Sgoldstino events in top decays at LHC

We study top-quark decays in models with light sgoldstinos. The off-diagonal entries in the squark mass matrices can lead to FCNC top two-body decays into sgoldstinos and u(c) quarks. We compute the rates for these decays and discuss the corresponding signatures that could manifest the presence of sgoldstinos in top decays at LHC. We expect that a supersymmetry breaking scale $\sqrt{F}$ up to a scale of order 10 TeV could be probed through this process, for a maximal squark mixing with the third generation. Justified by our preliminary analysis, a thorough study of the corresponding signal versus background and systematics in the LHC environment would be most welcome, in order to accurately assess the potential of this promising process in determining $\sqrt{F}$.Comment: Standard LaTeX, 11 pages, 4 figures, one reference adde

Ground state representations of loop algebras

Let g be a simple Lie algebra, Lg be the loop algebra of g. Fixing a point in S^1 and identifying the real line with the punctured circle, we consider the subalgebra Sg of Lg of rapidly decreasing elements on R. We classify the translation-invariant 2-cocycles on Sg. We show that the ground state representation of Sg is unique for each cocycle. These ground states correspond precisely to the vacuum representations of Lg.Comment: 22 pages, no figur

Comment on: Modular Theory and Geometry

In this note we comment on part of a recent article by B. Schroer and H.-W. Wiesbrock. Therein they calculate some new modular structure for the U(1)-current-algebra (Weyl-algebra). We point out that their findings are true in a more general setting. The split-property allows an extension to doubly-localized algebras.Comment: 13 pages, corrected versio

Beyond MFV in family symmetry theories of fermion masses

Minimal Flavour Violation (MFV) postulates that the only source of flavour changing neutral currents and CP violation, as in the Standard Model, is the CKM matrix. However it does not address the origin of fermion masses and mixing and models that do usually have a structure that goes well beyond the MFV framework. In this paper we compare the MFV predictions with those obtained in models based on spontaneously broken (horizontal) family symmetries, both Abelian and non-Abelian. The generic suppression of flavour changing processes in these models turns out to be weaker than in the MFV hypothesis. Despite this, in the supersymmetric case, the suppression may still be consistent with a solution to the hierarchy problem, with masses of superpartners below 1 TeV. A comparison of FCNC and CP violation in processes involving a variety of different family quantum numbers should be able to distinguish between various family symmetry models and models satisfying the MFV hypothesis.Comment: 34 pages, no figure

Chargino Contributions in B→ϕKSB \to \phi K_S Asymmetry

CP asymmetry in $B \to \phi K_S$ decay is studied in a special context of supersymmetry theories, in which the charginos play an important role. We find that in addition to the gluino, chargino can also make large contributions to CP asymmetry in $B \to \phi K_S$ decay. After considering the constraints from $B \to J/psi K_S$ decay, we study three special scenarios: (a). Large mixing on left-handed charm and top squarks (LL mixing); (b). Large mixing on right-handed charm and top squarks (RR mixing); (c). Large mixing on left-handed charm and top squarks plus right-handed charm and top squarks (LL + RR mixing). We show quantitatively that because of large squark mixing within second and third generations, an $\mathcal O$(1) effect on CP violation in $B \to \phi K_S$ is possible

Supersymmetric Flavor Models and the B --> phi K_S Anomaly

We consider the flavor structure of supersymmetric theories that can account for the deviation of the observed time-dependent CP asymmetry in B --> phi K_S from the standard model prediction. Assuming simple flavor symmetries and effective field theory, we investigate possible correlations between sizable supersymmetric contributions to b --> s transitions and to flavor changing processes that are more tightly constrained. With relatively few assumptions, we determine the properties of minimal Yukawa and soft mass textures that are compatible with the desired supersymmetric flavor-changing effect and constraints. We then present explicit models that are designed (at least approximately) to realize these textures. In particular, we present an Abelian model based on a single U(1) factor and a non-trivial extra-dimensional topography that can explain the CP asymmetry in B --> phi K_S, while suppressing other supersymmetric flavor changing effects through a high degree of squark-quark alignment.Comment: 18 pages LaTeX, 3 eps figure

New Mechanism of Flavor Symmetry Breaking from Supersymmetric Strong Dynamics

We present a class of supersymmetric models in which flavor symmetries are broken dynamically, by a set of composite flavon fields. The strong dynamics that is responsible for confinement in the flavor sector also drives flavor symmetry breaking vacuum expectation values, as a consequence of a quantum-deformed moduli space. Yukawa couplings result as a power series in the ratio of the confinement to Planck scale, and the fermion mass hierarchy depends on the differing number of preons in different flavor symmetry-breaking operators. We present viable non-Abelian and Abelian flavor models that incorporate this mechanism.Comment: 24 pp. LaTe

Asymptotic completeness in a class of massless relativistic quantum field theories

This paper presents the first examples of massless relativistic quantum field theories which are interacting and asymptotically complete. These two-dimensional theories are obtained by an application of a deformation procedure, introduced recently by Grosse and Lechner, to chiral conformal quantum field theories. The resulting models may not be strictly local, but they contain observables localized in spacelike wedges. It is shown that the scattering theory for waves in two dimensions, due to Buchholz, is still valid under these weaker assumptions. The concepts of interaction and asymptotic completeness, provided by this theory, are adopted in the present investigation.Comment: 15 pages, LaTeX. As appeared in Communications in Mathematical Physic

The effect of supersymmetric CP phases on Chargino-Pair Production via Drell-Yan Process at the LHC

We compute the rates for pp annihilation into chargino-pairs via Drell-Yan process taking into account the effects of supersymmetric soft phases, at proton-proton collider. In particular, the phase of the mu parameter gains direct accessibility via the production of dissimilar charginos. The phases of the trilinear soft masses do not have a significant effect on the cross sections.Comment: 24 pages, 7 figure

Minimal Gaugino Mediation

We propose Minimal Gaugino Mediation as the simplest known solution to the supersymmetric flavor and CP problems. The framework predicts a very minimal structure for the soft parameters at ultra-high energies: gaugino masses are unified and non-vanishing whereas all other soft supersymmetry breaking parameters vanish. We show that this boundary condition naturally arises from a small extra dimension and present a complete model which includes a new extra-dimensional solution to the mu problem. We briefly discuss the predicted superpartner spectrum as a function of the two parameters of the model. The commonly ignored renormalization group evolution above the GUT scale is crucial to the viability of Minimal Gaugino Mediation but does not introduce new model dependence.Comment: LaTeX, 16 pages, 4 figures, running of the bottom and tau Yukawas included, plots revise