Worldlines on Orbifolds and the Fayet-Iliopoulos Term

We adapt ``string-inspired'' worldline techniques to one-loop calculations on orbifolds, in particular on the $S^1/Z_2$ orbifold. Our method also allows for the treatment of brane-localized terms, or bulk-brane couplings. For demonstration, we reproduce the well-known result for the one-loop induced Fayet-Iliopoulos term in rigidly supersymmetric Abelian gauge theory, and generalize it to the case where soft supersymmetry breaking mass terms for the bulk scalar fields are present on the branes.Comment: Typos corrected, clarifying remarks adde

Online Signature Verification: Improving Performance through Pre-classification Based on Global Features

In this paper, a pre-classification stage based on global features is incorporated to an online signature verification system for the purposes of improving its performance. The pre-classifier makes use of the discriminative power of some global features to discard (by declaring them as forgeries) those signatures for which the associated global feature is far away from its respective mean. For the remaining signatures, features based on a wavelet approximation of the time functions associated with the signing process, are extracted, and a Random Forest based classification is performed. The experimental results show that the proposed pre-classification approach, when based on the apppropriate global feature, is capable of getting error rate improvements with respect to the case where no pre-classification is performed. The approach also has the advantages of simplifying and speeding up the verification process.Fil: Parodi, Marianela. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico - CONICET - Rosario. Centro Internacional Franco Argentino de Ciencias de la Información y Sistemas; ArgentinaFil: Gómez, Juan Carlos. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico - CONICET - Rosario. Centro Internacional Franco Argentino de Ciencias de la Información y Sistemas; Argentin

Holographic metastability

We show how supersymmetric QCD in a slice of AdS can naturally acquire metastable vacua. The formulation closely follows that of Intriligator, Seiberg and Shih (ISS), with an "electric" sector on the UV brane and a "magnetic" sector on the IR brane. However the 't Hooft anomaly matching that constrains the Seiberg duality central to ISS is replaced by anomaly inflow and cancellation, and the source of strong coupling is the CFT to which the theory couples rather than the gauge groups. The theory contains an anomaly free R-symmetry that, when broken by UV effects, leads to an O'Raifeartaigh model on the IR brane. In contrast to ISS, the R-symmetry breaking in the UV can be maximal, and yet the R-symmetry breaking in the IR theory remains under strict control: there is no need for retrofitting of small parameters.Comment: 20 pages, 2 figure

Second T = 3/2 state in 9^9B and the isobaric multiplet mass equation

Recent high-precision mass measurements and shell model calculations~[Phys. Rev. Lett. {\bf 108}, 212501 (2012)] have challenged a longstanding explanation for the requirement of a cubic isobaric multiplet mass equation for the lowest $A = 9$ isospin quartet. The conclusions relied upon the choice of the excitation energy for the second $T = 3/2$ state in $^9$B, which had two conflicting measurements prior to this work. We remeasured the energy of the state using the $^9{\rm Be}(^3{\rm He},t)$ reaction and significantly disagree with the most recent measurement. Our result supports the contention that continuum coupling in the most proton-rich member of the quartet is not the predominant reason for the large cubic term required for $A = 9$ nuclei