김충선 교수

The decay constants of pseudoscalar heavy mesons of 0− state are computed by means of the relativistic (instantaneous) Salpeter equation. We solved the full Salpeter equation without making any further approximation, such as ignoring the small component wave function. Therefore, our results for the decay constants include the complete relativistic contributions from the light and the heavy quarks. We obtain FDs≈248±27, FD≈230±25(D0,D±), FBs≈216±32, FB≈196±29(B0,B±), FBc≈322±42 and Fηc≈292±25MeV.

The average kinetic energy of the heavy quark inside B or D meson is computed by means of the instantaneous Bethe–Salpeter method. We first solve the relativistic Salpeter equation and obtain the relativistic wave function and mass of 0− state, then we use the relativistic wave function to calculate the average kinetic energy of the heavy quark inside heavy meson of 0− state. We find that the relativistic corrections to the average kinetic energy of the heavy quark inside B or D meson are quite

A simultaneous analytical method for 237Np, 239Pu and 240Pu has been developed using sector field inductively coupled plasma mass spectrometry (ICP-SF-MS) detection combined with an automated sequential injection (SI) separation system. The chemical purification of these actinides was carried out on an actinide-specific extraction chromatographic resin, TEVA-Spec, in an automated SI system. The similar chemical behaviors of Np and Pu on TEVA-Spec was confirmed by recovery test after treating wit

Some of the outstanding questions of particle physics today concern the neutrino sector, in particular whether there are more neutrinos than those already known and whether they are Dirac or Majorana particles. There are different ways to explore these issues. In this article we describe neutrino-mediated decays of charged pseudoscalar mesons such as π±,K± and B±, in scenarios where extra neutrinos are heavy and can be on their mass shell. We discuss semileptonic and leptonic decays of such kind

The updated CDF measurement of the forward–backward asymmetry AFB in the top quark production pp¯→tt¯ at Tevatron (with s=1.96TeV) shows a deviation of 2σ from the value predicted by the Standard QCD Model. We present calculation of this quantity in the scenario, where colored unparticle physics contributes to the s-channel of the process, and obtain the regions in the plane of the unparticle parameters λ and dU, which give the values of the AFB and of the total tt¯ production cross section comp

The value of the weak mixing parameter $|{V}_{\mathrm{ub}}|$ has recently been determined to be of order $0.1|{V}_{\mathrm{cb}}|$. A recent determination of $\frac{{\ensuremath{\epsilon}}^{\ensuremath{'}}}{\ensuremath{\epsilon}}$ in $\mathrm{CP}$-violating kaon decays gives (-0.5\ifmmode\pm\else\textpm\fi{}1.5)\ifmmode\times\else\texttimes\fi{}${10}^{\ensuremath{-}3}$, in contrast to an earlier measurement of (3.3\ifmmode\pm\else\textpm\fi{}1.1)\ifmmode\times\else\texttimes\fi{}${10}^{\ensuremat

We present the angular distribution of the rare B decay, $\stackrel{\ensuremath{\rightarrow}}{B}{K}^{*}(\ensuremath{\rightarrow}K\ensuremath{\pi}){\mathcal{l}}^{+}{\mathcal{l}}^{\ensuremath{-}}.$ By studying the azimuthal angle distribution in the low invariant mass region of dileptons, we can probe new physics effects efficiently. In particular, this distribution is found to be quite sensitive to the ratio of the contributions from two independent magnetic moment operators, which also contribut

We study the pion decays with intermediate on-shell neutrinos $N$ into two electrons and a muon, $\pi^{\pm} \to e^{\pm} N \to e^{\pm} e^{\pm} \mu^{\mp} \nu$. We investigate the branching ratios ${\rm Br}_{\pm} = [\Gamma(\pi^- \to e^- e^- \mu^+ \nu) \pm \Gamma(\pi^+ \to e^+e^+\mu^-\nu)]/\Gamma(\pi^- \to {\rm all})$ and the CP asymmetry ratio ${\cal A}_{\rm CP} = {\rm Br}_{-}/{\rm Br}_{+}$ for such decays, in the scenario with two different on-shell neutrinos. If $N$ is Dirac, only the lepton numb