Document Type


Publication Date




Publication Title

Physics Letters B




134890 (7 pg.)


We report the first measurement of the (e, e' p) reaction cross-section ratios for Helium-3 (3He), Tritium (3H), and Deuterium (d). The measurement covered a missing momentum range of 40 ≤ pmiss ≤ 550 MeV/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 planewave impulse approximation (PWIA) calculations using realistic spectral functions and momentum distributions. The measured and PWIA-calculated cross-section ratios for 3He/d and 3H/d extend to just above the typical nucleon Fermi-momentum (kF ≈ 250 MeV/c) and differ from each other by ∼ 20%, while for 3He/3H they agree within the measurement accuracy of about 3%. At momenta above kF , the measured 3He/3H ratios differ from the calculation by 20% −50%. Final state interaction (FSI) calculations using the generalized Eikonal Approximation indicate that FSI should change the 3He/3H cross-section ratio for this measurement by less than 5%. If these calculations are correct, then the differences at large missing momenta between the 3He/3H 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.


© 2019 The Author(s). Published by Elsevier B.V. This is an open access article under the CC BY license. Funded by SCOAP3.

Original Publication Citation

Cruz-Torres, R., Li, S., Hauenstein, F., Schmidt, A., Nguyen, D., Abrams, D., . . . Zhang, J. (2019). Comparing proton momentum distributions in A=2 and 3 nuclei via 2H 3H and 3He (e, e ' p) measurements. Physics Letters B, 797, 134890, 134891-134897. doi:10.1016/j.physletb.2019.134890


0000-0001-7282-8120 (Hyde), 0000-0001-5416-2900 (Weinstein)