ABSTRACT
The rare decay Bâπâ^{+}â^{-} arises from bâd flavor-changing neutral currents and could be sensitive to physics beyond the standard model. Here, we present the first ab initio QCD calculation of the Bâπ tensor form factor f_{T}. Together with the vector and scalar form factors f_{+} and f_{0} from our companion work [J. A. Bailey et al., Phys. Rev. D 92, 014024 (2015)], these parametrize the hadronic contribution to Bâπ semileptonic decays in any extension of the standard model. We obtain the total branching ratio BR(B^{+}âπ^{+}µ^{+}µ^{-})=20.4(2.1)×10^{-9} in the standard model, which is the most precise theoretical determination to date, and agrees with the recent measurement from the LHCb experiment [R. Aaij et al., J. High Energy Phys. 12 (2012) 125].
Subject(s)
Elementary Particles , Models, Theoretical , Nuclear Physics , ProtonsABSTRACT
We calculate the kaon semileptonic form factor f+(0) from lattice QCD, working, for the first time, at the physical light-quark masses. We use gauge configurations generated by the MILC Collaboration with Nf = 2 + 1 + 1 flavors of sea quarks, which incorporate the effects of dynamical charm quarks as well as those of up, down, and strange. We employ data at three lattice spacings to extrapolate to the continuum limit. Our result, f+(0) = 0.9704(32), where the error is the total statistical plus systematic uncertainty added in quadrature, is the most precise determination to date. Combining our result with the latest experimental measurements of K semileptonic decays, one obtains the Cabibbo-Kobayashi-Maskawa matrix element |V(us)| = 0.22290(74)(52), where the first error is from f+(0) and the second one is from experiment. In the first-row test of Cabibbo-Kobayashi-Maskawa unitarity, the error stemming from |V(us)| is now comparable to that from |V(ud)|.
ABSTRACT
A calculation of the ratio of leptonic decay constants f(K+)/f(π+) makes possible a precise determination of the ratio of Cabibbo-Kobayashi-Maskawa (CKM) matrix elements |V(us)|/|V(ud)| in the standard model, and places a stringent constraint on the scale of new physics that would lead to deviations from unitarity in the first row of the CKM matrix. We compute f(K+)/f(π+) numerically in unquenched lattice QCD using gauge-field ensembles recently generated that include four flavors of dynamical quarks: up, down, strange, and charm. We analyze data at four lattice spacings a ≈ 0.06, 0.09, 0.12, and 0.15 fm with simulated pion masses down to the physical value 135 MeV. We obtain f(K+)/f(π+) = 1.1947(26)(37), where the errors are statistical and total systematic, respectively. This is our first physics result from our N(f) = 2+1+1 ensembles, and the first calculation of f(K+)/f(π+) from lattice-QCD simulations at the physical point. Our result is the most precise lattice-QCD determination of f(K+)/f(π+), with an error comparable to the current world average. When combined with experimental measurements of the leptonic branching fractions, it leads to a precise determination of |V(us)|/|V(ud)| = 0.2309(9)(4) where the errors are theoretical and experimental, respectively.
ABSTRACT
The semileptonic decay channel BâDτν is sensitive to the presence of a scalar current, such as that mediated by a charged-Higgs boson. Recently, the BABAR experiment reported the first observation of the exclusive semileptonic decay BâDτ(-)ν, finding an approximately 2σ disagreement with the standard-model prediction for the ratio R(D)=BR(BâDτν)/BR(BâDâν), where â = e,µ. We compute this ratio of branching fractions using hadronic form factors computed in unquenched lattice QCD and obtain R(D)=0.316(12)(7), where the errors are statistical and total systematic, respectively. This result is the first standard-model calculation of R(D) from ab initio full QCD. Its error is smaller than that of previous estimates, primarily due to the reduced uncertainty in the scalar form factor f(0)(q(2)). Our determination of R(D) is approximately 1σ higher than previous estimates and, thus, reduces the tension with experiment. We also compute R(D) in models with electrically charged scalar exchange, such as the type-II two-Higgs-doublet model. Once again, our result is consistent with, but approximately 1σ higher than, previous estimates for phenomenologically relevant values of the scalar coupling in the type-II model. As a by-product of our calculation, we also present the standard-model prediction for the longitudinal-polarization ratio P(L)(D)=0.325(4)(3).
ABSTRACT
We review lattice results related to pion, kaon, D- and B-meson physics with the aim of making them easily accessible to the particle-physics community. More specifically, we report on the determination of the light-quark masses, the form factor [Formula: see text], arising in the semileptonic [Formula: see text] transition at zero momentum transfer, as well as the decay constant ratio [Formula: see text] and its consequences for the CKM matrix elements [Formula: see text] and [Formula: see text]. Furthermore, we describe the results obtained on the lattice for some of the low-energy constants of [Formula: see text] and [Formula: see text] Chiral Perturbation Theory. We review the determination of the [Formula: see text] parameter of neutral kaon mixing as well as the additional four B parameters that arise in theories of physics beyond the Standard Model. The latter quantities are an addition compared to the previous review. For the heavy-quark sector, we provide results for [Formula: see text] and [Formula: see text] (also new compared to the previous review), as well as those for D- and B-meson-decay constants, form factors, and mixing parameters. These are the heavy-quark quantities most relevant for the determination of CKM matrix elements and the global CKM unitarity-triangle fit. Finally, we review the status of lattice determinations of the strong coupling constant [Formula: see text].
ABSTRACT
Many guideline only implicitly or vaguely define the process of health care delivery. However, an explicit model of the medical tasks comprising this process is needed before active decision support at the patient encounter can take place. We propose to use a structured, but semi-formal representation as intermediate step in the process of enacting a guideline. This allows for the application independent representation of the content of a guideline enabled for decision support. The process and the tools of the methodology have been applied to enable guidelines from the field of Diabetes mellitus.
Subject(s)
Decision Making, Computer-Assisted , Decision Support Systems, Clinical , Practice Guidelines as Topic , Diabetic Nephropathies/diagnosis , Diabetic Nephropathies/therapy , Diabetic Neuropathies/diagnosis , Diabetic Neuropathies/therapy , Humans , Software DesignABSTRACT
BACKGROUND: Health care network eHealth.Braunschweig has been started in the South-East region of Lower Saxony in Germany in 2009. It composes major health care players, participants from research institutions and important local industry partners. OBJECTIVES: The objective of this paper is firstly to describe the relevant regional characteristics and distinctions of the eHealth.Braunschweig health care network and to inform about the goals and structure of eHealth.Braunschweig; secondly to picture and discuss the main concepts and domain fields which are addressed in the health care network; and finally to discuss the architectural challenges of eHealth.Braunschweig regarding the addressed domain fields and defined requirements. METHODS: Based on respective literature and former conducted projects we discuss the project structure and goals of eHealth.Braunschweig, depict major domain fields and requirements gained in workshops with participants and discuss the architectural challenges as well as the architectural approach of eHealth.Braunschweig network. RESULTS: The regional healthcare network eHealth.Braunschweig has been established in April 2009. Since then the network has grown constantly and a sufficient progress in network activities has been achieved. The main domain fields have been specified in different workshops with network participants and an architectural realization approach for the transinstitutional information system architecture in the healthcare network has been developed. However, the effects on quality of information processing and quality of patient care have not been proved yet. Systematic evaluation studies have to be done in future in order to investigate the impact of information and communication technology on the quality of information processing and the quality of patient care. CONCLUSIONS: In general, the aspects described in this paper are expected to contribute to a systematic approach for the establishment of regional health care networks with lasting and sustainable effects on patient-centered health care in a regional context.
Subject(s)
Delivery of Health Care, Integrated/organization & administration , Medical Informatics/organization & administration , Patient-Centered Care/organization & administration , Telemedicine/organization & administration , Computer Systems , Cooperative Behavior , Geography , Germany , Humans , Methicillin-Resistant Staphylococcus aureus , Program Evaluation , RegistriesABSTRACT
We present the first three-flavor lattice QCD calculations for D-->pilnu and D-->Klnu semileptonic decays. Simulations are carried out using ensembles of unquenched gauge fields generated by the MILC Collaboration. With an improved staggered action for light quarks, we are able to simulate at light quark masses down to 1/8 of the strange mass. Consequently, the systematic error from the chiral extrapolation is much smaller than in previous calculations with Wilson-type light quarks. Our results for the form factors at q(2)=0 are f(D-->pi)(+)(0)=0.64(3)(6) and f(D-->K)(+)(0)=0.73(3)(7), where the first error is statistical and the second is systematic, added in quadrature. Combining our results with experimental branching ratios, we obtain the Cabibbo-Kobayashi-Maskawa matrix elements |V(cd)|=0.239(10)(24)(20) and |V(cs)|=0.969(39)(94)(24), where the last errors are from experimental uncertainties.
ABSTRACT
We present the first lattice QCD calculation with realistic sea quark content of the D+-meson decay constant f(D+). We use the MILC Collaboration's publicly available ensembles of lattice gauge fields, which have a quark sea with two flavors (up and down) much lighter than a third (strange). We obtain f(D+)=201+/-3+/-17 MeV, where the errors are statistical and a combination of systematic errors. We also obtain f(Ds)=249+/-3+/-16 MeV for the Ds meson.
ABSTRACT
Tubal insufficiency evoked by inflammation or mechanical obstruction due to enlarged adenoids plays an important role in the pathogenesis of chronic serous otitis media. Serous and mucous tympanic effusions in the presence of immature middle ear mucosa and pneumatisation follow. An adhesive process can be the result. Secretory outflow as well as constant pressure compensation between the tympanic cavity and the auditory meatus can only be achieved by a long-term tympanic drainage. Progression of pneumatisation is achieved by recovery of the middle ear mucosa and in most cases an adhesive process can be prevented.
Subject(s)
Mastoid/diagnostic imaging , Middle Ear Ventilation , Otitis Media with Effusion/surgery , Postoperative Complications/diagnostic imaging , Child , Child, Preschool , Female , Humans , Long-Term Care , Radiography , Recurrence , Reoperation , Tissue AdhesionsABSTRACT
Single impulse stimulation in the area of locus coeruleus (LC) in freely moving rats evokes bilateral symmetrical potentials (EP) in the frontal cortex. Threshold intensity for this potential was higher when the stimulus electrode was in the LC than in the cholinergic dorsal parabrachial nucleus lateral of LC. Amplitudes and peak times of this EP were constant during relaxed wakefulness, exploratory behavior and unaffected by beta-blockade (propranolol, 2.5 mg/kg i.p.). Their amplitudes were strongly decreased and the peak times of later negativity (N50) were prolonged during slow wave sleep and by muscarinic blockade with scopolamine (0.5 mg/kg i.p.) which induced active behavior and synchronized EEG. These data suggest a direct participation of cholinergic structures in cortical potential evoked by electrical LC stimulation. Relations between stimulus effect and behavior regulating systems are discussed.
Subject(s)
Cerebral Cortex/physiology , Locus Coeruleus/physiology , Receptors, Muscarinic/physiology , Animals , Electric Stimulation , Evoked Potentials/drug effects , Male , Motor Activity , Olfactory Bulb/physiology , Propranolol/pharmacology , Rats , Receptors, Adrenergic, beta/drug effects , Receptors, Adrenergic, beta/physiology , Receptors, Muscarinic/drug effects , Respiration , Scopolamine/pharmacology , WakefulnessABSTRACT
Interactions between light-flash stimulation and electrical single impulse stimulation of locus coeruleus (LC) were investigated in 9 freely moving rats with chronically implanted electrodes during different behavioral states. The interaction of both showed different immediate and long-lasting effects. Simultaneous visual and electrical stimulation caused a clear decrease of trigger rate of photically evoked after-discharges from 60% to 15% and a reduction of the early primary component of visually evoked potentials (VEP) in area 17 compared with the values without LC stimulation during relaxed wakefulness (RW). On the contrary, the simultaneous LC stimulation was ineffective during exploratory behavioral states (E). At 100 ms stimulus interval and more there was no detectable LC stimulus effect on VEP components during RW, whereas the LC stimulation under beta-blockade (2.5 mg/kg propranolol i.p.) during RW-like behavior clearly reduced the early VEP component to 75% compared with values without LC stimulation. On the other hand, LC stimulation facilitated mainly the primary VEP component to about 160% during E compared with the flash response alone. This effect was observed from 100 to 300 ms after LC stimulus and was unaffected by muscarinic blockade (0.5 mg/kg scopolamine i.p.). We conclude from these data that the short-time effects are comparable with the influence of spontaneous behavioral activation and probably result from a costimulation of cholinergic neurons around LC, whereas the long-lasting effects may be attributed to the influence of noradrenergic LC cells. The noradrenergic-dependent facilitation of early VEP component counteracts the cholinergically-induced reduction.
Subject(s)
Evoked Potentials, Visual , Locus Coeruleus/physiology , Animals , Electric Stimulation , Evoked Potentials, Visual/drug effects , Male , Photic Stimulation , Propranolol/pharmacology , Rats , Receptors, Adrenergic, beta/drug effects , Receptors, Adrenergic, beta/physiology , Receptors, Muscarinic/drug effects , Receptors, Muscarinic/physiology , Scopolamine/pharmacologyABSTRACT
Immunoserological assays of patients with sudden deafness and progressive hearing losses have revealed the presence of different antibodies, leading to the assumption that immunological processes may be involved. Recent investigations have demonstrated that these patients have phospholipid antibodies that can cause venous or arterial vasculopathies. In the present study we analyzed the incidence of these antibodies in patients with inner ear disorders. Sera of 55 patients with sudden deafness and 80 patients with progressive hearing loss were tested. Phospholipid antibodies were demonstrable in 49% of the patients with sudden hearing loss and 50% of the patients with progressive hearing loss. Serotonin and ganglioside antibodies were found in 53% of the patients with sudden hearing loss and 63% of the patients with progressive hearing loss. Since these three antibodies are also frequently found in patients with fibromyalgia syndrome (FMS) and chronic fatigue syndrome (CFS), 28 of the patients studied displayed symptoms typical for these disorders, including fatigue, myalgia, arthralgia, depressions, sicca symptoms and diarrhea. We now recommend questioning patients suffering from inner ear disorders for symptoms typical for FMS or CFS, since these diseases are often closely related to inner ear disorders. If symptoms are present, antibodies should be tested against phospholipids, serotonin and gangliosides. If present, the antibodies are diagnostic for each syndrome. Additionally these immunologic and serologic findings show that these antibodies may play a role in the etiology of hearing loss disorders.
Subject(s)
Antibodies, Antiphospholipid/blood , Autoantibodies/blood , Autoimmune Diseases/immunology , Gangliosides/immunology , Hearing Loss, Sensorineural/immunology , Hearing Loss, Sudden/immunology , Serotonin/immunology , Adolescent , Adult , Aged , Antiphospholipid Syndrome/diagnosis , Antiphospholipid Syndrome/immunology , Autoimmune Diseases/diagnosis , Child , Diagnosis, Differential , Fatigue Syndrome, Chronic/diagnosis , Fatigue Syndrome, Chronic/immunology , Female , Fibromyalgia/diagnosis , Fibromyalgia/immunology , Hearing Loss, Sensorineural/diagnosis , Humans , Male , Middle Aged , Patient Care TeamABSTRACT
The recently developed Symanzik-improved staggered-quark discretization allows unquenched lattice-QCD simulations with much smaller (and more realistic) quark masses than previously possible. To test this formalism, we compare experiment with a variety of nonperturbative calculations in QCD drawn from a restricted set of "gold-plated" quantities. We find agreement to within statistical and systematic errors of 3% or less. We discuss the implications for phenomenology and, in particular, for heavy-quark physics.