Using b-tagging to enhance the SUSY reach of the CERN Large Hadron Collider

Assuming that supersymmetry is realized with parameters in the hyperbolic branch/focus point (HB/FP) region of the minimal supergravity (mSUGRA) model, we show that by searching for multijet + missing E_T events with tagged b jets the reach of experiments at the LHC may be extended by as much as 20% from current projections. The reason for this is that gluino decays to third generation quarks are enhanced because the lightest neutralino has substantial higgsino components. Although we were motivated to perform this analysis because the HB/FP region is compatible with the recent determination of the relic density of cold dark matter, our considerations may well have a wider applicability since decays of gluinos to third generation quarks are favoured in a wide variety of models.Comment: 16 pages, 1 figur

Commercial prospects for nanomaterials in India

The area of nanoscience and technology is growing rapidly around the world and nanomaterials based products, especially in the consumer sector, are coming into market very rapidly. India is competing, with great difficulty, with other developed countries to make its position strong in this field. In other respect, several challenges have to be overcome in terms of production of nanomaterials at commercial scale, their processing, applications and commercialization. The present article describes the present state of nanomaterials based technology development, commercialization and future prospects for this technology in our country

Unsuccessful Cassava Brown Streak Disease (CBSD) evaluation attempts in western Democratic Republic of Congo and implications with cassava root necrosis disease (CRND) etiology

Open Access ArticleCassava brown streak disease (CBSD) is the second most important virus disease after Cassava mosaic disease (CMD), infecting cassava (ManihotesculetaCrantz) in Africa. The disease is caused by two distinct viruses, Cassava brown streak virus [2, 3] and Ugandan Cassava brown streak virus (family, Potyviridae: genus, Ipomovirus). Transmission of CBSV from one plant to another is reported to occur through grafting CBSV-free with infected cuttings and subsequent dissemination by infected cuttings. The basic approach to control of CBSD is selecting planting material from symptomless mother plants. Graft inoculation is the most efficient and effective of the techniques for CBSD virus transmission and consequently cuttings are the most effective way of the disease spreading. In early 2000s, cassava root necrosis similar to those of CBSD were reported in western provinces of Democratic Republic of Congo (RDC) (Kinshasa and Kongo Central) and up to date PCR diagnoses did not detect any causal agent related to the observed symptoms and the disease which was still referred as ‘CBSD-like disease’. Due to lack of molecular data and the similarity of root symptoms with CBSD, the existence of a virus has always been suspected to be the cause of CBSD-like propagation. Thus, 2 field experiments were proposed in order to verify the existence of a systematic transmission of a possible CBSD related virus, knowing that CBSD viruses are transmitted efficiently by cuttings. The first trial focused on the field evaluation of CBSD – like infected and apparently uninfected planting materials, while the second trial involved the importation of tanzanian CBSD resistant genotypes for evaluation in INERA Mvuazi research center under CBSD-like infection conditions. Results of the first trial did not show a systemic transmission of any CBSD-like pathogen while CBSD-resistant parents involved in the second trial all succumbed to CBSD-like disease

LHC Reach for Gauge Mediated Supersymmetry Breaking Models Via Prompt Photon Channels

We evaluate the supersymmetry reach of the Large Hadron Collider within the gauge-mediated low energy supersymmetry breaking framework, assuming that a neutralino is the second lightest sparticle and that it decays promptly into a gravitino which escapes detection. We find that the maximum reach is obtained via a search for inclusive \gamma\gamma+\eslt events coming dominantly from chargino and neutralino production. Assuming an integrated luminosity of 10~$fb^{-1}$, we find that LHC experiments will be able to probe values of the model parameter \Lambda \alt 400 TeV, corresponding to $m_{\tg} \leq 2.8$ TeV. A measure of the model parameter $\Lambda$ may be possible from the photon $p_T$ spectrum.Comment: 10 page Revtex file plus 4 EPS figure

Electrophoretic Properties of Highly Charged Colloids: A Hybrid MD/LB Simulation Study

Using computer simulations, the electrophoretic motion of a positively charged colloid (macroion) in an electrolyte solution is studied in the framework of the primitive model. Hydrodynamic interactions are fully taken into account by applying a hybrid simulation scheme, where the charged ions (i.e. macroion and electrolyte), propagated via molecular dynamics (MD), are coupled to a Lattice Boltzmann (LB) fluid. In a recent experiment it was shown that, for multivalent salt ions, the mobility $\mu$ initially increases with charge density $\sigma$, reaches a maximum and then decreases with further increase of $\sigma$. The aim of the present work is to elucidate the behaviour of $\mu$ at high values of $\sigma$. Even for the case of monovalent microions, we find a decrease of $\mu$ with $\sigma$. A dynamic Stern layer is defined that includes all the counterions that move with the macroion while subject to an external electrical field. The number of counterions in the Stern layer, $q_0$, is a crucial parameter for the behavior of $\mu$ at high values of $\sigma$. In this case, the mobility $\mu$ depends primarily on the ratio $q_0/Q$ (with $Q$ the valency of the macroion). The previous contention that the increase in the distortion of the electric double layer (EDL) with increasing $\sigma$ leads to the lowering of $\mu$ does not hold for high $\sigma$. In fact, we show that the deformation of the EDL decreases with increase of $\sigma$. The role of hydrodynamic interactions is inferred from direct comparisons to Langevin simulations where the coupling to the LB fluid is switched off. Moreover, systems with divalent counterions are considered. In this case, at high values of $\sigma$ the phenomenon of charge inversion is found.Comment: accepted in J. Chem Phys., 10 pages, 9 figure

Remedies and the Supreme Court\u27s October 2007 Term

For this third annual review of Supreme Court decisions, I have identified three cases from very different areas all of which involve the remedies available for violations of federal law. These cases deal with the following issues: (a) federal remedies for state violations of federal labor policy (Chamber of Commerce); (b) state remedies for violations of the federal Bill of Rights (Danforth) and (c) federal common law standards for awarding punitive damages (Exxon Shipping)

Deployment of solar sails by joule effect: thermal analysis and experimental results

Space vehicles may be propelled by solar sails exploiting the radiation pressure coming from the sun and applied on their surfaces. This work deals with the adoption of Nickel-Titanium Shape Memory Alloy (SMA) elements in the sail deployment mechanism activated by the Joule Effect, i.e., using the same SMA elements as a resistance within suitable designed electrical circuits. Mathematical models were analyzed for the thermal analysis by implementing algorithms for the evaluation of the temperature trend depending on the design parameters. Several solar sail prototypes were built up and tested with different number, size, and arrangement of the SMA elements, as well as the type of the selected electrical circuit. The main parameters were discussed in the tested configurations and advantages discussed as well

Schiume metalliche: recenti risultati e sviluppi futuri

In questa rassegna vengono presentati e discussi i risultati degli studi condotti dagli autori negli ultimianni riguardo la produzione e caratterizzazione di materiali metallici porosi. Dopo le prime esperienzenella produzione di schiume di Al a porosità chiusa, partendo da polveri e con l’aggiunta di TiH2 comeagente soffiante, si è passati alla produzione di schiume di diversi metalli a porosità aperta mediante latecnica “SDP” (sintering and dissolution process) modificata. Un’altra via percorsa per la produzione dischiume a basso costo è la cosiddetta “RP” (replication process), anch’essa sottoposta ad alcune variantirispetto alla tecnica classica a seconda del metallo o della lega che si intende schiumare. Un importanteaspetto di questo filone di ricerca ha riguardato la produzione di schiume partendo da materiale diriciclo, truciolo tal quale per quanto riguarda Al e sue leghe, griglie e pasta recuperate da batterie esausteper le schiume di piombo. Questa rappresenta un’interessante prospettiva, anche sotto il profilo energeticoe ambientale, per la conversione diretta del materiale, prodotto di scarto di lavorazioni, in schiume di Al ePb rispettivamente. Vengono quindi presentati i risultati sperimentali e le problematiche emerse durante ilprocesso di ottenimento della schiuma utilizzando il materiale recuperato. Un ulteriore aspetto hariguardato la produzione di schiume di Fe che combinano un buon mix tra proprietà meccaniche erequisiti di leggerezza. Infine l’ultimo punto della rassegna illustra i principali risultati della ricerca piùrecente che riguarda la produzione di elettrodi porosi realizzati in schiume di Pb. Una possibileapplicazione potrebbe essere la realizzazione di lamierini in piombo da impiegare come elettrodimicroporosi in accumulatori al piombo acido con l’obiettivo di ridurne il peso e migliorarne le prestazioni.Critico da questo punto di vista si presenta il problema del controllo della dimensione della porosità. Atale proposito alcune problematiche devono ancora essere superate e sono tuttora oggetto disperimentazione. Per tutte le tipologie di schiume prodotte è stata effettuata una caratterizzazionemorfologica e meccanica

Decline and Fall of the Standard Model?

Motivations for physics beyond the Standard Model are reviewed, with particular emphasis on supersymmetry at the TeV scale. Constraints on the minimal supersymmetric extension of the Standard Model with universal soft supersymmetry-breaking terms (CMSSM) are discussed. These are also combined with the supersymmetric interpretation of the anomalous magnetic moment of the muon. The prospects for observing supersymmetry at accelerators are reviewed using benchmark scenarios to focus the discussion. Prospects for other experiments are discussed, including the detection of cold dark matter, mu -> e gamma and related processes, as well as proton decay.Comment: Invited talk at 20th International Symposium on Lepton and Photon Interactions at High Energies, Rome, 2001, 16 pages LaTeX, 13 eps figures, uses special .cls file (included