Browsing by Author "Wiese, C."

Now showing items 1-9 of 9

    • Conference Object  

      A lattice calculation of parton distributions 

      Alexandrou, Constantia; Cichy, K.; Hadjiyiannakou, Kyriakos; Jansen, K.; Steffens, F.; Wiese, C. (Proceedings of Science (PoS), 2016)
      We present results for the x dependence of the unpolarized, helicity, and transversity isovector quark distributions in the proton using lattice QCD, employing the method of quasi-distributions proposed by Ji in 2013. ...
    • Article  

      Lattice calculation of parton distributions 

      Alexandrou, Constantia; Cichy, K.; Drach, V.; Garcia-Ramos, E.; Hadjiyiannakou, Kyriakos; Jansen, K.; Steffens, F.; Wiese, C. (2015)
      We report on our exploratory study for the direct evaluation of the parton distribution functions from lattice QCD, based on a recently proposed new approach. We present encouraging results using N f = 2 + 1 + 1 twisted ...
    • 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 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 ...
    • Conference Object  

      Parton distributions from lattice QCD with momentum smearing 

      Alexandrou, Constantia; Cichy, K.; Constantinou, Martha; Hadjiyiannakou, Kyriakos; Jansen, K.; Steffens, F.; Wiese, C. (Proceedings of Science (PoS), 2016)
      In this work we continue our effort to explore a recent proposal, which allows light-cone distributions to be extracted from purely spatial correlations, being thus accessible to lattice methods. In order to test the ...
    • 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  

      Scalar mesons and tetraquarks by means of lattice QCD 

      Wagner, M.; Alexandrou, Constantia; Gravina, M.; Daldrop, J. O.; Urbach, C.; Brida, M. D.; Scorzato, L.; Wiese, C. (2012)
      We study the light scalar mesons a0(980) and κ using Nf = 2+1+1 flavor lattice QCD. In order to probe the internal structure of these scalar mesons, and in particular to identify, whether a sizeable tetraquark component ...
    • Article  

      Scalar mesons and tetraquarks from twisted mass lattice QCD 

      Wagner, M.; Alexandrou, Constantia; Daldrop, J. O.; Brida, M. D.; Gravina, M.; Scorzato, L.; Urbach, C.; Wiese, C. (2013)
      We study light scalar mesons with particular focus on the a 0(980) using lattice QCD with 2+1+1 dynamical quark flavors. To investigate the structure of these scalar mesons and to identify, whether a sizeable tetraquark ...
    • Article  

      Updated lattice results for parton distributions 

      Alexandrou, Constantia; Cichy, K.; Constantinou, Martha; Hadjiyiannakou, Kyriakos; Jansen, K.; Steffens, F.; Wiese, C. (2017)
      We provide an analysis of the x dependence of the bare unpolarized, helicity, and transversity isovector parton distribution functions (PDFs) from lattice calculations employing (maximally) twisted mass fermions. The x ...