Limits on the effective quark radius from inclusive $ep$ scattering at   HERA
  The high-precision HERA data allows searches up to TeV scales for Beyond the Standard Model contributions to electron-quark scattering. Combined measurements of the inclusive deep inelastic cross sections in neutral and charged current $ep$ scattering corresponding to a luminosity of around 1 fb$^{-1}$ have been used in this analysis. A new approach to the beyond the Standard Model analysis of the inclusive $ep$ data is presented; simultaneous fits of parton distribution functions together with contributions of "new physics" processes were performed. Results are presented considering a finite radius of quarks within the quark form-factor model. The resulting 95% C.L. upper limit on the effective quark radius is $0.43\cdot 10^{-16}$ cm. 
ZEUS Collaboration: H. Abramowicz, I. Abt, L. Adamczyk, M. Adamus, S.   Antonelli, V. Aushev, O. Behnke, U. Behrens, A. Bert...
hep-ex hep-ph