Related papers: On the CVC problem in tau-decay
We consider the possibility of several different mechanisms contributing to the $\betabeta$-decay amplitude in the general case of CP nonconservation: light Majorana neutrino exchange, heavy left-handed (LH) and heavy right-handed (RH)…
We consider chiral fluids, with (nearly) massless fermionic constituents, in the confining phase. Chiral vortical effect (CVE) is the flow of axial current along the axis of rotation of the fluid while the spin alignment is a non-vanishing…
We study phenomenological consequences of the Standard Model extension by the new spin-1 chiral fields with the internal quantum numbers of the electroweak Higgs doublets. There are at least three different classes of theories, all…
Three recent experiments, which looked at pionic effects in nuclei have concluded that there are no excess pions. This puts into serious question the conventional meson-exchange picture of the nucleon-nucleon interaction. Based on arguments…
Some experimental tests are suggested for possible CP-violations for decays of $B^\pm$ bosons. Especially, a detailed comparison of decays $B^+ \rightarrow D^0 \pi^+ \pi^+ \pi^-$ and $B^- \rightarrow \overline{D^0} \pi^- \pi^- \pi^+$ will…
We propose a novel method to reconstruct event by event the full kinematics of the cascade decay process, $h \to \tau^+\tau^- \to (\pi^+ \bar{\nu}) (\pi^- \nu)$, which allows us to measure the $\tau^+\tau^-$ spin correlation, a measure of…
In the framework of Chiral Perturbation Theory including photons, we found that the contribution of the photon exchange between two intermediate charged Kaons to the slope parameter of the decay (\eta\rightarrow 3\pi^{0}) amounts to…
We compute the electromagnetic corrections to neutron beta decay using a low-energy hadronic effective field theory. We identify and compute new radiative corrections arising from virtual pions that were missed in previous studies. The…
We show how the transverse tau tau spin correlations can be used to measure the parity of the Higgs boson and hence to distinguish a CP-even H boson from CP-odd A in the future high energy accelerator experiments. We investigate the…
We use spin correlations to constrain anomalous $\tau$-lepton couplings at the LHC including its anomalous magnetic moment, electric dipole moment and weak dipole moments. Single spin correlations are ideal to probe interference terms…
The tau is the only known lepton that can decay hadronically. From this class of decays, high precision measurements of several quantities can be extracted: the CKM matrix element $V_{us}$, the mass of the strange quark, etc. Also, as a…
Various theories beyond the Standard Model predict new particles with masses in the sub-eV range with very weak couplings to ordinary matter which can possess spin-dependent couplings to electrons and nucleons. Present laboratory…
We present first results on the scalar WIMP-pion coupling from 1 t$\times$yr of exposure with the XENON1T experiment. This interaction is generated when the WIMP couples to a virtual pion exchanged between the nucleons in a nucleus. In…
The anomalous magnetic and electric dipole moments in spin motion equation acquire pseudoscalar corrections if the $T(CP)$-noninvariance is admitted. It allows to explain the discrepancy between experimental and theoretical values of muon…
The possible anomalous New Physics contributions to magnetic and electric dipole moments of the $\tau$ lepton have brought renewed interest in studying $\tau$-pair production at energies of the LHC and future colliders. We discuss effects…
We adopt the heavy baryon chiral perturbation theory to calculate the $\Sigma_cN$ interaction to the next-to-leading order. We consider the contact interactions, one-pion-exchange contributions, two-pion-exchange diagrams, and…
I discuss isospin breaking effects within the standard model. Chiral perturbation theory presents the appropriate theoretical framework for such an investigation in the low--energy range. Recent results on the electromagnetic contributions…
The axion is a hypothesized particle appearing in various theories beyond the Standard Model. It is a light spin-0 boson initially postulated to solve the strong CP problem and is also a strong candidate for dark matter. If the axion or an…
We use experimental data on $e^+e^- \to \eta (\eta^{\prime})\pi^+\pi^-$ and conservation of vector current to estimate the branching fractions of $\tau^-$ decay to $\eta (\eta^{\prime})\pi^-\pi^0\nu_{\tau}$. The obtained values are compared…
We introduce a scenario for CP-violating (CPV) dark photon interactions in the context of non-abelian kinetic mixing. Assuming an effective field theory that extends the Standard Model (SM) field content with an additional $U(1)$ gauge…