On Metastability in Supersymmetric Models

We make a critical reappraisal of `unbounded-from-below' (UFB) constraints in the MSSM and R-parity violating models. We explain why the `traditional' UFB bounds are neither necessary nor sufficient and propose, instead, a sufficient condition which ensures that there are no local minima along the flat directions. This conservative (but meaningful) condition divides the parameter space into regions which are allowed, regardless of cosmology, and regions in which cosmology is expected to play a major role. We study both conditions at low tan-beta and obtain analytic approximations to the UFB bounds for all low tan-beta (<15). Finally we show that R-parity violation just below current experimental limits avoids UFB problems by lifting the dangerous flat directions.Comment: 28 Pages plain latex; includes 4 eps figures, numerical errors corrected plus additional reference, final version to appear in Nucl Phys

Sleptonarium (Constraints on the CP and Flavour Pattern of Scalar Lepton Masses)

The constraints on the flavour and CP structure of scalar lepton mass matrices are systematically collected. The display of the resulting upper bounds on the lepton -slepton misalignment parameters is designed for an easy inspection of very large classes of models and the formula are arranged so as to suggest useful approximations. Interferences among the different contributions to lepton flavour violating transitions and lepton electric and magnetic dipole moments of generic character can either tighten or loose the bounds. A combined analysis of all rare leptonic transitions can disentangle the different contributions to yield hints on several phenomenological issues. The possible impact of these results on the study of the slepton misalignment originated in the seesaw mechanism and grand-unified theories is emphasized since the planned experiments are getting close to the precision required in such tests.Comment: 29 pages, 13 figures; v3: corrected misprints in appendix

Level-1 pixel based tracking trigger algorithm for LHC upgrade

The Pixel Detector is the innermost detector of the tracking system of the Compact Muon Solenoid (CMS) experiment at CERN Large Hadron Collider (LHC). It precisely determines the interaction point (primary vertex) of the events and the possible secondary vertexes due to heavy flavours ($b$ and $c$ quarks); it is part of the overall tracking system that allows reconstructing the tracks of the charged particles in the events and combined with the magnetic field to measure their impulsion. The pixel detector allows measuring the tracks in the region closest to the interaction point. The Level-1 (real-time) pixel based tracking trigger is a novel trigger system that is currently being studied for the LHC upgrade. An important goal is developing real-time track reconstruction algorithms able to cope with very high rates and high flux of data in a very harsh environment. The pixel detector has an especially crucial role in precisely identifying the primary vertex of the rare physics events from the large pile-up (PU) of events. The goal of adding the pixel information already at the real-time level of the selection is to help reducing the total level-1 trigger rate while keeping an high selection capability. This is quite an innovative and challenging objective for the experiments upgrade for the High Luminosity LHC (HL-LHC). The special case here addressed is the CMS experiment. This document describes exercises focusing on the development of a fast pixel track reconstruction where the pixel track matches with a Level-1 electron object using a ROOT-based simulation framework.Comment: Submitted to JINST; 12 pages, 10 figures, Contribution to the JINST proceedings for the INFIERI2014 School in Paris, France, July 14-25, 201

Geometrical approach to duality in N=1 supersymmetric theories

We investigate the geometry of the moduli spaces of dual electric and magnetic N=1 supersymmetric field theories. Using the SU(N_c) gauge group as a guideline we show that the electric and magnetic moduli spaces coincide for a suitable choice of the Kahler potential of the magnetic theory. We analyse the Kahler structure of the dual moduli spaces.Comment: 14 pages, LaTe

Intermediate Symmetries in the Spontaneous Breaking of Supersymmetric SO(10)

We study the supersymmetric spontaneous symmetry breaking of SO(10) into SU(3)xSU(2)xU(1) for the most physically interesting cases of SU(5) or flipped SU(5)xU(1) intermediate symmetries. The first case is more easily realized while the second one requires a fine-tuning condition on the parameters of the superpotential. This is because in the case of SU(5) symmetry there is at most one singlet of the residual symmetry in each SO(10) irreducible representation. We also point out on more general grounds in supersymmetric GUT's that some intermediate symmetries can be exactly realized and others can only be approximated by fine-tuning. In the first category, there could occur some tunneling between the vacua with exact and approximate intermediate symmetry. The flipped SU(5)xU(1) symmetry improves the unification of gauge couplings if (B-L) is broken by (B-L)=1 scalars yielding right handed neutrino masses below 10^{14} GeV}.Comment: LaTex, 9 page

The Talking Points Tool: A Brief Intervention to Support Predoctoral Student and Faculty Advisor Communication

Excellent relationships between predoctoral students and faculty supervisors can lay the foundation for a satisfying degree program and productive future. Contrarily, poor relationships can frustrate both students and supervisors. We examined mentoring experiences focused on career development. Students desired enhanced career mentoring but were uncomfortable approaching their supervisors with these concerns. Faculty advisors reported willingness to support students’ career development, yet expected students to initiate those conversations. Responding to this communication disconnect, we developed a brief intervention to facilitate conversations—a Talking Points Tool (TPT). In this paper, we examine whether the TPT influenced students’ career conversations and development.Cockrell School of Engineerin

Overview of the SiLC R&D Activities

The R&D Collaboration SiLC (Silicon tracking for Linear Colliders) is based on generic R&D aiming to develop the next generation of large Silicon tracking systems for the Linear collider experiments; it serves all three ILC detector concepts. There is a strong involvement in ILD, a natural collaboration with SiD and recent 4th concept interest to use Silicon tracking technology as well. Here is a very brief summary of the latest results on sensors, Front End Electronics, Mechanics and Integration issues, test bench and test beam results and where to go from there.Comment: 3 pages, 3 figures, LCWS08 Worksho