The strange quark condensate in the nucleon in 2+1 flavor QCD

Understand

We calculate the &#34;strange quark content of the nucleon&#34;, <N| s s_bar |N>, which is important for interpreting the results of some dark matter detection experiments.

• The method is to evaluate quark-line disconnected correlations on the MILC lattice ensembles, which include the effects of dynamical strange quarks.
• After continuum and chiral extrapolations, the result is <N |s s_bar |N> = 0.69 +- 0.07(statistical) +- 0.09(systematic), in the modified minimal subtraction scheme (2 GeV), or for the renormalization scheme invariant form, m_s partial{M_N}/partial{m_s} = 59(6)(8) MeV.