We provide a comprehensive, up-to-date analysis of possible New Physics contributions to the mass difference $ΔM_D$ in $D^0$-${\bar D}^0$ mixing. We consider the most general low energy effective Hamiltonian and include leading order QCD running of effective operators. We then explore an extensive list of possible New Physics models that can generate these operators, which we organize as including Extra Fermions, Extra Gauge Bosons, Extra Scalars, Extra Space Dimensions and Extra Symmetries. For each model we place restrictions on the allowed parameter space using the recent evidence for observation of $D$ meson mixing. In many scenarios, we find strong constraints that surpass those from other search techniques and provide an important test of flavor changing neutral currents in the up-quark sector. We also review the recent BaBar and Belle findings, and describe the current status of the Standard Model predictions of $D^0$-${\bar D}^0$ mixing.
We propose a novel and simple mechanism where sizable effects of non-standard interactions (NSI) in neutrino propagation are induced from the mixing between an electrophilic second Higgs doublet and a charged singlet. The mixing arises from a dimensionful coupling of the scalar doublet and singlet to the standard model Higgs boson. In light of the small mass, the light mass eigenstate from the doublet-singlet mixing can generate much larger NSI than those induced by the heavy eigenstate. We show that a sizable NSI $\varepsilon_{eτ}$ ($\sim 0.3$) can be attained without being excluded by a vari…
We study the phenomenological implications of breaking the Tri-Bimaximal (TBM) mixing in such a way that either first or second column of TBM mixing matrix remains invariant. We present two such textures and confront them with the experimental data. We give the predictions of these textures for atmospheric mixing angle $θ_{23}$ and Dirac-type CP violating phase $δ$ that will be measured in the future experiments.
We study the phenomenological implications of the presence of two texture zeros in the neutrino mass matrix assuming that the neutrino mixing matrix has its first column identical to that of the tribimaximal mixing matrix. Only two patterns of this kind are compatible with the experimental data. These textures have definite predictions for the neutrino observables that are testable in future neutrino experiments.
We diagonalize Majorana neutrino mass matrix with the help of PMNS matrix and obtain analytical relations between the mass matrix elements and mixing parameters, viz., three mixing angles- $θ_{12}, θ_{23}, θ_{13}$ and Dirac CP phase δ. We analyse our results in a special $μ$-$τ$ symmetric mass matrix which corresponds to maximal atmospheric mixing ($θ_{23}=π/4$) and maximal CP violation ($δ=-π/2$). The analysis shows that a deviation of $θ_{23}$ from its maximal value can be correlated with the prediction of other two mixing angles.
A simple analysis of time-dependent $B_s\to K^+K^-$ transitions, based on recent results from the LHCb experiment, is presented. The benefits of adopting a fully consistent theoretical description of the $B^0_s$--$\bar B^0_s$ mixing are stressed. It is shown that bounds on CPT violation in the $B^0_s$--$\bar B^0_s$ system can be consistently obtained and that direct CP violation in $B_s\to K^+K^-$ can be robustly established, even in the presence of CPT violation in the mixing.
Prompted by the recent Dresden-II reactor data we examine its implications for the determination of the weak mixing angle, paying attention to the effect of the quenching function. We also determine the resulting constraints on the unitarity of the neutrino mixing matrix, as well as on the most general type of nonstandard neutral-current neutrino interactions.
The phenomenon of $B^0_q$-$\bar{B}^0_q$ mixing ($q=d,s$) provides a sensitive probe for physics beyond the Standard Model. We have a careful look at the determination of the Unitarity Triangle apex, which is needed for the Standard Model predictions of the $B_q$ mixing parameters, and explore how much space for New Physics is left through the current data. We study the impact of tensions between inclusive and exclusive determinations of the CKM matrix elements $|V_{ub}|$ and $|V_{cb}|$, and focus on the $γ$ angle extraction. We present various future scenarios and discuss the application of th…
The parameter $y_{CP}$ is used to characterize mixing in the $D^0$-$\bar{D}{}^0$ meson system. To determine $y_{CP}$, one measures the effective decay width of a $D^0$ or $\bar{D}{}^0$ decaying to a $CP$ eigenstate, relative to the effective width for a decay to a Cabibbo-favored, flavor-specific final state. When using $y_{CP}$ to extract information about $D^0$-$\bar{D}{}^0$ mixing and $CP$ violation, the decay width of the Cabibbo-favored decay is usually assumed to equal $1/τ$, the reciprocal of the $D^0$ lifetime. However, there is a small correction to this that should be taken into acco…
We present a method to identify symmetry groups of the Yukawa sector of the three-Higgs-doublet model and to determine the implication that the symmetry has on the lepton masses and mixing. The method can accommodate different hypotheses about the group representation assignments, and thus support the exploration of candidate symmetry groups. For one particular representation selection scheme we apply the computer-implemented method to scan all discrete groups of order less than 1035. It can be proven that none of these groups defines a flavor symmetry that implies masses and neutrino mixing a…
To accommodate the recently observed non-zero reactor mixing angle $θ_{13}$, we consider the lepton mixing matrix as Tri-bimaximal mixing (TBM) form in the leading order along with a perturbation in neutrino sector. The perturbation is taken to be a rotation in 23 plane followed by a rotation in 13 plane, i.e., $R_{23}(θ_{23}')R_{13}(θ_{13}',ϕ)$. We obtain the allowed values of the parameters $θ_{23}'$, $θ_{13}'$ and $ϕ$, which can accommodate all the observed mixing angles consistently and calculate the phenomenological observables such as the Dirac CP violating phase ($δ_{CP}$), Jarlskog inv…
We revisit mixing sum rule relations in the lepton and quark sectors under the assumption that the 1-3 elements of the flavour mixing matrices ($V^u_L,V^d_L,V^e_L,V^ν_L$) are zero in the flavour basis. We consider the exact relations resulting from the validity of this "zero 1-3 flavour mixing hypothesis" and analyse their implications based on the current experimental data, including effects from RG running. In particular, we analyse how the existing precise measurement of $θ_{13}^\mathrm{PMNS}$ allows to derive predictions for $θ_{23}^\mathrm{PMNS}$ in models with constrained $θ_{12}^\mathrm…
