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Constraining nucleon strangeness

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 Added by Timothy Hobbs
 Publication date 2014
  fields
and research's language is English




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Determining the nonperturbative $sbar{s}$ content of the nucleon has attracted considerable interest and been the subject of numerous experimental searches. These measurements used a variety of reactions and place important limits on the vector form factors observed in parity-violating (PV) elastic scattering and the parton distributions determined by deep inelastic scattering (DIS). In spite of this progress, attempts to relate information obtained from elastic and DIS experiments have been sparse. To ameliorate this situation, we develop an interpolating model using light-front wave functions capable of computing both DIS and elastic observables. This framework is used to show that existing knowledge of DIS places significant restrictions on our wave functions. The result is that the predicted effects of nucleon strangeness on elastic observables are much smaller than those tolerated by direct fits to PV elastic scattering data alone. Using our model, we find $-0.024 le mu_s le 0.035$, and $-0.137 le rho^D_s le 0.081$ for the strange contributions to the nucleon magnetic moment and charge radius. The model we develop also independently predicts the nucleons strange spin content $Delta s$ and scalar density $langle N| bar{s}s | N rangle$, and for these we find agreement with previous determinations.



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We study the properties of strange mesons in vacuum and in the hot nuclear medium within unitarized coupled-channel effective theories. We determine transition probabilities, cross sections and scattering lengths for strange mesons. These scattering observables are of fundamental importance for understanding the dynamics of strangeness production and propagation in heavy-ion collisions.
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