Browsing by Subject "Twisted mass fermions"

Now showing items 1-11 of 11

    • Conference Object  

      Computation of disconnected contributions to nucleon observables 

      Alexandrou, Constantia; Drach, V.; Jansen, K.; Koutsou, Giannis; Avilés-Casco, A. V. (Proceedings of Science (PoS), 2013)
      We compare several methods for computing disconnected fermion loops contributing to nucleon three-point functions. The comparison is carried out using one ensemble of Nf =2+1+1 twisted mass fermions with pion mass of 373 ...
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      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  

      Disconnected quark loop contributions to nucleon observables using Nf = 2 twisted clover fermions at the physical value of the light quark mass 

      Abdel-Rehim, A.; Alexandrou, Constantia; Constantinou, Martha; Hadjiyiannakou, Kyriakos; Jansen, K.; Kallidonis, Christos; Koutsou, Giannis; Avilés-Casco, A. V. (Proceedings of Science (PoS), 2015)
      We compute the disconnected quark loops contributions entering the determination of nucleon observables, by using a Nf = 2 ensemble of twisted mass fermions with a clover term at a pION mass mπ = 133 MeV. We employ exact ...
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      The electric dipole moment of the neutron from Nf = 2+1+1 twisted mass fermions 

      Petschlies, Marcus; Alexandrou, Constantia; Athenodorou, A.; Constantinou, Martha; Hadjiyiannakou, Kyriakos; Jansen, K.; Koutsou, Giannis; Ottnad, K. (Proceedings of Science (PoS), 2015)
      We extract the neutron electric dipole moment (nEDM) dn on configurations produced with Nf = 2+1+1 twisted mass fermions with lattice spacing of a ≃ 0.082fm and a light quark mass that correpsonds to Mπ ≃ 373 MeV. We do ...
    • Conference Object  

      Implementation of the twisted mass fermion operator in the QUDA library 

      Strelchenko, A.; Alexandrou, Constantia; Koutsou, Giannis; Avilés-Casco, A. V. (Proceedings of Science (PoS), 2013)
      We discuss an extension of the QUDA library for the Wilson twisted mass operator. A performance analysis is presented for both degenerate and non-degenerate flavor doublets. The degenerate twisted mass fermion operator ...
    • Conference Object  

      Looking at the gluon moment of the nucleon with dynamical twisted mass fermions 

      Alexandrou, Constantia; Drach, V.; Hadjiyiannakou, Kyriakos; Jansen, K.; Kostrzewa, B.; Wiese, C. (Proceedings of Science (PoS), 2013)
      To understand the structure of hadrons it is important to know the PDF of their constituents, the quarks and gluons. In our work we aim to compute the first moment of the gluon PDF h(x)ig for the nucleon. We follow two ...
    • Conference Object  

      Nucleon electromagnetic and axial form factors with Nf=2 twisted mass fermions at the physical point 

      Alexandrou, Constantia; Constantinou, Martha; Hadjiyiannakou, Kyriakos; Kallidonis, Christos; Koutsou, Giannis; Jansen, K.; Ottnad, K.; Vaquero, A. (Proceedings of Science (PoS), 2016)
      We present results for the nucleon electromagnetic and axial form factors using an Nf=2 twisted mass fermion ensemble with pion mass of about 131 MeV. We use multiple sink-source separations to identify excited state ...
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      Nucleon generalized form factors with twisted mass fermions 

      Alexandrou, Constantia; Constantinou, Martha; Drach, V.; Jansen, K.; Kallidonis, Christos; Koutsou, Giannis (Proceedings of Science (PoS), 2013)
      We present results on the nucleon form factors, momentum fraction and helicity moment for Nf = 2 and Nf = 2+1+1 twisted mass fermions for a number of lattice volumes and lattice spacings. First results for a new Nf = 2 ...
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      The quark contents of the nucleon and their implication for dark matter search 

      Alexandrou, Constantia; Constantinou, Martha; Drach, V.; Hadjiyiannakou, Kyriakos; Jansen, K.; Koutsou, Giannis; Strelchenko, A.; Vaquero, A. (Proceedings of Science (PoS), 2013)
      We present results concerning the light and strange quark contents of the nucleon using Nf = 2+1+1 flavours of maximally twisted mass fermions. The corresponding σ- Terms are casting light on the origin of the nucleon mass ...
    • Conference Object  

      Sigma- Terms and axial charges for hyperons and charmed baryons 

      Alexandrou, Constantia; Hadjiyiannakou, Kyriakos; Jansen, K.; Kallidonis, Christos (Proceedings of Science (PoS), 2013)
      We present results for the s- Terms and axial charges for various hyperons and charmed baryons using Nf = 2+1+1 twisted mass fermions. For the computation of the three-point function we use the fixed current method. For ...