Can nuclear physics explain the anomaly observed in the internal pair production in the Beryllium-8 nucleus?
Abstract
Recently the experimentalists in Krasznahorkay (2016) [1] announced observing an unexpected enhancement of the – pair production signal in one of the 8Be nuclear transitions. The subsequent studies have been focused on possible explanations based on introducing new types of particle. In this work, we improve the nuclear physics modeling of the reaction by studying the pair emission anisotropy and the interferences between different multipoles in an effective field theory inspired framework, and examine their possible relevance to the anomaly. The connection between the previously measured on-shell photon production and the pair production in the same nuclear transitions is established. These improvements, absent in the original experimental analysis, should be included in extracting new particle's properties from the experiment of this type. However, the improvements can not explain the anomaly. We then explore the nuclear transition form factor as a possible origin of the anomaly, and find the required form factor to be unrealistic for the 8Be nucleus. The reduction of the anomaly's significance by simply rescaling our predicted event count is also investigated.
- Publication Date:
- Research Org.:
- Univ. of Washington, Seattle, WA (United States)
- Sponsoring Org.:
- USDOE
- OSTI Identifier:
- 1437722
- Alternate Identifier(s):
- OSTI ID: 1499270
- Grant/Contract Number:
- FG02-97ER-41014; FG02-97ER41014
- Resource Type:
- Published Article
- Journal Name:
- Physics Letters B
- Additional Journal Information:
- Journal Name: Physics Letters B Journal Volume: 773 Journal Issue: C; Journal ID: ISSN 0370-2693
- Publisher:
- Elsevier
- Country of Publication:
- Netherlands
- Language:
- English
- Subject:
- 73 NUCLEAR PHYSICS AND RADIATION PHYSICS
Citation Formats
Zhang, Xilin, and Miller, Gerald A. Can nuclear physics explain the anomaly observed in the internal pair production in the Beryllium-8 nucleus?. Netherlands: N. p., 2017.
Web. doi:10.1016/j.physletb.2017.08.013.
Zhang, Xilin, & Miller, Gerald A. Can nuclear physics explain the anomaly observed in the internal pair production in the Beryllium-8 nucleus?. Netherlands. https://doi.org/10.1016/j.physletb.2017.08.013
Zhang, Xilin, and Miller, Gerald A. Sun .
"Can nuclear physics explain the anomaly observed in the internal pair production in the Beryllium-8 nucleus?". Netherlands. https://doi.org/10.1016/j.physletb.2017.08.013.
@article{osti_1437722,
title = {Can nuclear physics explain the anomaly observed in the internal pair production in the Beryllium-8 nucleus?},
author = {Zhang, Xilin and Miller, Gerald A.},
abstractNote = {Recently the experimentalists in Krasznahorkay (2016) [1] announced observing an unexpected enhancement of the – pair production signal in one of the 8Be nuclear transitions. The subsequent studies have been focused on possible explanations based on introducing new types of particle. In this work, we improve the nuclear physics modeling of the reaction by studying the pair emission anisotropy and the interferences between different multipoles in an effective field theory inspired framework, and examine their possible relevance to the anomaly. The connection between the previously measured on-shell photon production and the pair production in the same nuclear transitions is established. These improvements, absent in the original experimental analysis, should be included in extracting new particle's properties from the experiment of this type. However, the improvements can not explain the anomaly. We then explore the nuclear transition form factor as a possible origin of the anomaly, and find the required form factor to be unrealistic for the 8Be nucleus. The reduction of the anomaly's significance by simply rescaling our predicted event count is also investigated.},
doi = {10.1016/j.physletb.2017.08.013},
journal = {Physics Letters B},
number = C,
volume = 773,
place = {Netherlands},
year = {Sun Oct 01 00:00:00 EDT 2017},
month = {Sun Oct 01 00:00:00 EDT 2017}
}
https://doi.org/10.1016/j.physletb.2017.08.013
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Figures / Tables:
Fig. 1. : The top shows the kinematics for the $e$+–$e$− pair production as well as the photon production (without the lepton line). The bottom plots the allowed phase space (shaded area) in terms of $M$+− and cos $θ$+− assuming $m$e = 0.
Works referencing / citing this record:
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