相关论文: Flavor SU(4) breaking between effective couplings

We present a comparison of the strong couplings of light ($u$,~$d$,~and~$s$), $c$, and $b$ quarks determined from multijet rates in flavor-tagged samples of hadronic $Z^0$ decays recorded with the SLC Large Detector at the SLAC Linear…

In view of difficulty to reproduce observables in the $D^0-\bar{D}^0$ mixing via the operator product expansion, we discuss the Dyson-Schwinger approach to this process. Formulated by the parametrization of quark propagators, SU(3) breaking…

Based on a contact lagrangian that incorporates the SU(3) flavor and SU(2) spin symmetries, we discuss the symmetry properties of the interactions among the heavy flavor meson-baryon $P_{\psi}^N$, $P_{\psi s}^\Lambda$ (with quark components…

We investigate to what extent the recently measured value for a non-vanishing direct CP asymmetry in D0 -> K+ K- and D0 -> pi+ pi- decays can be accommodated in the Standard Model (SM) or extensions with a constrained flavour sector, for…

Recently, the LHCb Collaboration reported a signal for a new resonance in the $D_s^+ \pi^\pm$ invariant mass distribution in the decays $B\to \bar{D}^{(*)} D_s^+ \pi^+ \pi^-$ (arXiv:2411.03399). This could be a direct observation of an…

The $S_3$ symmetry is shown to be a very good approximate symmetry when it is broken in a specific way. This is true both in quark sector and in lepton sector. The way to break it is implied by the K-M mechanism applied not to the mixing…

We critically review the validity of heavy-quark spin and flavor symmetries in heavy-light decay constants, form factors and effective couplings obtained within a nonperturbative framework, the ingredients of which are all motivated by…

Heavy-light-flavor meson resonances with charm, in the $D^0$ and $D^*$ families, and charmonium-like states, in the $\eta_c$ and $\chi_{c1}$ families, are explored and discussed in the AdS/QCD model with four quark flavors. The differential…

We investigate the $\sigma$ and $\rho$ coupling constants for the $DD$ and $D^*D^*$ interactions, based on correlated $2\pi$ exchange in the $DD$ and $D^*D^*$ interactions. Starting from the $D\bar{D}\to \pi\pi$ and $D^*\bar{D}^*\to \pi\pi$…

We show how two principles - strong coupling and discrete symmetry - can work together to generate the flavour structure of the Standard Model. We propose that in the UV the full theory has a discrete flavour symmetry, typically only…

Extending the SU(3) flavour symmetry breaking expansion from up, down and strange sea quark masses to partially quenched valence quark masses allows an extrapolation to the charm quark mass. This approach leads to a determination of charmed…

The strong interactions of the negative-parity heavy mesons with $\rho$ meson may be described consistently in the context of an effective lagrangian, which is invariant under isospin SU(2) transformation. Four coupling constants…

We point out that the hypothesis of a SU(5)-like supersymmetric Grand Unified Theory (GUT) implies a generic relation within the flavour structure of up-type squarks. Contrary to other well-known SU(5) relations between the down-quark and…

We perform a global fits to charmless $B \to PP$ decays which independently constrain the $(\bar\rho,\bar\eta)$ vertex of the unitarity triangle. The fitted amplitudes and phase are used to predict the branching ratios and CP asymmetries of…

We investigate the phenomenology of a simplified model of flavoured Dark Matter (DM), with a dark fermionic flavour triplet coupling to the left-handed $SU(2)_L$ quark doublets via a scalar mediator. The DM-quark coupling matrix is assumed…

The stringent correlations between flavour observables in models with CMFV are consistent with the present data except for the correlation Delta M_{s,d}-epsilon_K. Motivated by the recent work of Barbieri et al, we compare the CMFV…

A SU(4) flavor symmetrical Lagrangian is constructed for the interaction of the pseudo-scalar mesons with the vector mesons. SU(4) symmetry is broken to SU(3) by suppression of terms in the Lagrangian where the interaction should be driven…

The charmed B decays, $B\to DP, ~D^*P$ and $DV$, are re-analyzed using the latest experimental data, where $P$ and $V$ denote the pseudoscalar meson and vector meson, respectively. We perform global fits under the assumption of flavor SU(3)…

The Standard Model contribution to D0-anti-D0 mixing is dominated by the contributions of light s and d quarks. Neglecting the tiny effects due to b quark, both mass and lifetime differences vanish in the limit of SU(3)_F symmetry. Thus,…

We analyze the higher-twist effects and the SU(3)-flavour symmetry breaking in the correlation functions used to calculate form factors of pseudoscalar mesons in the QCD light-cone sum rule approach. It is shown that the Ward identities for…