arXiv subjects

Kyriakos Hadjiyiannakou

Publications and source records attributed to Kyriakos Hadjiyiannakou.

57 records · Page 4Linked to original sources

arXiv2014

First results with twisted mass fermions towards the computation of parton distribution functions on the lattice

We report on our exploratory study for the evaluation of the parton distribution functions from lattice QCD, based on a new method proposed in Ref.~arXiv:1305.1539. Using the example of the nucleon, we compare two different methods to compute the matrix elements needed, and investigate the application of gauge link smearing. We also present first results from a large production ensemble and discuss the future challenges related to this method.

hep-lat↗

arXiv2014

A Stochastic Method for Computing Hadronic Matrix Elements

We present a stochastic method for the calculation of baryon three-point functions that is more versatile compared to the typically used sequential method. We analyze the scaling of the error of the stochastically evaluated three-point function with the lattice volume and find a favorable signal-to-noise ratio suggesting that our stochastic method can be used efficiently at large volumes to compute hadronic matrix elements.

hep-lat↗

arXiv2013

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

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 $\langle x \rangle_g$ for the nucleon. We follow two possible approaches in order to extract the gluon moment: the Feynman-Hellmann theorem and a direct method with smearing of the gluon operator. We present preliminary results computed on $24^3 \times 48$ lattices for the case where the Feynman-Hellman theorem is used and $32^3 \times 64$ lattices for the direct method, employing $N_f=2+1+1$ maximally twisted mass fermions.

hep-lat↗