相关论文: Three Exceptions to the Grossman-Nir Bound
Rare $K \to \pi \nu \bar \nu$ decays, being dominated by short distance contributions within the Standard Model (SM), open a window for New Physics (NP) searches at low energies. The $ K \to \pi \nu \bar\nu $ branching ratios are expected…
Rare processes in laboratory and within astrophysical environments can be highly sensitive probes of baryon-number violating interactions at the TeV scale. We demonstrate the power of neutron stars to constrain baryon number violation by…
During the last fifteen years B_{s,d} decays, B_{s,d}^0-\bar B^0_{s,d} mixings, CP-violating asymmetries S_{\psi K_S} and S_{\psi\phi} provided the dominant information about the pattern of flavour violation within the SM and its…
We discuss new physics (NP) contributions to kaon mixing parameter $\varepsilon_K$, direct CP violation parameter $\varepsilon^\prime/\varepsilon$ of $K\to \pi\pi$, and rare decays $K^+\to \pi^+\nu\bar\nu$, $K_L\to \pi^0\nu\bar\nu$ and…
Lorentz Invariance Violation (LIV) arises in various quantum-gravity theories. As the typical energy for quantum gravity is the Planck mass, $M_{pl}$, LIV will, most likely, be manifested at very high energies that are not accessible on…
Precise measurements of the branching ratios for the flavor-changing neutral current decays $K\to\pi\nu\bar{\nu}$ can provide unique constraints on CKM unitarity and, potentially, evidence for new physics. It is important to measure both…
Superpartners of goldstino -- scalar and pseudoscalar sgoldstinos -- interact weakly with ordinary particles. One or both of them may be light. We consider a class of supersymmetric extensions of the Standard Model in which interactions of…
I give a pedagogical introduction into flavour-changing neutral current interactions of kaons and their role to reveal or constrain physics beyond the Standard Model (SM). Then I discuss the measure $\epsilon_K^\prime$ of direct CP…
We calculate a number of observables related to particle-antiparticle mixing and the branching ratios for the most interesting rare and CP-violating K and B decays in the Standard Model (SM3) extended by a fourth generation of quarks and…
We perform a critical reassessment of the constraints on the R-parity and baryon number violating (s)top couplings coming from flavor physics. In particular, we study K0-K0bar mixing, including QCD corrections and a class of diagrams that…
The Fermi gamma ray space telescope data have pointed towards an excess of gamma rays with a peak around $1-3$ GeV in the region surrounding the galactic center. This anomalous excess can be described well by a dark matter candidate having…
The rare kaon decays K_L -> pi^0 nu {bar nu}, K^+ -> pi^+ nu {bar nu}, K_L -> pi^0 e^+ e^- and K_L -> pi^0 mu^+ mu^- are theoretically very clean and, being strongly CKM suppressed, highly sensitive to New Physics (NP). Recent Flavour…
We discuss the modes $B\to K^{(*)}\nu\bar\nu$ in the context of non-standard neutrino interactions that add incoherently to the SM rates. We consider two scenarios: an additional light neutrino; and neutrino lepton flavour violation. We…
We have analyzed the ${\bar B}^0\to \pi^0\pi^0$ puzzle in three kinds of models beyond the standard model (SM). It is shown that the minimal flavor violation (MFV) models, the minimal supersymmetric standard model (MSSM), and the two Higgs…
Improved branching ratios were measured for the $K_L \to 3 \pi^0 $ decay in a neutral beam at the CERN SPS with the NA31 detector: $\Gamma (K_L \to 3 \pi^0) / \Gamma (K_L \to \pi^+ \pi^- \pi^0) = 1.611 \pm 0.037$ and $\Gamma (K_L \to 3…
The non-observation of baryon number violation suggests that the scale of baryon-number violating interactions at zero temperature is comparable to the GUT scale. However, the pertinent measurements involve hadrons made of the…
The Standard-Model (SM) prediction for the CP-violating quantity $\epsilon_K^{\prime}/\epsilon_K$ deviates from its measured value by 2.8 $\sigma$. It has been shown that this tension can be resolved within the Minimal Supersymmetric…
Neutrino oscillations occur due to non-zero masses and mixings and most importantly they are believed to maintain quantum coherence even over astrophysical length scales. In the present study, we explore the quantumness of three flavour…
Many extensions of the leptonic sector of the Minimal Supersymmetric Standard Model (MSSM) are known, most of them leading to observable flavor violating effects. It has been recently shown that the 1-loop contributions to lepton flavor…
We analyze the MeV/GeV emission from four bright Gamma-Ray Bursts (GRBs) observed by the Fermi-Large Area Telescope to produce robust, stringent constraints on a dependence of the speed of light in vacuo on the photon energy (vacuum…