0000000001052504
AUTHOR
P Dimopoulos
Light quark masses and pseudoscalar decay constants from N(f)=2 Lattice QCD with twisted mass fermions
We present the results of a lattice QCD calculation of the average up-down and strange quark masses and of the light meson pseudoscalar decay constants with Nf=2 dynamical fermions. The simulation is carried out at a single value of the lattice spacing with the twisted mass fermionic action at maximal twist, which guarantees automatic O(a)-improvement of the physical quantities. Quark masses are renormalized by implementing the non-perturbative RI-MOM renormalization procedure. Our results for the light quark masses are m_ud^{msbar}(2 GeV)= 3.85 +- 0.12 +- 0.40 MeV, m_s^{msbar}(2 GeV) = 105 +- 3 +- 9 MeV and m_s/m_ud = 27.3 +- 0.3 +- 1.2. We also obtain fK = 161.7 +- 1.2 +- 3.1 MeV and the …
European Vegetation Archive: now EVA really starts!
European Vegetation Archive (EVA) was announced as a new initiative of the European Vegetation Survey at the EVS Meeting in Vienna in 2012. The aim of EVA is to create a centralized database of European vegetation plots by storing copies of national and regional databases on a single software platform using a unified taxonomic reference database. EVA does not affect the ongoing independent developments of source data bases and it guarantees that data property rights of the original contributors are re spected. EVA Data Property and Governance Rules were approved and the EVA website (www.euroveg.org/evadatabase) was established in 2012. Since then several European vegetationplot database…
B-K-parameter from N-f=2 twisted mass lattice QCD
We present an unquenched N-f = 2 lattice computation of the B-K parameter which controls K-0 - (K) over bar (0) oscillations. A partially quenched setup is employed with two maximally twisted dynamical (sea) light Wilson quarks, and valence quarks of both the maximally twisted and the Osterwalder-Seiler variety. Suitable combinations of these two kinds of valence quarks lead to a lattice definition of the B-K parameter which is both multiplicatively renormalizable and O(a) improved. Employing the nonperturbative RI-MOM scheme, in the continuum limit and at the physical value of the pion mass we get B-K(RGI) = 0.729 +/- 0.030, a number well in line with the existing quenched and unquenched d…
The Braun-Blanquet project: evaluating and characterizing European vegetation alliances
European tradition on vegetation classification provides an extraordinary legacy for understanding biodiversity. However, this classification lacks explicit data on vegetation attributes, especially if we extend national or regional concepts to a continental perspective. An additional effort for evaluating and characterizing European vegetation types is therefore needed, and the data contained in vegeta tion databases are probably the main tool for these purposes. The BraunBlanquet project is an initiative of the European Vegetation Survey for characterizing veg etation alliances across Europe. By analyzing more than 500,000 vegetation plots from 22 European countries, we developed a fra…