1,278 research outputs found
Condutitvidade hisráulica do solo coeso dos tabuleiros costeiros cultivado com citros.
Avalia através da determinação da condutividade hidráulica não saturada, o movimento de água em agrissolo acinzentado coeso dos tabuleiros costeiros cultivado com citros.bitstream/CPATC/19569/1/bp-22.pdfISSN 1678-1961
A Tumbling Top-Quark Condensate Model
We propose a renormalizable model with no fundamental scalars which breaks
itself in the manner of a "tumbling" gauge theory down to the standard model
with a top-quark condensate. Because of anomaly cancellation requirements, this
model contains two color sextet fermions (quixes), which are vector-like with
respect to the standard model gauge group. The model also has a large number of
pseudo-Nambu-Goldstone bosons, some of which can be light. The top-quark
condensate is responsible for breaking the electroweak gauge symmetry and gives
the top quark a large mass. We discuss the qualitative features and instructive
shortcomings of the model in its present form. We also show that this model can
be naturally embedded into an aesthetically pleasing model in which the
standard model fermion families appear symmetrically.Comment: 16 pages. v2: TeX formatting fixed, no other change
Radiomics-Based Inter-Lesion Relation Network to Describe [18F]FMCH PET/CT Imaging Phenotypes in Prostate Cancer
Advanced image analysis, specifically radiomics, has been recognized as a potential source of biomarkers for cancers. However, there are challenges to its application in the clinic, such as proper description of diseases where multiple lesions coexist. In this study, we aimed to characterize the intra-tumor heterogeneity of metastatic prostate cancer using an innovative approach. This approach consisted of a transformation method to build a radiomic profile of lesions extracted from [18F]FMCH PET/CT images, a qualitative assessment of intra-tumor heterogeneity of patients, and a quantitative representation of the intra-tumor heterogeneity of patients in terms of the relationship between their lesions’ profiles. We found that metastatic prostate cancer patients had lesions with different radiomic profiles that exhibited intra-tumor radiomic heterogeneity and that the presence of many radiomic profiles within the same patient impacted the outcome
Minimal Trinification
We study the trinified model, SU(3)_C x SU(3)_L x SU(3)_R x Z_3, with the
minimal Higgs sector required for symmetry breaking. There are five Higgs
doublets, and gauge-coupling unification results if all five are at the weak
scale, without supersymmetry. The radiative see-saw mechanism yields sub-eV
neutrino masses, without the need for intermediate scales, additional Higgs
fields, or higher-dimensional operators. The proton lifetime is above the
experimental limits, with the decay modes p -> \bar\nu K^+ and p -> \mu^+ K^0
potentially observable. We also consider supersymmetric versions of the model,
with one or two Higgs doublets at the weak scale. The radiative see-saw
mechanism fails with weak-scale supersymmetry due to the nonrenormalization of
the superpotential, but operates in the split-SUSY scenario.Comment: 23 pages, uses axodra
Hadron Collider Signatures for New Interactions of Top and Bottom Quarks
One of the main goals for hadron colliders is the study of the properties of
the third generation quarks. We study the signatures for new TeV resonances
that couple to top or bottom quarks both at the Tevatron Run II and at the LHC.
We find that in the simplest production processes of Drell-Yan type at the
Tevatron, the signals are overwhelmed by QCD backgrounds. We also find that it
is possible to study these resonances when they are produced in association
with a pair of heavy quarks or in association with a single top at the LHC.In
particular, with an integrated luminosity of 300 fb at the LHC, it is
possible to probe resonance masses up to around 2 TeV.Comment: 24 pages, 15 figures, Minor corrections, version to appear in Phys.
Rev.
Scattering and self-adjoint extensions of the Aharonov-Bohm hamiltonian
We consider the hamiltonian operator associated with planar sec- tions of
infinitely long cylindrical solenoids and with a homogeneous magnetic field in
their interior. First, in the Sobolev space , we characterize all
generalized boundary conditions on the solenoid bor- der compatible with
quantum mechanics, i.e., the boundary conditions so that the corresponding
hamiltonian operators are self-adjoint. Then we study and compare the
scattering of the most usual boundary con- ditions, that is, Dirichlet, Neumann
and Robin.Comment: 40 pages, 5 figure
Many-nodes/many-links spinfoam: the homogeneous and isotropic case
I compute the Lorentzian EPRL/FK/KKL spinfoam vertex amplitude for regular
graphs, with an arbitrary number of links and nodes, and coherent states peaked
on a homogeneous and isotropic geometry. This form of the amplitude can be
applied for example to a dipole with an arbitrary number of links or to the
4-simplex given by the compete graph on 5 nodes. All the resulting amplitudes
have the same support, independently of the graph used, in the large j (large
volume) limit. This implies that they all yield the Friedmann equation: I show
this in the presence of the cosmological constant. This result indicates that
in the semiclassical limit quantum corrections in spinfoam cosmology do not
come from just refining the graph, but rather from relaxing the large j limit.Comment: 8 pages, 4 figure
Detecting the intermediate-mass Higgs boson through the associate production channel pp --> t + anti-t + H + X
We examine the detection of the intermediate-mass Higgs boson (IMH) at LHC
through the associate production channel pp-->t+(anti-t)+H+X-->l+photon+
photon+X'. It is shown that by applying kinematic cuts or b-tagging on the
final state jets, the main backgrounds of W(-->l+nu)+photon+photon+(n-jet) can
be reduced substantially without significant loss of signals. It is possible to
detect the Higgs boson at LHC through the pp-->t+(anti-t)+H+X channel using a
modest photon detector with mass resolution of about 3% of the photon pair
invariant mass.Comment: 10 pages, standard LaTex fil
Electroweak radiative corrections to deep-inelastic neutrino scattering - implications for NuTeV ?
We calculate the O(alpha) electroweak corrections to charged- and
neutral-current deep-inelastic neutrino scattering off an isoscalar target. The
full one-loop-corrected cross sections, including hard photonic corrections,
are evaluated and compared to an earlier result which was used in the NuTeV
analysis. In particular, we compare results that differ in input-parameter
scheme, treatment of real photon radiation and factorization scheme. The
associated shifts in the theoretical prediction for the ratio of neutral- and
charged-current cross sections can be larger than the experimental accuracy of
the NuTeV result.Comment: 19 pages late
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