A multi-charged particle model with local $U(1)_{\mu - \tau}$ to explain muon $g-2$, flavor physics, and possible collider signature

We consider a model with multi-charged particles including vector-like fermions and a charged scalar under a local $U(1)_{\mu - \tau}$ symmetry. We search for allowed parameter region explaining muon anomalous magnetic moment (muon $g-2$) and $b \to s \ell^+ \ell^-$ anomalies, satisfying constraints from the lepton flavor violations, $Z$ boson decays, meson anti-meson mixing and collider experiments. Carrying out numerical analysis, we explore the typical size of the muon $g-2$ and Wilson coefficients to explain $b \to s \ell^+ \ell^-$ anomalies in our model when all other experimental constraints are satisfied. We then discuss the collider physics of the multicharged vectorlike fermions, considering some benchmark points in the allowed parameter space. Content from this work may be used under the terms of the Creative Commons Attribution 3.0 licence. Any further distribution of this work must maintain attribution to the author(s) and the title of the work, journal citation and DOI. Article funded by SCOAP3 and published under licence by Chinese Physical Society and the Institute of High Energy Physics of the Chinese Academy of Science and the Institute of Modern Physics of the Chinese Academy of Sciences and IOP Publishing Ltd.

Study of electroweak penguin B decays at Belle II experiment

The electroweak b → sll (l = e, µ) transition is a flavor-changing neutral current process that mediates through a one-loop penguin diagram. The decay is considered to be a good probe for the New Physics as particles predicted in the beyond Standard Model theories can enter into the loop. The exclusive decay B → K (*) l + l − was first observed by the Belle experiment and it provides many observables such as the branching fraction, CP asymmetry, forward-backward asymmetry, and other angular observables. Recently, the LHCb experiment has reported some clue of a lepton flavor universality violation from the branching fraction ratio of the B → Kµ + µ − and B → Ke + e − decays. In this presentation, we report the status of the B → Kl + l − decay analysis at the Belle II experiment which started the data taking in 2019. We also, present an activity at the Belle II Chulalongkorn University group where we study the B → KJ/ψ decay which has the same topology as the B → Kl + l − .

Generalized 2HDM with wrong-sign lepton-Yukawa coupling, in light of $$g_{\mu }-2$$ and lepton flavor violation at the future LHC

To explain the observed muon anomaly and simultaneously evade bounds from lepton flavor violation in the same model parameter space is a long-cherished dream. In view of a generalized Two Higgs Doublet Model, with a Yukawa structure as a perturbation of Type-X, we are able to get substantial parameter space satisfying these criteria. In this work, we focus on a region with “wrong-sign” lepton-Yukawa coupling which gives rise to interesting phenomenological consequences. Performing a simple cut-based analysis, we show that at 14 TeV run of the LHC with $$300 \mathrm{{fb}}^{-1}$$ 300 fb - 1 integrated luminosity, part of the model parameter space can be probed with significance "Equation missing" which further improves with Artificial Neural Network analysis.

Discriminating Chiral Insertions from BSM for the Muon (g-2) by non-Abelian Zero Modes

A sorting out method, between the New Physics and as vs. the Lepton Flavor Violated Chiral insertion is exposed, interpreting so the Light-by-Light scattered amplitude deviation in the muon magnetic moment, with a novel 2-color instead of 3-color in diagrams projective polarizations. The calculation is done using an extension-detention of the muon resonance interaction internal lines (which may be generically of a non-QCD nature)such its modes’ phonons decompose into instantons while the helicities are to meet the imposed polarizations. A confirmation comes out from a non-applicability of the Landau Gauge, to the one of the cases, the tri-vector-mode, giving it a double pole in its Goldstone propagator, vs. its truth in the Sudakov type with a single pole mode Goldstone propagator.The fits between expansions of the phonon derived from slicing’s, and the instanton derived from inverse arguments of differently coupled cosine’s, are surprisingly proportional to their projected (2 to 3 in their extended diagrams) normalization factors paving ways into a BSM popped up selectivity method.

Phenomenology of dark matter and mirror fermions from a left-right mirror model with singlet scalar

We investigate a left-right mirror model with SU(3)c×SU(2)L×SU(2)R×U(1)Y and a discrete Z2 symmetry, which introduces mirror fields that are copies of the standard model fields. The mirror fields have the opposite chirality to their standard model counterpart fields. We also introduce singlet scalars as dark matter. The new interaction between dark matter, standard model fermions, and mirror fermions can account for dark matter abundance, charged lepton flavor violation, lepton anomalous magnetic moment, and flavor changing neutral current. We demonstrated that if we choose dark matter annihilation into muon as the dominant annihilation channel for leptophilic dark matter, both the observed dark matter abundance and the observed discrepancy between theory and experiment in the muon anomalous magnetic moment can be explained without contradicting the bound derived from charged lepton flavor violating processes. We briefly discuss how mirror fermions will be produced at the future linear collider, as mirror fermions can interact with neutral gauge bosons in this model. Finally, we discuss the lightest mirror neutrino decay mechanism, which will be highly abundant if stable.