366 research outputs found
Measurement of the Branching Fraction of the Decay in Fully Reconstructed Events at Belle
We present an analysis of the exclusive
decay, where represents an
electron or a muon, with the assumption of charge-conjugation symmetry and
lepton universality. The analysis uses the full data sample
collected by the Belle detector, corresponding to 711 fb of integrated
luminosity. We select the events by fully reconstructing one meson in
hadronic decay modes, subsequently determining the properties of the other
meson. We extract the signal yields using a binned maximum-likelihood fit to
the missing-mass squared distribution in bins of the invariant mass of the two
pions or the momentum transfer squared. We measure a total branching fraction
of , where the
uncertainties are statistical and systematic, respectively. This result is the
first reported measurement of this decay.Comment: 23 pages, 19 figure
Training and Onboarding initiatives in High Energy Physics experiments
In this paper we document the current analysis software training and
onboarding activities in several High Energy Physics (HEP) experiments: ATLAS,
CMS, LHCb, Belle II and DUNE. Fast and efficient onboarding of new
collaboration members is increasingly important for HEP experiments as analyses
and the related software become ever more complex with growing datasets. A
meeting series was held by the HEP Software Foundation (HSF) in 2022 for
experiments to showcase their initiatives. Here we document and analyse these
in an attempt to determine a set of key considerations for future experiments
Measurement of the CKM Matrix Element from at Belle
We present a new measurement of the CKM matrix element from decays, reconstructed with the full Belle data set
of integrated luminosity. Two form factor
parameterizations, originally conceived by the Caprini-Lellouch-Neubert (CLN)
and the Boyd, Grinstein and Lebed (BGL) groups, are used to extract the product
and the decay form factors, where
is the normalization factor and is a small
electroweak correction. In the CLN parameterization we find
, , , . For the BGL parameterization we
obtain , which is consistent with the World Average when correcting for
. The branching fraction of is measured to be . We also present a new
test of lepton flavor universality violation in semileptonic decays,
. The errors correspond to the statistical and
systematic uncertainties respectively. This is the most precise measurement of
and form factors to date and the first
experimental study of the BGL form factor parameterization in an experimental
measurement
Evidence for a vector charmonium-like state in
We report the measurement of via
initial-state radiation using a data sample of an integrated luminosity of
921.9 fb collected with the Belle detector at the and
nearby. We find evidence for an enhancement with a 3.4 significance in
the invariant mass of The measured mass and width
are
and ,
respectively. The mass, width, and quantum numbers of this enhancement are
consistent with the charmonium-like state at 4626 MeV/ recently reported
by Belle in The product of the cross section and the branching fraction of
is measured from
threshold to 5.6 GeV.Comment: 9 pages, 4 figure
Software Training in HEP
The long-term sustainability of the high-energy physics (HEP) research software ecosystem is essential to the field. With new facilities and upgrades coming online throughout the 2020s, this will only become increasingly important. Meeting the sustainability challenge requires a workforce with a combination of HEP domain knowledge and advanced software skills. The required software skills fall into three broad groups. The first is fundamental and generic software engineering (e.g., Unix, version control, C++, and continuous integration). The second is knowledge of domain-specific HEP packages and practices (e.g., the ROOT data format and analysis framework). The third is more advanced knowledge involving specialized techniques, including parallel programming, machine learning and data science tools, and techniques to maintain software projects at all scales. This paper discusses the collective software training program in HEP led by the HEP Software Foundation (HSF) and the Institute for Research and Innovation in Software in HEP (IRIS-HEP). The program equips participants with an array of software skills that serve as ingredients for the solution of HEP computing challenges. Beyond serving the community by ensuring that members are able to pursue research goals, the program serves individuals by providing intellectual capital and transferable skills important to careers in the realm of software and computing, inside or outside HEP
Software Training in HEP
The long-term sustainability of the high-energy physics (HEP) research software ecosystem is essential to the field. With new facilities and upgrades coming online throughout the 2020s, this will only become increasingly important. Meeting the sustainability challenge requires a workforce with a combination of HEP domain knowledge and advanced software skills. The required software skills fall into three broad groups. The first is fundamental and generic software engineering (e.g., Unix, version control, C++, and continuous integration). The second is knowledge of domain-specific HEP packages and practices (e.g., the ROOT data format and analysis framework). The third is more advanced knowledge involving specialized techniques, including parallel programming, machine learning and data science tools, and techniques to maintain software projects at all scales. This paper discusses the collective software training program in HEP led by the HEP Software Foundation (HSF) and the Institute for Research and Innovation in Software in HEP (IRIS-HEP). The program equips participants with an array of software skills that serve as ingredients for the solution of HEP computing challenges. Beyond serving the community by ensuring that members are able to pursue research goals, the program serves individuals by providing intellectual capital and transferable skills important to careers in the realm of software and computing, inside or outside HEP
Training and Onboarding initiatives in High Energy Physics experiments
In this paper we document the current analysis software training and onboarding activities in several High Energy Physics (HEP) experiments: ATLAS, CMS, LHCb, Belle II and DUNE. Fast and efficient onboarding of new collaboration members is increasingly important for HEP experiments as analyses and the related software become ever more complex with growing datasets. A meeting series was held by the HEP Software Foundation (HSF) in 2022 for experiments to showcase their initiatives. Here we document and analyse these in an attempt to determine a set of key considerations for future experiments
Measurement of B(B →dX) with B semileptonic tagging
We report the first direct measurement of the inclusive branching fraction B(B →DX) via B tagging in ee→Υ(5S) events. Tagging is accomplished through a partial reconstruction of semileptonic decays B→DXℓν, where X denotes unreconstructed additional hadrons or photons and ℓ is an electron or muon. With 121.4 fb of data collected at the Υ(5S) resonance by the Belle detector at the KEKB asymmetric-energy ee collider, we obtain B(B →DX)=(60.2±5.8±2.3)%, where the first uncertainty is statistical and the second is systematic
Search for charged-lepton flavor violation in () decays at Belle
We report a search for the charged-lepton flavor violation in () decays using a
sample collected by the Belle detector at the KEKB
asymmetric-energy collider. We find no evidence for a signal and set upper
limits on the branching fractions () at 90 confidence level.
We obtain the most stringent upper limits: and .Comment: 11 pages, 3 figures, Submitted to JHE
Search for at Belle
We present a search for the decay in the
data sample collected at the
Belle detector, where the is produced in
and decays. We do not observe a signal, and set 90\%
credible upper limits for two different models of the decay processes: if the
decay products are distributed uniformly in phase space, ; if is concentrated near the mass
of the pair in the process ,
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