相关论文: The "4th generation", B-CP anomalies & the LHC

We consider the possibility that the neutral-current $B$ anomalies are due to radiative corrections generated by Yukawa interactions of quarks and leptons with new vector-like quark and lepton electroweak doublets and new Standard Model…

A heavy fourth family is an example of new physics which is well defined and familiar in some respects, but which nevertheless has radical implications. In particular it eliminates a light Higgs description of electroweak symmetry breaking.…

We consider the phenomenology of the fourth generation heavy quarks which would be pair produced at the LHC. We show that if such a quark with a mass in the phenomenologically interesting range of 400 GeV--600 GeV decays to a light quark…

We calculate a number of observables related to particle-antiparticle mixing and the branching ratios for the most interesting rare and CP-violating K and B decays in the Standard Model (SM3) extended by a fourth generation of quarks and…

Under the assumption that the various evidences of a `95 GeV' excess, seen in data at the Large Electron Positron (LEP) collider as well as the Large Hadron Collider (LHC), correspond to actual signals of new physics Beyond the Standard…

The LHC analyses of processes containing two or more leptons and missing energy, possibly in association with b-jets, show strong tensions with the Standard Model predictions and are known as multi-lepton anomalies. In particular, top-quark…

We propose a spontaneous A4 flavor symmetry breaking scheme implemented in a warped extra dimensional setup to explain the observed pattern of quark and lepton masses and mixings. The main advantages of this choice are the explanation of…

$B$-physics data and flavor symmetries suggest that leptoquarks can have masses as low as few ${\cal{O}}(\mbox{TeV})$, predominantly decay to third generation quarks, and highlight $pp \to b \mu \mu$ signatures from single production and…

We construct a gauge $B-L$ model with $D_4\times Z_4\times Z_2$ symmetry that can explain the quark and lepton mass hierarchies and their mixings with the realistic CP phases via the type-I seesaw mechanism. Six quark mases, three quark…

Direct CP violations in $B_{l4}$ decays ($B^\pm \to \pi^+\pi^- l^\pm {\nu}_l$) are investigated within the Standard Model (SM) and also in its extensions. In the decay processes, we include various excited states as intermediate states…

In recent papers a microscopic model for the SM Higgs mechanism has been proposed, and an idea how to determine the 24 quark and lepton masses of all 3 generations has emerged in that framework. This idea is worked out in detail here by…

Many new physics models that explain the intriguing anomalies in the $b$-quark flavour sector are severely constrained by $B_s$-mixing, for which the Standard Model prediction and experiment agreed well until recently. The most recent FLAG…

We study a second CP symmetry compatible with the $A_4$ flavor group, which interchanges the representations $\mathbf{1}'$ and $\mathbf{1}"$. We analyze the lepton mixing patterns arising from the $A_4$ and CP symmetry broken to residual…

The cross section for production at the 7 TeV LHC has been measured. For the first time it therefore becomes possible to measure Z couplings to top quarks. Interpreting the notorious LEP1 anomaly on Z couplings to b quarks in terms of an…

Recent improvements to the limit of Delta M_{B_s} imply that pure superweak theories, while not excluded, no longer provide a good fit to the data. A class of general superweak theories is introduced in which all flavor changing…

Using firmly established experimental inputs such as epsilon_K, Delta M_d, Delta M_s, BR(B -> tau nu), gamma, V_cb along with corresponding lattice matrix elements which have been well studied and are in full QCD such as B_K, SU3 breaking…

Within the broad context of quark-lepton unification, we investigate the implications of broken continuous family symmetries which result from requiring that in the limit of exact symmetry, the Dirac mass matrices yield hierarchical masses…

Motivated in part by the several observed anomalies involving CP asymmetries of B and B_s decays, we consider the Standard Model with a 4th sequential family (SM4) which seems to offer a rather simple resolution. We initially assume…

Influence of the fourth generation, if ever exists, on the experimentally measurable quantities such as invariant dilepton mass distribution, lepton forward-backward asymmetry, and the ratio (Gamma_L/Gamma_T) of the decay widths when K*…

In the light of the LHC, we revisit the implications of a fourth generation of chiral matter. We identify a specific ensemble of particle masses and mixings that are in agreement with all current experimental bounds as well as minimize the…