Search for the Anomalous Interactions of Up-Type Heavy Quarks in γγ\gamma \gamma Collision at the LHC

We investigate the anomalous interactions of heavy up-type quark t' in a $\gamma \gamma$ collision at the LHC. We have obtained 95% confidence level(CL)limit of $t'q \gamma$ anomalous coupling by taking into account three forward detector acceptances: $0.0015<\xi<0.15$,$0.0015<\xi<0.5$, and $0.1<\xi<0.5$.Comment: 16 pages, 3 figures, 3 table

Probe of the Anomalous Quartic Couplings with Beam Polarization at the CLIC

We have investigated the anomalous quartic couplings defined by the dimension-8 operators in semileptonic decay channel of the $e^{+}e^{-}\rightarrow \nu_{e} W^{-} W^{+} \bar{\nu}_{e}$ process for unpolarized and polarized electron (positron) beam at the Compact Linear Collider. We give the $95\%$ confidence level bounds on anomalous $\frac{f_{S0}}{\Lambda^{4}}$, $\frac{f_{S1}}{\Lambda^{4}}$ and $\frac{f_{T0}}{\Lambda^{4}}$ couplings for various values of the integrated luminosities and center-of-mass energies. The best sensitivities obtained on anomalous $\frac{f_{S0}}{\Lambda^{4}}$, $\frac{f_{S1}}{\Lambda^{4}}$ and $\frac{f_{T0}}{\Lambda^{4}}$ couplings through the process $e^{+}e^{-}\rightarrow \nu_{e} W^{-} W^{+} \bar{\nu}_{e}$ with beam polarization at $\sqrt{s}=3$ TeV and an integrated luminosity of $L_{int}=2000$ fb$^{-1}$ are $[-4.05;\, 3.67]\times 10^{-12}$ GeV$^{-4}$, $[-3.08; \, 2.12]\times 10^{-12}$ GeV$^{-4}$, $[-1.98; \, 0.64]\times 10^{-13}$ GeV$^{-4}$, which show improvement over the current bounds.Comment: 8 pages, 7 figures and 8 tables, published versio

Anomalous WWγWW\gamma couplings with beam polarization at the Compact Linear Collider

We study the anomalous $WW\gamma$ couplings at the Compact Linear Collider through the processes $e^{+}e^{-}\to W^+W^-$, $e^{-}e^{+} \to e^{-} \gamma^{*} e^{+} \to e^{+} \nu_{e} W^-$ and $e^{-}e^{+}\to e^{-} \gamma^{*} \gamma^{*} e^{+} \to e^{-} W^+ W^- e^{+}$ $(\gamma^{*}$ is the Weizsacker-Williams photon). We give the 95\% confidence level limits for unpolarized and polarized electron (positron) beam on the anomalous couplings for various values of the integrated luminosities and center-of-mass energies. We show that the obtained limits on the anomalous couplings through these processes can highly improve the current experimental limits. In addition, our limits with beam polarization are approximately two times better than the unpolarized case.Comment: Tables and references adde

The effect of electromagnetic properties of neutrinos on the photon-neutrino decoupling temperature

We examine the impact of electromagnetic properties of neutrinos on the annihilation of relic neutrinos with ultra high energy cosmic neutrinos for the $\nu \bar{\nu}\to \gamma\gamma$ process. For this process, photon-neutrino decoupling temperature is calculated via effective lagrangian model beyond the standard model. We find that photon-neutrino decoupling temperature can be importantly reduced below the QCD phase transition with the model independent analysis defining electromagnetic properties of neutrinos.Comment: 12 pages, 3 figures, published versio

Anticipation via canards in excitable systems

Neurons can anticipate incoming signals by exploiting a physiological mechanism that is not well understood. This article offers a novel explanation on how a receiver neuron can predict the sender’s dynamics in a unidirectionally-coupled configuration, in which both sender and receiver follow the evolution of a multi-scale excitable system. We present a novel theoretical viewpoint based on a mathematical object, called canard, to explain anticipation in excitable systems. We provide a numerical approach, which allows to determine the transient effects of canards. To demonstrate the general validity of canard-mediated anticipation in the context of excitable systems, we illustrate our framework in two examples, a multi-scale radio-wave circuit (the van der Pol model) that inspired a caricature neuronal model (the FitzHugh-Nagumo model) and a biophysical neuronal model (a 2-dimensional reduction of the Hodgkin-Huxley model), where canards act as messengers to the senders’ prediction. We also propose an experimental paradigm that would enable experimental neuroscientists to validate our predictions. We conclude with an outlook to possible fascinating research avenues to further unfold the mechanisms underpinning anticipation. We envisage that our approach can be employed by a wider class of excitable systems with appropriate theoretical extensions.ERC Advanced Grant NerVi no. 227747 Ikerbasque (The Basque Foundation for Science

Anomalous t

We have examined the constraints on the anomalous tqγ  (q=u,c) couplings through the process pp→pγp→pWbX at the LHC by considering four forward detector acceptances: 0.0015<ξ<0.5, 0.0015<ξ<0.15, 0.015<ξ<0.15, and 0.1<ξ<0.5, where ξ=Eγ/E with Eγ and E the energies of the photon and of the incoming proton, respectively. The sensitivity bounds on the anomalous couplings have been obtained at the 95% confidence level in a model independent effective Lagrangian approach. We have found that the bounds on these couplings can be highly improved compared to current experimental bounds

A search on the Nikiforov-Uvarov formalism

An alternative treatment is proposed for the calculations carried out within the frame of Nikiforov-Uvarov method, which removes a drawback in the original theory and by pass some difficulties in solving the Schrodinger equation. The present procedure is illustrated with the example of orthogonal polynomials. The relativistic extension of the formalism is discussed.Comment: 10 page

Derailer: interactive security analysis for web applications

Derailer is an interactive tool for finding security bugs in web applications. Using symbolic execution, it enumerates the ways in which application data might be exposed. The user is asked to examine these exposures and classify the conditions under which they occur as security-related or not; in so doing, the user effectively constructs a specification of the application's security policy. The tool then highlights exposures missing security checks, which tend to be security bugs. We have tested Derailer's scalability on several large open-source Ruby on Rails applications. We have also applied it to a large number of student projects (designed with different security policies in mind), exposing a variety of security bugs that eluded human reviewers.National Science Foundation (U.S.) (Grant 0707612

Two Electrons in a Quantum Dot: A Unified Approach

Low-lying energy levels of two interacting electrons confined in a two-dimensional parabolic quantum dot in the presence of an external magnetic field have been revised within the frame of a novel model. The present formalism, which gives closed algebraic solutions for the specific values of magnetic field and spatial confinement length, enables us to see explicitly individual effects of the electron correlation.Comment: 14 page