Exploiting the directional sensitivity of the Double Chooz near detector

In scintillator detectors, the forward displacement of the neutron in the reaction $\bar\nu_e+p\to e^++n$ provides neutrino directional information as demonstrated by the CHOOZ reactor experiment with 2,500 events. The near detector of the forthcoming Double Chooz experiment will collect $1.6\times10^5$ events per year, enough to determine the average neutrino direction with a $1 \sigma$ half-cone aperture of $2.3^\circ$ in one year. It is more difficult to separate the two Chooz reactors that are viewed at a separation angle $\phi=30^\circ$. If their strengths are known and approximately equal, the azimuthal location of each reactor is obtained with $\pm6^\circ$ ($1 \sigma$) and the probability of confusing them with a single source is less than 11%. Five year's data reduce this ``confusion probability'' to less than 0.3%, i.e., a $3 \sigma$ separation is possible. All of these numbers improve rapidly with increasing angular separation of the sources. For a setup with $\phi=90^\circ$ and one year's data, the azimuthal $1 \sigma$ uncertainty for each source decreases to $\pm3.2^\circ$. Of course, for Double Chooz the two reactor locations are known, allowing one instead to measure their individual one-year integrated power output to $\pm11$ ($1 \sigma$), and their five-year integrated output to $\pm4.8$ ($1 \sigma$).Comment: 7 pages, 10 figure

Neutrino Physics: Open Theoretical Questions

We know that neutrino mass and mixing provide a window to physics beyond the Standard Model. Now this window is open, at least partly. And the questions are: what do we see, which kind of new physics, and how far "beyond"? I summarize the present knowledge of neutrino mass and mixing, and then formulate the main open questions. Following the bottom-up approach, properties of the neutrino mass matrix are considered. Then different possible ways to uncover the underlying physics are discussed. Some results along the line of: see-saw, GUT and SUSY GUT are reviewed.Comment: 17 pages, latex, 12 figures. Talk given at the XXI International Symposium on Lepton and Photon Interactions at High Energies, ``Lepton Photon 2003", August 11-16, 2003 - Fermilab, Batavia, IL US

Resonance phenomena in discrete systems with bichromatic input signal

We undertake a detailed numerical study of the twin phenomena of stochastic and vibrational resonance in a discrete model system in the presence of bichromatic input signal. A two parameter cubic map is used as the model that combines the features of both bistable and threshold settings. Our analysis brings out several interesting results, such as, the existence of a cross over behaviour from vibrational to stochastic resonance and the possibility of using stochastic resonance as a filter for the selective detection/transmission of the component frequencies in a composite signal. The study also reveals a fundamental difference between the bistable and threshold mechanisms with respect to amplification of a multi signal input.Comment: 17 pages, 16 figures, submitted to European Physical Journa

A Formalism for Scattering of Complex Composite Structures. 1 Applications to Branched Structures of Asymmetric Sub-Units

We present a formalism for the scattering of an arbitrary linear or acyclic branched structure build by joining mutually non-interacting arbitrary functional sub-units. The formalism consists of three equations expressing the structural scattering in terms of three equations expressing the sub-unit scattering. The structural scattering expressions allows a composite structures to be used as sub-units within the formalism itself. This allows the scattering expressions for complex hierarchical structures to be derived with great ease. The formalism is furthermore generic in the sense that the scattering due to structural connectivity is completely decoupled from internal structure of the sub-units. This allows sub-units to be replaced by more complex structures. We illustrate the physical interpretation of the formalism diagrammatically. By applying a self-consistency requirement we derive the pair distributions of an ideal flexible polymer sub-unit. We illustrate the formalism by deriving generic scattering expressions for branched structures such as stars, pom-poms, bottle-brushes, and dendrimers build out of asymmetric two-functional sub-units.Comment: Complete rewrite generalizing the formalism to arbitrary functional sub-units and including a new Feynmann like diagrammatic interpretatio

A Universal Action Formula

A universal formula for an action associated with a noncommutative geometry, defined by a spectal triple (\Ac ,\Hc ,D), is proposed. It is based on the spectrum of the Dirac operator and is a geometric invariant. The new symmetry principle is the automorphism of the algebra \Ac which combines both diffeomorphisms and internal symmetries. Applying this to the geometry defined by the spectrum of the standard model gives an action that unifies gravity with the standard model at a very high energy scale.Comment: This is a short non technical letter based on the longer version, hep-th/9606001. Tex file, 10 page

Dynamical Gauge Symmetry Breaking in SU(3)L⊗U(1)XSU(3)_L\otimes U(1)_X Extension of the Standard Model

We study the $SU(3)_L\otimes U(1)_X$ extension of the Standard model with a strong U(1) coupling. We argue that current experiments limit this coupling to be relatively large. The model is dynamically broken to the Standard $SU(2)_L \otimes U(1)$ model at the scale of a few TeV with all the extra gauge bosons and the exotic quarks acquiring masses much larger than the scale of electroweak symmetry breaking. Furthermore we find that the model leads to large dynamical mass of the top quark and hence also breaks the electroweak gauge symmetry. It therefore leads to large dynamical effects within the Standard model and can partially replace the Higgs interactions.Comment: 4 pages, revtex, no figures; revised version predicting realistic mass spectru