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arXiv · 1112.2931

Excited State Effects in Nucleon Matrix Element Calculations

Constantia Alexandrou·Martha Constantinou·Simon Dinter·Vincent Drach·Karl Jansen·Theodoros Leontiou·Dru B. Renner
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Abstract

We perform a high-statistics precision calculation of nucleon matrix elements using an open sink method allowing us to explore a wide range of sink-source time separations. In this way the influence of excited states of nucleon matrix elements can be studied. As particular examples we present results for the nucleon axial charge $g_A$ and for the first moment of the isovector unpolarized parton distribution $ _{u-d}$. In addition, we report on preliminary results using the generalized eigenvalue method for nucleon matrix elements. All calculations are performed using $N_f=2+1+1$ maximally twisted mass Wilson fermions.

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Constantia Alexandrou, Martha Constantinou, Simon Dinter, Vincent Drach, Karl Jansen, Theodoros Leontiou, Dru B. Renner. 2011-12-13. Excited State Effects in Nucleon Matrix Element Calculations. https://arxiv.org/abs/1112.2931

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