scholarly journals Superspace approach to the renormalization of the O’Raifeartaigh model up to the second order in the linear delta expansion parameter

2012 ◽  
Vol 85 (12) ◽  
Author(s):  
M. C. B. Abdalla ◽  
J. A. Helayël-Neto ◽  
Daniel L. Nedel ◽  
Carlos R. Senise
Keyword(s):  
Second Order ◽  
Expansion Parameter

scholarly journals A CLOSER LOOK AT PERTURBATIVE CORRECTIONS IN THE b→c SEMILEPTONIC TRANSITIONS

1995 ◽  
Vol 10 (32) ◽  
pp. 4705-4714 ◽  
Author(s):  
M. SHIFMAN ◽  
N.G. URALTSEV
Keyword(s):  
Matrix Element ◽  
Kinetic Energy ◽  
Second Order ◽  
Heavy Flavor ◽  
Energy Matrix ◽  
Experimental Accuracy ◽  
Order Unity ◽  
Expansion Parameter ◽  
Perturbative Corrections ◽  
Theoretical Accuracy

We comment on two recent calculations of the second order perturbative corrections in the heavy flavor semileptonic transitions within the Brodsky-Lepage-Mackenzie approach. It is pointed out that the results do not show significant enhancement either in the inclusive b→c decays or in the exclusive amplitudes at zero recoil provided that the expansion parameter is chosen in a way appropriate to the kinematics at hand. The values of the second order coefficients inferred from the BLM type calculations appear to be of order unity in both cases. Thus, in both cases no significant uncertainty in extracting Vcb can be attributed to perturbative effects. The theoretical accuracy is mostly determined by the existing uncertainty in [Formula: see text] nonperturbative corrections in the exclusive B→D* amplitude, and, to a lesser extent, by the uncertainty in the estimated value of the kinetic energy matrix element [Formula: see text] in the case of Γ sl (b→c). The theoretical accuracy of the inclusive method of determining Vcb seemingly competes with and even exceeds the experimental accuracy.

Disappearance Voltage Determinations Using a Convergent Beam

1971 ◽  
Vol 29 ◽  
pp. 184-185
Author(s):  
W. L. Bell
Keyword(s):  
Second Order ◽  
Objective Method ◽  
Uniform Thickness ◽  
Rocking Curve ◽  
Crystal Perfection ◽  
Kikuchi Line ◽  
Central Maximum ◽  
Diffraction Patterns ◽  
Convergent Beam ◽  
Beam Technique

Disappearance voltages for second order reflections can be determined experimentally in a variety of ways. The more subjective methods, such as Kikuchi line disappearance and bend contour imaging, involve comparing a series of diffraction patterns or micrographs taken at intervals throughout the disappearance range and selecting that voltage which gives the strongest disappearance effect. The estimated accuracies of these methods are both to within 10 kV, or about 2-4%, of the true disappearance voltage, which is quite sufficient for using these voltages in further calculations. However, it is the necessity of determining this information by comparisons of exposed plates rather than while operating the microscope that detracts from the immediate usefulness of these methods if there is reason to perform experiments at an unknown disappearance voltage.The convergent beam technique for determining the disappearance voltage has been found to be a highly objective method when it is applicable, i.e. when reasonable crystal perfection exists and an area of uniform thickness can be found. The criterion for determining this voltage is that the central maximum disappear from the rocking curve for the second order spot.

Second order interference in two photon absorption

1996 ◽  
Vol 43 (9) ◽  
pp. 1765-1771 ◽  
Author(s):  
M. W. HAMILTON and D. S. ELLIOTT
Keyword(s):  
Second Order ◽  
Photon Absorption ◽  
Two Photon Absorption ◽  
Two Photon

Die faktorielle Struktur des Partnerschaftsfragebogens

2012 ◽  
Vol 41 (2) ◽  
pp. 109-113 ◽  
Author(s):  
Sören Kliem ◽  
Christoph Kröger ◽  
Yve Stöbel-Richter ◽  
Kurt Hahlweg ◽  
Elmar Brähler
Keyword(s):  
Maximum Likelihood ◽  
Second Order ◽  
Bundesrepublik Deutschland

Zusammenfassung. Theoretischer Hintergrund: Der Partnerschaftsfragebogen (PFB) wird im deutschen Sprachraum zur Erfassung der Partnerschafts- und Ehequalität bevorzugt eingesetzt. Fragestellung: Neben der Überprüfung der Eindimensionalität der PFB-Subskalen (Streitverhalten, Zärtlichkeit, Gemeinsamkeit/Kommunikation) wird in der vorliegenden Arbeit überprüft, ob das Zusammenfassen der PFB-Subskalen zu einem Generalfaktor „Partnerschaftsqualität” angemessen ist. Methoden: Es wurden Daten einer Bevölkerungsstichprobe für die Bundesrepublik Deutschland genutzt (N = 1.289). Aufgrund der Abweichung von einer multivariaten Normalverteilung wurden konfirmatorische Faktorenanalysen mittels Maximum-Likelihood-Methode mit robusten Standardfehlern und einem mittelwertsadjustierten Chi2-Wert (Satorra-Bentler-scaled-χ2) durchgeführt. Ergebnisse: Es ergaben sich sowohl für die Eindimensionalität der PFB-Subskalen als auch für die Second-Order-Faktorenanalyse sehr gute Modellanapassungen. Schlussfolgerungen: Die Subsumierung der PFB-Items zu Skalenwerten sowie der PFB-Subskalen zu einem Gesamtwert kann als angemessen eingestuft werden.

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