Comment on the Updated CDF "Ghost" Events

In 2008 the CDF Collaboration announced the discovery of an excess of events with two or more muons, dubbed "ghost" events for their unusual properties. In a recent update, CDF finds that the azimuthal angle distribution between the primary (trigger) muons is significantly more back-to-back than that of all known sources of di-muon backgrounds. Here we show that this angular distribution cannot be reproduced in models where the muons are produced in the decays of relatively light X-particles: all models of this kind also predict a much broader distribution than that found by CDF. We conclude that the CDF measurement cannot be described via the annihilation of strongly interacting partons, and thus seems to be in conflict with basic tenets of QCD.Comment: 5 pages, 3 figure

Determination of the CMSSM Parameters using Neural Networks

In most (weakly interacting) extensions of the Standard Model the relation mapping the parameter values onto experimentally measurable quantities can be computed (with some uncertainties), but the inverse relation is usually not known. In this paper we demonstrate the ability of artificial neural networks to find this unknown relation, by determining the unknown parameters of the constrained minimal supersymmetric extension of the Standard Model (CMSSM) from quantities that can be measured at the LHC. We expect that the method works also for many other new physics models. We compare its performance with the results of a straightforward \chi^2 minimization. We simulate LHC signals at a center of mass energy of 14 TeV at the hadron level. In this proof-of-concept study we do not explicitly simulate Standard Model backgrounds, but apply cuts that have been shown to enhance the signal-to-background ratio. We analyze four different benchmark points that lie just beyond current lower limits on superparticle masses, each of which leads to around 1000 events after cuts for an integrated luminosity of 10 fb^{-1}. We use up to 84 observables, most of which are counting observables; we do not attempt to directly reconstruct (differences of) masses from kinematic edges or kinks of distributions. We nevertheless find that m_0 and m_{1/2} can be determined reliably, with errors as small as 1% in some cases. With 500 fb^{-1} of data tan\beta as well as A_0 can also be determined quite accurately. For comparable computational effort the \chi^2 minimization yielded much worse results.Comment: 46 pages, 10 figures, 4 tables; added short paragraph in Section 5 about the goodness of the fit, version to appear in Phys. Rev.

The Passage of Ultrarelativistic Neutralinos through the Matter of the Moon

I consider the prospect to use the outer layer of the Moon as a detector volume for ultra-high energy (UHE) neutrino fluxes and the flux of the lightest neutralino which I assume is the lightest supersymmetric particle (LSP). For this purpose, I calculate the event rates of these fluxes for top-down scenarios. I show that a suitable experiment for the detection of radio waves might be able to detect sufficient event rates after a measurement period of one year.Comment: 3 pages, 1 figure, to appear in the proceedings of 16th International Conference on Supersymmetry and the Unification of Fundamental Interactions (SUSY08), Seoul, Korea, June 16-21 200

About its emancipatory function and the status of interpretation in critical psychoanalysis

Indexación: Web of Science; ScieloEl psicoanálisis es una práctica plural, múltiple y abierta. Su diálogo con otras disciplinas no solamente constituye una contribución relevante al debate público contemporáneo, sino que se torna en exigencia indispensable en cuanto a su devenir como discurso interesado en librarse de la tutela o servidumbre con respecto a los saberes establecidos. En este artículo se aborda el ejercicio del psicoanálisis ligado a la práctica crítica en su sentido estricto, función crítica asociada a la correspondiente concepción de interpretación y a la práctica interpretativa que se vuelve posible a partir de ella. En la medida en que la interpretación se pretenda reveladora, conlleva la necesidad de problematizar las relaciones de poder que la condicionan y contextualizan, por lo mismo, en este análisis se postula que una ética psicoanalítica debe considerar estos elementos en la medida en que quiera efectuar una contribución al debate contemporáneo y, en particular, al proyecto emancipador del cual forma parte.Psychoanalysis is a plural, multiple and open practice. Its dialogue with other disciplines not only constitutes a relevant contribution to the present public debate, but is an indispensable exigency towards its own future as a discourse interested in getting rid of the trusteeship or servitude of established knowledge. In that sense, the exercise of psychoanalysis is bound to the critical practice in its strict sense. This critical function is associated to the corresponding conception of interpretation and the respective interpretative practice. Interpretation, insofar as it pretends to be truly revealing, entails the necessity to promote a judicious analysis of the relations of power that condition and contextualize it. A psychoanalytical ethics must consider these elements if it wants to make a contribution to the contemporary debate and particularly to the emancipatory project of which it is part.http://ref.scielo.org/54gcr

Das unheimliche. Presencia e incidencia de lo ominoso en el pensamiento de Freud y Foucault a propósito del problema de la interpretación y sus consecuencias para la conceptualización del sujeto.

Indexación: Revista UNABLo Ominoso es un concepto presente tanto en la obra escrita de Sigmund Freud como de Michel Foucault, susceptible de ser relacionado con una serie de conceptos «fundamentales», arraigados en las respectivas formulaciones teóricas. El presente trabajo, a partir de la consideración del concepto de interpretación, analiza sus consecuencias para la constitución subjetiva y el lugar en el cual el sujeto resultante queda ubicado con respecto al lenguaje.The Uncanny is a so much present concept in Sigmund Freud's written works as of Michel Foucault's, susceptible to be related to a series of so-called «fundamentabconcepts. established in the respective theoretical formulations. The present article, starting frorn the consideration of the concept of interpretation, analyzes its consequences for the subjective constitution and the place in which the resultant subject remains located with respect to language

Prospects for Indirect Detection of Sneutrino Dark Matter with IceCube

We investigate the prospects for indirect detection of right-handed sneutrino dark matter at the IceCube neutrino telescope in a $U(1)_{B-L}$ extension of the MSSM. The capture and annihilation of sneutrinos inside the Sun reach equilibrium, and the flux of produced neutrinos is governed by the sneutrino-proton elastic scattering cross section, which has an upper bound of $8 \times 10^{-9}$ pb from the $Z^{\prime}$ mass limits in the $B-L$ model. Despite the absence of any spin-dependent contribution, the muon event rates predicted by this model can be detected at IceCube since sneutrinos mainly annihilate into leptonic final states by virtue of the fermion $B-L$ charges. These subsequently decay to neutrinos with 100% efficiency. The Earth muon event rates are too small to be detected for the standard halo model irrespective of an enhanced sneutrino annihilation cross section that can explain the recent PAMELA data. For modified velocity distributions, the Earth muon events increase substantially and can be greater than the IceCube detection threshold of 12 events $\mathrm{km}^{-2}$ $\mathrm{yr}^{-1}$. However, this only leads to a mild increase of about 30% for the Sun muon events. The number of muon events from the Sun can be as large as roughly 100 events $\mathrm{km}^{-2}$ $\mathrm{yr}^{-1}$ for this model.Comment: 13 pages, 9 figures, replaced to match the published version, only minor changes: addition of one reference in section 5, correction of two typo

Fragments: On Violence

Indexación: Web of Science; Scielo.La violencia es un fenómeno ubicuo, cambiante y polimorfo. Su análisis requiere de una metodología plural, capaz de dar cuenta de sus singularidades. Se exploran las relaciones entre la violencia, el orden y la ley, con especial consideración de sus vínculos con el lenguaje y la lengua.Violence is an ubiquitous, changing and polymorphic phenomenon. Its analysis requires a plural methodology, that reflects their peculiarities. The relationship between violence, law and order, with special consideration of the links towards language and tongues are explored.http://ref.scielo.org/znzgy

Some considerations on violence. “Beyond” words

Indexación: Web of Science; ScieloResumen La violencia es un fenómeno contemporáneo, complejo y sobredeterminado. Su comprensión requiere un abordaje múltiple y transdisciplinario, en el que se combinen diferentes epistemes. Se aborda el problema de la violencia principalmente a partir de tres ejes: Primero, su relación con el lenguaje en general y con la etimología en particular. Segundo, su relación con la ley o el ámbito del Derecho. Tercero, su relación con el sujeto, respectivamente, con las teorías del sujeto. Finalmente, se plantea la necesidad y las dificultades de pensar en una alternativa cualitativamente diferente a una sociedad violenta.Abstract Violence is a contemporary, complex and overdetermined phenomenon. Its understanding requires a multi- and transdisciplinary approach, which combines several epistemes. The problem of violence is analyzed following three axes: First, its relationship to language in general and in particular to etymology. Second, its relationship to law or the area of law. Third, its relationship to the subject, respectively, to the theories of the subject. Finally, the necessity and difficulty of a qualitatively different alternative to a violent society is brought up.http://ref.scielo.org/5fkh8

¿MODERNIDAD HOLOCAUSTO?

Indexación: Web of Science; ScieloEl Holocausto a lo largo de las últimas décadas ha dado lugar a una serie de interpretaciones, en las cuales convergen disciplinas como la historiografía, la sociología, las ciencias políticas, la psicología, el psicoanálisis, etc. A través de la paulatina consolidación del correspondiente “conflicto de las interpretaciones” (Ricœur, 2003) se ha convertido en un punto nodal y sobredeterminado del debate contemporáneo. Entre los diferentes abordajes del Holocausto destaca una corriente que relaciona, de un modo por precisar, Holocausto con Modernidad. Dicha relación será revisada, al menos en algunos de sus aspectos, interrogándose sobre su exactitud y pertinencia