Pion weak decay constant at finite density from the instanton vacuum

In this talk, we report our recent work on the pion weak decay constant (Fπ) and pion mass (mπ) using the nonlocal chiral quark model with the finite quark-number chemical potential (μ) taken into account. Considering the breakdown of Lorentz invariance at finite density, the time and space components are computed separately, and the corresponding results turn out to be: [Formula: see text] and [Formula: see text] at μc ≈ 320 MeV , respectively. Using the in-medium Gell-Mann-Oakes-Renner (GOR) relation, we show that the pion mass increases by about 15% at μc.

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Initial charm program on direct measurements of weak decay constant fDs and branching fraction B(Ds → μνμ) and prospect with high-precision

Modern Physics Letters A ◽

10.1142/s0217732320300189 ◽

2020 ◽

Vol 35 (35) ◽

pp. 2030018

Author(s):

C. C. Zhang

Keyword(s):

High Precision ◽

Decay Constant ◽

Branching Fraction ◽

Branching Fractions ◽

Weak Decay ◽

Precision Measurements ◽

Direct Measurements

First direct measurements of the weak decay constant [Formula: see text] and the [Formula: see text] branching fractions to [Formula: see text], [Formula: see text], [Formula: see text], [Formula: see text] at the BES experiments in 1990s are reviewed. Referring to the BESIII results of [Formula: see text] and branching fraction [Formula: see text] with best precision1 to date, prospect for challenge on precision measurements of [Formula: see text] and [Formula: see text] at BESIII is presented.

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Instanton vacuum at finite density of quark matter

Nuclear Physics B - Proceedings Supplements ◽

10.1016/s0920-5632(01)01750-9 ◽

2002 ◽

Vol 106-107 ◽

pp. 471-473 ◽

Cited By ~ 2

Author(s):

S.V. Molodtsov ◽

G.M. Zinovjev

Keyword(s):

Quark Matter ◽

Finite Density ◽

Instanton Vacuum

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EXCITED PIONS, ρ- AND ω-MESONS AND THEIR DECAYS IN A CHIRAL SU(2) × SU(2) LAGRANGIAN

International Journal of Modern Physics A ◽

10.1142/s0217751x9800247x ◽

1998 ◽

Vol 13 (32) ◽

pp. 5443-5457 ◽

Cited By ~ 53

Author(s):

M. K. VOLKOV ◽

D. EBERT ◽

M. NAGY

Keyword(s):

Experimental Data ◽

Excited State ◽

Decay Constant ◽

Three Dimensional ◽

Form Factors ◽

Weak Decay ◽

Wave Functions ◽

Spontaneous Breaking ◽

Gap Equation ◽

Decay Widths

A chiral SU(2) × SU(2) Lagrangian containing, besides the usual meson fields, their first radial excitations is considered. The Lagrangian is derived by bosonization of the Nambu–Jona-Lasinio (NJL) quark model with separable nonlocal interactions, with form factors corresponding to three-dimensional ground and excited state wave functions. The spontaneous breaking of chiral symmetry is governed by the NJL gap equation. The first radial excitations of the pions, ρ-and ω-mesons are described with the help of two form factors. The weak decay constant Fπ′ is calculated. The values for the decay widths of the processes ρ→2π, π′→ρπ, ρ′→2π, ρ′→ωπ and ω′→ρπ are obtained in agreement with the experimental data.

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Direct Measurements of the Weak Decay Constant fDs(fD) and the Ds(D) Branching Fractions to μνμ, ϕπ, eX, ϕX (μνμ) at C.M. Energy of 4.03 GeV

30 Years of BES Physics ◽

10.1142/9789811217739_0005 ◽

2020 ◽

Author(s):

C. C. Zhang

Keyword(s):

Decay Constant ◽

Branching Fractions ◽

Weak Decay ◽

Direct Measurements

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Pion radiative weak decay from the instanton vacuum

Physics Letters B ◽

10.1016/j.physletb.2017.07.037 ◽

2017 ◽

Vol 772 ◽

pp. 687-693 ◽

Cited By ~ 2

Author(s):

Sang-In Shim ◽

Hyun-Chul Kim

Keyword(s):

Weak Decay ◽

Instanton Vacuum

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Remarks on broken chiral SU(5) × SU(5) symmetry and B mesons

Canadian Journal of Physics ◽

10.1139/p85-213 ◽

1985 ◽

Vol 63 (10) ◽

pp. 1294-1298

Author(s):

D. Y. Kim ◽

S. N. Sinha

Keyword(s):

B Mesons ◽

Decay Constant ◽

B Meson ◽

Weak Decay ◽

Sum Rule ◽

Decay Constants ◽

Symmetry Approach ◽

Rule Model ◽

Pseudoscalar Mesons ◽

The Masses

In a recent paper, Hatzis has estimated the masses and weak decay constants of b-flavored pseudoscalar mesons in a broken chiral SU(5) × SU(5) symmetry method. The estimated weak decay constant of B meson, [Formula: see text], however, does not agree with the value [Formula: see text] evaluated by Mathur et al. with the quantum chromodynamics (QCD) sum-rule model. We re-examined the problem applying the broken chiral SU(5) × SU(5) symmetry approach using a set of mass formulae. With this method we estimate the symmetry-breaking parameters and decay constants of pseudoscalar mesons. We found a consistent result for the decay constant: [Formula: see text]. The explicit numerical value of these constants, however, are lower than that of the QCD sum rule. This may be due to the limited validity of the broken chiral symmetry approach for heavy mesons.

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