Measurement of Dijet Production at Low Q2 at HERA
نویسندگان
چکیده
The measurement of triple differential dijet cross sections in e±p interactions in the H1 experiment in the region of photon virtualities 2 < Q < 80GeV, inelasticities 0.1 < y < 0.85, jet transverse energies E∗ T 1 > 7GeV, E ∗ T 2 > 5GeV, and pseudorapidities −2.5 < η∗ 1 , η∗ 2 < 0 is presented. The analysis was done in the γ∗p centre-of-mass frame using an integrated luminosity of 57.6 pb−1. The data are compared with Monte Carlo event generators based on LO QCD cross sections and NLO QCD parton level calculations. The latter fail to describe the region of low Q and low jet transverse energies, in contrast to the LO Monte Carlo generators that include direct and resolved photon interactions. The effects of resolved photons with longitudinal polarisation and initial and final state parton showers are investigated in detail. The data show clear evidence for effects that go beyond the fixed-order NLO QCD calculations.
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