Application of current communtation relations to leptonic decay of mesons

1966 ◽  
Vol 42 (1) ◽  
pp. 198-200 ◽  
Author(s):  
Y. Iwasaki
Keyword(s):  
Leptonic Decay

scholarly journals Search for the rare semi-leptonic decay J/ψ → D−e+νe + c.c.

2021 ◽  
Vol 2021 (6) ◽  
Author(s):  
◽  
M. Ablikim ◽  
M. N. Achasov ◽  
P. Adlarson ◽  
S. Ahmed ◽  
...  
Keyword(s):  
Confidence Level ◽  
Branching Fraction ◽  
Center Of Mass ◽  
Leptonic Decay ◽  
Mass Energy ◽  
Center Of Mass Energy ◽  
Upper Limit ◽  
Electron Positron

Abstract Using 10.1 × 109J/ψ events produced by the Beijing Electron Positron Collider (BEPCII) at a center-of-mass energy $$ \sqrt{s} $$ s = 3.097 GeV and collected with the BESIII detector, we present a search for the rare semi-leptonic decay J/ψ → D−e+νe + c.c. No excess of signal above background is observed, and an upper limit on the branching fraction ℬ(J/ψ → D−e+νe + c. c.) < 7.1 × 10−8 is obtained at 90% confidence level. This is an improvement of more than two orders of magnitude over the previous best limit.

scholarly journals Contribution of the Darwin operator to non-leptonic decays of heavy quarks

2020 ◽  
Vol 2020 (12) ◽  
Author(s):  
Alexander Lenz ◽  
Maria Laura Piscopo ◽  
Aleksey V. Rusov
Keyword(s):  
Standard Technique ◽  
Quark Propagator ◽  
Leptonic Decay ◽  
Leptonic Decays ◽  
Interference Contribution ◽  
The Standard Model ◽  
Strength Tensor ◽  
Quark Flavour ◽  
Quark Decay ◽  
B Quark

Abstract We compute the Darwin operator contribution ($$ 1/{m}_b^3 $$ 1 / m b 3 correction) to the width of the inclusive non-leptonic decay of a B meson (B+, Bd or Bs), stemming from the quark flavour-changing transition b → $$ {q}_1{\overline{q}}_2{q}_3 $$ q 1 q ¯ 2 q 3 , where q1, q2 = u, c and q3 = d, s. The key ideas of the computation are the local expansion of the quark propagator in the external gluon field including terms with a covariant derivative of the gluon field strength tensor and the standard technique of the Heavy Quark Expansion (HQE). We confirm the previously known expressions of the $$ 1/{m}_b^3 $$ 1 / m b 3 contributions to the semi-leptonic decay b → $$ {q}_1\mathrm{\ell}{\overline{\nu}}_{\mathrm{\ell}} $$ q 1 ℓ ν ¯ ℓ , with ℓ = e, μ, τ and of the $$ 1/{m}_b^2 $$ 1 / m b 2 contributions to the non-leptonic modes. We find that this new term can give a sizeable correction of about −4 % to the non-leptonic decay width of a B meson. For Bd and Bs mesons this turns out to be the dominant correction to the free b-quark decay, while for the B+ meson the Darwin term gives the second most important correction — roughly 1/2 to 1/3 of the phase space enhanced Pauli interference contribution. Due to the tiny experimental uncertainties in lifetime measurements the incorporation of the Darwin term contribution is crucial for precision tests of the Standard Model.

scholarly journals Leptonic decay constants and in three flavor lattice QCD

2005 ◽  
Vol 140 ◽  
pp. 443-445 ◽  
Author(s):  
J.N. Simone ◽  
C. Aubin ◽  
C. Bernard ◽  
C. DeTar ◽  
M. di Pierro ◽  
...  
Keyword(s):  
Lattice Qcd ◽  
Leptonic Decay ◽  
Decay Constants

Aspects of the chirality of weak b→c transitions in the exclusive semi-leptonic decay

1989 ◽  
Vol 226 (1-2) ◽  
pp. 185-191 ◽  
Author(s):  
Jürgen G. Körner ◽  
Gerhard A. Schuler
Keyword(s):  
Leptonic Decay

scholarly journals B - and D -meson leptonic decay constants from four-flavor lattice QCD

2018 ◽  
Vol 98 (7) ◽  
Author(s):  
A. Bazavov ◽  
C. Bernard ◽  
N. Brown ◽  
C. DeTar ◽  
A. X. El-Khadra ◽  
...  
Keyword(s):  
Lattice Qcd ◽  
D Meson ◽  
Leptonic Decay ◽  
Decay Constants ◽  
Four Flavor

scholarly journals Measurement of the leptonic decay width of J/ψ using initial state radiation

2016 ◽  
Vol 761 ◽  
pp. 98-103 ◽  
Author(s):  
M. Ablikim ◽  
M.N. Achasov ◽  
X.C. Ai ◽  
O. Albayrak ◽  
M. Albrecht ◽  
...  
Keyword(s):  
Decay Width ◽  
Leptonic Decay ◽  
Initial State Radiation ◽  
Initial State ◽  
State Radiation

scholarly journals Electromagnetic corrections to the leptonic decay rates of charged pseudoscalar mesons: lattice results

2016 ◽  
Author(s):  
Silvano Simula ◽  
Vittorio Lubicz ◽  
Guido Martinelli ◽  
Christopher Sachrajda ◽  
Francesco Sanfilippo ◽  
...  
Keyword(s):  
Leptonic Decay ◽  
Decay Rates ◽  
Pseudoscalar Mesons

Limits on variances from symmetry in neutral kaon decays

1972 ◽  
Vol 330 (1582) ◽  
pp. 331-347 ◽  
Keyword(s):  
Experimental Data ◽  
Relative Magnitude ◽  
Neutral Kaon ◽  
Leptonic Decay ◽  
Kaon Decays ◽  
Conservative View ◽  
Better Than

An analysis is made o f the limits on the possible departures from CP -, T -, and TCP -invariance, both in the structure of K L and K S states and in the decay amplitudes to xx and xIv channels. A small violation of the requirements of CP - and T -invariance on the structure of K L and K S states can be deduced under quite plausible assumptions, but there is no evidence of any other departure from the requirements of CP -, or T -, or TCP -in variance. However, the present limit for one measure 8 of TCP -noninvariance is several times larger than the estim ated value of the corresponding CP - and T -noninvariance parameter or = Re<K L |K S >. Taking a conservative view of the experimental data, symmetry-violating parts of decay amplitudes are lim ited to better than 1 % for the I = 0 channel and to within a small percentage for the I = 2 channel, in relative magnitude. The corresponding limits which can be deduced for leptonic decay amplitudes are som ewhat larger but there are indications that symmetry-violating amplitudes are unlikely to exceed a small percentage in relative magnitude.

scholarly journals Light-meson leptonic decay rates in lattice QCD+QED

2019 ◽  
Vol 100 (3) ◽  
Author(s):  
M. Di Carlo ◽  
G. Martinelli ◽  
D. Giusti ◽  
V. Lubicz ◽  
C. T. Sachrajda ◽  
...  
Keyword(s):  
Lattice Qcd ◽  
Leptonic Decay ◽  
Decay Rates ◽  
Light Meson
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