Measurement of the helicity-dependent response in quasi-elastic proton knockout from40Ca

T. Kolar; I. Sabo-Napadensky; P. Achenbach; M. Christmann; M. O. Distler; L. Doria; P. Eckert; A. Esser; C. Giusti; J. Geimer; P. Gülker; M. Hoek; P. Klag; J. Lichtenstadt; M. Littich; T. Manoussos; D. Markus; H. Merkel; M. Mihovilovič; J. Müller; U. Müller; J. Pätschke; S. J. Paul; E. Piasetzky; S. Plura; J. Pochodzalla; M. Požun; G. Ron; B. S. Schlimme; C. Sfienti; S. Stengel; E. Stephan; S. Strauch; C. Szyszka; S. širca; M. Thiel; A. Wilczek

doi:10.1016/j.physletb.2025.139977

Measurement of the helicity-dependent response in quasi-elastic proton knockout from⁴⁰Ca

T. Kolar^*
, I. Sabo-Napadensky
, P. Achenbach
, M. Christmann
, M. O. Distler
, L. Doria
, P. Eckert
, A. Esser
, C. Giusti
, J. Geimer
, P. Gülker
, M. Hoek
, P. Klag
, J. Lichtenstadt
, M. Littich
, T. Manoussos
, D. Markus
, H. Merkel
, M. Mihovilovič
, J. Müller

U. Müller, J. Pätschke, S. J. Paul, E. Piasetzky, S. Plura, J. Pochodzalla, M. Požun, G. Ron, B. S. Schlimme, C. Sfienti, S. Stengel, E. Stephan, S. Strauch, C. Szyszka, S. širca, M. Thiel, A. Wilczek

^*Corresponding author for this work

Racah Institute of Physics

Research output: Contribution to journal › Article › peer-review

Abstract

The role of the electron-helicity-dependent cross-section term and the structure function f₀₁^′ in the quasi-elastic A(e→,e^′p) process was studied. The f₀₁^′ was measured for proton knockout from the 1d_3/2 shell in ⁴⁰Ca via the ⁴⁰Ca(e→,e′p)³⁹K_g.s. reaction, leaving the residual nucleus in a well-defined state. It requires a longitudinally polarized electron beam and out-of-plane proton detection. This structure function vanishes in the absence of final-state interactions (FSI) involving the ejected proton. Presented are the dependencies of f₀₁^′ on the missing momentum (closely related to the initial proton’s Fermi momentum) and the angle between the knocked-out proton and the virtual photon momenta. The role of the spin-orbit interaction in FSI through the L→·S→ term in a nuclear optical potential is discussed.

Original language	English
Article number	139977
Journal	Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics
Volume	871
DOIs	https://doi.org/10.1016/j.physletb.2025.139977
State	Published - Dec 2025

Bibliographical note

Publisher Copyright:
© 2025 The Authors.

Keywords

Beam helicity asymmetry
Electron scattering
Final-state interactions
Nuclear optical potential
Nuclear structure
Polarized electron scattering

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10.1016/j.physletb.2025.139977

Cite this

Kolar, T., Sabo-Napadensky, I., Achenbach, P., Christmann, M., Distler, M. O., Doria, L., Eckert, P., Esser, A., Giusti, C., Geimer, J., Gülker, P., Hoek, M., Klag, P., Lichtenstadt, J., Littich, M., Manoussos, T., Markus, D., Merkel, H., Mihovilovič, M., ... Wilczek, A. (2025). Measurement of the helicity-dependent response in quasi-elastic proton knockout from⁴⁰Ca. Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics, 871, Article 139977. https://doi.org/10.1016/j.physletb.2025.139977

@article{0324cf8abd424e8ea399f5527d8352b9,

title = "Measurement of the helicity-dependent response in quasi-elastic proton knockout from40Ca",

abstract = "The role of the electron-helicity-dependent cross-section term and the structure function f01′ in the quasi-elastic A(e→,e′p) process was studied. The f01′ was measured for proton knockout from the 1d3/2 shell in 40Ca via the 40Ca(e→,e′p)39Kg.s. reaction, leaving the residual nucleus in a well-defined state. It requires a longitudinally polarized electron beam and out-of-plane proton detection. This structure function vanishes in the absence of final-state interactions (FSI) involving the ejected proton. Presented are the dependencies of f01′ on the missing momentum (closely related to the initial proton{\textquoteright}s Fermi momentum) and the angle between the knocked-out proton and the virtual photon momenta. The role of the spin-orbit interaction in FSI through the L→·S→ term in a nuclear optical potential is discussed.",

keywords = "Beam helicity asymmetry, Electron scattering, Final-state interactions, Nuclear optical potential, Nuclear structure, Polarized electron scattering",

author = "T. Kolar and I. Sabo-Napadensky and P. Achenbach and M. Christmann and Distler, \{M. O.\} and L. Doria and P. Eckert and A. Esser and C. Giusti and J. Geimer and P. G{\"u}lker and M. Hoek and P. Klag and J. Lichtenstadt and M. Littich and T. Manoussos and D. Markus and H. Merkel and M. Mihovilovi{\v c} and J. M{\"u}ller and U. M{\"u}ller and J. P{\"a}tschke and Paul, \{S. J.\} and E. Piasetzky and S. Plura and J. Pochodzalla and M. Po{\v z}un and G. Ron and Schlimme, \{B. S.\} and C. Sfienti and S. Stengel and E. Stephan and S. Strauch and C. Szyszka and S. {\v s}irca and M. Thiel and A. Wilczek",

note = "Publisher Copyright: {\textcopyright} 2025 The Authors.",

year = "2025",

month = dec,

doi = "10.1016/j.physletb.2025.139977",

language = "אנגלית",

volume = "871",

journal = "Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics",

issn = "0370-2693",

publisher = "Elsevier B.V.",

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Kolar, T, Sabo-Napadensky, I, Achenbach, P, Christmann, M, Distler, MO, Doria, L, Eckert, P, Esser, A, Giusti, C, Geimer, J, Gülker, P, Hoek, M, Klag, P, Lichtenstadt, J, Littich, M, Manoussos, T, Markus, D, Merkel, H, Mihovilovič, M, Müller, J, Müller, U, Pätschke, J, Paul, SJ, Piasetzky, E, Plura, S, Pochodzalla, J, Požun, M, Ron, G, Schlimme, BS, Sfienti, C, Stengel, S, Stephan, E, Strauch, S, Szyszka, C, širca, S, Thiel, M & Wilczek, A 2025, 'Measurement of the helicity-dependent response in quasi-elastic proton knockout from⁴⁰Ca', Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics, vol. 871, 139977. https://doi.org/10.1016/j.physletb.2025.139977

TY - JOUR

T1 - Measurement of the helicity-dependent response in quasi-elastic proton knockout from40Ca

AU - Kolar, T.

AU - Sabo-Napadensky, I.

AU - Achenbach, P.

AU - Christmann, M.

AU - Distler, M. O.

AU - Doria, L.

AU - Eckert, P.

AU - Esser, A.

AU - Giusti, C.

AU - Geimer, J.

AU - Gülker, P.

AU - Hoek, M.

AU - Klag, P.

AU - Lichtenstadt, J.

AU - Littich, M.

AU - Manoussos, T.

AU - Markus, D.

AU - Merkel, H.

AU - Mihovilovič, M.

AU - Müller, J.

AU - Müller, U.

AU - Pätschke, J.

AU - Paul, S. J.

AU - Piasetzky, E.

AU - Plura, S.

AU - Pochodzalla, J.

AU - Požun, M.

AU - Ron, G.

AU - Schlimme, B. S.

AU - Sfienti, C.

AU - Stengel, S.

AU - Stephan, E.

AU - Strauch, S.

AU - Szyszka, C.

AU - širca, S.

AU - Thiel, M.

AU - Wilczek, A.

PY - 2025/12

Y1 - 2025/12

N2 - The role of the electron-helicity-dependent cross-section term and the structure function f01′ in the quasi-elastic A(e→,e′p) process was studied. The f01′ was measured for proton knockout from the 1d3/2 shell in 40Ca via the 40Ca(e→,e′p)39Kg.s. reaction, leaving the residual nucleus in a well-defined state. It requires a longitudinally polarized electron beam and out-of-plane proton detection. This structure function vanishes in the absence of final-state interactions (FSI) involving the ejected proton. Presented are the dependencies of f01′ on the missing momentum (closely related to the initial proton’s Fermi momentum) and the angle between the knocked-out proton and the virtual photon momenta. The role of the spin-orbit interaction in FSI through the L→·S→ term in a nuclear optical potential is discussed.

AB - The role of the electron-helicity-dependent cross-section term and the structure function f01′ in the quasi-elastic A(e→,e′p) process was studied. The f01′ was measured for proton knockout from the 1d3/2 shell in 40Ca via the 40Ca(e→,e′p)39Kg.s. reaction, leaving the residual nucleus in a well-defined state. It requires a longitudinally polarized electron beam and out-of-plane proton detection. This structure function vanishes in the absence of final-state interactions (FSI) involving the ejected proton. Presented are the dependencies of f01′ on the missing momentum (closely related to the initial proton’s Fermi momentum) and the angle between the knocked-out proton and the virtual photon momenta. The role of the spin-orbit interaction in FSI through the L→·S→ term in a nuclear optical potential is discussed.

KW - Beam helicity asymmetry

KW - Electron scattering

KW - Final-state interactions

KW - Nuclear optical potential

KW - Nuclear structure

KW - Polarized electron scattering

UR - https://www.scopus.com/pages/publications/105021837497

U2 - 10.1016/j.physletb.2025.139977

DO - 10.1016/j.physletb.2025.139977

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AN - SCOPUS:105021837497

SN - 0370-2693

VL - 871

JO - Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics

JF - Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics

M1 - 139977

ER -