SUSY mass reconstruction methods in ATLAS

International audienceMethods to measure the sparticle masses with the ATLAS detector at the LHC are reported. The supersymmetric phenomenology is first briefly discussed in the context of the mSUGRA constrained model. Many examples of recent studies aiming at measuring the sparticle masses are then described. Most of these examples are based on recent full simulation of the ATLAS detector

CKM Matrix: Status and New Developments

An analysis of the CKM matrix parameters within the {\it R}fit approach is presented using updated input values with special emphasis on the recent $\sin{2\beta}$ measurements from BABAR and Belle. The QCD Factorisation Approach describing $B \to \pi\pi,K\pi$ decays has been implemented in the software package CKMfitter. Fits using branching ratios and CP asymmetries are discussed.Comment: 5 pages, 6 postscript figures, contribution to the proceedings of the 9th International Symposium on Heavy Flavour Physics, September 2001, Pasadena, US

A New Approach to a Global Fit of the CKM Matrix

We report on a global CKM matrix analysis taking into account most recent experimental and theoretical results. The statistical framework (Rfit) developed in this paper advocates formal frequentist statistics. Other approaches, such as Bayesian statistics or the 95% CL scan method are also discussed. We emphasize the distinction of a model testing and a model dependent, metrological phase in which the various parameters of the theory are determined. Measurements and theoretical parameters entering the global fit are thoroughly discussed, in particular with respect to their theoretical uncertainties. Graphical results for confidence levels are drawn in various one and two-dimensional parameter spaces. Numerical results are provided for all relevant CKM parameterizations, the CKM elements and theoretical input parameters. Predictions for branching ratios of rare K and B meson decays are obtained. A simple, predictive SUSY extension of the Standard Model is discussed.Comment: 66 pages, added figures, corrected typos, no quantitative change

Proposed parametric cooling of bilayer cuprate superconductors by terahertz excitation

We propose and analyze a scheme for parametrically cooling bilayer cuprates based on the selective driving of a $c$-axis vibrational mode. The scheme exploits the vibration as a transducer making the Josephson plasma frequencies time-dependent. We show how modulation at the difference frequency between the intra- and interbilayer plasmon substantially suppresses interbilayer phase fluctuations, responsible for switching $c$-axis transport from a superconducting to resistive state. Our calculations indicate that this may provide a viable mechanism for stabilizing non-equilibrium superconductivity even above $T_c$, provided a finite pair density survives between the bilayers out of equilibrium.Comment: 4 pages + 7 page supplementa

Hierarchy of Conservation Laws of Diffusion--Convection Equations

We introduce notions of equivalence of conservation laws with respect to Lie symmetry groups for fixed systems of differential equations and with respect to equivalence groups or sets of admissible transformations for classes of such systems. We also revise the notion of linear dependence of conservation laws and define the notion of local dependence of potentials. To construct conservation laws, we develop and apply the most direct method which is effective to use in the case of two independent variables. Admitting possibility of dependence of conserved vectors on a number of potentials, we generalize the iteration procedure proposed by Bluman and Doran-Wu for finding nonlocal (potential) conservation laws. As an example, we completely classify potential conservation laws (including arbitrary order local ones) of diffusion--convection equations with respect to the equivalence group and construct an exhaustive list of locally inequivalent potential systems corresponding to these equations.Comment: 24 page

Active Mass Under Pressure

After a historical introduction to Poisson's equation for Newtonian gravity, its analog for static gravitational fields in Einstein's theory is reviewed. It appears that the pressure contribution to the active mass density in Einstein's theory might also be noticeable at the Newtonian level. A form of its surprising appearance, first noticed by Richard Chase Tolman, was discussed half a century ago in the Hamburg Relativity Seminar and is resolved here.Comment: 28 pages, 4 figure

Testing Hawking particle creation by black holes through correlation measurements

Hawking's prediction of thermal radiation by black holes has been shown by Unruh to be expected also in condensed matter systems. We show here that in a black hole-like configuration realised in a BEC this particle creation does indeed take place and can be unambiguously identified via a characteristic pattern in the density-density correlations. This opens the concrete possibility of the experimental verification of this effect.Comment: 13 pages, 2 figures. Honorable mention in the 2010 GRF Essay Competitio

Benchmark calculations for elastic fermion-dimer scattering

We present continuum and lattice calculations for elastic scattering between a fermion and a bound dimer in the shallow binding limit. For the continuum calculation we use the Skorniakov-Ter-Martirosian (STM) integral equation to determine the scattering length and effective range parameter to high precision. For the lattice calculation we use the finite-volume method of L\"uscher. We take into account topological finite-volume corrections to the dimer binding energy which depend on the momentum of the dimer. After subtracting these effects, we find from the lattice calculation kappa a_fd = 1.174(9) and kappa r_fd = -0.029(13). These results agree well with the continuum values kappa a_fd = 1.17907(1) and kappa r_fd = -0.0383(3) obtained from the STM equation. We discuss applications to cold atomic Fermi gases, deuteron-neutron scattering in the spin-quartet channel, and lattice calculations of scattering for nuclei and hadronic molecules at finite volume.Comment: 16 pages, 5 figure

Complete list of Darboux Integrable Chains of the form t1x=tx+d(t,t1)t_{1x}=t_x+d(t,t_1)

We study differential-difference equation of the form $$\frac{d}{dx}t(n+1,x)=f(t(n,x),t(n+1,x),\frac{d}{dx}t(n,x))$$ with unknown $t(n,x)$ depending on continuous and discrete variables $x$ and $n$. Equation of such kind is called Darboux integrable, if there exist two functions $F$ and $I$ of a finite number of arguments $x$, $\{t(n\pm k,x)\}_{k=-\infty}^\infty$, ${\frac{d^k}{dx^k}t(n,x)}_{k=1}^\infty$, such that $D_xF=0$ and $DI=I$, where $D_x$ is the operator of total differentiation with respect to $x$, and $D$ is the shift operator: $Dp(n)=p(n+1)$. Reformulation of Darboux integrability in terms of finiteness of two characteristic Lie algebras gives an effective tool for classification of integrable equations. The complete list of Darboux integrable equations is given in the case when the function $f$ is of the special form $f(u,v,w)=w+g(u,v)$

A Thermodynamic Approach to Predict the Metallic and Oxide Phases Precipitations in Nuclear Waste Glass Melts

AbstractAmong the large number of matrixes explored as hosts for high-level nuclear wastes, conditioning of fission products and minor actinides into a homogeneous borosilicate glass is the most promising technique already implemented at the industrial scale. The advantage of this vitrification process is the volume reduction of the high level waste coming from the spent fuel reprocessing and its stability for the long-term storage. Nevertheless, some fission products are poorly soluble in molten glasses:•Platinoids (Pd, Ru, Rh) which precipitate as (Pd-Te, Ru-Rh) metallic particles and (Rh,Ru)O2 oxide phases with acicular or polyhedral shapes during the vitrification process.•Molybdenum oxide (MoO3) which can form complex molybdates.In order to point out the chemical interactions between the glass and these precipitated phases issuing from the calcinated waste, a thermodynamic approach is developed using the Calphad method. The objective of this work is to calculate thermodynamic properties for complex fission product systems in order to predict the precipitation of platinoids or molybdate phases.This thermodynamic database is being developed on the Mo-Pd-Rh-Ru-Se-Te-O complex system. This flexible tool enables to predict phase diagrams, composition and relative stability of the metallic or oxide precipitated phases as a function of both temperature and oxygen potential in the glass melt