1,856 research outputs found

    Flavour Changing Neutral Currents and Inverted Sfermion Mass Hierarchy

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    We study the contraints on non-flavour-blind soft supersymmetry breaking terms coming from flavour and CP violating processes in the presence of hierarchical Yukawa couplings, and quantify how much these constraints are weakened in the regions of the MSSM parameter space characterized by heavy gauginos and multi-TeV sfermion masses, respectively. We also study the inverted sfermion mass hierarchy scenario in the context of D-term supersymmetry breaking, and show that generic hierarchical Yukawa couplings with arbitrary phases require first generation squarks in the few 10 TeV range.Comment: 9 pages, 6 figures. Talk given at the XLth Rencontres de Moriond on Electroweak Interactions and Unified Theories, La Thuile, Aosta Valley, Italy, 5-12 March 2005. V3: one reference correcte

    Traceability to ensure food safety and consumer protection as typified by case studies of three meat processing plants

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    Ensuring food safety is a legal obligation of the manufacturer or of the entity that places the product on sale. Traceability is one of the tools that are used to ensure food safety. It allows the withdrawal of a dangerous or non-compliant product from the market and determines the source of a threat. The aim of the study was to compare the functioning and effectiveness of traceability systems in selected approved meat industry plants. The system functioning in a large meat processing plant, in which the circulation of documents was implemented in a computer system, was compared with two smaller ones, in which paper documentation was carried out, but supported by a computer system. In these plants, the traceability system was based on internal procedures. Properly developed traceability procedures and simulations support and enable response in a crisis. Computer systems streamline and facilitate the traceability process. However, the comparative analysis showed that the use of paper records allowed for efficient identification of the source of the threat. The possibility of performing product traceability was confirmed in these plants. Internal markings and codes and documentation flow, staff training, and awareness proved helpful

    Constrained MSSM favoring new territories: The impact of new LHC limits and a 125 GeV Higgs boson

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    We present an updated and extended global analysis of the Constrained MSSM (CMSSM) taking into account new limits on supersymmetry from ~5/fb data sets at the LHC. In particular, in the case of the razor limit obtained by the CMS Collaboration we simulate detector efficiency for the experimental analysis and derive an approximate but accurate likelihood function. We discuss the impact on the global fit of a possible Higgs boson with mass near 125 GeV, as implied by recent data, and of a new improved limit on BR(B_s->\mu\mu). We identify high posterior probability regions of the CMSSM parameters as the stau-coannihilation and the A-funnel region, with the importance of the latter now being much larger due to the combined effect of the above three LHC results and of dark matter relic density. We also find that the focus point region is now disfavored. Ensuing implications for superpartner masses favor even larger values than before, and even lower ranges for dark matter spin-independent cross section, \sigma^{SI}_p<10^{-9} pb. We also find that relatively minor variations in applying experimental constraints can induce a large shift in the location of the best-fit point. This puts into question the robustness of applying the usual chisquare approach to the CMSSM. We discuss the goodness-of-fit and find that, while it is difficult to calculate a p-value, the g-2 constraint makes, nevertheless, the overall fit of the CMSSM poor. We consider a scan without this constraint, and we allow \mu\ to be either positive or negative. We find that the global fit improves enormously for both signs of \mu, with a slight preference for \mu<0 caused by a better fit to BR(b->s\gamma) and BR(B_s->\mu\mu).Comment: 24 pages, 17 figures. PRD-approved version; Higgs bounds case removed as obsolete in light of the Higgs discover

    Update on Fermion Mass Models with an Anomalous Horizontal U(1) Symmetry

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    We reconsider models of fermion masses and mixings based on a gauge anomalous horizontal U(1) symmetry. In the simplest model with a single flavon field and horizontal charges of the same sign for all Standard Model fields, only very few charge assignements are allowed when all experimental data, including neutrino oscillation data, is taken into account. We show that a precise description of the observed fermion masses and mixing angles can easily be obtained by generating sets of the order one parameters left unconstrained by the U(1) symmetry. The corresponding Yukawa matrices show several interesting features which may be important for flavour changing neutral currents and CP violation effects in supersymmetric models.Comment: 23 pages, 8 figure

    High-energy electron measurements with thin Si detectors

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    A technique for measuring high-energy electrons using Si detectors of various thicknesses that are much smaller than the range of the examined electrons is presented. The advantages of the method are discussed on the basis of electron-positron pair creation recently studied in deuteron-deuteron fusion reactions at very low energies. Careful Geant 4 Monte Carlo simulations enabled the identification of the main spectral contributions of emitted electrons and positrons resulting from the energy loss mechanisms and scattering processes within the target, detector and their holders. Significant changes in the intensity of the detected electrons, depending on the detector thickness and the thicknesses of absorption foils placed in the front of the detector could be observed. The corresponding correction factors have been calculated and can be used for different applications in basic and applied research

    Nuclear spins, magnetic moments and quadrupole moments of Cu isotopes from N = 28 to N = 46: probes for core polarization effects

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    Measurements of the ground-state nuclear spins, magnetic and quadrupole moments of the copper isotopes from 61Cu up to 75Cu are reported. The experiments were performed at the ISOLDE facility, using the technique of collinear laser spectroscopy. The trend in the magnetic moments between the N=28 and N=50 shell closures is reasonably reproduced by large-scale shell-model calculations starting from a 56Ni core. The quadrupole moments reveal a strong polarization of the underlying Ni core when the neutron shell is opened, which is however strongly reduced at N=40 due to the parity change between the pfpf and gg orbits. No enhanced core polarization is seen beyond N=40. Deviations between measured and calculated moments are attributed to the softness of the 56Ni core and weakening of the Z=28 and N=28 shell gaps.Comment: 13 pagers, 19 figures, accepted by Physical Review

    Aortic coarctation in the recipient in TTTS – diagnostic problems – a case report

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    The paper presents a case of coexistence of the aortic coarctation with TTTS. This rare coincidence and hemodynamic disturbances resulting from hypovolemia interfere with the hemodynamic picture of the structural cardiac defect. Prenatal diagnosis is based on the assessment of the size of both ventricles. If the defect is present, the left ventricle is usually smaller than the right one. Coarctation may be also suspected in case there is disparity between large vessels in the mediastinum. Comparison of the width of the aorta, and ductus arteriosus, especially if the rate is 2:1 in favor of the latter, may suggest such defect. Furthermore, the finding of continuous flow through the aortic isthmus increases the likelihood of the defect 16-fold. The presence of „coarctation shelf” in color Doppler may suggest the existence of the cardiac defect that will require an intervention. In the present study the aortic coarctation was diagnosed in the recipient, who presented marked features of hypervolemia in venous Doppler studies, and in echocardiographic assessment of the right heart. The paper presents signs of hemodynamic disturbances in Doppler studies and changes of Doppler blood flow parameters observed during therapy (i.e. amnioreduction, fetoscopy). Diagnosis of coarctation may be hindered by the presence of the right heart volume overload, hypertrophy of the heart muscle as a result of associated hemodynamic disturbances in twin-to-twin transfusion syndrome. The impact of therapeutic interventions such as amnioreduction and fetoscopy the on cardiovascular hemodynamic parameters of both fetuses is also discussed. Also, a wide ductus arteriosus may make it difficult to diagnose this defect in utero. The paper presents diagnostic and therapeutic management in a case of TTTS complicated by an aortic coarctation in the recipient

    Penning trap mass measurements on (99-109)$Cd with ISOLTRAP and implications on the rp process

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    Penning trap mass measurements on neutron-deficient Cd isotopes (99-109)Cd have been performed with the ISOLTRAP mass spectrometer at ISOLDE/CERN, all with relative mass uncertainties below 3*10^8. A new mass evaluation has been performed. The mass of 99Cd has been determined for the first time which extends the region of accurately known mass values towards the doubly magic nucleus 100Sn. The implication of the results on the reaction path of the rp process in stellar X-ray bursts is discussed. In particular, the uncertainty of the abundance and the overproduction created by the rp-process for the mass A = 99 is demonstrated by reducing the uncertainty of the proton-separation energy of 100In Sp(100In) by a factor of 2.5.Comment: 14 pages, 9 figure

    Distinct roles of DBHS family members in the circadian transcriptional feedback loop

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    Factors interacting with core circadian clock components are essential to achieve transcriptional feedback necessary for metazoan clocks. Here we show that all three members of the Drosophila Behavior Human Splicing (DBHS) family of RNA-binding proteins play a role in the mammalian circadian oscillator, abrogating or altering clock function when overexpressed or depleted in cells. Although these proteins are members of so-called nuclear paraspeckles, depletion of paraspeckles themselves via silencing of the structural non-coding RNA (ncRNA) Neat1 did not affect overall clock function, suggesting that paraspeckles are not required for DBHS-mediated circadian effects. Instead, we show that the proteins bound to circadian promoter DNA in a fashion that required the PERIOD (PER) proteins, and potently repressed E box-mediated transcription but not CMV promoter-mediated transcription when exogenously recruited. Nevertheless, mice with one or both copies of these genes deleted show only small changes in period length or clock gene expression in vivo. Data from transient transfections show that each of these proteins can either repress or activate depending on the context. Taken together, our data suggest that all of the DBHS family members serve overlapping or redundant roles as transcriptional cofactors at circadian clock-regulated genes
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