Strange quark content of the nucleon and dark matter searches

Autor: Young, R. D.
Rok vydání: 2013
Předmět:
Zdroj: PoS LATTICE2012 (2012) 014
Druh dokumentu: Working Paper
Popis: The strange quark scalar content plays an important role in both the description of nucleon structure and in the determination of dark matter direct detection cross sections. As a measure of the strange-quark contribution to the nucleon mass, the strange-quark sigma term (\sigma_s) provides important insight into the nature of mass generation in QCD. The phenomenological determination of \sigma_s exhibits a wide range of variation, with values suggesting that the strange quark contributes anywhere between 0 and more than 30% of the nucleon mass. In the context of dark matter searches, coupled with relatively large Higgs coupling to strangeness, this variation dominates the uncertainty in predicted cross sections for a large class of dark matter models. Here we report on the recent results in lattice QCD, which are now giving a far more precise determination of \sigma_s than can be inferred from phenomenology. As a consequence, the lattice determinations of \sigma_s can now dramatically reduce the uncertainty in dark matter cross sections associated with the hadronic matrix elements.
Comment: 12 pages, 6 figures; plenary talk presented at The 30th International Symposium on Lattice Field Theory - Lattice 2012, June 24-29, 2012 Cairns, Australia
Databáze: arXiv