206 research outputs found
Rare and CP-Violating K and B Decays in the Littlest Higgs Model with T-Parity
We calculate the most interesting rare and CP-violating K and B decays in the
Littlest Higgs model with T-parity. We give a collection of Feynman rules
including v^2/f^2 contributions that are presented here for the first time and
could turn out to be useful also for applications outside flavour physics. We
adopt a model-independent parameterization of rare decays in terms of the gauge
independent functions X_i,Y_i,Z_i (i=K,d,s), which is in particular useful for
the study of the breaking of the universality between K, B_d and B_s systems
through non-MFV interactions. Performing the calculation in the unitary and 't
Hooft-Feynman gauge, we find that the final result contains a divergence which
signals some sensitivity to the ultraviolet completion of the theory. Including
an estimate of this contribution, we calculate the branching ratios for the
decays , , , , and , paying particular attention to non-MFV contributions
present in the model.
Imposing all available constraints we find that the decay rates for and can be enhanced by at most
50% and 35% relative to the SM values, while and
can be both as high as .
Significant enhancements of the decay rates are also
possible. Simultaneously, the CP-asymmetries and
can be enhanced by an order of magnitude, while the electroweak
penguin effects in turn out to be small, in agreement with the
recent data.Comment: 65 pages, 19 figures. Note added on omitted term in Z-penguin
contribution. For an updated analysis see arXiv:0906.545
Engineering failure analysis and design optimisation with HiP-HOPS
The scale and complexity of computer-based safety critical systems, like those used in the transport and manufacturing industries, pose significant challenges for failure analysis. Over the last decade, research has focused on automating this task. In one approach, predictive models of system failure are constructed from the topology of the system and local component failure models using a process of composition. An alternative approach employs model-checking of state automata to study the effects of failure and verify system safety properties. In this paper, we discuss these two approaches to failure analysis. We then focus on Hierarchically Performed Hazard Origin & Propagation Studies (HiP-HOPS) - one of the more advanced compositional approaches - and discuss its capabilities for automatic synthesis of fault trees, combinatorial Failure Modes and Effects Analyses, and reliability versus cost optimisation of systems via application of automatic model transformations. We summarise these contributions and demonstrate the application of HiP-HOPS on a simplified fuel oil system for a ship engine. In light of this example, we discuss strengths and limitations of the method in relation to other state-of-the-art techniques. In particular, because HiP-HOPS is deductive in nature, relating system failures back to their causes, it is less prone to combinatorial explosion and can more readily be iterated. For this reason, it enables exhaustive assessment of combinations of failures and design optimisation using computationally expensive meta-heuristics. (C) 2010 Elsevier Ltd. All rights reserved
Another Look at Minimal Lepton Flavour Violation, l_i -> l_j gamma, Leptogenesis, and the Ratio M_nu/ Lambda_LFV
We analyze lepton flavour violation (LFV), as well as generation of the
observed baryon-antibaryon asymmetry of the Universe (BAU) within a generalized
minimal lepton flavour violation (MLFV) framework where we allow for CP
violation both at low and high energies. The generation of BAU is obtained
through radiative resonant leptogenesis (RRL), where starting with three
exactly degenerate right-handed neutrinos at Lambda_GUT, we demonstrate
explicitly within the SM and the MSSM that the splittings between their masses
at the see-saw scale M_nu, generated by renormalization group effects, are
sufficient for a successful leptogenesis for M_nu even as low as 10^6 GeV. The
inclusion of flavour effects plays an important role in this result and can
lead to the observed BAU even in the absence of CP violation beyond the PMNS
phases. The absence of a stringent lower bound on M_nu in this type of
leptogenesis allows to easily satisfy present and near future upper bounds on
mu -> e gamma and other charged lepton flavour violating (LFV) processes even
for Lambda_LFV = O(1 TeV). We find, that the MLFV framework in the presence of
heavy right-handed neutrinos and leptogenesis is not as predictive as MFV in
the quark sector and point out that without a specific MLFV model, there is a
rich spectrum of possibilities for charged LFV processes and for their
correlation with low energy neutrino physics and the LHC physics, even if the
constraint from the observed BAU is taken into account. While certain
qualitative features of our analysis confirm findings of Cirigliano et al., at
the quantitative level we find phenomenologically important differences. We
explain the origin of these differences.Comment: 48 pages, 9 figure
Thermoresponsive Microgel Coatings as Versatile Functional Compounds for Novel Cell Manipulation Tools
Uhlig K, Wegener T, Hertle Y, et al. Thermoresponsive Microgel Coatings as Versatile Functional Compounds for Novel Cell Manipulation Tools. POLYMERS. 2018;10(6): 656.For the effective use of live cells in biomedicine as in vitro test systems or in biotechnology, non-invasive cell processing and characterisation are key elements. Thermoresponsive polymer coatings have been demonstrated to be highly beneficial for controlling the interaction of adherent cells through their cultivation support. However, the widespread application of these coatings is hampered by limitations in their adaptability to different cell types and because the full range of applications has not yet been fully explored. In the work presented here, we address these issues by focusing on three different aspects. With regard to the first aspect, by using well-defined laminar flow in a microchannel, a highly controllable and reproducible shear force can be applied to adherent cells. Employing this tool, we demonstrate that cells can be non-invasively detached from a support using a defined shear flow. The second aspect relates to the recent development of simple methods for patterning thermoresponsive coatings. Here, we show how such patterned coatings can be used for improving the handling and reliability of a wound-healing assay. Two pattern geometries are tested using mouse fibroblasts and CHO cells. In terms of the third aspect, the adhesiveness of cells depends on the cell type. Standard thermoresponsive coatings are not functional for all types of cells. By coadsorbing charged nanoparticles and thermoresponsive microgels, it is demonstrated that the adhesion and detachment behaviour of cells on such coatings can be modulated
Sobre la presència de Teucrium pumilum i Teucrium libanitis (Lamiaceae) a la província de València.
12p. fotog.color.[EN] About the presence of Teucrium pumilum and Teucrium libanitis (Lamiaceae) in the Valencian province, Spain.- Teucrium
pumilum and T. libanitis have been cited from Valencia province (Spain) since the middle of the XXth Century
from the gypsic soils in the Valle de Ayora-Cofrentes shire. The analysis of specimens and labels is not conclusive;
no specimen would certify the presence of any of these taxa. The field identification and their inclusion in a phyotosociological
table (relevé) by Rivas Goday are the only basis of their presence in the territory in a particular moment
of the recent Spanish botanical history. Additionally, the unique herbarium specimen from Valencia, impossible to
assign a concrete geographic locality, which was traditionally assigned to T. pumilum by some authors, is actually
its congeneric T. carolipaui.[ES] Sobre la presencia de Teucrium pumilum y Teucrium libanitis (Lamiaceae) en la provincia de Valencia.- Teucrium
pumilum y T. libanitis son dos especies que han sido citadas como presentes en la provincia de Valencia desde mediados
del siglo XX, para los yesos que afloran en la comarca del Valle de Ayora-Cofrentes. El análisis de las etiquetas
de los pliegos de los herbarios no es concluyente; ningún pliego testigo certificaría la presencia de estas especies. La
determinación de visu por parte de Rivas Goday, y su inclusión en una tabla de inventarios fitosociológica, son el
único fundamento de su existencia en la zona en algún momento determinado de la reciente historia botánica española.
Además, para T. pumilum, el pliego de herbario que tradicionalmente se ha asignado a la cita valenciana se trata de
una confusión en la determinación por parte de algunos autores con su congénere T. carolipaui, siendo imposible al
mismo tiempo asignar una localidad geográfica concreta a este material.[CAT] Sobre la presència de Teucrium pumilum i Teucrium libanitis (Lamiaceae) a la província de València.- Teucrium pumilum
i T. libanitis són dues espècies que han estat citades com a presents a la província de València des de mitjans
del segle XX, sobre els guixos que afloren a la comarca de la Vall d’Aiora-Cofrents. L’anàlisi de les etiquetes dels
plecs dels herbaris no és concloent; cap plec testimoni certificaria la presència d’aquestes espècies. La determinació
de visu per part de Rivas Goday, i la seva inclusió en una taula d’inventaris fitosociològica, són l’únic fonament de la
seva existència a la zona en un moment determinat de la recent història botànica espanyola. A més, per a T. pumilum,
el plec d’herbari que tradicionalment s’ ha assignat a la cita valenciana es tracta d’una confusió en la determinació
per part d’alguns autors amb el seu congènere.Peer reviewe
Kaon and Antikaon Production in Heavy Ion Collisions at 1.5 AGeV
At the Kaon Spectrometer KaoS at SIS, GSI the production of kaons and
antikaons in heavy ion reactions at a beam energy of 1.5 AGeV has been measured
for the collision systems Ni+Ni and Au+Au. The K-/K+ ratio is found to be
constant for both systems and as a function of impact parameter but the slopes
of K+ and K- spectra differ for all impact parameters. Furthermore the
respective polar angle distributions will be presented as a function of
centrality.Comment: 4 pages, 4 figures, SQM2001 in Frankfurt, Sept.2001, submitted to
Journal of Physics
Экспериментальное исследование синхронного генератора периодических импульсов
Приводятся результаты экспериментального исследования влияния величины нагрузки синхронного генератора периодических импульсов с обычной геометрией зубцовой зоны на форму импульсов тока. Рассматривается возможность регулировки параметров импульсов
Impact of Right Atrial Physiology on Heart Failure and Adverse Events after Myocardial Infarction
Background: Right ventricular (RV) function is a known predictor of adverse events in heart failure and following acute myocardial infarction (AMI). While right atrial (RA) involvement is well characterized in pulmonary arterial hypertension, its relative contributions to adverse events following AMI especially in patients with heart failure and congestion need further evaluation. Methods: In this cardiovascular magnetic resonance (CMR)-substudy of AIDA STEMI and TATORT NSTEMI, 1235 AMI patients underwent CMR after primary percutaneous coronary intervention (PCI) in 15 centers across Germany (n = 795 with ST-elevation myocardial infarction and 440 with non-ST-elevation MI). Right atrial (RA) performance was evaluated using CMR myocardial feature tracking (CMR-FT) for the assessment of RA reservoir (total strain εs), conduit (passive strain εe), booster pump function (active strain εa), and associated strain rates (SR) in a blinded core-laboratory. The primary endpoint was the occurrence of major adverse cardiac events (MACE) 12 months post AMI. Results: RA reservoir (εs p = 0.061, SRs p = 0.049) and conduit functions (εe p = 0.006, SRe p = 0.030) were impaired in patients with MACE as opposed to RA booster pump (εa p = 0.579, SRa p = 0.118) and RA volume index (p = 0.866). RA conduit function was associated with the clinical onset of heart failure and MACE independently of RV systolic function and atrial fibrillation (AF) (multivariable analysis hazard ratio 0.95, 95% confidence interval 0.92 to 0.99, p = 0.009), while RV systolic function and AF were not independent prognosticators. Furthermore, RA conduit strain identified low- and high-risk groups within patients with reduced RV systolic function (p = 0.019 on log rank testing). Conclusions: RA impairment is a distinct feature and independent risk factor in patients following AMI and can be easily assessed using CMR-FT-derived quantification of RA strain
Particle-Antiparticle Mixing, epsilon_K, Delta Gamma_q, A_SL^q, A_CP(B_d -> psi K_S), A_CP(B_s -> psi phi) and B -> X_{s,d} gamma in the Littlest Higgs Model with T-Parity
We calculate a number of observables related to particle-antiparticle mixing
in the Littlest Higgs model with T-parity (LHT). The resulting effective
Hamiltonian for Delta F=2 transitions agrees with the one of Hubisz et al., but
our phenomenological analysis goes far beyond the one of these authors. In
particular, we point out that the presence of mirror fermions with new flavour
and CP-violating interactions allows to remove the possible Standard Model (SM)
discrepancy between the CP asymmetry S_{psi K_S} and large values of |V_ub| and
to obtain for the mass difference Delta M_s < (Delta M_s)_SM as suggested by
the recent result by the CDF collaboration. We also identify a scenario in
which simultaneously significant enhancements of the CP asymmetries S_{phi psi}
and A_SL^q relative to the SM are possible, while satisfying all existing
constraints, in particular from the B -> X_s gamma decay and A_CP(B -> X_s
gamma) that are presented in the LHT model here for the first time. In another
scenario the second, non-SM, value for the angle gamma=-(109+-6) from tree
level decays, although unlikely, can be made consistent with all existing data
with the help of mirror fermions. We present a number of correlations between
the observables in question and study the implications of our results for the
mass spectrum and the weak mixing matrix of mirror fermions. In the most
interesting scenarios, the latter one turns out to have a hierarchical
structure that differs significantly from the CKM one.Comment: 51 pages, 20 figures, 1 table. Extended discussion of the phases in
the new mixing matrix V_Hd, some references added or updated, conclusions
unchanged. Final version published in JHE
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