Aharonov-Bohm Scattering, Contact Interactions and Scale Invariance

We perform a perturbative analysis of the Aharonov-Bohm problem to one loop in a field-theoretic formulation, and show that contact interactions are necessary for renormalizability. In general, the classical scale invariance of this problem is broken quantum mechanically. There exists however a critical point for which this anomaly disappears.Comment: 9 pages, TEX, CTP#218

Relativistic Quantum Scattering of High Energy Fermions in the Presence of Phase Transition

We study the high energy behaviour of fermions hitting a general wall caused by a first-order phase transition. The wall profile is introduced through a general analytic function. The reflection coefficient is computed in the high energy limit and expressed in terms of the poles of the wall profile function. It is shown that the leading singularity gives the high energy behaviour.Comment: 10 page

Hints of 5d Fixed Point Theories from Non-Abelian T-duality

In this paper we investigate the properties of the putative 5d fixed point theory that should be dual, through the holographic correspondence, to the new supersymmetric AdS(6) solution constructed in Lozano et al. This solution is the result of a non-Abelian T-duality transformation on the known supersymmetric AdS(6) solution of massive Type IIA. The analysis of the charge quantization conditions seems to put constraints on the global properties of the background, which, combined with the information extracted from considering probe branes, suggests a 2-node quiver candidate for the dual CFT.Comment: v2, typos corrected, comments added, to appear in JHE

Supersymmetric AdS_6 via T-duality

We present a new supersymmetric AdS_6 solution of type IIB supergravity with SU(2) isometry. Through the AdS/CFT correspondence, this has potentially very interesting implications for 5d fixed point theories. This solution is the result of a non-Abelian T-duality on the known supersymmetric AdS_6 solution of massive IIA. The SU(2) R-symmetry is untouched, leading to sixteen supercharges and preserved supersymmetry.Comment: 4 pages, published versio

Experimental scheme for unambiguous discrimination of linearly independent symmetric states

We propose an optimal discrimination scheme for a case of four linearly independent nonorthogonal symmetric quantum states, based on linear optics only. The probability of discrimination is in agreement with the optimal probability for unambiguous discrimination among N symmetric states [Phys. Lett. A \textbf{250}, 223 (1998)]. The experimental setup can be extended for the case of discrimination among $2^M$ nonorthogonal symmetric quantum states

Displaced vertices and long-lived charged particles in the NMSSM with right-handed sneutrinos

We study LHC signatures of displaced vertices and long-lived charged particles within the context of the Next-to-Minimal Supersymmetric Standard Model with right-handed (RH) sneutrinos. In this construction the RH neutrino can be produced directly from Higgs decays or in association with a RH sneutrino when the latter is the lightest supersymmetric particle. The RH neutrino is generally long-lived, since its decay width is proportional to the neutrino Yukawa, a parameter which is predicted to be small. The RH neutrino late decay can therefore give rise to displaced vertices at the LHC, which can be identified through the decay products, which involve two leptons (2ℓ + https://static-content.springer.com/image/art%3A10.1007%2FJHEP05%282014%29035/MediaObjects/13130_2014_8145_Figa_HTML.gifT ) or a lepton with two jets (ℓjj). We simulate this signal for the current LHC configuration (a centre of mass of 8 TeV and an integrated luminosity of LL = 20 fb−1), and a future one (13 TeV and LL = 100 fb−1). We show that a region of the parameter space of this model can be probed and that the RH neutrino mass can be reconstructed from the end-point of the two-lepton invariant mass distribution or the central value of the mass distribution for two jets plus one lepton. Another exotic signature of this construction is the production of a long-lived stau. If the stau is the next-to-lightest supersymmetric particle, it can decay through diagrams involving the small neutrino Yukawa, and would escape the detector leaving a characteristic trail. We also simulate this signal for various benchmark points and show that the model can be within the reach of the future run of the LHC

Concepciones y actitudes hacia el aprendizaje de las matem?ticas en los estudiantes de grado sexto en la instituci?n educativa colegio de San Sim?n Ibagu? Tolima

154 p. Recurso Electr?nicoEl presente proyecto de investigaci?n est? orientado a indagar sobre las concepciones y actitudes que inciden en el aprendizaje de las matem?ticas en los estudiantes de la instituci?n educativa colegio de San Sim?n del municipio de Ibagu?, as? mismo, se pretende plantear una estrategia did?ctica que a partir de criterios claros, definidos y generalizados fundamente procesos de cambio en relaci?n a las ideolog?as y visiones distorsionadas que se encuentran fuertemente arraigadas en el accionar acad?mico de dicha ?rea de conocimiento. Por otro lado, dentro del enfoque cualitativo de la investigaci?n el dise?o se basa, en un an?lisis de contenido, frente a los tipos de acercamiento y la relaci?n directa que existe entre la intervenci?n del docente, como en la participaci?n de los estudiantes en procesos de aprendizaje de las matem?ticas, para lo cual, se realiz? una triangulaci?n de enfoques en instrumentos de recolecci?n de datos, con la finalidad de que sustente una informaci?n profunda frente a la problem?tica, es decir, a trav?s de ello se pretende estudiar a fondo los factores que sujetan una mala adaptaci?n, apropiaci?n y adecuaci?n de los conocimientos matem?ticos. Como resultado, se observa que en el accionar pedag?gico se encuentra a?n inmersos enfoques tradicionalistas y conductistas en relaci?n a los procesos de ense?anza del docente, los cuales pueden tener su lugar de relevancia en la asignaci?n de concepciones y actitudes propias de las estructuras mentales de los estudiantes que impiden un aprendizaje significativo de las matem?ticas. Como conclusi?n, se evidencia que el origen de las concepciones y actitudes arraigadas en el accionar de los estudiantes hacia el aprendizaje de las matem?ticas, parte de la mediaci?n que realiza el docente en el sal?n de clases como de la ideolog?a construida socialmente.This research project is aimed to investigate the design and attitudes that affect the learning of mathematics in students of the educational Institution College of S?n. Simon of the city of Ibague, also, is intended to raise a teaching strategy that from clear, defined and criteria substantiate widespread processes of change in relation to ideologies and distorted views that are strongly rooted in the academic actions of this area of knowledge. On the other hand, within the qualitative research approach design is based on an analysis of content, compared to the types of approach and the direct relationship between the intervention of the teacher, and the student participation in processes learning mathematics , for which a triangulation approach was made into instruments of data collection , in order that sustains a deep information against the problem , that is, through it is to study in depth the factors maladaptive holding, appropriation and adaptation of mathematical knowledge. As a result, we see that in the pedagogical action is still engaged traditionalists and behavioral approaches regarding the teaching of teachers, which may have their place of importance in the allocation of conceptions and attitudes of mental structures students prevent meaningful learning of mathematics. In conclusion, it is evident that the origin of the conceptions and attitudes rooted in the actions of the students towards learning mathematics, part of the mediation carried out by the teacher in the classroom as socially constructed ideology. Keyswords: Attitude, Design, Mathematics, Learning, Teaching strategy, Teaching practice, Cultural ideology

Structure of the Effective Potential in Nonrelativistic Chern-Simons Field Theory

We present the scalar field effective potential for nonrelativistic self-interacting scalar and fermion fields coupled to an Abelian Chern-Simons gauge field. Fermions are non-minimally coupled to the gauge field via a Pauli interaction. Gauss's law linearly relates the magnetic field to the matter field densities; hence, we also include radiative effects from the background gauge field. However, the scalar field effective potential is transparent to the presence of the background gauge field to leading order in the perturbative expansion. We compute the scalar field effective potential in two gauge families. We perform the calculation in a gauge reminiscent of the $R_\xi$-gauge in the limit $\xi\rightarrow 0$ and in the Coulomb family gauges. The scalar field effective potential is the same in both gauge-fixings and is independent of the gauge-fixing parameter in the Coulomb family gauge. The conformal symmetry is spontaneously broken except for two values of the coupling constant, one of which is the self-dual value. To leading order in the perturbative expansion, the structure of the classical potential is deeply distorted by radiative corrections and shows a stable minimum around the origin, which could be of interest when searching for vortex solutions. We regularize the theory with operator regularization and a cutoff to demonstrate that the results are independent of the regularization scheme.Comment: 24 pages, UdeM-LPN-TH-93-185, CRM-192