Measurement of single $pi^0$ production by coherent neutral-current $ u$ Fe interactions in the MINOS Near Detector


Abstract in English

Forward single $pi^0$ production by coherent neutral-current interactions, $ u mathcal{A} to u mathcal{A} pi^0$, is investigated using a 2.8$times 10^{20}$ protons-on-target exposure of the MINOS Near Detector. For single-shower topologies, the event distribution in production angle exhibits a clear excess above the estimated background at very forward angles for visible energy in the range~1-8 GeV. Cross sections are obtained for the detector medium comprised of 80% iron and 20% carbon nuclei with $langle mathcal{A} rangle = 48$, the highest-$langle mathcal{A} rangle$ target used to date in the study of this coherent reaction. The total cross section for coherent neutral-current single-$pi^0$ production initiated by the $ u_mu$ flux of the NuMI low-energy beam with mean (mode) $E_{ u}$ of 4.9 GeV (3.0 GeV), is $77.6pm5.0,(text{stat}) ^{+15.0}_{-16.8},(text{syst})times10^{-40},text{cm}^2~text{per nucleus}$. The results are in good agreement with predictions of the Berger-Sehgal model.

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