Browsing by Author "Vaquero, A."

Now showing items 1-10 of 10

    • Article  

      Composition and histone substrates of polycomb repressive group complexes change during cellular differentiation 

      Kuzmichev, A.; Margueron, R.; Vaquero, A.; Preissner, T. S.; Scher, M.; Kirmizis, Antonis; Ouyang, X.; Brockdorff, N.; Abate-Shen, C.; Farnham, P.; Reinberg, D. (2005)
      Changes in the substrate specificities of factors that irreversibly modify the histone components of chromatin are expected to have a profound effect on gene expression through epigenetics. Ezh2 is a histone-lysine ...
    • Article  

      Disconnected quark loop contributions to nucleon observables in lattice QCD 

      Abdel-Rehim, A.; Alexandrou, Constantia; Constantinou, Martha; Drach, V.; Hadjiyiannakou, Kyriakos; Jansen, K.; Koutsou, Giannis; Vaquero, A. (2014)
      We perform a high statistics calculation of disconnected fermion loops on graphics processing units for a range of nucleon matrix elements extracted using lattice QCD. The isoscalar electromagnetic and axial vector form ...
    • Article  

      Evaluation of disconnected quark loops for hadron structure using GPUs 

      Alexandrou, Constantia; Constantinou, Martha; Drach, V.; Hadjiyiannakou, Kyriakos; Jansen, K.; Koutsou, Giannis; Strelchenko, A.; Vaquero, A. (2014)
      A number of stochastic methods developed for the calculation of fermion loops are investigated and compared, in particular with respect to their efficiency when implemented on Graphics Processing Units (GPUs). We assess ...
    • Article  

      First moment of the flavour octet nucleon parton distribution function using lattice QCD 

      Alexandrou, Constantia; Constantinou, Martha; Dinter, S.; Drach, V.; Hadjiyiannakou, Kyriakos; Jansen, K.; Koutsou, Giannis; Vaquero, A. (2015)
      Abstract: We perform a lattice computation of the flavour octet contribution to the average quark momentum in the nucleon, (Formula presented.). In particular, we fully take the disconnected contributions into account in ...
    • 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 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  

      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  

      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 ...
    • Article  

      Steps toward understanding the inheritance of repressive methyl-lysine marks in histones 

      Reinberg, D.; Chuikov, S.; Farnham, P.; Karachentsev, D.; Kirmizis, Antonis; Kuzmichev, A.; Margueron, R.; Nishioka, K.; Preissner, T. S.; Sarma, K.; Abate-Shen, C.; Steward, R.; Vaquero, A. (2004)
    • Article  

      Strangeness of the nucleon from lattice QCD 

      Alexandrou, Constantia; Constantinou, Martha; Dinter, S.; Drach, V.; Hadjiyiannakou, Kyriakos; Jansen, K.; Koutsou, Giannis; Vaquero, A. (2015)
      We present a nonperturbative calculation of the strangeness of the nucleon yN within the framework of lattice QCD. This observable is known to be an important cornerstone to interpret results from direct dark matter detection ...