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M. Misiak

Publications and source records attributed to M. Misiak.

23 records · Page 2Linked to original sources
arXiv2002

Two-time synchronism and induced synchronization

A pair (A,B) of interacting oscillators treated as a master system sending signals to its slave copy (a,b) through two communication channels A-->a and B-->b is considered. The effect of non-simultaneous (two-time) synchronization of the pairs (a,A) and (b,B) is demonstrated with the help of coupled Kerr oscillators producing hyperchaos. An individual pair, for example, (b,B) can also be synchronized when its communication channel B-->b is turned off, provided that the second channel for the pair (a,A) is turned on. The resulted synchronization is termed induced. The efficiencies of the presented synchronization precesses are studied.

nlin.CD↗
arXiv1994

Two-loop mixing of dimension-five flavor-changing operators

We calculate the two-loop QCD mixing of the dimension-five flavor-changing operators that arise in the Standard Model after integrating out the $W$, $Z$ and Higgs bosons and the top-quark, i.e.~the mixing among gluonic and photonic magnetic moment operators. Our calculation completes the two-loop anomalous dimension matrix of operators that govern low energy flavor-changing processes. It is an important ingredient of the next-to-leading calculation of the $B \rightarrow X_s γ$ decay rate.

hep-ph↗
arXiv1994

Direct CP Violation in K_L --> π^0 e^+e^- Beyond Leading Logarithms

We analyze the direct CP violation in the rare decay K_L --> Pi^0 e+e- with QCD effects taken into account consistently in the next-to-leading order. We calculate the two-loop mixing between the four-quark ΔS=1 operators and the operator Q_7V = (sd)_(V-A)(ee)_V in the NDR and HV renormalization schemes. Using the known two-loop anomalous dimension matrix of the four-quark operators, we find that the coefficient C_7V(μ) depends only very weakly on μ, renormalization scheme and Λ_MSbar. The next-to-leading QCD corrections enhance the direct CP violating contribution over its leading order estimate so that it remains dominant in spite of the recent decrease of |V_ub/V_cb| and |V_cb|. We expect typically BR(K_L --> π^0 e^+ e^-)_dir ~ 6*10^(-12), although values as high as 10^(-11) are not yet excluded.

hep-ph↗
arXiv1993

Theoretical Uncertainties and Phenomenological Aspects of $B \rightarrow X_s γ$ Decay

We analyze uncertainties in the theoretical prediction for the inclusive branching ratio $BR[B \rightarrow X_s γ]$. We find that the dominant uncertainty in the leading order expression comes from its $μ$-dependence. We discuss a next-to-leading order calculation of $B \rightarrow X_s γ$ in general terms and check to what extent the $μ$-dependence can be reduced in such a calculation. We present constraints on the Standard and Two-Higgs-Doublet Model parameters coming from the measurement of $b \rightarrow s γ$ decay. The current theoretical uncertainties do not allow one to definitively restrict the Standard Model parameters much beyond the limits coming from other experiments. The bounds on the Two-Higgs-Doublet Model remain very strong, though significantly weaker than the ones present in the recent literature. In the Two-Higgs-Doublet Model case, the $b \rightarrow s γ$, $Z \rightarrow b \bar{b}$ and $b \rightarrow c τ\barν_τ$ processes are enough to give the most restrictive bounds in the $M_{H^{\pm}}-tan β$ plane.

hep-ph↗