Precise Measurement of the Pi+ -> Pi0 e+ nu Branching Ratio

Abstract

Using a large acceptance calorimeter and a stopped pion beam we have made a precise measurement of the rare Pi+ -> Pi0 e+ Nu,(pi_beta) decay branching ratio. We have evaluated the branching ratio by normalizing the number of observed pi_beta decays to the number of observed Pi+ -> e+ Nu, (pi_{e2}) decays. We find the value of Gamma(Pi+ -> Pi0 e+ Nu)/Gamma(total) = [1.036 +/- 0.004(stat.) +/- 0.004(syst.) +/- 0.003(pi_{e2})] x 10^{-8}$, where the first uncertainty is statistical, the second systematic, and the third is the pi_{e2} branching ratio uncertainty. Our result agrees well with the Standard Model prediction.

4 pages, 5 figures, 1 table, revtex4; changed content; updated analysis

References in corpus (4)

• Big Bang Nucleosynthesis (in "The Review of Particle Properties" 2004)
• The pionic beta decay in chiral perturbation theory
• Design, Commissioning and Performance of the PIBETA Detector at PSI
• Radiative corrections of $O(\a)$ for pion beta decay in the light-front quark model

Cited by in corpus (61)

• Tests of the standard electroweak model in beta decay
• Flavor structures of charged fermions and massive neutrinos
• Improved Calculation of Electroweak Radiative Corrections and the Value of V_ud
• Non-unitarity of the leptonic mixing matrix: Present bounds and future sensitivities
• Flavor Physics in the Quark Sector
• The neutron and its role in cosmology and particle physics
• 50 Years of Quantum Chromodynamics
• New physics searches in nuclear and neutron $\beta$ decay
• Low Energy Precision Test of Supersymmetry
• Determination of |Vud| from nuclear mirror transitions
• Isospin corrections for superallowed Fermi beta decay in self-consistent relativistic random phase approximation approaches
• Constraints on Sterile Neutrinos in the MeV to GeV Mass Range
• Beta decays as sensitive probes of lepton flavor universality
• Quasielastic axial-vector mass from experiments on neutrino-nucleus scattering
• Experiments in Fundamental Neutron Physics
• Scrutinizing CKM unitarity with a new measurement of the $K_{\mu 3}/K_{\mu 2}$ branching fraction
• First-principles calculation of electroweak box diagrams from lattice QCD
• New Precise Measurement of the Pion Weak Form Factors in the Pi+ -> e+ nu gamma Decay
• The Fermi constant from muon decay versus electroweak fits and CKM unitarity
• Radiative Corrections in Precision Electroweak Physics: a Historical Perspective
• Isospin-breaking corrections to superallowed Fermi beta-decay in isospin- and angular-momentum-projected nuclear Density Functional Theory
• First-Generation New Physics in Simplified Models: From Low-Energy Parity Violation to the LHC
• Diphotons from Tetraphotons in the Decay of a 125 GeV Higgs at the LHC
• Precise Measurement of the Pion Axial Form Factor in the Pi+ -> e+ nu gamma Decay
• Heavy QCD Axion in $b\to s$ transition: Enhanced Limits and Projections
• $|V_{us}|$ from $K_{\ell 3}$ decay and four-flavor lattice QCD
• Heavy QCD Axion at Belle II: Displaced and Prompt Signals
• Constraining axion-like particles from rare pion decays
• Testing Lepton Flavor Universality with Pion, Kaon, Tau, and Beta Decays
• Axion-like Particle Searches at DarkQuest
• Update on $|V_{us}|$ and $|V_{us}/V_{ud}|$ from semileptonic kaon and pion decays
• Ab-initio electroweak corrections to superallowed $\beta$ decays and their impact on $V_{ud}$
• Radiative corrections to superallowed $\beta$ decays in effective field theory
• Radiative corrections to semileptonic beta decays: Progress and challenges
• Experimental study of rare charged pion decays
• Probing the non-unitarity of the leptonic mixing matrix at the CEPC
• Heavy+light pseudoscalar meson semileptonic transitions
• Isospin effects in N~Z nuclei in extended Density Functional Theory
• Measuring $|V_{td}|$ at LHC
• Observations on the radiative corrections to pion beta-decay
• Radiative (anti)neutrino energy spectra from muon, pion, and kaon decays
• Isospin mixing in the vicinity of the N=Z line
• Towards a discovery of BSM physics from the Cabibbo angle anomaly
• New results in rare allowed muon and pion decays
• Experimental Status of the CKM Matrix
• A Review of the Magnitudes of the CKM Matrix Elements
• Accessing CKM suppressed top decays at the LHC
• CP-violation and unitarity triangle test of the Standard Model
• Probing the Standard Model via rare pion and muon decays
• ${\pi }_{e3}$ form factor $f_{-}$ near the mass shell
• Beam particle tracking with a low-mass mini time projection chamber in the PEN experiment
• The Role of Ab Initio Beta-Decay Calculations in Light Nuclei for Probes of Physics Beyond the Standard Model
• Chiral perturbation theory confronted with experiment
• Superallowed Fermi transitions in RPA with a relativistic point-coupling energy functional
• On V_ud determination from kaon decays
• Fundamental Neutron Physics: a White Paper on Progress and Prospects in the US
• Precise Measurement of pi+ -> e+ nu Branching Ratio
• Measurement of stopping beam distributions in the PIBETA detector
• The automatic gain-matching in the PIBETA CsI calorimeter
• Pion $\beta$ decay and $\tau \to \pi \pi {\nu }_{\tau }$ beyond leading logarithms
• V_ud and V_us: CKM 2010 working group I summary