First measurement of the polarization observable E and helicity-dependent cross sections in single π0 photoproduction from quasi-free nucleons

M. Dieterle; L. Witthauer; F. Cividini; S. Abt; P. Achenbach; P. Adlarson; F. Afzal; Z. Ahmed; C. S. Akondi; J. R.M. Annand; H. J. Arends; M. Bashkanov; R. Beck; M. Biroth; N. S. Borisov; A. Braghieri; W. J. Briscoe; S. Costanza; C. Collicott; A. Denig; E. J. Downie; P. Drexler; M. I. Ferretti-Bondy; S. Gardner; S. Garni; D. I. Glazier; D. Glowa; W. Gradl; M. Günther; G. M. Gurevich; D. Hamilton; D. Hornidge; G. M. Huber; A. Käser; V. L. Kashevarov; S. Kay; I. Keshelashvili; R. Kondratiev; M. Korolija; B. Krusche; A. B. Lazarev; J. M. Linturi; V. Lisin; K. Livingston; S. Lutterer; I. J.D. MacGregor; J. Mancell; D. M. Manley; P. P. Martel; V. Metag; W. Meyer; R. Miskimen; E. Mornacchi; A. Mushkarenkov; A. B. Neganov; A. Neiser; M. Oberle; M. Ostrick; P. B. Otte; D. Paudyal; P. Pedroni; A. Polonski; S. N. Prakhov; A. Rajabi; G. Reicherz; G. Ron; T. Rostomyan; A. Sarty; C. Sfienti; M. H. Sikora; V. Sokhoyan; K. Spieker; O. Steffen; I. I. Strakovsky; Th Strub; I. Supek; A. Thiel; M. Thiel; A. Thomas; M. Unverzagt; Yu A. Usov; S. Wagner; N. K. Walford; D. P. Watts; D. Werthmüller; J. Wettig; M. Wolfes; L. Zana

doi:10.1016/j.physletb.2017.04.079

First measurement of the polarization observable E and helicity-dependent cross sections in single π⁰ photoproduction from quasi-free nucleons

M. Dieterle, L. Witthauer, F. Cividini, S. Abt, P. Achenbach, P. Adlarson, F. Afzal, Z. Ahmed, C. S. Akondi, J. R.M. Annand, H. J. Arends, M. Bashkanov, R. Beck, M. Biroth, N. S. Borisov, A. Braghieri, W. J. Briscoe, S. Costanza, C. Collicott, A. DenigE. J. Downie, P. Drexler, M. I. Ferretti-Bondy, S. Gardner, S. Garni, D. I. Glazier, D. Glowa, W. Gradl, M. Günther, G. M. Gurevich, D. Hamilton, D. Hornidge, G. M. Huber, A. Käser, V. L. Kashevarov, S. Kay, I. Keshelashvili, R. Kondratiev, M. Korolija, B. Krusche^*, A. B. Lazarev, J. M. Linturi, V. Lisin, K. Livingston, S. Lutterer, I. J.D. MacGregor, J. Mancell, D. M. Manley, P. P. Martel, V. Metag, W. Meyer, R. Miskimen, E. Mornacchi, A. Mushkarenkov, A. B. Neganov, A. Neiser, M. Oberle, M. Ostrick, P. B. Otte, D. Paudyal, P. Pedroni, A. Polonski, S. N. Prakhov, A. Rajabi, G. Reicherz, G. Ron, T. Rostomyan, A. Sarty, C. Sfienti, M. H. Sikora, V. Sokhoyan, K. Spieker, O. Steffen, I. I. Strakovsky, Th Strub, I. Supek, A. Thiel, M. Thiel, A. Thomas, M. Unverzagt, Yu A. Usov, S. Wagner, N. K. Walford, D. P. Watts, D. Werthmüller, J. Wettig, M. Wolfes, L. Zana

^*Corresponding author for this work

Racah Institute of Physics

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

21 Scopus citations

Abstract

The double-polarization observable E and the helicity-dependent cross sections σ_1/2 and σ_3/2 have been measured for the first time for single π⁰ photoproduction from protons and neutrons bound in the deuteron at the electron accelerator facility MAMI in Mainz, Germany. The experiment used a circularly polarized photon beam and a longitudinally polarized deuterated butanol target. The reaction products, recoil nucleons and decay photons from the π⁰ meson were detected with the Crystal Ball and TAPS electromagnetic calorimeters. Effects from nuclear Fermi motion were removed by a kinematic reconstruction of the π⁰N final state. A comparison to data measured with a free proton target showed that the absolute scale of the cross sections is significantly modified by nuclear final-state interaction (FSI) effects. However, there is no significant effect on the asymmetry E since the σ_1/2 and σ_3/2 components appear to be influenced in a similar way. Thus, the best approximation of the two helicity-dependent cross sections for the free neutron is obtained by combining the asymmetry E measured with quasi-free neutrons and the unpolarized cross section corrected for FSI effects under the assumption that the FSI effects are similar for neutrons and protons.

Original language	American English
Pages (from-to)	523-531
Number of pages	9
Journal	Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics
Volume	770
DOIs	https://doi.org/10.1016/j.physletb.2017.04.079
State	Published - 10 Jul 2017

Bibliographical note

Funding Information:
We wish to acknowledge the outstanding support of the accelerator group and operators of MAMI. This work was supported by Schweizerischer Nationalfonds ( 200020-156983 , 132799 , 121781 , 117601 ), Deutsche Forschungsgemeinschaft ( SFB 443 , SFB 1044 , SFB/TR16 ), the INFN -Italy, the European Community-Research Infrastructure Activity under FP7 programme (Hadron Physics, grant agreement No. 227431 ), the UK Science and Technology Facilities Council ( ST/J000175/1 , ST/G008604/1 , ST/G008582/1 , ST/J00006X/1 , and ST/L00478X/1 ), the Natural Sciences and Engineering Research Council ( NSERC , FRN: SAPPJ-2015-00023 ), Canada. This material is based upon work also supported by the U.S. Department of Energy , Office of Science, Office of Nuclear Physics Research Division, under Award Numbers DE-FG02-99-ER41110 , DE-FG02-88ER40415 , and DE-FG02-01-ER41194 and by the National Science Foundation , under Grant Nos. PHY-1039130 and IIA-1358175 .

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© 2017 The Authors

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10.1016/j.physletb.2017.04.079

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Dieterle, M., Witthauer, L., Cividini, F., Abt, S., Achenbach, P., Adlarson, P., Afzal, F., Ahmed, Z., Akondi, C. S., Annand, J. R. M., Arends, H. J., Bashkanov, M., Beck, R., Biroth, M., Borisov, N. S., Braghieri, A., Briscoe, W. J., Costanza, S., Collicott, C., ... Zana, L. (2017). First measurement of the polarization observable E and helicity-dependent cross sections in single π⁰ photoproduction from quasi-free nucleons. Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics, 770, 523-531. https://doi.org/10.1016/j.physletb.2017.04.079

@article{c0dbe94a39db4efeb2593bc290c1dc12,

title = "First measurement of the polarization observable E and helicity-dependent cross sections in single π0 photoproduction from quasi-free nucleons",

abstract = "The double-polarization observable E and the helicity-dependent cross sections σ1/2 and σ3/2 have been measured for the first time for single π0 photoproduction from protons and neutrons bound in the deuteron at the electron accelerator facility MAMI in Mainz, Germany. The experiment used a circularly polarized photon beam and a longitudinally polarized deuterated butanol target. The reaction products, recoil nucleons and decay photons from the π0 meson were detected with the Crystal Ball and TAPS electromagnetic calorimeters. Effects from nuclear Fermi motion were removed by a kinematic reconstruction of the π0N final state. A comparison to data measured with a free proton target showed that the absolute scale of the cross sections is significantly modified by nuclear final-state interaction (FSI) effects. However, there is no significant effect on the asymmetry E since the σ1/2 and σ3/2 components appear to be influenced in a similar way. Thus, the best approximation of the two helicity-dependent cross sections for the free neutron is obtained by combining the asymmetry E measured with quasi-free neutrons and the unpolarized cross section corrected for FSI effects under the assumption that the FSI effects are similar for neutrons and protons.",

author = "M. Dieterle and L. Witthauer and F. Cividini and S. Abt and P. Achenbach and P. Adlarson and F. Afzal and Z. Ahmed and Akondi, {C. S.} and Annand, {J. R.M.} and Arends, {H. J.} and M. Bashkanov and R. Beck and M. Biroth and Borisov, {N. S.} and A. Braghieri and Briscoe, {W. J.} and S. Costanza and C. Collicott and A. Denig and Downie, {E. J.} and P. Drexler and Ferretti-Bondy, {M. I.} and S. Gardner and S. Garni and Glazier, {D. I.} and D. Glowa and W. Gradl and M. G{\"u}nther and Gurevich, {G. M.} and D. Hamilton and D. Hornidge and Huber, {G. M.} and A. K{\"a}ser and Kashevarov, {V. L.} and S. Kay and I. Keshelashvili and R. Kondratiev and M. Korolija and B. Krusche and Lazarev, {A. B.} and Linturi, {J. M.} and V. Lisin and K. Livingston and S. Lutterer and MacGregor, {I. J.D.} and J. Mancell and Manley, {D. M.} and Martel, {P. P.} and V. Metag and W. Meyer and R. Miskimen and E. Mornacchi and A. Mushkarenkov and Neganov, {A. B.} and A. Neiser and M. Oberle and M. Ostrick and Otte, {P. B.} and D. Paudyal and P. Pedroni and A. Polonski and Prakhov, {S. N.} and A. Rajabi and G. Reicherz and G. Ron and T. Rostomyan and A. Sarty and C. Sfienti and Sikora, {M. H.} and V. Sokhoyan and K. Spieker and O. Steffen and Strakovsky, {I. I.} and Th Strub and I. Supek and A. Thiel and M. Thiel and A. Thomas and M. Unverzagt and Usov, {Yu A.} and S. Wagner and Walford, {N. K.} and Watts, {D. P.} and D. Werthm{\"u}ller and J. Wettig and M. Wolfes and L. Zana",

note = "Funding Information: We wish to acknowledge the outstanding support of the accelerator group and operators of MAMI. This work was supported by Schweizerischer Nationalfonds ( 200020-156983 , 132799 , 121781 , 117601 ), Deutsche Forschungsgemeinschaft ( SFB 443 , SFB 1044 , SFB/TR16 ), the INFN -Italy, the European Community-Research Infrastructure Activity under FP7 programme (Hadron Physics, grant agreement No. 227431 ), the UK Science and Technology Facilities Council ( ST/J000175/1 , ST/G008604/1 , ST/G008582/1 , ST/J00006X/1 , and ST/L00478X/1 ), the Natural Sciences and Engineering Research Council ( NSERC , FRN: SAPPJ-2015-00023 ), Canada. This material is based upon work also supported by the U.S. Department of Energy , Office of Science, Office of Nuclear Physics Research Division, under Award Numbers DE-FG02-99-ER41110 , DE-FG02-88ER40415 , and DE-FG02-01-ER41194 and by the National Science Foundation , under Grant Nos. PHY-1039130 and IIA-1358175 . Publisher Copyright: {\textcopyright} 2017 The Authors",

year = "2017",

month = jul,

day = "10",

doi = "10.1016/j.physletb.2017.04.079",

language = "American English",

volume = "770",

pages = "523--531",

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

issn = "0370-2693",

publisher = "Elsevier",

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Dieterle, M, Witthauer, L, Cividini, F, Abt, S, Achenbach, P, Adlarson, P, Afzal, F, Ahmed, Z, Akondi, CS, Annand, JRM, Arends, HJ, Bashkanov, M, Beck, R, Biroth, M, Borisov, NS, Braghieri, A, Briscoe, WJ, Costanza, S, Collicott, C, Denig, A, Downie, EJ, Drexler, P, Ferretti-Bondy, MI, Gardner, S, Garni, S, Glazier, DI, Glowa, D, Gradl, W, Günther, M, Gurevich, GM, Hamilton, D, Hornidge, D, Huber, GM, Käser, A, Kashevarov, VL, Kay, S, Keshelashvili, I, Kondratiev, R, Korolija, M, Krusche, B, Lazarev, AB, Linturi, JM, Lisin, V, Livingston, K, Lutterer, S, MacGregor, IJD, Mancell, J, Manley, DM, Martel, PP, Metag, V, Meyer, W, Miskimen, R, Mornacchi, E, Mushkarenkov, A, Neganov, AB, Neiser, A, Oberle, M, Ostrick, M, Otte, PB, Paudyal, D, Pedroni, P, Polonski, A, Prakhov, SN, Rajabi, A, Reicherz, G, Ron, G, Rostomyan, T, Sarty, A, Sfienti, C, Sikora, MH, Sokhoyan, V, Spieker, K, Steffen, O, Strakovsky, II, Strub, T, Supek, I, Thiel, A, Thiel, M, Thomas, A, Unverzagt, M, Usov, YA, Wagner, S, Walford, NK, Watts, DP, Werthmüller, D, Wettig, J, Wolfes, M & Zana, L 2017, 'First measurement of the polarization observable E and helicity-dependent cross sections in single π⁰ photoproduction from quasi-free nucleons', Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics, vol. 770, pp. 523-531. https://doi.org/10.1016/j.physletb.2017.04.079

First measurement of the polarization observable E and helicity-dependent cross sections in single π⁰ photoproduction from quasi-free nucleons. / Dieterle, M.; Witthauer, L.; Cividini, F. et al.
In: Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics, Vol. 770, 10.07.2017, p. 523-531.

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

TY - JOUR

T1 - First measurement of the polarization observable E and helicity-dependent cross sections in single π0 photoproduction from quasi-free nucleons

AU - Dieterle, M.

AU - Witthauer, L.

AU - Cividini, F.

AU - Abt, S.

AU - Achenbach, P.

AU - Adlarson, P.

AU - Afzal, F.

AU - Ahmed, Z.

AU - Akondi, C. S.

AU - Annand, J. R.M.

AU - Arends, H. J.

AU - Bashkanov, M.

AU - Beck, R.

AU - Biroth, M.

AU - Borisov, N. S.

AU - Braghieri, A.

AU - Briscoe, W. J.

AU - Costanza, S.

AU - Collicott, C.

AU - Denig, A.

AU - Downie, E. J.

AU - Drexler, P.

AU - Ferretti-Bondy, M. I.

AU - Gardner, S.

AU - Garni, S.

AU - Glazier, D. I.

AU - Glowa, D.

AU - Gradl, W.

AU - Günther, M.

AU - Gurevich, G. M.

AU - Hamilton, D.

AU - Hornidge, D.

AU - Huber, G. M.

AU - Käser, A.

AU - Kashevarov, V. L.

AU - Kay, S.

AU - Keshelashvili, I.

AU - Kondratiev, R.

AU - Korolija, M.

AU - Krusche, B.

AU - Lazarev, A. B.

AU - Linturi, J. M.

AU - Lisin, V.

AU - Livingston, K.

AU - Lutterer, S.

AU - MacGregor, I. J.D.

AU - Mancell, J.

AU - Manley, D. M.

AU - Martel, P. P.

AU - Metag, V.

AU - Meyer, W.

AU - Miskimen, R.

AU - Mornacchi, E.

AU - Mushkarenkov, A.

AU - Neganov, A. B.

AU - Neiser, A.

AU - Oberle, M.

AU - Ostrick, M.

AU - Otte, P. B.

AU - Paudyal, D.

AU - Pedroni, P.

AU - Polonski, A.

AU - Prakhov, S. N.

AU - Rajabi, A.

AU - Reicherz, G.

AU - Ron, G.

AU - Rostomyan, T.

AU - Sarty, A.

AU - Sfienti, C.

AU - Sikora, M. H.

AU - Sokhoyan, V.

AU - Spieker, K.

AU - Steffen, O.

AU - Strakovsky, I. I.

AU - Strub, Th

AU - Supek, I.

AU - Thiel, A.

AU - Thiel, M.

AU - Thomas, A.

AU - Unverzagt, M.

AU - Usov, Yu A.

AU - Wagner, S.

AU - Walford, N. K.

AU - Watts, D. P.

AU - Werthmüller, D.

AU - Wettig, J.

AU - Wolfes, M.

AU - Zana, L.

N1 - Funding Information: We wish to acknowledge the outstanding support of the accelerator group and operators of MAMI. This work was supported by Schweizerischer Nationalfonds ( 200020-156983 , 132799 , 121781 , 117601 ), Deutsche Forschungsgemeinschaft ( SFB 443 , SFB 1044 , SFB/TR16 ), the INFN -Italy, the European Community-Research Infrastructure Activity under FP7 programme (Hadron Physics, grant agreement No. 227431 ), the UK Science and Technology Facilities Council ( ST/J000175/1 , ST/G008604/1 , ST/G008582/1 , ST/J00006X/1 , and ST/L00478X/1 ), the Natural Sciences and Engineering Research Council ( NSERC , FRN: SAPPJ-2015-00023 ), Canada. This material is based upon work also supported by the U.S. Department of Energy , Office of Science, Office of Nuclear Physics Research Division, under Award Numbers DE-FG02-99-ER41110 , DE-FG02-88ER40415 , and DE-FG02-01-ER41194 and by the National Science Foundation , under Grant Nos. PHY-1039130 and IIA-1358175 . Publisher Copyright: © 2017 The Authors

PY - 2017/7/10

Y1 - 2017/7/10

N2 - The double-polarization observable E and the helicity-dependent cross sections σ1/2 and σ3/2 have been measured for the first time for single π0 photoproduction from protons and neutrons bound in the deuteron at the electron accelerator facility MAMI in Mainz, Germany. The experiment used a circularly polarized photon beam and a longitudinally polarized deuterated butanol target. The reaction products, recoil nucleons and decay photons from the π0 meson were detected with the Crystal Ball and TAPS electromagnetic calorimeters. Effects from nuclear Fermi motion were removed by a kinematic reconstruction of the π0N final state. A comparison to data measured with a free proton target showed that the absolute scale of the cross sections is significantly modified by nuclear final-state interaction (FSI) effects. However, there is no significant effect on the asymmetry E since the σ1/2 and σ3/2 components appear to be influenced in a similar way. Thus, the best approximation of the two helicity-dependent cross sections for the free neutron is obtained by combining the asymmetry E measured with quasi-free neutrons and the unpolarized cross section corrected for FSI effects under the assumption that the FSI effects are similar for neutrons and protons.

AB - The double-polarization observable E and the helicity-dependent cross sections σ1/2 and σ3/2 have been measured for the first time for single π0 photoproduction from protons and neutrons bound in the deuteron at the electron accelerator facility MAMI in Mainz, Germany. The experiment used a circularly polarized photon beam and a longitudinally polarized deuterated butanol target. The reaction products, recoil nucleons and decay photons from the π0 meson were detected with the Crystal Ball and TAPS electromagnetic calorimeters. Effects from nuclear Fermi motion were removed by a kinematic reconstruction of the π0N final state. A comparison to data measured with a free proton target showed that the absolute scale of the cross sections is significantly modified by nuclear final-state interaction (FSI) effects. However, there is no significant effect on the asymmetry E since the σ1/2 and σ3/2 components appear to be influenced in a similar way. Thus, the best approximation of the two helicity-dependent cross sections for the free neutron is obtained by combining the asymmetry E measured with quasi-free neutrons and the unpolarized cross section corrected for FSI effects under the assumption that the FSI effects are similar for neutrons and protons.

UR - http://www.scopus.com/inward/record.url?scp=85033468071&partnerID=8YFLogxK

U2 - 10.1016/j.physletb.2017.04.079

DO - 10.1016/j.physletb.2017.04.079

M3 - Article

AN - SCOPUS:85033468071

SN - 0370-2693

VL - 770

SP - 523

EP - 531

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

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

ER -

First measurement of the polarization observable E and helicity-dependent cross sections in single π⁰ photoproduction from quasi-free nucleons

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