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Register a new userSimultaneous explanation of $K$ and $B$ anomalies in vectorlike compositeness
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We address the presently reported significant flavor anomalies in the $K$ and $B$ meson systems such as the CP violating Kaon decay ($epsilon/epsilon$) and lepton-flavor universality violation in $B$ meson decays ($R_{K^{(*)}},$ and also commenting ${R_{D^{(*)}}}$), by proposing flavorful and chiral vector bosons as the new physics constitution at $sim 1,mathrm{TeV}$. Interestingly, if the new (composite) vector bosons are quite heavier than $sim 1,mathrm{TeV}$, we face a difficulty in addressing the anomaly in $epsilon/epsilon$ consistently with the constraint from the $K^0$-$overline{K^0}$ mixing. Both of the anomalies can be addressed within $1sigma$ confidence levels individually, where the relevant parameter space will be investigated by the NA62 and KOTO experiments, in addition to direct searches at the large hadron collider.
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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 broken, gauged $U(1)_{B_3-L_2}$ extension to the Standard Model, where the extra quantum numbers of Standard Model fields are given by third family baryon number minus second family lepton number. The only fields beyond those of the Standard Model are three right-handed neutrinos, a gauge field associated with $U(1)_{B_3-L_2}$ and a Standard Model singlet complex scalar which breaks $U(1)_{B_3-L_2}$, a `flavon. This simple model, via interactions involving a TeV scale force-carrying $Z^prime$ vector boson, can successfully explain the neutral current $B-$anomalies whilst accommodating other empirical constraints. In an ansatz for fermion mixing, a combination of up-to-date $B-$anomaly fits, LHC direct $Z^prime$ search limits and other bounds rule out the domain 0.15 TeV$< M_{Z^prime} <$ 1.9 TeV at the 95$%$ confidence level. For more massive $Z^prime$s, the model possesses a {em flavonstrahlung} signal, where $pp$ collisions produce a $Z^prime$ and a flavon, which subsequently decays into two Higgs bosons.
There are four models of tree-level new physics (NP) that can potentially explain the $bto s mu^+ mu^-$ and $b to cell bar u$ anomalies simultaneously. They are the S3, U3, and U1 leptoquarks and a standard-model-like triplet vector boson (VB). In this talk, I describe an analysis of these models with general couplings. We find that even in this most general case S3 and U3 are excluded. For the U1 model, I discuss the importance of the constraints from lepton-flavor-violating(LFV) processes. As for the VB model, it is shown to be excluded by the additional tree level constraints and LHC bounds on high-mass resonant dimuon pairs. This conclusion is reached without any assumptions about the NP couplings.
The deviation of the measured value of the muon anomalous magnetic moment from the standard model prediction can be completely explained by mixing of the muon with extra vectorlike leptons, L and E, near the electroweak scale. This mixing simultaneously contributes to the muon mass. We show that the correlation between contributions to the muon mass and muon g-2 is controlled by the mass of the neutrino originating from the doublet L. Positive correlation, simultaneously explaining both measured values, requires this mass below 200 GeV. The decay rate of the Higgs boson to muon pairs is modified and, in the region of the parameter space that can explain the muon anomalous magnetic moment within one standard deviation, it ranges from 0.5 to 24 times the standard model prediction. In the same scenario, $h to gamma gamma$ can be enhanced or lowered by ~50% from the standard model prediction. The explanation of the muon g-2 anomaly and predictions for $h to gamma gamma$ are not correlated since these are controlled by independent parameters. This scenario can be embedded in a model with three complete vectorlike families featuring gauge coupling unification, sufficiently stable proton, and the Higgs quartic coupling remaining positive all the way to the grand unification scale.
We offer a new solution to an old puzzle in the penguin-dominated $Btopi K$ decays. The puzzle is the inconsistency among the measurements of the branching ratios and CP asymmetries of the four $Btopi K$ decays: $B^+ to pi^+ K^0$, $B^+to pi^0 K^+$, $B_d^0topi^- K^+$, $B_d^0topi^0 K^0$. We solve the $Btopi K$ puzzle by considering the effect of an axion-like particle (ALP) that mixes with the $pi^0$ and has mass close to the $pi^0$ mass. We show that the ALP can also explain the anomalies in the electron and muon anomalous magnetic moments.
Vectorlike quarks have been shown to resolve certain long-standing discrepancies pertaining to the bottom sector. We investigate, here, the prospects of identifying the existence of a topless vectorlike doublet $(B,~Y)$, as is preferred by the electroweak precision measurements. Concentrating on single production, $viz.$ $B bar b$ with $B to b + Z/H$ subsequently, we find that the fully hadronic decay-channel is susceptible to discovery provided jet substructure observables are used. At the 13 TeV LHC with an integrated luminosity of 300 fb$^{-1}$, a modest value of the chromomagnetic transition moments allows for the exclusion of $M lesssim 1.8(2.2)$ TeV in the $Z$ and $H$ channels respectively.
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