Related papers: Three-Loop Contributions to Hyperfine Splitting: M…
The increasing accuracy of current and planned experiments to measure the anomalous magnetic moment of the muon requires more precision and reliability of its theoretical calculation. For this purpose, we calculate the differential cross…
We report on our computation of the pion transition form factor ${\cal F}_{P\rightarrow \gamma^*\gamma^*}$ from twisted mass lattice QCD in order to determine the numerically dominant light pseudoscalar pole contribution in the hadronic…
We investigate the muon anomalous magnetic moment in the context of the supersymmetric version of the economical 3-3-1 model. We compute the 1-loop contribution of super-partner particles. We show that contribution of superparticle loop…
We compute the charged pion loop contribution to the light-by-light scattering amplitude for off-shell photons in chiral perturbation theory through next-to-leading order (NLO). We show that NLO contributions are relatively more important…
Axions and axion-like particles emerge in many models for physics beyond the Standard Model. Thus, they have gained increasing research interest in both experimental and theoretical physics apart from their original proposition as a…
We compute the hadronic light-by-light scattering contributions to the muon anomalous magnetic moment, $\amulbl$, in chiral perturbation theory that are enhanced by large logarithms and a factor of $N_C$. They depend on a low-energy…
We present updated results for the hadronic light-by-light (HLbL) contribution to the muon anomalous magnetic moment. The calculations are based on ETMC's $N_f=2+1+1$ Wilson-clover twisted-mass ensembles at the physical point. We perform…
This thesis investigates the Hadronic Light by Light (HLL) scattering contribution to the muon $g-2$, which is one of the most important low energy hadronic effects and consists mainly of the quark loop, the pion pole and the charged pion…
This paper reports the evaluation of the tenth-order QED contribution to the lepton g-2 from the gauge-invariant set of 2072 Feynman diagrams, called Set IV, which are obtained by inserting a second-order lepton vacuum-polarization loop…
Contributions to HFS and to the Lamb shift intervals of order $\alpha^2(Z\alpha)^5$ induced by the graph with the two-loop overlapping electron self-energy diagram inserted in the electron line are considered. Explicit expression for the…
We present a first model-independent calculation of $\pi\pi$ intermediate states in the hadronic-light-by-light (HLbL) contribution to the anomalous magnetic moment of the muon $(g-2)_\mu$ that goes beyond the scalar QED pion loop. To this…
Exclusive nonleptonic decays of bottom baryons to charm baryons and pseudoscalar light mesons are analyzed within a relativistic three-quark model. We include factorizing as well as nonfactorizing contributions to the decay amplitudes. The…
The hyperfine splitting in hydrogenlike $^{209}$Bi, $^{203}$Tl, and $^{205}$Tl is calculated with the nuclear magnetization determined from experimental data on the hyperfine splitting in the corresponding muonic atoms. The single-particle…
The hadronic light-by-light contribution to the anomalous magnetic moment of the muon was recently analyzed in the framework of dispersion theory, providing a systematic formalism where all input quantities are expressed in terms of…
In our previous work, the connected and leading disconnected hadronic light-by-light contributions to the muon anomalous magnetic moment (g - 2) have been computed using lattice QCD ensembles corresponding to physical pion mass generated by…
Effects of strong interactions on the two loop electroweak radiative corrections to the muon anomalous magnetic moment, $a_\mu=(g_\mu-2)/2$, are examined. Short-distance logs are shown to be unaffected. Computation of long-distance…
The "recoil" correction of order $m \alpha^6$ to the hyperfine splitting of positronium ground state was found. The formalism employed is based on the noncovariant perturbation theory in QED. Equation for two-particle component of full…
Hadronic contributions dominate the uncertainty of the Standard Model prediction for the anomalous magnetic moment of the muon. In this work, we present results on the hadronic light-by-light contribution obtained from the evaluation of the…
We compute the three-loop QCD corrections to the massive quark-anti-quark-photon form factors $F_1$ and $F_2$ involving a closed loop of massless fermions. This subset is gauge invariant and contains both planar and non-planar…
We calculate convergent 3-loop Feynman diagrams containing a single massive loop equipped with twist $\tau =2$ local operator insertions corresponding to spin $N$. They contribute to the massive operator matrix elements in QCD describing…