Comparing proton momentum distributions in A = 2 and 3 nuclei via [superscript 2]H [superscript 3]H and [superscript 3]He (e,e′p) measurements
Author(s)Cruz Torres, Reynier; Schmidt, A.; Beck, Arie; Gilad, Shalev; Hen, Or; Laskaris, Georgios; Beck, S. May-Tal; Ou, Longwu; Papadopoulou, A.; Patsyuk, Maria; Segarra, E. P.; Schmookler, Barak Abraham; ... Show more Show less
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We report the first measurement of the (e,e′p) reaction cross-section ratios for Helium-3 (He3), Tritium (H3), and Deuterium (d). The measurement covered a missing momentum range of 40≤pmiss≤550MeV/c, at large momentum transfer (〈Q2〉≈1.9 (GeV/c)2) and xB>1, which minimized contributions from non quasi-elastic (QE) reaction mechanisms. The data is compared with plane-wave impulse approximation (PWIA) calculations using realistic spectral functions and momentum distributions. The measured and PWIA-calculated cross-section ratios for He3/d and H3/d extend to just above the typical nucleon Fermi-momentum (kF≈250 MeV/c) and differ from each other by ∼20%, while for He3/H3 they agree within the measurement accuracy of about 3%. At momenta above kF, the measured He3/H3 ratios differ from the calculation by 20%−50%. Final state interaction (FSI) calculations using the generalized Eikonal Approximation indicate that FSI should change the He3/H3 cross-section ratio for this measurement by less than 5%. If these calculations are correct, then the differences at large missing momenta between the He3/H3 experimental and calculated ratios could be due to the underlying NN interaction, and thus could provide new constraints on the previously loosely-constrained short-distance parts of the NN interaction.
DepartmentMassachusetts Institute of Technology. Laboratory for Nuclear Science
Physics Letters B
Cruz-Torres, R. et al. "Comparing proton momentum distributions in A = 2 and 3 nuclei via 2H 3H and 3He (e, e'p) measurements" Physics Letter B 797 (August 2019): 134890 © 2019 The Author(s)
Final published version