Target-normal single spin asymmetries measured with positrons
Abstract Two-photon exchange and the larger class of hadronic box diagrams are difficult to calculate without a large degree of model-dependence. At the same time, these processes are significant radiative corrections in parity-violating electron scattering, in neutron decay, and may...
| Main Authors: | , , |
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| Other Authors: | |
| Format: | Article |
| Language: | English |
| Published: |
Springer Berlin Heidelberg
2021
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| Online Access: | https://hdl.handle.net/1721.1/136843 |
| _version_ | 1826189846274637824 |
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| author | Grauvogel, G. N. Kutz, T. Schmidt, A. |
| author2 | Massachusetts Institute of Technology. Laboratory for Nuclear Science |
| author_facet | Massachusetts Institute of Technology. Laboratory for Nuclear Science Grauvogel, G. N. Kutz, T. Schmidt, A. |
| author_sort | Grauvogel, G. N. |
| collection | MIT |
| description | Abstract
Two-photon exchange and the larger class of hadronic box diagrams are difficult to calculate without a large degree of model-dependence. At the same time, these processes are significant radiative corrections in parity-violating electron scattering, in neutron decay, and may even be responsible for the proton’s form factor ratio discrepancy. New kinds of experimental data are needed to help constrain models and guide future box-diagram calculations. The target-normal single spin asymmetry,
$$A_n$$
A
n
, formed with an unpolarized beam scattering from a target that is polarized normal to the scattering plane, is sensitive to the imaginary part of the two-photon exchange amplitude, and can provide a valuable constraint. A measurement with both electrons and positrons can reduce sources of experimental error, and distinguish between the effects of two-photon exchange and those of time-reversal symmetry violation. This article describes a proposed experiment in Hall A, using the new Super Big-Bite Spectrometer that can cover a momentum transfer range in the critical zone of uncertainty between where hadronic calculations and those based on partonic degrees of freedom are expected to be accurate. |
| first_indexed | 2024-09-23T08:24:34Z |
| format | Article |
| id | mit-1721.1/136843 |
| institution | Massachusetts Institute of Technology |
| language | English |
| last_indexed | 2024-09-23T08:24:34Z |
| publishDate | 2021 |
| publisher | Springer Berlin Heidelberg |
| record_format | dspace |
| spelling | mit-1721.1/1368432023-02-16T20:46:54Z Target-normal single spin asymmetries measured with positrons Grauvogel, G. N. Kutz, T. Schmidt, A. Massachusetts Institute of Technology. Laboratory for Nuclear Science Abstract Two-photon exchange and the larger class of hadronic box diagrams are difficult to calculate without a large degree of model-dependence. At the same time, these processes are significant radiative corrections in parity-violating electron scattering, in neutron decay, and may even be responsible for the proton’s form factor ratio discrepancy. New kinds of experimental data are needed to help constrain models and guide future box-diagram calculations. The target-normal single spin asymmetry, $$A_n$$ A n , formed with an unpolarized beam scattering from a target that is polarized normal to the scattering plane, is sensitive to the imaginary part of the two-photon exchange amplitude, and can provide a valuable constraint. A measurement with both electrons and positrons can reduce sources of experimental error, and distinguish between the effects of two-photon exchange and those of time-reversal symmetry violation. This article describes a proposed experiment in Hall A, using the new Super Big-Bite Spectrometer that can cover a momentum transfer range in the critical zone of uncertainty between where hadronic calculations and those based on partonic degrees of freedom are expected to be accurate. 2021-11-01T14:33:44Z 2021-11-01T14:33:44Z 2021-06-29 2021-06-30T03:26:37Z Article http://purl.org/eprint/type/JournalArticle https://hdl.handle.net/1721.1/136843 The European Physical Journal A. 2021 Jun 29;57(6):213 en https://doi.org/10.1140/epja/s10050-021-00531-7 Article is made available in accordance with the publisher's policy and may be subject to US copyright law. Please refer to the publisher's site for terms of use. The Author(s), under exclusive licence to Società Italiana di Fisica and Springer-Verlag GmbH Germany, part of Springer Nature application/pdf Springer Berlin Heidelberg Springer Berlin Heidelberg |
| spellingShingle | Grauvogel, G. N. Kutz, T. Schmidt, A. Target-normal single spin asymmetries measured with positrons |
| title | Target-normal single spin asymmetries measured with positrons |
| title_full | Target-normal single spin asymmetries measured with positrons |
| title_fullStr | Target-normal single spin asymmetries measured with positrons |
| title_full_unstemmed | Target-normal single spin asymmetries measured with positrons |
| title_short | Target-normal single spin asymmetries measured with positrons |
| title_sort | target normal single spin asymmetries measured with positrons |
| url | https://hdl.handle.net/1721.1/136843 |
| work_keys_str_mv | AT grauvogelgn targetnormalsinglespinasymmetriesmeasuredwithpositrons AT kutzt targetnormalsinglespinasymmetriesmeasuredwithpositrons AT schmidta targetnormalsinglespinasymmetriesmeasuredwithpositrons |