68 research outputs found
Quantum affine Cartan matrices, Poincare series of binary polyhedral groups, and reflection representations
We first review some invariant theoretic results about the finite subgroups
of SU(2) in a quick algebraic way by using the McKay correspondence and quantum
affine Cartan matrices. By the way it turns out that some parameters
(a,b,h;p,q,r) that one usually associates with such a group and hence with a
simply-laced Coxeter-Dynkin diagram have a meaningful definition for the
non-simply-laced diagrams, too, and as a byproduct we extend Saito's formula
for the determinant of the Cartan matrix to all cases. Returning to invariant
theory we show that for each irreducible representation i of a binary
tetrahedral, octahedral, or icosahedral group one can find a homomorphism into
a finite complex reflection group whose defining reflection representation
restricts to i.Comment: 19 page
Solitons in nonlocal nonlinear media: exact results
We investigate the propagation of one-dimensional bright and dark spatial
solitons in a nonlocal Kerr-like media, in which the nonlocality is of general
form. We find an exact analytical solution to the nonlinear propagation
equation in the case of weak nonlocality. We study the properties of these
solitons and show their stability.Comment: 9 figures, submitted to Phys. Rev.
Modulational instability in nonlocal nonlinear Kerr media
We study modulational instability (MI) of plane waves in nonlocal nonlinear
Kerr media. For a focusing nonlinearity we show that, although the nonlocality
tends to suppress MI, it can never remove it completely, irrespectively of the
particular profile of the nonlocal response function. For a defocusing
nonlinearity the stability properties depend sensitively on the response
function profile: for a smooth profile (e.g., a Gaussian) plane waves are
always stable, but MI may occur for a rectangular response. We also find that
the reduced model for a weak nonlocality predicts MI in defocusing media for
arbitrary response profiles, as long as the intensity exceeds a certain
critical value. However, it appears that this regime of MI is beyond the
validity of the reduced model, if it is to represent the weakly nonlocal limit
of a general nonlocal nonlinearity, as in optics and the theory of
Bose-Einstein condensates.Comment: 8 pages, submitted to Phys. Rev.
Tracking azimuthons in nonlocal nonlinear media
We study the formation of azimuthons, i.e., rotating spatial solitons, in
media with nonlocal focusing nonlinearity. We show that whole families of these
solutions can be found by considering internal modes of classical non-rotating
stationary solutions, namely vortex solitons. This offers an exhaustive method
to identify azimuthons in a given nonlocal medium. We demonstrate formation of
azimuthons of different vorticities and explain their properties by considering
the strongly nonlocal limit of accessible solitons.Comment: 11 pages, 7 figure
Measurement of spin correlation in ttbar production using dilepton final states
We measure the correlation between the spin of the top quark and the spin of
the anti-top quark in (ttbar -> W+ W- b bbar -> l+ nu b l- nubar bbar) final
states produced in ppbar collisions at a center of mass energy sqrt(s)=1.96
TeV, where l is an electron or muon. The data correspond to an integrated
luminosity of 5.4 fb-1 and were collected with the D0 detector at the Fermilab
Tevatron collider. The correlation is extracted from the angles of the two
leptons in the t and tbar rest frames, yielding a correlation strength C=
0.10^{+0.45}_{-0.45}, in agreement with the NLO QCD prediction within two
standard deviations, but also in agreement with the no correlation hypothesis.Comment: 10 pages, 3 figures, submitted to PL
Selection of bee species for environmental risk assessment of GM cotton in the Brazilian Cerrado
A measurement of the ratio of inclusive cross sections at TeV
The ratio of the cross section for interactions producing a
boson and at least one quark jet to the inclusive cross
section is measured using of collisions
collected with the \dzero\ detector at the Fermilab Tevatron collider at
TeV. The candidate events with at
least one jet are discriminated from charm and light jet(s) events by
a novel technique that exploits the properties of the tracks associated to the
jet. The measured ratio is for events having a jet with
transverse momentum \pt > 20 \GeV and pseudorapidity , which
is the most precise to date and is consistent with theoretical predictions.Comment: Submitted to Phys. Rev. Let
Search for W'->tb resonances with left- and right-handed couplings to fermions
We present a search for the production of a heavy gauge boson, W', that
decays to third-generation quarks, by the D0 Collaboration in ppbar collisions
at sqrt(s)= 1.96 TeV. We set 95% confidence level upper limits on the
production cross section times branching fraction. For the first time, we set
limits for arbitrary combinations of left- and right-handed couplings of the W'
boson to fermions. For couplings with the same strength as the standard model W
boson, we set the following limits for M(W') > m(nu_R): M(W')>863 GeV for
purely left-handed couplings, M(W')>885 GeV for purely right-handed couplings,
and M(W')>916 GeV if both left- and right-handed couplings are present. The
limit for right-handed couplings improves for M(W') 890 GeV.Comment: 7 pages, 6 figures, submitted to Physics Letters
Volume I. Introduction to DUNE
The preponderance of matter over antimatter in the early universe, the dynamics of the supernovae that produced the heavy elements necessary for life, and whether protons eventually decay—these mysteries at the forefront of particle physics and astrophysics are key to understanding the early evolution of our universe, its current state, and its eventual fate. The Deep Underground Neutrino Experiment (DUNE) is an international world-class experiment dedicated to addressing these questions as it searches for leptonic charge-parity symmetry violation, stands ready to capture supernova neutrino bursts, and seeks to observe nucleon decay as a signature of a grand unified theory underlying the standard model. The DUNE far detector technical design report (TDR) describes the DUNE physics program and the technical designs of the single- and dual-phase DUNE liquid argon TPC far detector modules. This TDR is intended to justify the technical choices for the far detector that flow down from the high-level physics goals through requirements at all levels of the Project. Volume I contains an executive summary that introduces the DUNE science program, the far detector and the strategy for its modular designs, and the organization and management of the Project. The remainder of Volume I provides more detail on the science program that drives the choice of detector technologies and on the technologies themselves. It also introduces the designs for the DUNE near detector and the DUNE computing model, for which DUNE is planning design reports. Volume II of this TDR describes DUNE\u27s physics program in detail. Volume III describes the technical coordination required for the far detector design, construction, installation, and integration, and its organizational structure. Volume IV describes the single-phase far detector technology. A planned Volume V will describe the dual-phase technology
Deep Underground Neutrino Experiment (DUNE), far detector technical design report, volume III: DUNE far detector technical coordination
The preponderance of matter over antimatter in the early universe, the dynamics of the supernovae that produced the heavy elements necessary for life, and whether protons eventually decay—these mysteries at the forefront of particle physics and astrophysics are key to understanding the early evolution of our universe, its current state, and its eventual fate. The Deep Underground Neutrino Experiment (DUNE) is an international world-class experiment dedicated to addressing these questions as it searches for leptonic charge-parity symmetry violation, stands ready to capture supernova neutrino bursts, and seeks to observe nucleon decay as a signature of a grand unified theory underlying the standard model. The DUNE far detector technical design report (TDR) describes the DUNE physics program and the technical designs of the single- and dual-phase DUNE liquid argon TPC far detector modules. Volume III of this TDR describes how the activities required to design, construct, fabricate, install, and commission the DUNE far detector modules are organized and managed. This volume details the organizational structures that will carry out and/or oversee the planned far detector activities safely, successfully, on time, and on budget. It presents overviews of the facilities, supporting infrastructure, and detectors for context, and it outlines the project-related functions and methodologies used by the DUNE technical coordination organization, focusing on the areas of integration engineering, technical reviews, quality assurance and control, and safety oversight. Because of its more advanced stage of development, functional examples presented in this volume focus primarily on the single-phase (SP) detector module
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