Helicity dependence of the γ 3He → πX reactions in the Δ(1232) resonance region

S. Costanza; A. Mushkarenkov; F. Rigamonti; M. Romaniuk; P. Aguar Bartolomé; J. Ahrens; J. R.M. Annand; H. J. Arends; R. Beck; A. Braghieri; V. Bekrenev; H. Berghäuser; W. J. Briscoe; S. N. Cherepnya; C. Collicott; E. J. Downie; P. Drexler; L. V. Fil’kov; A. Fix; D. I. Glazier; D. Hamilton; E. Heid; W. Heil; D. Hornidge; D. Howdle; I. Jaegle; G. M. Huber; O. Jahn; T. Jude; V. L. Kashevarov; I. Keshelashvili; R. Kondratiev; M. Korolija; J. Krimmer; B. Krusche; S. Kruglov; A. Kulbardis; V. Lisin; K. Livingston; I. J.D. MacGregor; J. Mancell; G. Mandaglio; D. M. Manley; J. C. McGeorge; D. G. Middleton; V. Metag; B. M.K. Nefkens; A. Nikolaev; M. Oberle; M. Ostrick; H. Ortega; P. B. Otte; B. Oussena; P. Pedroni; F. Pheron; A. Polonski; S. Prakhov; G. Rosner; T. Rostomyan; A. J. Sarty; S. Schumann; A. Starostin; I. Supek; M. Thiel; M. Unverzagt; D. P. Watts; D. Werthmüller

doi:10.1140/epja/i2014-14173-y

Helicity dependence of the γ ³He → πX reactions in the Δ(1232) resonance region

S. Costanza, A. Mushkarenkov, F. Rigamonti, M. Romaniuk, P. Aguar Bartolomé, J. Ahrens, J. R.M. Annand, H. J. Arends, R. Beck, A. Braghieri, V. Bekrenev, H. Berghäuser, W. J. Briscoe, S. N. Cherepnya, C. Collicott, E. J. Downie, P. Drexler, L. V. Fil’kov, A. Fix, D. I. GlazierD. Hamilton, E. Heid, W. Heil, D. Hornidge, D. Howdle, I. Jaegle, G. M. Huber, O. Jahn, T. Jude, V. L. Kashevarov, I. Keshelashvili, R. Kondratiev, M. Korolija, J. Krimmer, B. Krusche, S. Kruglov, A. Kulbardis, V. Lisin, K. Livingston, I. J.D. MacGregor, J. Mancell, G. Mandaglio, D. M. Manley, J. C. McGeorge, D. G. Middleton, V. Metag, B. M.K. Nefkens, A. Nikolaev, M. Oberle, M. Ostrick, H. Ortega, P. B. Otte, B. Oussena, P. Pedroni^*, F. Pheron, A. Polonski, S. Prakhov, G. Rosner, T. Rostomyan, A. J. Sarty, S. Schumann, A. Starostin, I. Supek, M. Thiel, M. Unverzagt, D. P. Watts, D. Werthmüller

^*Corresponding author for this work

Physics

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

Abstract

The helicity dependences of the differential cross sections for the semi-inclusive γ³He → π⁰X and γ³He → π^±X reactions have been measured for the first time in the energy region 200 < E_γ 450 MeV. The experiment was performed at the tagged photon beam facility of the MAMI accelerator in Mainz using a longitudinally polarised high-pressure ³He gas target. Hadronic products were measured with the large-acceptance Crystal Ball detector complemented with additional devices for charged-particle tracking and identification. Unpolarised differential cross sections and their helicity dependence are compared with theoretical calculations using the Fix-Arenhövel model. The effect of the intermediate excitation of the Δ(1232) resonance can be clearly seen from this comparison, especially for the polarised case, where nuclear effects are relatively small. The model provides a better theoretical description of the unpolarised charged pion photoproduction data than the neutral pion channel. It does significantly better in describing the helicity-dependent data in both channels. These comparisons provide new information on the mechanisms involved in pion photoproduction on ³He and suggest that a polarised ³He target can provide valuable information on the corresponding polarised quasi-free neutron reactions.

Original language	English
Article number	173
Journal	European Physical Journal A
Volume	50
Issue number	11
DOIs	https://doi.org/10.1140/epja/i2014-14173-y
Publication status	Published - Nov 2014

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Costanza, S., Mushkarenkov, A., Rigamonti, F., Romaniuk, M., Aguar Bartolomé, P., Ahrens, J., Annand, J. R. M., Arends, H. J., Beck, R., Braghieri, A., Bekrenev, V., Berghäuser, H., Briscoe, W. J., Cherepnya, S. N., Collicott, C., Downie, E. J., Drexler, P., Fil’kov, L. V., Fix, A., ... Werthmüller, D. (2014). Helicity dependence of the γ ³He → πX reactions in the Δ(1232) resonance region. European Physical Journal A, 50(11), Article 173. https://doi.org/10.1140/epja/i2014-14173-y

@article{e5aad96f25b44a9ab0f1a14453a856ea,

title = "Helicity dependence of the γ 3He → πX reactions in the Δ(1232) resonance region",

abstract = "The helicity dependences of the differential cross sections for the semi-inclusive γ3He → π0X and γ3He → π±X reactions have been measured for the first time in the energy region 200 < Eγ 450 MeV. The experiment was performed at the tagged photon beam facility of the MAMI accelerator in Mainz using a longitudinally polarised high-pressure 3He gas target. Hadronic products were measured with the large-acceptance Crystal Ball detector complemented with additional devices for charged-particle tracking and identification. Unpolarised differential cross sections and their helicity dependence are compared with theoretical calculations using the Fix-Arenh{\"o}vel model. The effect of the intermediate excitation of the Δ(1232) resonance can be clearly seen from this comparison, especially for the polarised case, where nuclear effects are relatively small. The model provides a better theoretical description of the unpolarised charged pion photoproduction data than the neutral pion channel. It does significantly better in describing the helicity-dependent data in both channels. These comparisons provide new information on the mechanisms involved in pion photoproduction on 3He and suggest that a polarised 3He target can provide valuable information on the corresponding polarised quasi-free neutron reactions.",

author = "S. Costanza and A. Mushkarenkov and F. Rigamonti and M. Romaniuk and {Aguar Bartolom{\'e}}, P. and J. Ahrens and Annand, {J. R.M.} and Arends, {H. J.} and R. Beck and A. Braghieri and V. Bekrenev and H. Bergh{\"a}user and Briscoe, {W. J.} and Cherepnya, {S. N.} and C. Collicott and Downie, {E. J.} and P. Drexler and Fil{\textquoteright}kov, {L. V.} and A. Fix and Glazier, {D. I.} and D. Hamilton and E. Heid and W. Heil and D. Hornidge and D. Howdle and I. Jaegle and Huber, {G. M.} and O. Jahn and T. Jude and Kashevarov, {V. L.} and I. Keshelashvili and R. Kondratiev and M. Korolija and J. Krimmer and B. Krusche and S. Kruglov and A. Kulbardis and V. Lisin and K. Livingston and MacGregor, {I. J.D.} and J. Mancell and G. Mandaglio and Manley, {D. M.} and McGeorge, {J. C.} and Middleton, {D. G.} and V. Metag and Nefkens, {B. M.K.} and A. Nikolaev and M. Oberle and M. Ostrick and H. Ortega and Otte, {P. B.} and B. Oussena and P. Pedroni and F. Pheron and A. Polonski and S. Prakhov and G. Rosner and T. Rostomyan and Sarty, {A. J.} and S. Schumann and A. Starostin and I. Supek and M. Thiel and M. Unverzagt and Watts, {D. P.} and D. Werthm{\"u}ller",

year = "2014",

month = nov,

doi = "10.1140/epja/i2014-14173-y",

language = "English",

volume = "50",

journal = "European Physical Journal A",

issn = "1434-6001",

publisher = "Springer",

number = "11",

}

Costanza, S, Mushkarenkov, A, Rigamonti, F, Romaniuk, M, Aguar Bartolomé, P, Ahrens, J, Annand, JRM, Arends, HJ, Beck, R, Braghieri, A, Bekrenev, V, Berghäuser, H, Briscoe, WJ, Cherepnya, SN, Collicott, C, Downie, EJ, Drexler, P, Fil’kov, LV, Fix, A, Glazier, DI, Hamilton, D, Heid, E, Heil, W, Hornidge, D, Howdle, D, Jaegle, I, Huber, GM, Jahn, O, Jude, T, Kashevarov, VL, Keshelashvili, I, Kondratiev, R, Korolija, M, Krimmer, J, Krusche, B, Kruglov, S, Kulbardis, A, Lisin, V, Livingston, K, MacGregor, IJD, Mancell, J, Mandaglio, G, Manley, DM, McGeorge, JC, Middleton, DG, Metag, V, Nefkens, BMK, Nikolaev, A, Oberle, M, Ostrick, M, Ortega, H, Otte, PB, Oussena, B, Pedroni, P, Pheron, F, Polonski, A, Prakhov, S, Rosner, G, Rostomyan, T, Sarty, AJ, Schumann, S, Starostin, A, Supek, I, Thiel, M, Unverzagt, M, Watts, DP & Werthmüller, D 2014, 'Helicity dependence of the γ ³He → πX reactions in the Δ(1232) resonance region', European Physical Journal A, vol. 50, no. 11, 173. https://doi.org/10.1140/epja/i2014-14173-y

TY - JOUR

T1 - Helicity dependence of the γ 3He → πX reactions in the Δ(1232) resonance region

AU - Costanza, S.

AU - Mushkarenkov, A.

AU - Rigamonti, F.

AU - Romaniuk, M.

AU - Aguar Bartolomé, P.

AU - Ahrens, J.

AU - Annand, J. R.M.

AU - Arends, H. J.

AU - Beck, R.

AU - Braghieri, A.

AU - Bekrenev, V.

AU - Berghäuser, H.

AU - Briscoe, W. J.

AU - Cherepnya, S. N.

AU - Collicott, C.

AU - Downie, E. J.

AU - Drexler, P.

AU - Fil’kov, L. V.

AU - Fix, A.

AU - Glazier, D. I.

AU - Hamilton, D.

AU - Heid, E.

AU - Heil, W.

AU - Hornidge, D.

AU - Howdle, D.

AU - Jaegle, I.

AU - Huber, G. M.

AU - Jahn, O.

AU - Jude, T.

AU - Kashevarov, V. L.

AU - Keshelashvili, I.

AU - Kondratiev, R.

AU - Korolija, M.

AU - Krimmer, J.

AU - Krusche, B.

AU - Kruglov, S.

AU - Kulbardis, A.

AU - Lisin, V.

AU - Livingston, K.

AU - MacGregor, I. J.D.

AU - Mancell, J.

AU - Mandaglio, G.

AU - Manley, D. M.

AU - McGeorge, J. C.

AU - Middleton, D. G.

AU - Metag, V.

AU - Nefkens, B. M.K.

AU - Nikolaev, A.

AU - Oberle, M.

AU - Ostrick, M.

AU - Ortega, H.

AU - Otte, P. B.

AU - Oussena, B.

AU - Pedroni, P.

AU - Pheron, F.

AU - Polonski, A.

AU - Prakhov, S.

AU - Rosner, G.

AU - Rostomyan, T.

AU - Sarty, A. J.

AU - Schumann, S.

AU - Starostin, A.

AU - Supek, I.

AU - Thiel, M.

AU - Unverzagt, M.

AU - Watts, D. P.

AU - Werthmüller, D.

PY - 2014/11

Y1 - 2014/11

N2 - The helicity dependences of the differential cross sections for the semi-inclusive γ3He → π0X and γ3He → π±X reactions have been measured for the first time in the energy region 200 < Eγ 450 MeV. The experiment was performed at the tagged photon beam facility of the MAMI accelerator in Mainz using a longitudinally polarised high-pressure 3He gas target. Hadronic products were measured with the large-acceptance Crystal Ball detector complemented with additional devices for charged-particle tracking and identification. Unpolarised differential cross sections and their helicity dependence are compared with theoretical calculations using the Fix-Arenhövel model. The effect of the intermediate excitation of the Δ(1232) resonance can be clearly seen from this comparison, especially for the polarised case, where nuclear effects are relatively small. The model provides a better theoretical description of the unpolarised charged pion photoproduction data than the neutral pion channel. It does significantly better in describing the helicity-dependent data in both channels. These comparisons provide new information on the mechanisms involved in pion photoproduction on 3He and suggest that a polarised 3He target can provide valuable information on the corresponding polarised quasi-free neutron reactions.

AB - The helicity dependences of the differential cross sections for the semi-inclusive γ3He → π0X and γ3He → π±X reactions have been measured for the first time in the energy region 200 < Eγ 450 MeV. The experiment was performed at the tagged photon beam facility of the MAMI accelerator in Mainz using a longitudinally polarised high-pressure 3He gas target. Hadronic products were measured with the large-acceptance Crystal Ball detector complemented with additional devices for charged-particle tracking and identification. Unpolarised differential cross sections and their helicity dependence are compared with theoretical calculations using the Fix-Arenhövel model. The effect of the intermediate excitation of the Δ(1232) resonance can be clearly seen from this comparison, especially for the polarised case, where nuclear effects are relatively small. The model provides a better theoretical description of the unpolarised charged pion photoproduction data than the neutral pion channel. It does significantly better in describing the helicity-dependent data in both channels. These comparisons provide new information on the mechanisms involved in pion photoproduction on 3He and suggest that a polarised 3He target can provide valuable information on the corresponding polarised quasi-free neutron reactions.

UR - http://www.scopus.com/inward/record.url?scp=84912075781&partnerID=8YFLogxK

U2 - 10.1140/epja/i2014-14173-y

DO - 10.1140/epja/i2014-14173-y

M3 - Article

AN - SCOPUS:84912075781

SN - 1434-6001

VL - 50

JO - European Physical Journal A

JF - European Physical Journal A

IS - 11

M1 - 173

ER -

Helicity dependence of the γ 3He → πX reactions in the Δ(1232) resonance region

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Helicity dependence of the γ ³He → πX reactions in the Δ(1232) resonance region