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Measurement of the diffractive cross section in deep inelastic scattering using ZEUS 1994 data

  • The ZEUS Collaboration
  • J. Breitweg et al.
Experimental physics

Abstract.

The DIS diffractive cross section, \(d\sigma^{di\!f\!f}_{\gamma^* p \to XN}/dM_X\), has been measured in the mass range \(M_X < 15\) GeV for \(\gamma^*p\) c.m. energies \(60 < W < 200\) GeV and photon virtualities \(Q^2 = 7\) to 140 GeV\(^2\). For fixed \(Q^2\) and \(M_X\), the diffractive cross section rises rapidly with \(W\), \(d\sigma^{di\!f\!f}_{\gamma^*p \to XN}(M_X,W,Q^2)/dM_X \propto W^{a^{diff}}\) with \(a^{diff} = 0.507 \pm 0.034 (stat)^{+0.155}_{-0.046}(syst)\) corresponding to a t-averaged pomeron trajectory of \(\overline{ \alpha_{_{{\mathbb P}}} } = 1.127 \pm 0.009 (stat)^{+0.039}_{-0.012} (syst)\) which is larger than \(\overline{ \alpha_{_{{\mathbb P}}} }\) observed in hadron-hadron scattering. The W dependence of the diffractive cross section is found to be the same as that of the total cross section for scattering of virtual photons on protons. The data are consistent with the assumption that the diffractive structure function \(F^{D(3)}_2\) factorizes according to \(x_{_{{\mathbb P}}} F^{D(3)}_2 (x_{_{{\mathbb P}}},\beta,Q^2) = (x_0/ x_{_{{\mathbb P}}})^n F^{D(2)}_2(\beta,Q^2)\). They are also consistent with QCD based models which incorporate factorization breaking. The rise of \(x_{_{{\mathbb P}}} F^{D(3)}_2\) with decreasing \(x_{_{{\mathbb P}}}\) and the weak dependence of \(F^{D(2)}_2\) on \(Q^2\) suggest a substantial contribution from partonic interactions.

Keywords

Structure Function Mass Range Total Cross Section Inelastic Scattering Substantial Contribution 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

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Copyright information

© Springer-Verlag Berlin Heidelberg 1999

Authors and Affiliations

  • The ZEUS Collaboration
  • J. Breitweg et al.
    • 1
  1. 1. Argonne National Laboratory, Argonne, IL, USA US

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