76 research outputs found

    Models of Neutrino Masses: Anarchy versus Hierarchy

    Get PDF
    We present a quantitative study of the ability of models with different levels of hierarchy to reproduce the solar neutrino solutions, in particular the LA solution. As a flexible testing ground we consider models based on SU(5)xU(1)_F. In this context, we have made statistical simulations of models with different patterns from anarchy to various types of hierachy: normal hierarchical models with and without automatic suppression of the 23 (sub)determinant and inverse hierarchy models. We find that, not only for the LOW or VO solutions, but even in the LA case, the hierarchical models have a significantly better success rate than those based on anarchy. The normal hierachy and the inverse hierarchy models have comparable performances in models with see-saw dominance, while the inverse hierarchy models are particularly good in the no see-saw versions. As a possible distinction between these categories of models, the inverse hierarchy models favour a maximal solar mixing angle and their rate of success drops dramatically as the mixing angle decreases, while normal hierarchy models are far more stable in this respect.Comment: v1: 28 pages, 12 figures; v2: 34 pages, 14 figures, updated previous analysis with the inclusion of recent SNO result

    Rare Kaon Decays

    Get PDF
    The current status of rare kaon decay experiments is reviewed. New limits in the search for Lepton Flavor Violation are discussed, as are new measurements of the CKM matrix.Comment: 8 pages, 3 figures, LaTeX, presented at the 3rd International Conference on B Phyiscs and CP Violation, Taipei December 3-7, 199

    Thermal leptogenesis in a model with mass varying neutrinos

    Full text link
    In this paper we consider the possibility of neutrino mass varying during the evolution of the Universe and study its implications on leptogenesis. Specifically, we take the minimal seesaw model of neutrino masses and introduce a coupling between the right-handed neutrinos and the dark energy scalar field, the Quintessence. In our model, the right-handed neutrino masses change as the Quintessence scalar evolves. We then examine in detail the parameter space of this model allowed by the observed baryon number asymmetry. Our results show that it is possible to lower the reheating temperature in this scenario in comparison with the case that the neutrino masses are unchanged, which helps solve the gravitino problem. Furthermore, a degenerate neutrino mass patten with mim_i larger than the upper limit given in the minimal leptogenesis scenario is permitted.Comment: 18 pages, 7 figures, version to appear in PR

    Experimental Probes of Localized Gravity: On and Off the Wall

    Get PDF
    The phenomenology of the Randall-Sundrum model of localized gravity is analyzed in detail for the two scenarios where the Standard Model (SM) gauge and matter fields are either confined to a TeV scale 3-brane or may propagate in a slice of five dimensional anti-deSitter space. In the latter instance, we derive the interactions of the graviton, gauge, and fermion Kaluza-Klein (KK) states. The resulting phenomenological signatures are shown to be highly dependent on the value of the 5-dimensional fermion mass and differ substantially from the case where the SM fields lie on the TeV-brane. In both scenarios, we examine the collider signatures for direct production of the graviton and gauge KK towers as well as their induced contributions to precision electroweak observables. These direct and indirect signatures are found to play a complementary role in the exploration of the model parameter space. In the case where the SM field content resides on the TeV-brane, we show that the LHC can probe the full parameter space and hence will either discover or exclude this model if the scale of electroweak physics on the 3-brane is less than 10 TeV. We also show that spontaneous electroweak symmetry breaking of the SM must take place on the TeV-brane.Comment: 62 pages, Latex, 22 figure

    Mudança organizacional: uma abordagem preliminar

    Full text link

    The Impact of Blue Light Cystoscopy with Hexaminolevulinate (HAL) on Progression of Bladder Cancer - A New Analysis

    No full text
    Background: The International Bladder Cancer Group (IBCG) recently proposed a new definition of disease progression in non-muscle invasive bladder cancer (NMIBC), including change in T-stage, change to T2 or higher or change from low to high grade. Objective: To establish whether blue light cystoscopy with hexaminolevulinate (HAL) impacts the rate of progression and time to progression using the revised definition. Methods: An earlier long-term follow-up of a controlled Phase III study reported outcomes following blue light cystoscopy with HAL (255 patients) or white light (WL) cystoscopy (261 patients) in NMIBC patients. The data was re-analysed according to the new definition. Results: In the original analysis, after 4.5 years (median), eight HAL and 16 WL patients were deemed to have progressed (transition from NMIBC to muscle invasive bladder cancer, (T2-4)). According to the new definition, additional patients in both groups were found to have progressed: 31 (12.2%) HAL vs 46 (17.6%) WL (p = 0.085) with four (1.6%) HAL and 11 (4.2%) WL patients progressing from Ta to CIS. Time to progression was longer in the HAL group (p = 0.05). Conclusions: Applying the new IBCG definition there was a trend towards a lower rate of progression in HAL patients, particularly in those progressing from Ta to CIS. Time to progression was significantly prolonged. This suggests that patients should receive blue light cystoscopy with HAL rather than WL at resection. Adoption of the new definition could allow more patients at risk of progression to be treated appropriately earlier

    Safety of hexaminolevulinate for blue light cystoscopy in bladder cancer. A combined analysis of the trials used for registration and postmarketing data

    Get PDF
    Contains fulltext : 136763.pdf (publisher's version ) (Closed access)OBJECTIVE: To detail and put into perspective, safety of hexaminolevulinate blue light cystoscopy (HAL-BLC), including repeated use, based on combined data of controlled trials used for registration of HAL and postmarketing experience. METHODS: Safety data of 2 randomized comparative studies (group 1) and 4 within patient control studies (group 2) were combined. Postmarketing data from >200,000 patients were analyzed. RESULTS: In group 1, 533 patients were examined with HAL-BLC and 499 with white light (WL) cystoscopy. In group 2, 791 patients were examined with both WL and HAL-BLC. Between 73% and 93% of these patients had concomitant diseases. Between 41% and 58% of the patients had at least 1 adverse event (AE), although predominantly mild to moderate. The majority was considered as not related to HAL-BLC and reported in the urinary tract. No serious adverse events (SAEs) were considered definitely related to HAL-BLC, but in 6 patients serious AEs were of an uncertain relationship. Four possibly related hypersensitivity reactions have been reported. Repeated use did not reveal additional toxicity, also supported by data from 3 European centers. CONCLUSION: This combined and detailed analysis of patients from 6 HAL-BLC studies with very comparable criteria shows that HAL-BLC is safe and poses very little additional risks other than expected for WL cystoscopy for bladder tumor resection in this specific patient population. This is supported by 9 years of postmarketing experience. Repeated use also seems safe
    • …
    corecore