Search results for "Viola"

showing 10 items of 697 documents

10.8 Conclusion

2008

Nuclear physicsPhysicsHiggs fieldParticle physicsBaryon asymmetryPontecorvo–Maki–Nakagawa–Sakata matrixCP violationCosmology
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Observation of the suppressed ADS modes B±→[π±K∓π+π−]DK± and B±→[π±K∓π+π−]Dπ±

2013

An analysis of and B-+/- -> DK +/- and B-+/- -> D pi(+/-) decays is presented where the D meson is reconstructed in the four-body final state K-+/-pi(-/+)pi(+)pi(-). Using LHCb data corresponding to an integrated luminosity of 1.0 fb(-1), first observations are made of the suppressed ADS modes B-+/- ->[pi K-+/-(-/+)pi(+)pi(-)](D)K-+/- and B +/- -> [pi K-+/-(-/+)pi(+)pi(-)](D)pi(+/-) with a significance of 5.1 sigma and greater than 10 sigma, respectively. Measurements of CP asymmetries and CP-conserving ratios of partial widths from this family of decays are also performed. The magnitude of the ratio between the suppressed and favoured B-+/- -> DK +/- amplitudes is determined to be r(B)(K) …

Nuclear physicsPhysicsNuclear and High Energy Physics010308 nuclear & particles physics0103 physical sciencesD mesonPiAnalytical chemistryCP violation010306 general physics01 natural sciencesPhysics Letters B
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Precise measurement of the K±→π±e+e− decay

2009

Abstract A sample of 7253 K ± → π ± e + e − ( γ ) decay candidates with 1.0% background contamination has been collected by the NA48/2 experiment at the CERN SPS, which allowed a precise measurement of the decay properties. The branching ratio in the full kinematic range was measured to be BR = ( 3.11 ± 0.12 ) × 10 − 7 , where the uncertainty includes also the model dependence. The shape of the form factor W ( z ) , where z = ( M e e / M K ) 2 , was parameterized according to several models, and, in particular, the slope δ of the linear form factor W ( z ) = W 0 ( 1 + δ z ) was determined to be δ = 2.32 ± 0.18 . A possible CP violating asymmetry of K + and K − decay widths was investigated,…

Nuclear physicsPhysicsNuclear and High Energy PhysicsMesonBranching fractionHadronGamma rayAnalytical chemistryCP violationRadioactive decayLeptonDimensionless quantityPhysics Letters B
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Search for CP violation in K0→3π0 decays

2005

Abstract Using data taken during the year 2000 with the NA48 detector at the CERN SPS, a search for the CP violating decay K S → 3 π 0 has been performed. From a fit to the lifetime distribution of about 4.9 million reconstructed K 0 / K ¯ 0 → 3 π 0 decays, the CP violating amplitude η 000 = A ( K S → 3 π 0 ) / A ( K L → 3 π 0 ) has been found to be Re ( η 000 ) = − 0.002 ± 0.011 ± 0.015 and Im ( η 000 ) = − 0.003 ± 0.013 ± 0.017 . This corresponds to an upper limit on the branching fraction of Br ( K S → 3 π 0 ) 7.4 × 10 −7 at 90% confidence level. The result is used to improve knowledge of Re ( e ) and the CPT violating quantity Im ( δ ) via the Bell–Steinberger relation.

Nuclear physicsPhysicsNuclear and High Energy PhysicsParticle physicsAmplitude010308 nuclear & particles physicsBranching fraction0103 physical sciencesPiCP violation010306 general physicsLifetime distribution01 natural sciencesPhysics Letters B
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Study of the rare Bs0 and B0 decays into the π+π−μ+μ− final state

2015

A search for the rare decays B0s→π+π−μ+μ− and B0→π+π−μ+μ− is performed in a data set corresponding to an integrated luminosity of 3.0 fb−1 collected by the LHCb detector in proton-proton collisions at centre-of-mass energies of 7 and 8 TeV. Decay candidates with pion pairs that have invariant mass in the range 0.5-1.3 GeV/c2 and with muon pairs that do not originate from a resonance are considered. The first observation of the decay B0s→π+π−μ+μ− and the first evidence of the decay B0→π+π−μ+μ− are obtained and the branching fractions are measured to be B(B0s→π+π−μ+μ−)=(8.6±1.5(stat)±0.7(syst)±0.7(norm))×10−8 and B(B0→π+π−μ+μ−)=(2.11±0.51(stat)±0.15(syst)±0.16(norm))×10−8, where the third unc…

Nuclear physicsPhysicsNuclear and High Energy PhysicsParticle physicsLarge Hadron ColliderMuonPionBranching fractionPiCP violationInvariant massPhysics Letters B
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The tagging detector of the CP-violation experiment NA48 at CERN

1998

Abstract The CP-violation experiment NA48 at CERN aims at measuring direct CP-violation in the decays of neutral kaons into π + π − and π 0 π 0 . The experiment uses simultaneous, almost collinear beams of neutral K L 0 and K S 0 mesons, which are produced on two different targets. K S 0 events are “tagged” by measuring the times of the protons that fly towards the K S 0 production target. In order to sustain the high rate of 10 7  protons/s in this beam without suffering from too many pile-up events, the detector consists of 24 separate scintillators (12 horizontal and 12 vertical), each of which sees only a small fraction of the beam. Their signals are digitized by specially developed 1 G…

Nuclear physicsPhysicsNuclear and High Energy PhysicsPionLarge Hadron ColliderMesonDetectorMeasuring instrumentCP violationInstrumentationParticle detectorBeam (structure)Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment
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10.7 Weak quark mixing and the CKM matrix

2008

Nuclear physicsQuarkPhysicsTop quarkParticle physicsCabibbo–Kobayashi–Maskawa matrixW and Z bosonsCP violationBottom quarkMixing (physics)
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Object Recognition and Modeling Using SIFT Features

2013

In this paper we present a technique for object recognition and modelling based on local image features matching. Given a complete set of views of an object the goal of our technique is the recognition of the same object in an image of a cluttered environment containing the object and an estimate of its pose. The method is based on visual modeling of objects from a multi-view representation of the object to recognize. The first step consists of creating object model, selecting a subset of the available views using SIFT descriptors to evaluate image similarity and relevance. The selected views are then assumed as the model of the object and we show that they can effectively be used to visual…

Object RecognitionSettore ING-INF/05 - Sistemi Di Elaborazione Delle InformazioniSIFT.business.industryComputer science3D single-object recognitionObject Recognition; Pose Estimation; Object Model; SIFT.ComputingMethodologies_IMAGEPROCESSINGANDCOMPUTERVISIONPattern recognition3D pose estimationObject (computer science)Object-oriented designPose EstimationHaar-like featuresObject modelViola–Jones object detection frameworkComputer visionArtificial intelligencebusinessPoseObject Model
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Macroalgal responses to ocean acidification depend on nutrient and light levels

2015

Ocean acidification may benefit algae that are able to capitalize on increased carbon availability for photosynthesis, but it is expected to have adverse effects on calcified algae through dissolution. Shifts in dominance between primary producers will have knock-on effects on marine ecosystems and will likely vary regionally, depending on factors such as irradiance (light vs. shade) and nutrient levels (oligotrophic vs. eutrophic). Thus experiments are needed to evaluate interactive effects of combined stressors in the field. In this study, we investigated the physiological responses of macroalgae near a CO2 seep in oligotrophic waters off Vulcano (Italy). The algae were incubated in situ …

Ocean Acidification International Coordination Centre (OA-ICC)TemperateSalinityChlorophyll aFucoxanthininorganicAlkalinityPhotosynthetic efficiency standard errorChlorophyll cNitrogen content per dry mass standard errorLight saturation point standard errorPhenolics allTemperature waterCarbon inorganic dissolvedMacroalgaeCalculated using seacarb after Nisumaa et al 2010Carbon Nitrogen ratioAragonite saturation stateAlkalinity totalallCarbon per dry massSalinity standard errortotalCarbon content per dry mass standard errorPhenolics all standard errorCO2 ventChromistapHMaximum photochemical quantum yield of photosystem II standard errorTemperaturePartial pressure of carbon dioxide (water) at sea surface temperature (wet air) standard errordissolvedAntioxidant activity standard errorCarbonate ionMaximum photochemical quantum yield of photosystem IIPartial pressure of carbon dioxide (water) at sea surface temperature (wet air)Field experimentstandard errorNitrogen content per dry massElectron transport rate standard errorFucoxanthin standard errorEarth System ResearchViolaxanthinPhenolicsChlorophyll a standard errorCarbon dioxide standard errorPotentiometric titrationCalcite saturation stateCarbon/Nitrogen ratio standard errorNitrogenOchrophytaPotentiometricper dry masswaterChlorophyll c standard errorBenthosAlkalinity total standard errorAntioxidant activityElectron transport rateLight saturation pointOcean Acidification International Coordination Centre OA ICCMacro-nutrientsMediterranean SeaNitrogen per dry massBicarbonate ionTemperature water standard errorCalculated using seacarb after Nisumaa et al. (2010)Primary production PhotosynthesisSpeciespH standard errorCalcite saturation state standard errorCystoseira compressaCalculated using CO2SYSNon photochemical quenchingCarbon content per dry massCarbonate system computation flagViolaxanthin standard errorPrimary production/PhotosynthesisFugacity of carbon dioxide (water) at sea surface temperature (wet air)CarbonCarbon/Nitrogen ratioBiomass/Abundance/Elemental compositionTreatmentPartial pressure of carbon dioxide water at sea surface temperature wet airAragonite saturation state standard errorCarbon dioxideMacro nutrientsCarbonate ion standard errorSingle speciesFugacity of carbon dioxide water at sea surface temperature wet airPadina pavonicaBiomass Abundance Elemental compositionCoast and continental shelfPhotosynthetic efficiencyBicarbonate ion standard errorNon photochemical quenching standard error
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Search for flavor-changing neutral current and lepton-flavor violating decays of D-0 -> l(+)l(-)

2004

We report on a search for the flavor-changing neutral current decays $\Dz\to e^+e^-$ and $\Dz\to\mu^+\mu^-$, and the lepton-flavor violating decay $\Dz\to e^\pm\mu^\mp$. The measurement is based on $122 {fb}^{-1}$ of data collected by the \babar detector at the PEP-II asymmetric $e^+e^-$ collider. No evidence is found for any of the decays. The upper limits on the branching fractions, at the 90 % confidence level, are $1.2\times 10^{-6}$ for $\Dz\to e^+e^-$, $1.3\times 10^{-6}$ for $\Dz\to\mu^+\mu^-$, and $8.1\times 10^{-7}$ for $\Dz\to e^\pm\mu^\mp$.

OptimizationParticle physicsLepton-flavor violating (LFV)Electron–positron annihilationBABARCharged particleGeneral Physics and Astronomy-Standard model (SM)Lambda baryon01 natural sciencesPARTICLE PHYSICS; PEP2; BABARHigh Energy Physics - ExperimentNONuclear physicsSilicon microstrip detector0103 physical sciencesPEP2010306 general physicsDETECTOR; BABAR; SLACDETECTORFlavorProbabilityPhysicsNeutral current010308 nuclear & particles physicsEnergy dissipationFlavor-changing neutral currentColliding beam acceleratorMicrostrip deviceHEPFlavor-changing neutral current (FCNC)Drift chamberPARTICLE PHYSICSHigh Energy Physics::ExperimentParticle detectorSLACLepton
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