On the meaning of the minimal Wess-Zumino term

The physical meaning of the recently proposed minimal Wess-Zumino (MWZ) term is discussed. It is shown that the only relativistically acceptable MWZ corresponds to a gauged Floreanini-Jackiw chiral boson. This leads to the conclusion that the very mechanism in action is that of closing families like it happens in the standard model, and not that of the WZ term, in the spirit of Faddeev-Shatashvilli.

Anelastic relaxation due to OH pairs in NbZr alloys

In the last 30 years several studies have been made to understand the relaxation mechanisms of the hydrogen atoms present in transition metals and their alloys. In this work, we observed the stress-induced ordering of hydrogen atoms around the interstitial oxygen atoms near the niobium matrix atoms. We studied this relaxation process by measuring the attenuation of longitudinal ultrasonic waves. These measurements were made in Nb1.0%Zr polycrystalline alloys at 10 and 30 MHz, pure and doped with 0.7 and 4.2 at.% hydrogen. The results revealed a thermally activated relaxation structure around 202 K and 235 K for 10 MHz and 30 MHz respectively. This relaxation structure increases with increasing hydrogen concentration. © 1994.

The δ expansion and the principle of minimal sensitivity

The δ-expansion is a nonperturbative approach for field theoretic models which combines the techniques of perturbation theory and the variational principle. Different ways of implementing the principle of minimal sensitivity to the δ-expansion produce in general different results for observables. For illustration we use the Nambu-Jona-Lasinio model for chiral symmetry restoration at finite density and compare results with those obtained with the Hartree-Fock approximation.

Bell inequalities for entangled pairs of neutral kaons

We extend the use of Bell inequalities to Φ → K0K̄0 decays by exploiting analogies and differences to the well-known and experimentally verified singlet-spin case. Contrasting with other analyses, our Bell inequalities are violated by quantum mechanics and can strictly be derived from local realistic theories. In principle, quantum mechanics could then be tested using unstable, oscillating states governed by a CP-violating Hamiltonian. © 1999 The American Physical Society.

Direct signals for large extra dimensions in the production of fermion pairs at linear colliders

We analyze the potential of the next generation of e+e- linear colliders to search for large extra dimensions via the production of fermion pairs in association with Kaluza-Klein gravitons (G), i.e., e+e- →ff̃G. This process leads to a final state exhibiting a significant amount of missing energy in addition to acoplanar lepton or jet pairs. We study in detail this reaction using the full tree level contributions due to the graviton emission and the standard model backgrounds. After choosing the cuts to enhance the signal, we show that a linear collider with a center-of-mass energy of 500 GeV will be able to probe quantum gravity scales from 0.96 (0.86) up to 4.1 (3.3) TeV at a 2 (5)σ level, depending on the number of extra dimensions. ©2001 The American Physical Society.

Comparative analysis of noncoding sequences of orthologous bovine and human gene pairs

Genomic sequence comparison across species has enabled the elucidation of important coding and regulatory sequences encoded within DNA. Of particular interest are the noncoding regulatory sequences, which influence gene transcriptional and posttranscriptional processes. A phylogenetic footprinting strategy was employed to identify noncoding conservation patterns of 39 human and bovine orthologous genes. Seventy-three conserved noncoding sequences were identified that shared greater than 70% identity over at least 100 bp. Thirteen of these conserved sequences were also identified in the mouse genome. Evolutionary conservation of noncoding sequences across diverse species may have functional significance, and these conserved sequences may be good candidates for regulatory elements.

Minimal cross-subsidies approach for loss allocation in distribution networks with open access

Open access philosophy applied by regulatory agencies may lead to a scenario where captive consumers will solely face the responsibility on distribution network's losses even with Independent Energy Producers (also known as Distributed Generation) and Independent Energy Consumers connected to the system. This work proposes the utilization of a loss allocation method in distribution systems where open access is allowed, in which cross-subsidies, that appear due to the influence the generators have over the system losses, are minimized. Thus, guaranteeing to some extent the efficiency and transparency of the economic signals of the market. Results obtained through the Zbus loss allocation method adapted for distribution networks are processed in such a way that the corresponding allocation to the generation buses is divided among the consumer buses, while still considering consumers spatial characteristics. © 2007 IEEE.

Search for long-lived particles decaying into electron or photon pairs with the D0 detector

In this Letter we report on a search for long-lived particles that decay into final states with two electrons or photons. Such long-lived particles arise in a variety of theoretical models, such as hidden valleys and supersymmetry with gauge-mediated breaking. By precisely reconstructing the direction of the electromagnetic shower we are able to probe much longer lifetimes than previously explored. We see no evidence of the existence of such long-lived particles and interpret this search as a quasi model-independent limit on their production cross section, as well as a limit on a long-lived fourth generation quark. © 2008 The American Physical Society.

RBF circuits based on folded cascode differential pairs

We propose new circuits for the implementation of Radial Basis Functions such as Gaussian and Gaussian-like functions. These RBFs are obtained by the subtraction of two differential pair output currents in a folded cascode configuration. We also propose a multidimensional version based on the unidimensional circuits. SPICE simulation results indicate good functionality. These circuits are intended to be applied in the implementation of radial basis function networks. One possible application of these networks is transducer signal conditioning in aircraft and spacecraft vehicles onboard telemetry systems. Copyright 2008 ACM.

The gyromagnetic factor of elementary particles and non-minimal coupling

In this work we investigate a possible magnetic moment generation for massive neutral particles with spins-1 and -2 coupled non-minimally, in a specific way, to an external electromagnetic field. It is found that, in the nonrelativistic limit, these particles present g = 1. This result, worked out in the framework of Relativistic Quantum Mechanics, seems to suggest that g = 1 for all massive and neutral particles of any spin ≤ 2. We also compare with the results obtained for massive charged particles of spins-1 and -2, in the same regime (nonrelativistic), in order to investigate the role played by the spin separetely from the charge. Copyright © owned by the author(s) under the terms of the Creative Commons Attribution-NonCommercial-ShareAlike Licence.

Search for a resonance decaying into WZ boson Pairs in pp̄ collisions

We present the first search for an electrically charged resonance W′ decaying to a WZ boson pair using 4.1fb-1 of integrated luminosity collected with the D0 detector at the Fermilab Tevatron pp̄ collider. The WZ pairs are reconstructed through their decays into three charged leptons (≤=e, μ). A total of 9 data events is observed in good agreement with the background prediction. We set 95% C.L. limits on the W′WZ coupling and on the W′ production cross section multiplied by the branching fractions. We also exclude W′ masses between 188 and 520 GeV within a simple extension of the standard model and set the most restrictive limits to date on low-scale technicolor models. © 2010 The American Physical Society.

Radial basis function circuits using folded cascode differential pairs

In this paper, we propose new circuits for the implementation of Radial Basis Functions (RBF). These RBFs are obtained by the subtraction of two differential pair output currents in a folded cascode configuration. We also propose a multidimensional version based on the unidimensional circuits. SPICE simulation and experimental results indicate good functionality. These circuits are intended to be applied in the implementation of radial basis function networks. Possible applications of these networks include transducer signal conditioning and processing in onboard telemetry systems for aircraft and spacecraft vehicles. © 2010 IEEE.

The higgs boson mass in minimal technicolor models

Recently a Minimal and an Ultraminimal Technicolor models were proposed where the presence of TC fermions in other representations than the fundamental one led to viable models without conflict with the known value for the measured S parameter. In this work we apply the results of [5] to compute the masses of the Higgs boson in the case of the Minimal and Ultraminimal Technicolor models. © 2010 American Institute of Physics.

Some remarks about Poincaré duality pairs

Bieri-Eckmann [6] introduced the concept of relative cohomology for a group pair (G, S), where G is a group and S is a family of subgroups of G and, by using that theory, they introduced the concept of Poincaré duality pairs (G, S) and provided a topological interpretation for such pairs through Eilenberg-MacLane pairs K(G, S, 1). A Poincaré duality pair is a pair (G, S) that satisfies two isomorphisms, one between absolute cohomology and relative homology and the second between relative cohomology and absolute homology. In this paper, we present a proof that those two isomorphisms are equivalent. We also present some calculations on duality pairs by using the cohomological invariant defined in [1] and studied in [2-4]. © 2012 Pushpa PublishingHouse.

Forward-backward asymmetry of Drell-Yan lepton pairs in pp collisions at s=7TeV

A measurement of the forward-backward asymmetry (AFB) of Drell-Yan lepton pairs in pp collisions at s=7TeV is presented. The data sample, collected with the CMS detector, corresponds to an integrated luminosity of 5fb-1. The asymmetry is measured as a function of dilepton mass and rapidity in the dielectron and dimuon channels. Combined results from the two channels are presented, and are compared with the standard model predictions. The AFB measurement in the dimuon channel and the combination of the two channels are the first such results obtained at a hadron collider. The measured asymmetries are consistent with the standard model predictions. © 2012 CERN.