相关论文: FCNC and Rare B Decays in 3-3-1 Models
We investigate a speculative short-distance force, proposed to explain discrepancies observed between measurements of certain neutral current decays of $B$ hadrons and their Standard Model predictions. The force derives from a spontaneously…
The custodial Randall-Sundrum model based on SU(2)_L X SU(2)_R X U(1)_(B-L) generates new flavor-changing-neutral-current (FCNC) phenomena at tree level, mediated by Kaluza-Klein neutral gauge bosons. Based on two natural assumptions of…
The 3-3-1 model, based on the gauge group $SU(3)_c\times SU(3)_L\times U(1)_X$, makes a natural prediction of three generations based on anomaly cancellation. Since this is accomplished by incorporating the third family of quarks…
New vector bosons that are coupled to conserved currents in the Standard Model exhibit enhanced rates below the electroweak scale from anomalous triangle amplitudes, leading to (energy/vector mass)$^2$ enhancements to rare Z decays and…
In this talk an analysis of the rare exclusive $B$ decays $B\to K\nu\bar\nu$ and $B\to K^{*}\nu\bar\nu$ within and beyond the Standard Model is presented. Combining new form factor determinations from lattice QCD with light-cone sum rule…
In models with an extra U(1)' gauge boson family non-universal couplings to the weak eigenstates of the standard model fermions generally induce flavor-changing neutral currents. This phenomenon leads to interesting results in various B…
Anomalous b --> s transitions from LHCb data may suggest a new massive gauge boson Z' that couples to the left-handed b --> s current, which in turn implies a coupling to the t --> c current. In this paper, we study flavor-changing neutral…
The 331 model, an extension of the standard electroweak theory to $SU(3)_L\times U(1)_X$, naturally predicts three families of quarks and leptons via the requirement of anomaly cancellation. This is accomplished by making one of the quark…
The mass and weak interaction eigenstates for the quarks of the third generation are very well aligned, an empirical fact for which the Standard Model offers no explanation. We explore the possibility that this alignment is due to an…
B-decays mediated by both charged currents and neutral currents have provided hints of violation of lepton flavour universality. By assuming an explanation of these anomalies in terms of new physics at the TeV scale affecting the third…
We present a search for the rare flavor-changing neutral-current decay $B^+ \to K^+ \nu \bar{\nu}$ based on data sample of 82 fb$^{-1}$ collected with the BABAR detector at the PEP-II B-factory. Signal events are selected by examining the…
We report on the extrapolated measurements related to the flavour-changing-neutral-current(FCNC) $b\rightarrow s$ and $b\rightarrow d$ transitions with the Belle II data. The branching fraction(BF) and raw asymmetry measurements of the…
In light of the recent $R_{K^{(*)}}$ data on neutral current flavour anomalies in $B \to K^{(*)} \ell^+ \ell^-$ decays, we re-examine their quantitative interpretation in terms of an extended 331 gauge theory framework. We achieve this by…
We present a search for the rare decays B+ -> K+ nu nubar and B0 -> K0 nu nubar using 459 million BBbar pairs collected with the BaBar detector at the SLAC National Accelerator Laboratory. Flavor-changing neutral-current decays such as…
We present a class of minimally extended standard models with the gauge group $SU(3)_C \times SU(N)_L \times U(1)_X$ where for all $N \geq 3$, anomaly cancelation requires three generations. At low energy, we recover the Standard Model…
Most of the existing analyses of FCNC processes in the 331 models, based on the gauge group SU(3)_C x SU(3)_L x U(1)_X, take only into account tree-level exchanges of a new heavy neutral gauge boson Z'. However due to the Z-Z' mixing also…
This presentation reviews the main results of our recent work [A.K., D.M., N.N., Phys. Rev. D97, 053007 (2018)] on rare radiative leptonic decays $B_{d,s}\to\gamma\mu^+\mu^-$ and $B_{d,s}\to\gamma e^+e ^-$ induced by flavour-changing…
We present measurements of the flavor-changing neutral current decays B -> Kl+l- and B -> K*l+l-, where l+l- is either an e+e- or mu+mu- pair. The data sample comprises 229 X 10^6 Y(4S) -> BBbar decays collected with the BaBar detector at…
We present a 3-3-1 model as a subgroup of SU(4)PS X SU(4)L+R gauge symmetry with symmetry-breaking pattern SU(4)->SU(3) X U(1) for both SU(4) groups. A Pleitez-Frampton type of 3C-3L-1X model is obtained with charged heavy leptons and…
We review the status of rare decays and CP violation in extensions of the Standard Model. We analyze the determination of the unitarity triangle and the model-independent constraints on new physics that can be derived from this analysis. We…