Search results for "NPE"
showing 10 items of 121 documents
Renormalization Constants of Quark Operators for the Non-Perturbatively Improved Wilson Action
2004
We present the results of an extensive lattice calculation of the renormalization constants of bilinear and four-quark operators for the non-perturbatively O(a)-improved Wilson action. The results are obtained in the quenched approximation at four values of the lattice coupling by using the non-perturbative RI/MOM renormalization method. Several sources of systematic uncertainties, including discretization errors and final volume effects, are examined. The contribution of the Goldstone pole, which in some cases may affect the extrapolation of the renormalization constants to the chiral limit, is non-perturbatively subtracted. The scale independent renormalization constants of bilinear quark…
Light Quark Masses from Lattice Quark Propagators at Large Momenta
1999
We compute non-perturbatively the average up-down and strange quark masses from the large momentum (short-distance) behaviour of the quark propagator in the Landau gauge. This method, which has never been applied so far, does not require the explicit calculation of the quark mass renormalization constant. Calculations were performed in the quenched approximation, by using O(a)-improved Wilson fermions. The main results of this study are ml^RI(2GeV)=5.8(6)MeV and ms^RI(2GeV)=136(11)MeV. Using the relations between different schemes, obtained from the available four-loop anomalous dimensions, we also find ml^RGI=7.6(8)MeV and ms^RGI=177(14)MeV, and the MSbar-masses, ml^MS(2GeV)=4.8(5)MeV and …
Tuhoisa influentsa tarttui leskipastorska Pihlin kotikirjastoon: pandemian vaikutus 1800-luvun perheen kirjakokoelmaan
2023
1800-luvulla kirjoilla oli esineinä vielä rahallista ja yhteiskunnalliseen statukseen liittyvää arvoa, ja omistajan kuolema aloitti yleensä vain uuden luvun kirjan elämässä. Tutkin kuolinpesien kirjakokoelmien kohtaloja käyttämällä esimerkkinä erästä 1800-luvun lopun tapausta, jossa leskipastorska Pihl antoi kotikirjastonsa kirjoja helsinkiläiselle Minerva-antikvariaatille myytäväksi. Mikrohistoriallinen esimerkki kertoo perheenjäsenen kuolemantapauksen vaikutuksesta eri sukupuolten ja sukupolvien kirjanomistukseen. Tarkastelen, miten säätyläisperheissä, kuten pappisperheissä, yhtäkkinen kuolema muutti kirjojen omistussuhteita, ja kuinka perheen sisällä miesten ja naisten suhtautuminen kirj…
Late consequences of traumatic rupture of the diaphragm.
2013
A 54-year-old man was admitted to our clinic due to elevated γ-glutamyltransferase, without any clinical symptoms. About 25 years ago, he had undergone blunt abdominal and thoracic trauma during an accident. No diagnostic measures or therapy had been performed at that time. Serum bilirubin was normal, but the values for alanine transaminase, aspartate transaminase, and alkaline phosphatase were slightly above the reference range. Sonography of the abdomen revealed dilated intrahepatic bile ducts up to 3 mm in diameter and steatosis of the liver grade I. CT scan and MRI of the thorax and abdomen showed a giant hiatal hernia with transposition of upper abdominal organs into the chest. As the …
Low-energy couplings of QCD from topological zero-mode wave functions
2003
By matching 1/m^2 divergences in finite-volume two-point correlation functions of the scalar or pseudoscalar densities with those obtained in chiral perturbation theory, we derive a relation between the Dirac operator zero-mode eigenfunctions at fixed non-trivial topology and the low-energy constants of QCD. We investigate the feasibility of using this relation to extract the pion decay constant, by computing the zero-mode correlation functions on the lattice in the quenched approximation and comparing them with the corresponding expressions in quenched chiral perturbation theory.
QCD effective charges from lattice data
2010
We use recent lattice data on the gluon and ghost propagators, as well as the Kugo-Ojima function, in order to extract the non-perturbative behavior of two particular definitions of the QCD effective charge, one based on the pinch technique construction, and one obtained from the standard ghost-gluon vertex. The construction relies crucially on the definition of two dimensionful quantities, which are invariant under the renormalization group, and are built out of very particular combinations of the aforementioned Green's functions. The main non-perturbative feature of both effective charges, encoded in the infrared finiteness of the gluon propagator and ghost dressing function used in their…
The hadronic contribution to the running of the electromagnetic coupling and the electroweak mixing angle
2019
37th International Symposium on Lattice Field Theory, Wuhan, China, 16 Jun 2019 - 22 Jun 2019; PoS(LATTICE 2019)010 (2019).
Reconciling open charm production at the Fermilab Tevatron with QCD
2005
We study the inclusive hadrodroduction of D^0, D^+, D^{*+}, and D_s^+ mesons at next-to-leading order in the parton model of quantum chromodynamics endowed with universal non-perturbative fragmentation functions (FFs) fitted to e^+e^- annihilation data from CERN LEP1. Working in the general-mass variable-flavor-number scheme, we resum the large logarithms through the evolution of the FFs and, at the same time, retain the full dependence on the charm-quark mass without additional theoretical assumptions. In this way, the cross section distributions in transverse momentum recently measured by the CDF Collaboration in run II at the Fermilab Tevatron are described within errors.
Nye læreres erfaringer med skolen som organisasjon
2019
While research on newly qualified teachers often focuses on the performative aspect of teaching, this article investigates novice teachers’ encounter with the school as an organization. Five new teachers were interviewed during the last semester of teacher education and after working for three first months. Through teacher education they have a certain knowledge of the school and its culture, and they both look forward to and dread to start working as teachers. Nevertheless, as job seekers they make few demands of their future workplace. The results of the study indicate that new teachers meet very challenging working conditions and inadequate mentor support. The conclusion gives rise to co…