A minimal flavored U(1)′U(1)' for BB-meson anomalies

We consider an anomaly-free $U(1)'$ model with favorable couplings to heavy flavors in the Standard Model(SM), as motivated by $B$-meson anomalies at LHCb. Taking the $U(1)'$ charge to be $Q'=y(L_\mu-L_\tau)+ x(B_3-L_3)$, we can explain the $B$-meson anomalies without invoking extra charged fermions or flavor violation beyond the SM. We show that there is a viable parameter space with a small $x$ that is compatible with other meson decays, tau lepton and neutrino experiments as well as the LHC dimuon searches. We briefly discuss the prospects of discovering the $Z'$ gauge boson at the LHC in the proposed model.Comment: 20 pages, 4 figures, v2: references and discussion on electroweak precision test added, v3: Version to appear in Physical Review

BB-meson anomalies and Higgs physics in flavored U(1)′U(1)' model

We consider a simple extension of the Standard Model with flavor-dependent $U(1)'$, that has been proposed to explain some of $B$-meson anomalies recently reported at LHCb. The $U(1)'$ charge is chosen as a linear combination of anomaly-free $B_3-L_3$ and $L_\mu-L_\tau$. In this model, the flavor structure in the SM is restricted due to flavor-dependent $U(1)'$ charges, in particular, quark mixings are induced by a small vacuum expectation value of the extra Higgs doublet. As a result, it is natural to get sizable flavor-violating Yukawa couplings of heavy Higgs bosons involving the bottom quark. In this article, we focus on the phenomenology of the Higgs sector of the model including extra Higgs doublet and singlet scalars. We impose various bounds on the extended Higgs sector from Higgs and electroweak precision data, $B$-meson mixings and decays as well as unitarity and stability bounds, then discuss the productions and decays of heavy Higgs bosons at the LHC.Comment: 40 pages, 11 figures, 1 table; v2: references added; v3: accepted version for publication in EPJ

Flavor and CP-violating Higgs sector in two Higgs doublet models with U(1)′U(1)'

We investigate the role of a local $U(1)'$ symmetry for the problem of CP violation in the effective theory for two Higgs doublet models and its microscopic counterparts. First, in two Higgs doublet models with $U(1)'$, we show that the higher-dimensional operators in the scalar potential violate the CP symmetry with an interplay with the mixing mass parameter, giving rise to small mixings between CP-even and CP-odd scalars. Motivated by the $B$-meson anomalies in recent years, we take the flavored $U(1)'$ to be a benchmark model for specifying the flavor structure. Then, we calculate the electric dipole moment of electron (eEDM) at two loops due to the CP-violating higher-dimensional operators and identify the correlation between the masses of heavy Higgs bosons and the cutoff scale from the bound on eEDM. We also comment on the possibility of making an independent test of the CP violation in the collider searches for heavy Higgs bosons. Finally, we show how the obtained eEDM results in the effective theory can be used to constrain microscopic models with an explicit CP violation in the partially decoupled or dark sectors.Comment: 37 pages, 5 figures, Journal versio

Study on the Simulation and Evolution Model of Unexpected Emergencies’ spreading Network

AbstractThe cycle characteristic of unexpected emergencies’ spreading is quantitatively characterized by Gaussian distribution, and Systemic Science is combined with complex network theory to constructs the evolution model of unexpected emergencies’ spreading from the two dimensions of spreading object and event subject so as to study the evolution of unexpected emergencies’ spreading network. By comparing the resolving results with the simulating results, the feature of unexpected emergencies’ spreading network which is in accordance with scale-free network's characteristics of γ=3 is founded which reflects the objective characteristic of unexpected emergencies’ spreading network, so that it means a lot for the emergency department to make “Scene-In response to” control strategy