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

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.

B′ MIXING AND THE PSEUDOSCALAR DECAY CONSTANT

1990 ◽  
Vol 05 (17) ◽  
pp. 3335-3346
Author(s):  
WEI-SHU HOU
Keyword(s):  
Decay Constant ◽  
B Meson ◽  
Meson Decay ◽  
Vector Mesons ◽  
Decay Constants ◽  
Light System ◽  
Meson Mixing ◽  
Pseudoscalar Decay Constant ◽  
Present Understanding ◽  
B Mixing

The possibilities of B′ meson mixing is discussed. It is found that if fB′ is not much smaller than fπ, B's (or B'd) mixing is possible if |Vt′s Vt′b′/Vcb′| is large, but only for not too heavy b′ masses, e.g. below LEP I energies. The B'b meson will have large mixing for a broad range of parameters; however, it is hard to produce. The vector mesons (B′*) may exhibit mixing phenomena as well. A discussion of our present understanding of meson decay constants of a heavy-light system [Formula: see text] is given. Further efforts on this problem is needed, which will have an impact on our understanding of B mixing as well.

B-MESON DECAY CONSTANT REVISITED AND EXTRACTION OF $|\frac{v_{td}}{v_{ts}}|$ FROM $B^0\hbox{--}{\bar B}^0$ MIXING

2004 ◽  
Vol 19 (12) ◽  
pp. 921-925 ◽  
Author(s):  
A. BHATTACHARYA ◽  
S. N. BANERJEE ◽  
B. CHAKRABARTI ◽  
S. BANERJEE
Keyword(s):  
Variational Method ◽  
Decay Constant ◽  
B Meson ◽  
Heavy Meson ◽  
Meson Decay ◽  
Matrix Elements ◽  
Ckm Matrix ◽  
B Meson Decay ◽  
Decay Constants ◽  
Good Agreement

The ratios of Bd and Bs meson decay constant have been estimated using the variational method in conjunction with the relativistic Hamiltonian of the heavy meson in the framework of the statistical model. The ratio of CKM matrix elements [Formula: see text] has been extracted from [Formula: see text] mixing using the estimated decay constants and ratio of Bd and Bs mass differences. The results are found to be in good agreement with the existing theoretical and experimental predictions.

scholarly journals ON THE COMPLEXION OF PSEUDOSCALAR MESONS

2005 ◽  
Vol 20 (08n09) ◽  
pp. 1778-1784 ◽  
Author(s):  
A. HÖLL ◽  
A. KRASSNIGG ◽  
C. D. ROBERTS ◽  
S. V. WRIGHT
Keyword(s):  
Quark Mass ◽  
Decay Constant ◽  
Chiral Limit ◽  
Mass Function ◽  
Mass Scale ◽  
Radial Excitation ◽  
Decay Constants ◽  
Pseudoscalar Mesons ◽  
Constituent Quark Mass ◽  
Goldstone Modes

A strongly momentum-dependent dressed-quark mass function is basic to QCD. It is central to the appearance of a constituent-quark mass-scale and an existential prerequisite for Goldstone modes. Dyson-Schwinger equation (DSEs) studies have long emphasised this importance, and have proved that QCD's Goldstone modes are the only pseudoscalar mesons to possess a nonzero leptonic decay constant in the chiral limit when chiral symmetry is dynamically broken, while the decay constants of their radial excitations vanish. Such features are readily illustrated using a rainbow-ladder truncation of the DSEs. In this connection we find (in GeV): fηc(1S)=0.233, mηc(2S)=3.42; and support for interpreting η(1295), η(1470) as the first radial excitations of η(548), η′(958), respectively, and K(1460) as the first radial excitation of the kaon. Moreover, such radial excitations have electromagnetic diameters greater than 2 fm. This exceeds the spatial length of lattices used typically in contemporary lattice-QCD.

scholarly journals HEAVY PSEUDOSCALAR-MESON DECAY CONSTANTS WITH STRANGENESS FROM THE EXTENDED NONLOCAL CHIRAL-QUARK MODEL

2012 ◽  
Vol 27 (27) ◽  
pp. 1250153 ◽  
Author(s):  
SEUNG-IL NAM
Keyword(s):  
Heavy Quark ◽  
Quark Model ◽  
Weak Decay ◽  
Heavy Meson ◽  
Effective Field ◽  
Numerical Results ◽  
Meson Decay ◽  
Chiral Quark Model ◽  
Decay Constants ◽  
Pseudoscalar Mesons

We study the weak-decay constants for the heavy pseudoscalar mesons, D, Ds, B and Bs. For this purpose, we employ the extended nonlocal chiral-quark model (ExNLChQM), motivated by the heavy-quark effective field theory as well as the instanton-vacuum configuration. In addition to the heavy-quark symmetry and the nonlocal interactions between quarks and pseudoscalar mesons in ExNLChQM, a correction for the strange-quark content inside Ds and Bs is also taken into account and found to be crucial to reproduce the empirical values. From those numerical results, we obtain fD, Ds, B, Bs = (207.53, 262.56, 208.13, 262.39) MeV , which are in good agreement with experimental data and other theoretical estimations. Using those numerical results, we estimate the CKM matrix elements and the Cabibbo angle with the various mesonic and leptonic heavy-meson decay channels, resulting in (|Vcd|, |Vcs|, |Vub|, |Vtd|/|Vts|) = (0.224, 0.968, <5.395×10-3, 0.215) and θC = 12.36° which are well compatible with available data.

scholarly journals LEPTONIC DECAY OF HEAVY–LIGHT MESONS IN A QCD POTENTIAL MODEL

2013 ◽  
Vol 28 (02) ◽  
pp. 1350010 ◽  
Author(s):  
KRISHNA KINGKAR PATHAK ◽  
D. K. CHOUDHURY ◽  
N. S. BORDOLOI
Keyword(s):  
Wave Function ◽  
B Mesons ◽  
Potential Model ◽  
Branching Ratio ◽  
Leptonic Decay ◽  
Decay Constants ◽  
Decay Widths ◽  
Mesonic Wave Function ◽  
Experimental Values ◽  
The Masses

We study the masses and decay constants of heavy–light flavor mesons D, Ds, B and Bs in a QCD potential model. The mesonic wave function is used to compute the masses of D and B mesons in the ground state and the wave function is transformed to momentum space to estimate the pseudoscalar decay constants of these mesons. The leptonic decay widths and branching ratio of these mesons for different leptonic channels are also computed to compare with the experimental values. The results are found to be compatible with available data.

scholarly journals NONLEPTONIC DECAYS OF B MESONS AND STRONG COUPLING CONSTANTS

1998 ◽  
Vol 13 (19) ◽  
pp. 3361-3384 ◽  
Author(s):  
GUSTAV KRAMER ◽  
CAI-DIAN LÜ
Keyword(s):  
Strong Coupling ◽  
B Mesons ◽  
B Meson ◽  
Axial Vector ◽  
Coupling Constants ◽  
Charmed Meson ◽  
Sum Rule ◽  
Pole Dominance ◽  
Factorization Model ◽  
Nonleptonic Decays

Nonleptonic decays of B mesons into two mesons or meson resonances are studied on the basis of two versions of simple pole dominance models involving scalar, vector, pseudoscalar and axial vector poles. The results are compared with those obtained from the usual factorization model and are used to obtain information on strong coupling constants between the B meson and one light or one charmed meson, respectively. These coupling constants are compared to results from various QCD sum rule calculations.

scholarly journals MESON DECAY IN AN INDEPENDENT QUARK MODEL

2000 ◽  
Vol 09 (05) ◽  
pp. 407-415 ◽  
Author(s):  
HAKAN CİFTCİ ◽  
HÜSEYIN KORU
Keyword(s):  
Experimental Data ◽  
Quark Model ◽  
Weak Decay ◽  
Leptonic Decay ◽  
Meson Decay ◽  
Decay Constants ◽  
Pseudoscalar Mesons ◽  
Light Vector ◽  
Decay Widths ◽  
Good Agreement

Leptonic decay widths and leptonic decay constants of light vector mesons and weak leptonic decay widths and weak decay constants of light and heavy pseudoscalar mesons have been studied in a field-theoretic framework based on the independent quark model with a scalar-vector power-law potential. The results are in very good agreement with the experimental data.

scholarly journals Semileptonic B-meson decays to light pseudoscalar mesons on the HISQ ensembles

2018 ◽  
Vol 175 ◽  
pp. 13024 ◽  
Author(s):  
Zechariah Gelzer ◽  
C. Bernard ◽  
C. De Tar ◽  
AX El-Khadra ◽  
E. Gámiz ◽  
...  
Keyword(s):  
Correlation Function ◽  
B Mesons ◽  
B Meson ◽  
Form Factors ◽  
Beyond The Standard Model ◽  
B Meson Decays ◽  
Quark Masses ◽  
Pseudoscalar Mesons ◽  
The Standard Model ◽  
The Status

We report the status of an ongoing lattice-QCD calculation of form factors for exclusive semileptonic decays of B mesons with both charged currents (B → πlv, Bs → Klv) and neutral currents (B → πl+l-, B → Kl+l-). The results are important for constraining or revealing physics beyond the Standard Model. This work uses MILC’s (2+1 + 1)-flavor ensembles with the HISQ action for the sea and light valence quarks and the clover action in the Fermilab interpretation for the b quark. Simulations are carried out at three lattice spacings down to 0.088 fm, with both physical and unphysical sea-quark masses. We present preliminary results for correlation-function fits.

Broken chiral symmetry and the classification of B mesons

1984 ◽  
Vol 62 (5) ◽  
pp. 520-526 ◽  
Author(s):  
M. Hatzis
Keyword(s):  
Mass Spectrum ◽  
Chiral Symmetry ◽  
B Mesons ◽  
Axial Current ◽  
Pseudoscalar Mesons ◽  
The Masses

We consider broken SU(5) × SU(5) chiral symmetry and we assume that the vacuum is SU(5)-symmetric. Using the observed mass spectrum of pseudoscalar mesons, and setting the [Formula: see text] mass in the range 5.2 ± 0.06 GeV, we predict the masses of [Formula: see text], [Formula: see text], and ηb states as well as axial current couplings fi/fπ. SU(5) × SU(5) is found to be consistent with SU(4) × SU(4) breaking. The problem of η − η′ − ηe − ηb mixing is also discussed.

scholarly journals Weak decay constant of pseudoscalar mesons in a QCD-inspired model

2004 ◽  
Vol 34 (1a) ◽  
pp. 297-299 ◽  
Author(s):  
L. A. M. Salcedo ◽  
J.P.B.C. de Melo ◽  
D. Hadjmichef ◽  
T. Frederico
Keyword(s):  
Decay Constant ◽  
Weak Decay ◽  
Pseudoscalar Mesons ◽  
Qcd Inspired Model
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