Search arXiv⌕ Search

arXiv · hep-ex/0408139

Moments of the Hadronic Mass Spectrum in Inclusive Semileptonic B Decays at Belle

Abstract

We report a measurement of the first and second moment of the hadronic mass distribution M_X in B -> X_c l nu decays for lepton threshold momenta ranging from 0.9 to 1.6 GeV/c in the center of mass frame. The measurement uses B Bbar events in which the hadronic decay of one B meson is fully reconstructed and a charged lepton from the decay of the other B meson is identified. These results are obtained from a 140 fb^-1 data sample collected near the Upsilon(4S) resonance with the Belle detector at the KEKB asymmetric energy e^+ e^- collider.

Explore related subjects

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

Belle Collaboration. 2004-08-27. Moments of the Hadronic Mass Spectrum in Inclusive Semileptonic B Decays at Belle. https://arxiv.org/abs/hep-ex/0408139

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related papers

Prediction of the Geoneutrino Signal at the Jinping Neutrino Experiment

We present refined predictions of the geoneutrino flux for the 500-tonne Jinping Neutrino Experiment (JNE). We construct a local crustal model with a resolution of \(0.2^\circ\times0.2^\circ\) based on the SWChinaCVM-2.0 seismic velocity model and integrate it with CRUST1.0 to establish our reference model. For comparison, we also calculate the geoneutrino flux using ECM1 and CRUST1.0 as standalone global crustal models. Assuming an energy scale of 500~p.e./MeV and an exposure of 500~t$\times$1500~days, we predict the inverse beta decay event spectrum, including both the geoneutrino signal and the reactor antineutrino background. The distinct spectral shapes of the $^{238}$U, $^{232}$Th, and reactor antineutrino components allow their respective contributions to be obtained through spectral fitting. These predictions provide inputs for the JNE data analysis, particularly for extracting the mantle geoneutrino signal and testing competing bulk silicate Earth models.

hep-ex↗

Construction, commissioning, and performance of the ENUBET demonstrator

A final full-size prototype of the instrumented decay tunnel of ENUBET, referred to as the Demonstrator, was constructed and its performance was tested during the 2022, 2023 and 2024 beam test campaigns at the CERN East Area facility. We demonstrate the full scalability of this specialized longitudinal sampling calorimeter technology, based on iron absorbers and scintillator tiles readout by wavelength-shifting fibers and SiPMs. In addition, we evaluate the channel-by- channel response and the performance in terms of electron energy resolution, linearity, and particle identification capabilities, using charged particle beams with energies up to 5 GeV. A comparison with the predictions of a GEANT4 simulation of the prototype is also presented. The achieved energy resolution ($\sim 17$\% at 1 GeV and 10\% at 3 GeV) fully satisfies the requirements for positron identification. The results meet the requirements for neutrino monitoring through lepton identification in the decay tunnel and validate the ENUBET full simulation. Although some limitations have been identified, they can be readily addressed in future developments.

hep-ex↗

First Measurement of the Superscaling Variable as a Function of Visible Kinematics in Charged-Current Quasi-Elastic Neutrino--Nucleus Scattering

We report the first measurement of the superscaling variable $ψ^{\prime}_{\rm vis}$ in neutrino--nucleus scattering, using charged-current quasielastic-like $ν_μ$-Carbon interactions collected by the MINERvA experiment in the medium-energy NuMI beam. Originally developed to characterize phenomena of scaling with respect to atomic number and momentum transfer in quasielastic electron-nucleus scattering, $ψ^{\prime}$ is reconstructed here from visible final-state kinematics ($ψ^{\prime}_{\rm vis}$). $ψ^{\prime}_{\rm vis}$ is used here as an externally calibrated variable whose peak position is sensitive to the invisible nuclear missing energy. We measure $ψ^{\prime}_{\rm vis}$ as functions of the hadronic recoil $ΣT_p$ and muon transverse momentum $p_{\text{T}μ}$, comparing background-subtracted data to five neutrino--nucleus interaction models via a forward-folding technique. The predicted $ψ^{\prime}_{\rm vis}$ diverges most strongly among model predictions at low $ΣT_p$ and $p_{\text{T}μ}$, where agreement with data is also poorest, exposing which models fail to capture the phase-space dependence of the missing energy and therefore the neutrino energy as extrapolated from visible kinematics. Among tested models, we find that the Relativistic Mean Field approach predicts more accurately the $ψ^{\prime}_{\rm vis}$ peak position.

hep-ex↗