Browsing Τμήμα Φυσικής / Department of Physics by Author "Kallidonis, Christos"

Now showing items 1-19 of 19

    • Article  

      Axial charges of hyperons and charmed baryons using Nf=2+1+1 twisted mass fermions 

      Alexandrou, Constantia; Hadjiyiannakou, Kyriakos; Kallidonis, Christos (2016)
      The axial couplings of the low lying baryons are evaluated using a total of five ensembles of dynamical twisted mass fermion gauge configurations. The simulations are performed using the Iwasaki gauge action and two ...
    • Article  

      Baryon spectrum with Nf=2+1+1 twisted mass fermions 

      Alexandrou, Constantia; Drach, V.; Jansen, K.; Kallidonis, Christos; Koutsou, Giannis (2014)
      The masses of the low-lying baryons are evaluated using a total of ten ensembles of dynamical twisted mass fermion gauge configurations. The simulations are performed using two degenerate flavors of light quarks, and a ...
    • Article  

      Direct Evaluation of the Quark Content of Nucleons from Lattice QCD at the Physical Point 

      Abdel-Rehim, A.; Alexandrou, Constantia; Constantinou, Martha; Hadjiyiannakou, Kyriakos; Jansen, K.; Kallidonis, Christos; Koutsou, Giannis; Avilés-Casco, A. V. (2016)
      We evaluate the light, strange, and charm scalar content of the nucleon using one lattice QCD ensemble generated with two degenerate light quarks with mass fixed to their physical value. We use improved techniques to ...
    • 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, ...
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      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 ...
    • Article  

      Erratum: Nucleon and pion structure with lattice QCD simulations at physical value of the pion mass (Physical Review D - Particles, Fields, Gravitation and Cosmology (2015) 92 (114513)) 

      Abdel-Rehim, A.; Alexandrou, Constantia; Constantinou, Martha; Dimopoulos, Petros; Frezzotti, R.; Hadjiyiannakou, Kyriakos; Jansen, K.; Kallidonis, Christos; Kostrzewa, B.; Koutsou, Giannis; Mangin-Brinet, M.; Oehm, M.; Rossi, G. C.; Urbach, C.; Wenger, U. (2016)
      We present results on the nucleon scalar, axial, and tensor charges as well as on the momentum fraction and the helicity and transversity moments. The pion momentum fraction is also presented. The computation of these key ...
    • Article  

      First physics results at the physical pion mass from Nf=2 Wilson twisted mass fermions at maximal twist 

      Petschlies, Marcus; Abdel-Rehim, A.; Alexandrou, Constantia; Burger, F.; Constantinou, Martha; Dimopoulos, Petros; Frezzotti, R.; Hadjiyiannakou, Kyriakos; Helmes, C.; Jansen, K.; Jost, C.; Kallidonis, Christos; Knippschild, B.; Kostrzewa, B.; Koutsou, Giannis; Liu, L.; Mangin-Brinet, M.; Ottnad, K.; Pientka, G.; Rossi, G. C.; Urbach, C.; Wenger, U.; Werner, M. (2017)
      We present physics results from simulations of QCD using Nf=2 dynamical Wilson twisted mass fermions at the physical value of the pion mass. These simulations are enabled by the addition of the clover term to the twisted ...
    • Article  

      Low-lying baryon masses using Nf=2 twisted mass clover-improved fermions directly at the physical pion mass 

      Alexandrou, Constantia; Kallidonis, Christos (2017)
      The masses of the low-lying baryons are evaluated using an ensemble with two degenerate light twisted mass clover-improved quarks with mass tuned to reproduce the physical pion mass. The Iwasaki improved gluonic action is ...
    • Article  

      Moments of nucleon generalized parton distributions from lattice QCD 

      Alexandrou, Constantia; Carbonell, J.; Constantinou, Martha; Harraud, P. A.; Guichon, P.; Jansen, K.; Kallidonis, Christos; Korzec, T.; Papinutto, M. (2011)
      We present results on the lower moments of the nucleon generalized parton distributions within lattice QCD using two dynamical flavors of degenerate twisted mass fermions. Our simulations are performed on lattices with ...
    • Article  

      Nucleon and pion structure with lattice QCD simulations at physical value of the pion mass 

      Abdel-Rehim, A.; Alexandrou, Constantia; Constantinou, Martha; Dimopoulos, Petros; Frezzotti, R.; Hadjiyiannakou, Kyriakos; Jansen, K.; Kallidonis, Christos; Kostrzewa, B.; Koutsou, Giannis; Mangin-Brinet, M.; Oehm, M.; Rossi, G. C.; Urbach, C.; Wenger, U. (2015)
      We present results on the nucleon scalar, axial, and tensor charges as well as on the momentum fraction, and the helicity and transversity moments. The pion momentum fraction is also presented. The computation of these key ...
    • 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 ...
    • Article  

      Nucleon electromagnetic form factors using lattice simulations at the physical point 

      Alexandrou, Constantia; Constantinou, Martha; Hadjiyiannakou, Kyriakos; Jansen, K.; Kallidonis, Christos; Koutsou, Giannis; Vaquero Aviles-Casco, A. (2017)
      We present results for the nucleon electromagnetic form factors using an ensemble of maximally twisted mass clover-improved fermions with pion mass of about 130 MeV. We use multiple sink-source separations and three analysis ...
    • Article  

      Nucleon form factors and moments of generalized parton distributions using Nf=2+1+1 twisted mass fermions 

      Alexandrou, Constantia; Constantinou, Martha; Dinter, S.; Drach, V.; Jansen, K.; Kallidonis, Christos; Koutsou, Giannis (2013)
      We present results on the axial and the electromagnetic form factors of the nucleon, as well as on the first moments of the nucleon generalized parton distributions using maximally twisted mass fermions. We analyze two N ...
    • Conference Object  

      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 ...
    • Article  

      Nucleon scalar and tensor charges using lattice QCD simulations at the physical value of the pION mass 

      Alexandrou, Constantia; Constantinou, Martha; Dimopoulos, Petros; Frezzotti, R.; Hadjiyiannakou, Kyriakos; Jansen, K.; Kallidonis, Christos; Kostrzewa, B.; Koutsou, Giannis; Mangin-Brinet, M.; Vaquero Avilès-Casco, A.; Wenger, U. (2017)
      We present results on the light, strange and charm nucleon scalar and tensor charges from lattice QCD, using simulations with Nf=2 flavors of twisted mass clover-improved fermions with a physical value of the pION mass. ...
    • Conference Object  

      Nucleon spin and quark content at the physical point 

      Alexandrou, Constantia; Constantinou, Martha; Hadjiyiannakou, Kyriakos; Kallidonis, Christos; Koutsou, Giannis; Jansen, K.; Wiese, C.; Avilés-Casco, A. V. (Proceedings of Science (PoS), 2016)
      We present results on the spin and quark content of the nucleon using Nf =2 twisted mass cloverimproved fermion simulations with a pion mass close to its physical value. We use recently developed methods to obtain accurate ...
    • Article  

      Nucleon structure using lattice QCD 

      Alexandrou, Constantia; Constantinou, Martha; Drach, V.; Hadjiyiannakou, Kyriakos; Jansen, K.; Kallidonis, Christos; Koutsou, Giannis; Leontiou, Theodoros; Vaquero, A. (2013)
      A review of recent nucleon structure calculations within lattice QCD is presented. The nucleon excited states, the axial charge, the isovector momentum fraction and helicity distribution are discussed, assessing the methods ...
    • Conference Object  

      Recent results for the proton spin decomposition from lattice QCD 

      Alexandrou, Constantia; Constantinou, Martha; Hadjiyiannakou, Kyriakos; Kallidonis, Christos; Koutsou, Giannis; Jansen, K.; Panagopoulos, Haralambos G.; Steffens, F.; Vaquero, A.; Wiese, C. (Proceedings of Science (PoS), 2016)
      The exact decomposition of the proton spin has been a much debated topic, on the experimental as well as the theoretical side. In this talk we would like to report on recent non-perturbative results and ongoing efforts to ...
    • 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 ...