• Article  

      Adaptive aggregation-based domain decomposition multigrid for twisted mass fermions 

      Alexandrou, Constantia; Bacchio, S.; Finkenrath, J.; Frommer, A.; Kahl, K.; Rottmann, M. (2016)
      The adaptive aggregation-base domain decomposition multigrid method [A. Frommer, SIAM J. Sci. Comput. 36, A1581 (2014)] is extended for two degenerate flavors of twisted mass fermions. By fine-tuning the parameters we ...
    • Conference Object  

      DDalphaAMG for twisted mass fermions 

      Bacchio, S.; Alexandrou, Constantia; Finkenrath, J.; Frommer, A.; Kahl, K.; Rottmann, M. (Proceedings of Science (PoS), 2016)
      We present the Adaptive Aggregation-based Domain Decomposition Multigrid method extended to the twisted mass fermion discretization action. We show comparisons of results as a function of tuning the parameters that enter ...
    • Conference Object  

      Disconnected diagrams with twisted-mass fermions 

      Abdel-Rehim, A.; Alexandrou, Constantia; Constantinou, Martha; Finkenrath, J.; Hadjiyiannakou, Kyriakos; Jansen, K.; Kallidonis, Christos; Koutsou, Giannis; Avilés-Casco, A. V.; Volmer, J. (Proceedings of Science (PoS), 2016)
      The latest results from the Twisted-Mass collaboration on disconnected diagrams at the physical value of the pion mass are presented. In particular, we focus on the sigma terms, the axial charges and the momentum fraction, ...
    • Conference Object  

      Importance of closed quark loops for lattice QCD studies of tetraquarks 

      Berlin, J.; Abdel-Rehim, A.; Alexandrou, Constantia; Brida, M. D.; Finkenrath, J.; Gravina, M.; Leontiou, Theodoros; Wagner, M. (Proceedings of Science (PoS), 2016)
      To investigate the light scalar tetraquark candidate a0(980) (quantum numbers JP =0+), a correlation matrix including a variety of two- and four-quark interpolating operators has to be computed. We discuss efficient ...
    • Article  

      Investigating efficient methods for computing four-quark correlation functions 

      Abdel-Rehim, A.; Alexandrou, Constantia; Berlin, J.; Dalla Brida, M.; Finkenrath, J.; Wagner, M. (2017)
      We discuss and compare the efficiency of various methods, combinations of point-to-all propagators, stochastic timeslice-to-all propagators, the one-end trick and sequential propagators, to compute two-point correlation ...
    • Conference Object  

      Using a new analysis method to extract excited states in the scalar meson sector 

      Finkenrath, J.; Alexandrou, Constantia; Berlin, J.; Brida, M. D.; Leontiou, Theodoros; Wagner, M. (Proceedings of Science (PoS), 2016)
      We explore a method to extract energy eigenstates, called Athens Model Independent Analysis Scheme (AMIAS), which is an alternative to solving standard Generalized Eigenvalue Problems (GEVP). The method is based on ...