arXiv · 1501.05607
A precision measurement of the $p$($e,e^\prime p\,$)$π^0$ reaction at threshold
Abstract
New results are reported from a measurement of $π^0$ electroproduction near threshold using the $p(e,e^{\prime} p)π^0$ reaction. The experiment was designed to determine precisely the energy dependence of $s-$ and $p-$wave electromagnetic multipoles as a stringent test of the predictions of Chiral Perturbation Theory (ChPT). The data were taken with an electron beam energy of 1192 MeV using a two-spectrometer setup in Hall A at Jefferson Lab. For the first time, complete coverage of the $ϕ^*_π$ and $θ^*_π$ angles in the $p π^0$ center-of-mass was obtained for invariant energies above threshold from 0.5 MeV up to 15 MeV. The 4-momentum transfer $Q^2$ coverage ranges from 0.05 to 0.155 (GeV/c)$^2$ in fine steps. A simple phenomenological analysis of our data shows strong disagreement with $p-$wave predictions from ChPT for $Q^2>0.07$ (GeV/c)$^2$, while the $s-$wave predictions are in reasonable agreement.
Explore related subjects
Keep this discovery
K. Chirapatpimol, M. H. Shabestari, R. A. Lindgren, L. C. Smith, J. R. M. Annand, D. W. Higinbotham, B. Moffit, V. Nelyubin, B. E. Norum, K. Allada, K. Aniol, K. Ardashev, D. S. Armstrong, R. A. Arndt, F. Benmokhtar, A. M. Bernstein, W. Bertozzi, W. J. Briscoe, L. Bimbot, A. Camsonne, J. -P. Chen, S. Choi, E. Chudakov, E. Cisbani, F. Cusanno, M. M. Dalton, C. Dutta, K. Egiyan, C. Fernandez-Ramirez, R. Feuerbach, K. G. Fissum, S. Frullani, F. Garibaldi, O. Gayou, R. Gilman, S. Gilad, J. Goity, J. Gomez, B. Hahn, D. Hamilton, J. -O. Hansen, J. Huang, R. Igarashi, D. Ireland, C. W. de Jager, X. Jin, X. Jiang, T. Jinasundera, J. Kellie, C. E. Keppel, N. Kolb, J. LeRose, N. Liyanage, K. Livingston, D. McNulty, L. Mercado, R. Michaels, M. Mihovilovic, S. Qian, X. Qian, S. Mailyan, V. Mamyan, S. Marrone, P. Monaghan, S. Nanda, C. F. Perdrisat, E. Piasetzky, D. Protopopescu, V. Punjabi, Y. Qiang, I. A. Rachek, A. Rakhman, G. Ron, G. Rosner, A. Saha, B. Sawatzky, A. Shahinyan, S. Sirca, N. Sparveris, R. R. Subedi, R. Suleiman, I. Strakovsky, V. Sulkosky, J. Moinelo, H. Voskanyan, K. Wang, Y. Wang, J. Watson, D. Watts, B. Wojtsekhowski, R. L. Workman, H. Yao, X. Zhan, Y. Zhang. 2015-04-10. A precision measurement of the $p$($e,e^\prime p\,$)$π^0$ reaction at threshold. https://doi.org/10.1103/physrevlett.114.192503
Cite the original work for its findings. Save a collection to share your selection of sources.