Strategy for early SUSY searches at ATLAS

The CERN Large Hadron Collider (LHC) is scheduled to commence operation in 2008 and inclusive searches for supersymmetry (SUSY) will be one of our primary tasks in the first days of LHC operation. It is certain that the final state of multijets + missing transverse energy will provide a superior performance in SUSY searches. Strategies to understand the instrumental background and to understand the Standard Model (SM) background are still under development and are urgent issues for the coming data. We describe the strategy for early SUSY searches at the ATLAS experiment using the fist data corresponding to an integrated luminosity up to 1fb^-1, which comprises much progress in the data-driven technique for the SM background estimations.Comment: Submitted for the SUSY07 proceedings, 4 pages, LaTeX, 8 eps figure

Nonlinear d'Alembert formula for discrete pseudospherical surfaces

On the basis of loop group decompositions (Birkhoff decompositions), we give a discrete version of the nonlinear d'Alembert formula, a method of separation of variables of difference equations, for discrete constant negative Gauss curvature (pseudospherical) surfaces in Euclidean three space. We also compute two examples by this formula in detail.Comment: 21 pages, fixed typos (v3

Search for long-lived particles with the ATLAS detector

Several scenarios beyond the Standard Model predict heavy long-lived particles as a result of a kinematic constraint, a conserved quantum number or a weak coupling. Such particles are possibly identified based on the detection through abnormal energy losses, appearing or disappearing tracks, displaced vertices, lepton-jet signatures, long time-of-flight or late calorimetric energy deposits. This contribution summarizes recent results of searches for heavy long-lived particles with the ATLAS detector using pp collision data at a center of mass energy of 8 TeV.Comment: 6 pages, 8 figures, proceedings of the LHCP2014 conferenc

General-affine invariants of plane curves and space curves

We present a fundamental theory of curves in the affine plane and the affine space, equipped with the general-affine groups ${\rm GA}(2)={\rm GL}(2,{\bf R})\ltimes {\bf R}^2$ and ${\rm GA}(3)={\rm GL}(3,{\bf R})\ltimes {\bf R}^3$, respectively. We define general-affine length parameter and curvatures and show how such invariants determine the curve up to general-affine motions. We then study the extremal problem of the general-affine length functional and derive a variational formula. We give several examples of curves and also discuss some relations with equiaffine treatment and projective treatment of curves.Comment: 51 pages, 4 figures, to appear in Czechoslovak Mathematical Journal, version2: typos are fixe

Timelike minimal Lagrangian surfaces in the indefinite complex hyperbolic two-space

It has been known for some time that there exist $5$ essentially different real forms of the complex affine Kac-Moody algebra of type $A_2^{(2)}$ and that one can associate $4$ of these real forms with certain classes of "integrable surfaces", such as minimal Lagrangian surfaces in $\mathbb {CP}^2$ and $\mathbb {CH}^2$, as well as definite and indefinite affine spheres in $\mathbb R^3$. In this paper we consider the class of timelike minimal Lagrangian surfaces in the indefinite complex hyperbolic two-space $\mathbb{CH}^2_1$. We show that this class of surfaces corresponds to the fifth real form. Moreover, for each timelike Lagrangian surface in $\mathbb {CH}^2_1$ we define natural Gauss maps into certain homogeneous spaces and prove a Ruh-Vilms type theorem, characterizing timelike minimal Lagrangian surfaces among all timelike Lagrangian surfaces in terms of the harmonicity of these Gauss maps.Comment: Typological errors have been fixe