On a relation between production processes and total cross sections

Perturbative QCD is the appropriate tool to describe many important properties of the inclusive observables measured at electron-proton (or ion) colliders, such as the energy dependence of the total cross sections in well-chosen kinematical regions. This is because the electron may effectively be replaced by its cloud of photons, whose virtualities provide a hard scale that enables perturbative expansions. At hadron colliders instead, there is no hard scale in the initial state. Therefore, the observables one may compute perturbatively involve the production of jets, and thus belong to a quite different class of observables. However, it turns out that there is a formal relation between production processes and total cross sections, enabling one to apply calculations of the latter to the former. We review this relation, and present our recent proof that it holds at next-to-leading order (in the BFKL sense).Comment: 7 pages; talk presented at the XXI international workshop on Deep-Inelastic Scattering and Related Subjects (DIS2013), Marseille, 22-26 April 2013, and at the ECT* workshop on high energy, high density and hot QCD, Trento, 17-21 June 201

Fractional Superspace Formulation of Generalized Super-Virasoro Algebras

We present a fractional superspace formulation of the centerless parasuper-Viraso-ro and fractional super-Virasoro algebras. These are two different generalizations of the ordinary super-Virasoro algebra generated by the infinitesimal diffeomorphisms of the superline. We work on the fractional superline parametrized by $t$ and $\theta$, with $t$ a real coordinate and $\theta$ a paragrassmann variable of order $M$ and canonical dimension $1/F$. We further describe a more general structure labelled by $M$ and $F$ with $M\geq F$. The case $F=2$ corresponds to the parasuper-Virasoro algebra of order $M$, while the case $F=M$ leads to the fractional super-Virasoro algebra of order $F$. The ordinary super-Virasoro algebra is recovered at $F=M=2$. The connection with $q$-oscillator algebras is discussed.Comment: 9 pages, McGill/92-30 (small corrections and elimination of the parameter "alpha"

Electroweak and Heavy Flavor Physics at SLD

We review recent electroweak and B physics results obtained in polarized e+e- interactions at the SLC by the SLD experiment. Unique and precise measurements of the electroweak parameters Ae, Ab, Ac, Rb and Rc provide powerful constraints on the Standard Model. The excellent 3-D vertexing capabilities of SLD are further exploited to extract precise B+ and B0 lifetimes, as well as measurements of the time evolution of B0-B0-bar mixing.Comment: 11 pages, 5 figures. Presented at the Workshop on Physics at the First Muon Collider and at the Front End of a Muon Collider, 6-9 November 1997, Fermilab, Batavia, I

Neutrino matter with PLANCK

After reviewing the main mechanisms by which cosmological measurements constrain the sum of neutrino masses, I give the current reached upper limits, emphasizing the level of model-dependence. A large improvement is to be expected with PLANCK's satellite data, on which I give some news, in particular due to the characterization of the CMB-lensing effect. It will however require a thorough control of many systematics effects upon which progress has been made recently.Comment: Invited Talk at Identification of Dark Matter 2010-IDM2010, July 26-30, 2010, Montpellier France. This paper has been temporarily withdrawn until it receives approval from the Planck Editorial Boar

Local extremality of the Calabi-Croke sphere for the length of the shortest closed geodesic

Recently, F. Balacheff proved that the Calabi-Croke sphere made of two flat 1-unit-side equilateral triangles glued along their boundaries is a local extremum for the length of the shortest closed geodesic among the Riemannian spheres with conical singularities of fixed area. We give an alternative proof of this theorem, which does not make use of the uniformization theorem, and extend the result to Finsler metrics

Can Rats Reason?

Since at least the mid-1980s claims have been made for rationality in rats. For example, that rats are capable of inferential reasoning (Blaisdell, Sawa, Leising, & Waldmann, 2006; Bunsey & Eichenbaum, 1996), or that they can make adaptive decisions about future behavior (Foote & Crystal, 2007), or that they are capable of knowledge in propositional-like form (Dickinson, 1985). The stakes are rather high, because these capacities imply concept possession and on some views (e.g., Rödl, 2007; Savanah, 2012) rationality indicates self-consciousness. I evaluate the case for rat rationality by analyzing 5 key research paradigms: spatial navigation, metacognition, transitive inference, causal reasoning, and goal orientation. I conclude that the observed behaviors need not imply rationality by the subjects. Rather, the behavior can be accounted for by noncognitive processes such as hard-wired species typical predispositions or associative learning or (nonconceptual) affordance detection. These mechanisms do not necessarily require or implicate the capacity for rationality. As such there is as yet insufficient evidence that rats can reason. I end by proposing the ‘Staircase Test,’ an experiment designed to provide convincing evidence of rationality in rats