No Arabic abstract
Vector leptoquarks can address the lepton flavor universality anomalies in decays associated with the $b to c ell u$ and $b to s ell ell$ transitions, as observed in recent years. Generically, these leptoquarks yield new sources of CP violation. In this paper, we explore constraints and discovery potential for electric dipole moments (EDMs) in leptonic and hadronic systems. We provide the most generic expressions for dipole moments induced by vector leptoquarks at one loop. We find that $O(1)$ CP-violating phases in tau and muon couplings can lead to corresponding EDMs within reach of next-generation EDM experiments, and that existing bounds on the electron EDM already put stringent constraints on CP-violating electron couplings.
We analyze the implications of CP-violating scalar leptoquark (LQ) interactions for experimental probes of parity- and time-reversal violating properties of polar molecules. These systems are predominantly sensitive to the electric dipole moment (EDM) of the electron and nuclear-spin-independent (NSID) electron-nucleon interaction. The LQ model can generate both a tree-level NSID interaction as well as the electron EDM at one-loop order. Including both interactions, we find that the NSID interaction can dominate the molecular response. For moderate values of couplings, the current experimental results give roughly two orders of magnitude stronger limits on the electron EDM than one would otherwise infer from a sole-source analysis.
Searches for permanent electric dipole moments of fundamental particles and systems with spin are the experiments most sensitive to new CP violating physics and a top priority of a growing international community. We briefly review the current status of the field emphasizing on the charged leptons and lightest baryons.
Electric dipole moments are extremely sensitive probes for additional sources of CP violation in new physics models. The multi-scale problem of relating the high-precision measurements with neutrons, atoms and molecules to fundamental parameters can be approached model-independently to a large extent; however, care must be taken to include the uncertainties from especially nuclear and QCD calculations properly. The resulting bounds on fundamental parameters are illustrated in the context of Two-Higgs-Doublet models.
Many experiments are underway in the world to search for a non-zero electric dipole moment (EDM) of a particle with spin 1/2 such as the neutron or the electron. Finding an EDM would reveal new sources of CP violation. EDM measurements are motivated by the high sensitivity to new physics beyond the Standard Model. They are relevant to find the explanation for the matter-antimatter asymmetry of the Universe. A variety of programs with different systems are being pursued, with free neutrons, diamagnetic atoms, paramagnetic systems, and charged particles in storage rings. This article presents a basic introduction of the subject and attempts to compile the ongoing projects.
We show that a single vector leptoquark can explain both the muon $g-2$ anomaly recently measured by the Muon g-2 experiment at Fermilab, and the various $B$ decay anomalies, including the $R_{D^{(*)}}$ and $R_{K^{(*)}}$ anomalies which have been recently reported by the LHCb experiment. In order to provide sizeable positive new physics contributions to the muon $g-2$, we assume that the vector leptoquark particle couples to both left-handed and right-handed fermions with equal strength. Our model is found to satisfy the experimental constraints from the large hadron collider.