A scrutiny of hard pion chiral perturbation theory

In the recently proposed framework of hard pion chiral perturbation theory, the leading chiral logarithms are predicted to factorize with respect to the energy dependence in the chiral limit. We have scrutinized this assumption in the case of vector and scalar pion form factors FV;S(s) by means of standard chiral perturbation theory and dispersion relations. We show that this factorization property is valid for the elastic contribution to the dispersion integrals for FV;S(s) but it is violated starting at three loops when the inelastic four-pion contributions arise.

Schiller und das Wiener Burgtheater. Don Karlos-Inszenierungen 1938 und 1955 als Beispiele

Der Beitrag untersucht anhand der Rezeption von zwei exemplarischen Don Karlos-Inszenierungen, die beide in politisch markanten Jahren der österreichischen Geschichte ihre Premiere erlebten, die Funktionalisierung der Institution Burgtheater in Verbindung mit der Funktionalisierung des Dramatikers Friedrich Schiller für eben diese Institution. Eine Neueinstudierung erfolgte 1938, dem Jahr von Österreichs ‚Anschluss’ an Nazi-Deutschland, die andere 1955, dem Jahr der Unterzeichnung des Österreichischen Staatsvertrages. Beide Don Karlos-Inszenierungen fanden als spezifische Festvorstellungen im Rahmen von Feierlichkeiten rund um die Institution Burgtheater statt. Diente 1938 Schillers Don Karlos dazu, als ‚Schlüsselstück’ der ‚nationalsozialistischen Revolution’ einen politisch-gesellschaftlichen Aufbruch zu markieren, so wurde 1955 die Inszenierung des Dramas zum Triumph einer Schauspielerelite, deren Können sich in die konstruierte Tradition eines k.k. ‚Schauspieleradels’ einreihte. Während 1938 der ‚nationale Dichter’ dem ‚heimgekehrten’ Nationaltheater zum ästhetischen ‚Anschluss’ verhalf, diente der ‚überzeitliche’ Klassiker 1955 dazu, eine ästhetische ‚Wiedergeburt’ zu behaupten, die dem restaurativen Kunst- und Kulturbegriff Nachkriegsösterreichs verpflichtet war.

Factorization of leading chiral logarithms in the pion form factors

In the recently proposed framework of hard pion chiral perturbation theory, the leading chiral logarithms are predicted to factorize with respect to the energy dependence in the chiral limit. We have scrutinized this assumption in the case of vector and scalar pion form factors FV;S(s) by means of standard chiral perturbation theory and dispersion relations. We show that this factorization property is valid for the elastic contribution to the dispersion integrals for FV;S(s) but it is violated starting at three loops when the inelastic four-pion contributions arise.

Pion emission from the T2K replica target: method, results and application

The T2K long-baseline neutrino oscillation experiment in Japan needs precise predictions of the initial neutrino flux. The highest precision can be reached based on detailed measurements of hadron emission from the same target as used by T2K exposed to a proton beam of the same kinetic energy of 30 GeV. The corresponding data were recorded in 2007-2010 by the NA61/SHINE experiment at the CERN SPS using a replica of the T2K graphite target. In this paper details of the experiment, data taking, data analysis method and results from the 2007 pilot run are presented. Furthermore, the application of the NA61/SHINE measurements to the predictions of the T2K initial neutrino flux is described and discussed.

Dispersive analysis of the pion transition form factor

We analyze the pion transition form factor using dispersion theory. We calculate the singly-virtual form factor in the time-like region based on data for the e+e−→3π cross section, generalizing previous studies on ω,ϕ→3π decays and γπ→ππ scattering, and verify our result by comparing to e+e−→π0γ data. We perform the analytic continuation to the space-like region, predicting the poorly-constrained space-like transition form factor below 1GeV, and extract the slope of the form factor at vanishing momentum transfer aπ=(30.7±0.6)×10−3. We derive the dispersive formalism necessary for the extension of these results to the doubly-virtual case, as required for the pion-pole contribution to hadronic light-by-light scattering in the anomalous magnetic moment of the muon.

Measurement of negatively charged pion spectra in inelastic p+p interactions at plab = 20, 31, 40, 80 and 158 GeV/c

We present experimental results on inclusive spectra and mean multiplicities of negatively charged pions produced in inelastic p+p interactions at incident projectile momenta of 20, 31, 40, 80 and 158GeV/c (√s = 6.3, 7.7,8.8, 12.3 and 17.3GeV, respectively). The measurements were performed using the large acceptance NA61/SHINE hadron spectrometer at the CERN super proton synchrotron. Two-dimensional spectra are determined in terms of rapidity and transverse momentum. Their properties such as the width of rapidity distributions and the inverse slope parameter of transverse mass spectra are extracted and their collision energy dependences are presented. The results on inelastic p+p interactions are compared with the corresponding data on central Pb+Pb collisions measured by the NA49 experiment at the CERNSPS. The results presented in this paper are part of the NA61/SHINE ion program devoted to the study of the properties of the onset of deconfinement and search for the critical point of strongly interacting matter. They are required for interpretation of results on nucleus–nucleus and proton–nucleus collisions.