computer. This paper presents: 1)
the state of the art and the next evolution of the design of \Totem{}; 2) its
ability in the Higgs search at LHC as an example.Comment: Latex, elsart.sty, 5 pages, talk presented by I.Lazzizzera at CHEP97
(Berlin, April 1997
Searching the Higgs with the Neurochip TOTEM
We show that neural network classifiers can be helpful in discriminating
Higgs production events from the huge background at LHC, assuming the case of a
mass value GeV. We use the high performance neurochip TOTEM,
trained by the Reactive Tabu Search algorithm (RTS), which could be used for
on-line purposes. Two different sets of input variables are compared.Comment: 4 pages,1 figure, requres espcrc2.sty and epsfig.sty. Work prsented
in The 5th Topical Seminar on ``The irresistible rise of the Standard
Model'', San Miniato, Tuscany, Italy, April 21-25 199
Investigation of in the full hadronic final state at CDF with a neural network approach
Abstract In this work we present the results of a neural network (NN) approach to the measurement of the t t production cross-section and top mass in the all-hadronic channel, analyzing data collected at the Collider Detector at Fermilab (CDF) experiment. We have used a hardware implementation of a feed forward neural network, TOTEM , the product of a collaboration of INFN (Istituto Nazionale Fisica Nucleare)—IRST (Istituto per la Ricerca Scientifica e Tecnologica)—University of Trento, Italy. Particular attention has been payed to the evaluation of the systematics specifically related to the NN approach. The results are consistent with those obtained at CDF by conventional data selection techniques
Canonical Quantisation in n.A=0 gauges
We give a unified derivation of the propagator in the gauges for
timelike, spacelike or lightlike. We discuss the physical states and
other physical questions.Comment: 7 pages, DAMTP 93-33, ITP-SB-93-3
Dirac Quantization of the Chern-Simons Field Theory in the Coulomb Gauge
In this letter the Chern-Simons field theories are studied in the Coulomb
gauge using the Dirac's canonical formalism for constrained systems. As a
strategy, we first work out the constraints and then quantize, replacing the
Dirac brackets with quantum commutators. We find that the Chern-Simons field
theories become two dimensional models with no propagation along the time
direction. Moreover, we prove that, despite of the presence of non-trivial
self-interactions in the gauge fixed functional, the commutation relations
between the fields are trivial at any order in perturbation theory in the
absence of couplings with matter fields. If these couplings are present,
instead, the commutation relations become rather involved, but it is still
possible to study their main properties and to show that they vanish at the
tree level.Comment: 15 pages, Latex+RevTex, no figure
Measurement of the Dipion Mass Spectrum in X(3872) -> J/Psi Pi+ Pi- Decays
We measure the dipion mass spectrum in X(3872)--> J/Psi Pi+ Pi- decays using
360 pb-1 of pbar-p collisions at 1.96 TeV collected with the CDF II detector.
The spectrum is fit with predictions for odd C-parity (3S1, 1P1, and 3DJ)
charmonia decaying to J/Psi Pi+ Pi-, as well as even C-parity states in which
the pions are from Rho0 decay. The latter case also encompasses exotic
interpretations, such as a D0-D*0Bar molecule. Only the 3S1 and J/Psi Rho
hypotheses are compatible with our data. Since 3S1 is untenable on other
grounds, decay via J/Psi Rho is favored, which implies C=+1 for the X(3872).
Models for different J/Psi-Rho angular momenta L are considered. Flexibility in
the models, especially the introduction of Rho-Omega interference, enable good
descriptions of our data for both L=0 and 1.Comment: 7 pages, 4 figures -- Submitted to Phys. Rev. Let
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