Top Quark Decays into Heavy Quark Mesons

For top quark decays into heavy quark mesons $\Upsilon$ and $\bar{B}_c^*$ , a complete calculation to the leading order both in QCD coupling constant $\alpha_s$ and in $v$, the typical velocity of the heavy quarks inside the mesons, is performed. Relatons between the top quark mass and the decay branching ratios are studied. Comparion with the results which are obtained by using the quark frangmentation functions is also discussed. The branching ratios are consistent (within a factor of $2\sim 3$) with that obtained using fragmentation functions at $m_t\sim 150$ GeV.Comment: 15 pages in LaTex form, 4 figures include

Resonance tongues in the quasi-periodic Hill-Schrödinger equation with three frequencies

n this article we investigate numerically the spectrum of some representative examples of discrete one-dimensional Schrödinger operators with quasi-periodic potential in terms of a perturbative constant b and the spectral parameter a. Our examples include the well-known Almost Mathieu model, other trigonometric potentials with a single quasi-periodic frequency and generalisations with two and three frequencies. We computed numerically the rotation number and the Lyapunov exponent to detect open and collapsed gaps, resonance tongues and the measure of the spectrum. We found that the case with one frequency was significantly different from the case of several frequencies because the latter has all gaps collapsed for a sufficiently large value of the perturbative constant and thus the spectrum is a single spectral band with positive Lyapunov exponent. In contrast, in the cases with one frequency considered, gaps are always dense in the spectrum, although some gaps may collapse either for a single value of the perturbative constant or for a range of values. In all cases we found that there is a curve in the (a, b)-plane which separates the regions where the Lyapunov exponent is zero in the spectrum and where it is positive. Along this curve, which is b = 2 in the Almost Mathieu case, the measure of the spectrum is zero.Peer ReviewedPostprint (published version

Grouping of TRIZ Inventive Principles to facilitate automatic patent classification

10.1016/j.eswa.2006.10.015Expert Systems with Applications341788-795ESAP

Left Ventricular Thrombosis after Myocardial Infarction

To the Editor: Asinger et al. have made a solid contribution to our understanding of left ventricular thrombosis after acute myocardial infarction (August 6 issue).1 Yet, one is astonished to note that the authors and the Journal's usually Olympian reviewers permit misleading use of the word “transmural.“ A large body of work performed from 1951 to 1980 has demonstrated that infarcts producing Q-waves and those with only ST-T changes cannot reliably identify transmural and nontransmural infarcts.2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 Recent work also shows that the two echocardiographic patterns indicate comparable five-year survival17 and do not discriminate between single-vessel and multivessel disease.18 The report. . . © 1981, Massachusetts Medical Society. All rights reserved.SCOPUS: le.jinfo:eu-repo/semantics/publishe