Search results for "FCNC"

showing 6 items of 6 documents

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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Minimal Flavour Violation and Multi-Higgs Models

2010

We propose an extension of the hypothesis of Minimal Flavour Violation (MFV) to general multi-Higgs models without the assumption of Natural Flavour Conservation (NFC) in the Higgs sector. We study in detail under what conditions the neutral Higgs couplings are only functions of V-CKM and propose a MFV expansion for the neutral Higgs couplings to fermions

PhysicsNuclear and High Energy PhysicsParticle physicsMinimal Flavour Violation010308 nuclear & particles physicsCabibbo–Kobayashi–Maskawa matrixHigh Energy Physics::LatticeFlavourHigh Energy Physics::PhenomenologyFísicaFOS: Physical sciencesFCNCFermion01 natural sciencesHiggs sectorFlavour symmetriesHigh Energy Physics - PhenomenologyHigh Energy Physics - Phenomenology (hep-ph)Multi-Higgs models0103 physical sciencesHiggs bosonHigh Energy Physics::Experiment010306 general physicsParticle Physics - Phenomenology
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"Selection efficiency" of "Search for $B^{+}\to K^{+}\nu\bar{\nu}$ decays using an inclusive tagging method at Belle II"

2022

Signal efficiency as a function of the dineutrino invariant mass squared $q^{2}$ for events in the signal region (SR) ($\rm{BDT}_{1} > 0.9$ and $\rm{BDT}_{2} > 0.95$). The error bars indicate the statistical uncertainty.

electroweak penguin decay$B^+ \rightarrow K^+\nu\bar\nu$FCNCmissing energyb --> s l l transition
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"Expected and observed limit" of "Search for $B^{+}\to K^{+}\nu\bar{\nu}$ decays using an inclusive tagging method at Belle II"

2022

CL$_{s}$ value as a function of the branching fraction of $B^{+} \rightarrow K^{+} \nu \bar{\nu}$ for expected and observed signal yields and the corresponding upper limits at 90% confidence level (CL). The expected limit is derived for the background-only hypothesis. The observed limit is derived from a simultaneous fit to the on-resonance and off-resonance data, corresponding to an integrated luminosity of 63 fb$^{−1}$ and 9 fb$^{−1}$, respectively.

electroweak penguin decay$B^+ \rightarrow K^+\nu\bar\nu$FCNCmissing energyb --> s l l transition
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"Postfit yields Y(4S)" of "Search for $B^{+}\to K^{+}\nu\bar{\nu}$ decays using an inclusive tagging method at Belle II"

2022

Yields in on-resonance data and as predicted by the simultaneous fit to the on- and off-resonance data, corresponding to an integrated luminosity of 63 and 9 fb$^{−1}$, respectively. The predicted yields are shown individually for charged and neutral B-meson decays and the five continuum background categories. The leftmost three bins belong to the first control region (CR1) with BDT$_{2} \in [0.93; 0.95]$ and the other nine bins correspond to the signal region (SR), three for each range of BDT$_{2} \in [0.95; 0.97; 0.99; 1.0]$. Each set of three bins is defined by $p_{T}(K^{+}) \in [0.5; 2.0; 2.4; 3.5] \rm{GeV}/c^{2}$.

signal strenghth $\mu$electroweak penguin decay$B^+ \rightarrow K^+\nu\bar\nu$FCNCmissing energyb --> s l l transition
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"Postfit yields off-resonance" of "Search for $B^{+}\to K^{+}\nu\bar{\nu}$ decays using an inclusive tagging method at Belle II"

2022

Yields in off-resonance data and as predicted by the simultaneous fit to the on- and off-resonance data, corresponding to an integrated luminosity of 63 and 9 fb$^{−1}$, respectively. The predicted yields are shown individually for the five continuum background categories. The leftmost three bins belong to the third control region (CR3) with BDT$_{2} \in [0.93; 0.95]$ and the other nine bins correspond to the second control region (CR2), three for each range of BDT$_{2} \in [0.95; 0.97; 0.99; 1.0]$. Each set of three bins is defined by $p_{T}(K^{+}) \in [0.5; 2.0; 2.4; 3.5] \rm{GeV}/c^{2}$.

signal strenghth $\mu$electroweak penguin decay$B^+ \rightarrow K^+\nu\bar\nu$FCNCmissing energyb --> s l l transition
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