Improved limits on Fierz Interference using asymmetry measurements from the UCNA experiment
| Autor: | Sun, Xuan, Adamek, E., Allgeier, B., Bagdasarova, Y., Berguno, D. B., Blatnik, M., Bowles, T. J., Broussard, L. J., Brown, M. A. -P., Carr, R., Clayton, S., Cude-Woods, C., Currie, S., Dees, E. B., Ding, X., Filippone, B. W., García, A., Geltenbort, P., Hasan, S., Hickerson, K. P., Hoagland, J., Hong, R., Holley, A. T., Ito, T. M., Knecht, A., Liu, C. -Y., Liu, J., Makela, M., Mammei, R., Martin, J. W., Melconian, D., Mendenhall, M. P., Moore, S. D., Morris, C. L., Nepal, S., Nouri, N., Pattie Jr., R. W., Galván, A. Pérez, Phillips II, D. G., Picker, R., Pitt, M. L., Plaster, B., Salvat, D. J., Saunders, A., Sharapov, E. I., Sjue, S., Slutsky, S., Sondheim, W., Swank, C., Tatar, E., Vogelaar, R. B., VornDick, B., Wang, Z., Wei, W., Wexler, J. W., Womack, T., Wrede, C., Young, A. R., Zeck, B. A. |
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| Rok vydání: | 2019 |
| Předmět: | |
| Zdroj: | Phys. Rev. C 101, 035503 (2020) |
| Druh dokumentu: | Working Paper |
| DOI: | 10.1103/PhysRevC.101.035503 |
| Popis: | The Ultracold Neutron Asymmetry (UCNA) experiment was designed to measure the $\beta$-decay asymmetry parameter, $A_0$, for free neutron decay. In the experiment, polarized ultracold neutrons are transported into a decay trap, and their $\beta$-decay electrons are detected with $\approx 4\pi$ acceptance into two detector packages which provide position and energy reconstruction. The experiment also has sensitivity to $b_{n}$, the Fierz interference term in the neutron $\beta$-decay rate. In this work, we determine $b_{n}$ from the energy dependence of $A_0$ using the data taken during the UCNA 2011-2013 run. In addition, we present the same type of analysis using the earlier 2010 $A$ dataset. Motivated by improved statistics and comparable systematic errors compared to the 2010 data-taking run, we present a new $b_{n}$ measurement using the weighted average of our asymmetry dataset fits, to obtain $b_{n} = 0.066 \pm 0.041_{\text{stat}} \pm 0.024_{\text{syst}}$ which corresponds to a limit of $-0.012 < b_{n} < 0.144$ at the 90% confidence level. Comment: 6 pages, 3 figures. Submission to PRC |
| Databáze: | arXiv |
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