8,361 research outputs found

    Difficult Scenarios for NMSSM Higgs Discovery at the LHC

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    We identify scenarios not ruled out by LEP data in which NMSSM Higgs detection at the LHC will be particularly challenging. We first review the `no-lose' theorem for Higgs discovery at the LHC that applies if Higgs bosons do not decay to other Higgs bosons - namely, with L=300 fb^-1, there is always one or more `standard' Higgs detection channel with at least a 5 sigma signal. However, we provide examples of no-Higgs-to-Higgs cases for which all the standard signals are no larger than 7 sigma implying that if the available L is smaller or the simulations performed by ATLAS and CMS turn out to be overly optimistic, all standard Higgs signals could fall below 5 sigma even in the no-Higgs-to-Higgs part of NMSSM parameter space. In the vast bulk of NMSSM parameter space, there will be Higgs-to-Higgs decays. We show that when such decays are present it is possible for all the standard detection channels to have very small significance. In most such cases, the only strongly produced Higgs boson is one with fairly SM-like couplings that decays to two lighter Higgs bosons (either a pair of the lightest CP-even Higgs bosons, or, in the largest part of parameter space, a pair of the lightest CP-odd Higgs bosons). A number of representative bench-mark scenarios of this type are delineated in detail and implications for Higgs discovery at various colliders are discussed.Comment: 31 pages, 5 figure

    Tree-formed Verification Data for Trusted Platforms

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    The establishment of trust relationships to a computing platform relies on validation processes. Validation allows an external entity to build trust in the expected behaviour of the platform based on provided evidence of the platform's configuration. In a process like remote attestation, the 'trusted' platform submits verification data created during a start up process. These data consist of hardware-protected values of platform configuration registers, containing nested measurement values, e.g., hash values, of loaded or started components. Commonly, the register values are created in linear order by a hardware-secured operation. Fine-grained diagnosis of components, based on the linear order of verification data and associated measurement logs, is not optimal. We propose a method to use tree-formed verification data to validate a platform. Component measurement values represent leaves, and protected registers represent roots of a hash tree. We describe the basic mechanism of validating a platform using tree-formed measurement logs and root registers and show an logarithmic speed-up for the search of faults. Secure creation of a tree is possible using a limited number of hardware-protected registers and a single protected operation. In this way, the security of tree-formed verification data is maintained.Comment: 15 pages, 11 figures, v3: Reference added, v4: Revised, accepted for publication in Computers and Securit

    A birth cohort study

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    Funding Information: The MINA‐Brazil Study has been funded by the Brazilian National Council for Scientific and Technological Development (CNPq, grant number 407255/2013‐3) and the SĂŁo Paulo Research Foundation (FAPESP, grant number 2016/00270‐6). Dr Matijasevich, Dr Antunes and Dr Cardoso are recipients of CNPq senior research scholarships. Mrs Maruyama and Mrs Pinheiro received doctoral scholarship from FAPESP (grant 2017/22723‐5) and CAPES, respectively. The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication. Publisher Copyright: © 2022 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.Objectives: Previous cohort studies have found a positive association between prolonged breastfeeding (≄12 months) on dental caries, but few of them analysed the mediated effect of sugar consumption on this association. This study investigated whether prolonged breastfeeding is a risk factor for caries at 2-year follow-up assessment (21–27 months of age) and whether this effect is mediated by sugar consumption. Methods: A birth cohort study was performed in the Brazilian Amazon (n = 800). Dental caries was assessed using the dmf-t index. Prolonged breastfeeding was the main exposure. Data on baseline covariables and sugar consumption at follow-up visits were analysed. We estimated the OR for total causal effect (TCE) and natural indirect effect (NIE) of prolonged breastfeeding on dental caries using the G-formula. Results: The prevalence of caries was 22.8% (95% CI: 19.8%–25.8%). Children who were breastfed for 12–23 months (TCE = 1.13, 95% CI: 1.05–1.20) and for ≄24 months (TCE = 1.27, 95% CI: 1.14–1.40) presented a higher risk of caries at age of 2 years than those breastfed <12 months. However, this risk was slightly mediated by a decreased frequency of sugar consumption at age of 2 years only for breastfeeding from 12 to 23 months (NIE; OR = 0.95, 95% CI: 0.91–0.97). Conclusions: In this study, the effect of prolonged breastfeeding on the increased risk of dental caries was slightly mediated by sugar consumption. Early feeding practices for caries prevention and promoting breastfeeding while avoiding sugar consumption should be targeted in the first 2 years of life.publishersversioninpres

    CP violation in the secluded U(1)'-extended MSSM

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    We study the Higgs sector of the secluded U(1)â€ČU(1)'-extended MSSM (sMSSM) focusing on CP violation. Using the one-loop effective potential that includes contributions from quarks and squarks in the third generation, we search for the allowed region under theoretical and experimental constraints. It is found that the possible region for the electroweak vacuum to exist is quite limited, depending on the parameters in the model. The masses and couplings of the Higgs bosons are calculated with/without CP violation. Even at the tree level, CP violation is possible by complex soft SUSY breaking masses. Similar to the CPX scenario in the MSSM, the scalar-pseudoscalar mixing enables the lightest Higgs boson mass to become smaller than the ZZ boson mass while the coupling with the ZZ boson is sufficiently suppressed to avoid the LEP experimental constraints. However, unlike the CPX scenario, large ÎŒ\mu and AA are not required for the realization of large CP violation. The typical spectrum of the SUSY particles is thus different. We also investigate the possible upper bound of the lightest Higgs boson in the case of spontaneous CP violation. The maximal value of it can reach above 100 GeV with maximal CP-violating phases.Comment: 28 pages, 16 figures, JHEP styl

    An origin for small neutrino masses in the NMSSM

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    We consider the Next to Minimal Supersymmetric Standard Model (NMSSM) which provides a natural solution to the so-called mu problem by introducing a new gauge-singlet superfield S. We realize that a new mechanism of neutrino mass suppression, based on the R-parity violating bilinear terms mu_i L_i H_u mixing neutrinos and higgsinos, arises within the NMSSM, offering thus an original solution to the neutrino mass problem (connected to the solution for the mu problem). We generate realistic (Majorana) neutrino mass values without requiring any strong hierarchy amongst the fundamental parameters, in contrast with the alternative models. In particular, the ratio |mu_i/mu| can reach about 10^-1, unlike in the MSSM where it has to be much smaller than unity. We check that the obtained parameters also satisfy the collider constraints and internal consistencies of the NMSSM. The price to pay for this new cancellation-type mechanism of neutrino mass reduction is a certain fine tuning, which get significantly improved in some regions of parameter space. Besides, we discuss the feasibility of our scenario when the R-parity violating bilinear terms have a common origin with the mu term, namely when those are generated via a VEV of the S scalar component from the couplings lambda_i S L_i H_u. Finally, we make comments on some specific phenomenology of the NMSSM in the presence of R-parity violating bilinear terms.Comment: 21 pages, 5 figures, Latex fil

    Theoretical predictions for the direct detection of neutralino dark matter in the NMSSM

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    We analyse the direct detection of neutralino dark matter in the framework of the Next-to-Minimal Supersymmetric Standard Model. After performing a detailed analysis of the parameter space, taking into account all the available constraints from LEPII, we compute the neutralino-nucleon cross section, and compare the results with the sensitivity of detectors. We find that sizable values for the detection cross section, within the reach of dark matter detectors, are attainable in this framework. For example, neutralino-proton cross sections compatible with the sensitivity of present experiments can be obtained due to the exchange of very light Higgses with m_{h_1^0}\lsim 70 GeV. Such Higgses have a significant singlet composition, thus escaping detection and being in agreement with accelerator data. The lightest neutralino in these cases exhibits a large singlino-Higgsino composition, and a mass in the range 50\lsim m_{\tilde\chi_1^0}\lsim 100 GeV.Comment: Final version to appear in JHEP. References added. LaTeX, 53 pages, 23 figure

    The UK Paediatric Familial Hypercholesterolaemia Register: preliminary data

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    BACKGROUND: The National Institute for Health and Care Excellence 2008 guidelines on the treatment and management of familial hypercholesterolaemia (FH) recommend that children with FH should be considered for statin treatment by the age of 10 years. The Paediatric FH Register was established in 2012 to collect baseline and long-term follow-up data on all children with FH in the UK. METHODS: Paediatricians and adult lipidologists have been invited to enter baseline data on any child with a clinical diagnosis of FH using an electronic capture record. RESULTS: Baseline data is on 232 children (50% boys, 80% Caucasian), with an untreated mean (SD) total cholesterol of 7.61 (1.48) mmol/L and low-density lipoprotein cholesterol (LDL-C) of 5.67 (1.46) mmol/L. Overall 111/232 (47.8%) of the children were on statins. Children over the age of 10 years at the most recent follow-up were twice as likely to be on statin treatment than those under 10 years (57.6% (102/177) vs 23.1% (9/39), p=0.00009). In both age groups, those subsequently on statin treatment had significantly higher diagnostic total and LDL-C (overall 6.01 (1.46) mmol/L vs 5.31 (1.37) mmol/L, p=0.00007), and had stronger evidence of a family history of early coronary heart disease (CHD) in parent or first-degree relative (overall 28.4% vs 19.0%, p=0.09). In statin-treated children LDL-C level was reduced by 35% (2.07 (1.38) mmol/L) compared with a reduction of 5.5% (0.29 (0.87) mmol/L), p=0.0001 in those not treated. None of those on statin had measured plasma levels of creatine kinase, alanine aminotransferase and AST indicative of statin toxicity (ie, >2.5 times the upper limit of the normal range). CONCLUSIONS: The data indicates that treatment decisions in children with FH are appropriately based on a stronger family history of CHD and higher LDL-C
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