8,480 research outputs found
The Neron-Severi group of a proper seminormal complex variety
We prove a Lefschetz (1,1)-Theorem for proper seminormal varieties over the
complex numbers. The proof is a non-trivial geometric argument applied to the
isogeny class of the Lefschetz 1-motive associated to the mixed Hodge structure
on H^2.Comment: 16 pages; Mathematische Zeitschrift (2008
A diversidade de abóboras no Brasil e sua relação histórica com a cultura.
bitstream/item/55401/1/15423.pdfDisponível em: http://www.slowfoodbrasil.com/textos/alimentacao-e-cultura/501-aboboras-e-cultura. Acesso em: 08 mar. 2012
O potencial da diversificação no cultivo das frutas nativas.
bitstream/item/59073/1/nativas-Lia.pd
Supersymmetry phenomenology beyond the MSSM after 5/fb of LHC data
We briefly review the status of motivated beyond-the-MSSM phenomenology in
the light of the LHC searches to date. In particular, we discuss the conceptual
consequences of the exclusion bounds, of the hint for a Higgs boson at about
125 GeV, and of interpreting the excess of direct CP violation in the charm
sector as a signal of New Physics. We try to go into the various topics in a
compact way while providing a relatively rich list of references, with
particular attention to the most recent developments.Comment: 20 pages + refs. v2: minor modifications, published versio
PhysioNet 2012 Challenge: Predicting mortality of ICU patients using a cascaded SVM-GLM paradigm
The focus of the PhysioNet/CinC Challenge 2012 is to develop methods for patient-specific prediction of inhospital mortality using general descriptors recorded at the time of admission to the ICU and up to 37 time-series measurements collected during the first 48 hours after admission. We developed an algorithm that uses both general descriptors and time-series measurements to predict the in-hospital death (IHD) of ICU patients in Event 1, and to provide a probability estimate of IHD in Event 2. Both aggregated variables and general descriptors were used as features of quadratic Support Vector Machine (SVM) classifiers. Six SVMs were trained using, for each one, all the positive examples plus, in turn, one sixth of the negative examples in the training set. Finally, a Generalized Linear Model with probit link was used to predict the probability of IHD for Event 2 using the raw outputs of the six SVMs as regressors. A positive binary prediction of IHD for Event 1 was made when the probability estimate was higher than an optimized threshold. Official final results of the challenge reported that our entry achieved an Event 2 score of 17.88, which is the best score out of the total 23 submissions, and Event 1 score of 0.5345 (second best score). © 2012 CCAL
New Physics and CP Violation in Singly Cabibbo Suppressed D Decays
We analyze various theoretical aspects of CP violation in singly Cabibbo
suppressed (SCS) D-meson decays, such as . In particular, we
explore the possibility that CP asymmetries will be measured close to the
present level of experimental sensitivity of . Such measurements
would signal new physics. We make the following points: (i) The mechanism at
work in neutral D decays could be indirect or direct CP violation (or both).
(ii) One can experimentally distinguish between these possibilities. (iii) If
the dominant CP violation is indirect, then there are clear predictions for
other modes. (iv) Tree-level direct CP violation in various known models is
constrained to be much smaller than . (v) SCS decays, unlike Cabibbo
favored or doubly Cabibbo suppressed decays, are sensitive to new contributions
from QCD penguin operators and especially from chromomagnetic dipole operators.
This point is illustrated with supersymmetric gluino-squark loops, which can
yield direct CP violating effects of .Comment: 36 pages, 5 figure
Lepton flavor violation in the supersymmetric standard model with vectorlike leptons
Lepton flavor violating processes are obtained from the mixing between
ordinary leptons and vectorlike SU(2)_L doublet leptons which may originate in
E_6. The effects of this lepton mixing are, however, suppressed naturally by
the hierarchy of the charged lepton masses. In the supersymmetric model,
significant effects of lepton flavor violation may appear rather through
slepton mixing, which is in the present case generated by radiative corrections
with ordinary-exotic lepton couplings. We are especially interested in the mu
-> e gamma decay. In the model without the bare mass term of vectorlike
leptons, the supersymmetric contributions are rather suppressed due to the
approximate U(1)_e X U(1)_mu. It is, however, remarkable that they are
substantially enhanced by tan^6 beta. Then, B(mu -> e gamma) might be
comparable to the experimental bound for large tan beta. In the model with the
bare mass term, much larger contributions are obtained through slepton mixing.
These investigations show that the supersymmetric effects on lepton flavor
violation due to the vectorlike leptons can be observed in the near future
experiments.Comment: 25 pages, 5 figures, comments about K0-K0bar mixing adde
Pimentas - muitos tipos, muitas opções.
bitstream/CPACT-2010/12305/1/pimenta-Barbieri.pdfPublicado nos sites: Cultivar, em 08/12/2009, Jornal Diário da Manhã, em 09/12/2009, Portal do Agronegócio, em 09/12/2009, Agronline, em 09/12/2009 e no Infobibos, em 11/12/2009
Logarithmic SUSY electroweak effects on four-fermion processes at TeV energies
We compute the MSSM one-loop contributions to the asymptotic energy behaviour
of fermion-antifermion pair production at future lepton-antilepton colliders.
Besides the conventional logarithms of Renormalization Group origin, extra SUSY
linear logarithmic terms appear of "Sudakov-type". In the TeV range their
overall effect on a variety of observables can be quite relevant and
drastically different from that obtained in the SM case.Comment: 19 pages and 14 figures, corrected version. e-mail:
[email protected]
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