First moment of the flavour octet nucleon parton distribution function using lattice QCD
| Autor: | Alexandrou, C., Constantinou, M., Dinter, S., Drach, V., Hadjiyiannakou, K., Jansen, K., Koutsou, G., Vaquero, A. |
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| Rok vydání: | 2015 |
| Předmět: | |
| Druh dokumentu: | Working Paper |
| Popis: | We perform a lattice computation of the flavour octet contribution to the average quark momentum in a nucleon, $\la x\ra^{(8)}_{\mu^2 = 4 \gev^2}$. In particular, we fully take the disconnected contributions into account in our analysis for which we use a generalization of the technique developed in \cite{Dinter:2012tt}. We investigate systematic effects with a particular emphasis on the excited states contamination. We find that in the renormalization free ratio $\frac{\la x \ra^{(3)}}{\la x \ra^{(8)}}$ (with $\la x \ra^{(3)}$ the non-singlet moment) the excited state contributions cancel to a large extend making this ratio a promising candidate for a comparison to phenomenological analyses. Our final result for this ratio is in agreement with the phenomenological value and we find, including systematic errors, $\frac{\la x \ra^{(3)}}{\la x \ra^{(8)}} = 0.39(1)(4)$. Comment: 18 pages, 7 figures |
| Databáze: | arXiv |
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