Determination of the strange quark mass from Cabibbo-suppressed tau decays with resummed perturbation theory in an effective scheme

We present an analysis of the m_s^2-corrections to Cabibbo-suppressed tau lepton decays employing contour improved resummation within an effective scheme which is an essential new feature as compared to previous analyses. The whole perturbative QCD dynamics of the tau-system is described by the beta-function of the effective coupling constant and by two gamma-functions for the effective mass parameters of the strange quark in different spin channels. We analyze the stability of our results with regard to high-order terms in the perturbative expansion of the renormalization group functions. A numerical value for the strange quark mass in the MS scheme is extracted m_s(M_\tau)=130\pm 27_{exp}\pm 9_{th} MeV. After running to the scale 1 GeV this translates into m_s(1 GeV)=176 \pm 37_{exp}\pm 13_{th} MeV.Comment: 32 pages, latex, 4 postscript figures, revised version to appear in European Physical Journal C, discussion of the choice of the moments added, some errors correcte

Asymptotic structure of perturbative series for τ\tau lepton decay observables: ms2m_s^2 corrections

In a previous paper we performed an analysis of asymptotic structure of perturbation theory series for semileptonic $\tau$-lepton decays in massless limit. We extend our analysis to the Cabibbo suppressed $\Delta S=1$ decay modes of the $\tau$ lepton. In particular we address the problem of $m_s^2$ corrections to theoretical formulas. The properties of the asymptotic behavior of the finite order perturbation theory series for the coefficient functions of the $m_s^2$ corrections are studied.Comment: 25 page

Asymptotic structure of perturbative series for tau lepton observables

We analyze tau lepton decay observables, namely moments of the hadronic spectral density in the finite energy interval (0,M_\tau), within finite order perturbation theory including \alpha_s^4 corrections. The start of asymptotic growth of perturbation theory series is found at this order in a scheme invariant manner. We establish the ultimate accuracy of finite order perturbation theory predictions and discuss the construction of optimal observables.Comment: 21 page

A Purification of venom phosphodiesterase

For purposes of analysis of polynucleotides, it is desirable to have a phosphodiesterase, substantially free of 5-nucleotidase or other phosphatase activity. The presence of a phosphodiesterase in a wide variety of snake venoms was demonstrated by Gullan and Jackson (1). These venoms were found also to contain a potent 5-nucleotidase, but were free of alkaline phosphatase activity. Hurst and Butler (2) found that certain samples of Russell's viper venom were nearly free of 5-nucleotidase activity, while retaining potent phosphodiesterase action. By a chromatographic procedure, involving the use of cellulose columns, they were able to reduce the 5-nucleotidase activity of rattlesnake venom, relative to its phosphodiesterase activity, and to obtain fractions nearly comparable to the viper venom

A Deoxyribonuclease from Calf Spleen. II. Mode of Action

When highly polymerized deoxyribonucleic acid is digested with pancreatic DNase and the digest further degraded with phosphodiesterase from intestinal mucose or snake venom, the mononucleotides formed are 5'-phosphates. Since a digest prepared in this manner with a purified venom diesterase contains only 5'-mononucleotides and practically no nucleosides or polynucleotides, the pancreatic DNase must form only polynucleotides with 5' monoesterified phosphate end groups. Recently the enzymatic synthesis of polydeoxyribonucleotides from eoxyribonucleoside 5'-triphosphates has been demonstrated. Thus both enzymatic synthesis and degradation of deoxyribonucleic acids have as yet involved only derivatives with 5'-monoesterified phosphate

A Deoxyribonuclease from Calf Spleen: I Purification and Properties

The deoxyribonucleases1 of animal tissues are of two types which are readily distinguishable by the conditions necessary for activity on their substrate, DNA. The pancreatic DNase, which has been crystallized by Kunitz (1), is active in neutral solution in the presence of magnesium or certain other divalent cations (2). The DN ase predominant in most other tissues is active at a lower pH, in the presence of adequate ionic strength, but does not specifically require divalent ions