First measurement of helicity-dependent cross sections in π0η photoproduction from quasi-free nucleons

A. Käser; M. Dieterle; L. Witthauer; S. Abt; P. Achenbach; P. Adlarson; F. Afzal; Z. Ahmed; J. Ahrens; J. R.M. Annand; H. J. Arends; M. Bashkanov; R. Beck; M. Biroth; N. S. Borisov; A. Braghieri; W. J. Briscoe; F. Cividini; C. Collicott; S. Costanza; A. Denig; E. J. Downie; P. Drexler; A. Fix; S. Garni; D. I. Glazier; I. Gorodnov; W. Gradl; M. Günther; G. M. Gurevich; L. Heijkenskjöld; D. Hornidge; G. M. Huber; V. L. Kashevarov; S. Kay; I. Keshelashvili; R. Kondratiev; M. Korolija; B. Krusche; A. B. Lazarev; V. Lisin; K. Livingston; S. Lutterer; I. J.D. MacGregor; 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; G. Reicherz; G. Ron; T. Rostomyan; A. Sarty; C. Sfienti; 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.2018.10.006

First measurement of helicity-dependent cross sections in π⁰η photoproduction from quasi-free nucleons

A. Käser, M. Dieterle, L. Witthauer, S. Abt, P. Achenbach, P. Adlarson, F. Afzal, Z. Ahmed, J. Ahrens, J. R.M. Annand, H. J. Arends, M. Bashkanov, R. Beck, M. Biroth, N. S. Borisov, A. Braghieri, W. J. Briscoe, F. Cividini, C. Collicott, S. CostanzaA. Denig, E. J. Downie, P. Drexler, A. Fix, S. Garni, D. I. Glazier, I. Gorodnov, W. Gradl, M. Günther, G. M. Gurevich, L. Heijkenskjöld, D. Hornidge, G. M. Huber, V. L. Kashevarov, S. Kay, I. Keshelashvili, R. Kondratiev, M. Korolija, B. Krusche^*, A. B. Lazarev, V. Lisin, K. Livingston, S. Lutterer, I. J.D. MacGregor, 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, G. Reicherz, G. Ron, T. Rostomyan, A. Sarty, C. Sfienti, 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

11 Scopus citations

Abstract

The helicity-dependent cross sections for the photoproduction of π⁰η pairs have been measured for the first time. The experiment was performed at the tagged photon facility of the Mainz MAMI accelerator with the combined Crystal Ball – TAPS calorimeter. The experiment used a polarized deuterated butanol target and a circularly polarized photon beam. This arrangement allowed the σ_1/2 (photon and target spin antiparallel) and σ_3/2 (parallel spins) components to be measured for quasi-free production of π⁰η pairs off protons and neutrons. The main finding is that the two helicity components contribute identically, within uncertainties, for both participant protons and neutrons. The absolute couplings for protons and neutrons are also identical. This means that nucleon resonances contributing to this reaction in the investigated energy range have almost equal electromagnetic helicity couplings, A_1/2 ^n,p and A_3/2 ^n,p. Identical couplings for protons and neutrons are typical for Δ resonances and identical A_1/2 and A_3/2 components are only possible for J≥3/2 states, which constrains possible contributions of nucleon resonances.

Original language	English
Pages (from-to)	305-312
Number of pages	8
Journal	Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics
Volume	786
DOIs	https://doi.org/10.1016/j.physletb.2018.10.006
State	Published - 10 Nov 2018

Bibliographical note

Publisher Copyright:
© 2018

Access to Document

10.1016/j.physletb.2018.10.006

Cite this

Käser, A., Dieterle, M., Witthauer, L., Abt, S., Achenbach, P., Adlarson, P., Afzal, F., Ahmed, Z., Ahrens, J., Annand, J. R. M., Arends, H. J., Bashkanov, M., Beck, R., Biroth, M., Borisov, N. S., Braghieri, A., Briscoe, W. J., Cividini, F., Collicott, C., ... Zana, L. (2018). First measurement of helicity-dependent cross sections in π⁰η photoproduction from quasi-free nucleons. Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics, 786, 305-312. https://doi.org/10.1016/j.physletb.2018.10.006

@article{db3895eab07b46e584440be11ff9f029,

title = "First measurement of helicity-dependent cross sections in π0η photoproduction from quasi-free nucleons",

abstract = "The helicity-dependent cross sections for the photoproduction of π0η pairs have been measured for the first time. The experiment was performed at the tagged photon facility of the Mainz MAMI accelerator with the combined Crystal Ball – TAPS calorimeter. The experiment used a polarized deuterated butanol target and a circularly polarized photon beam. This arrangement allowed the σ1/2 (photon and target spin antiparallel) and σ3/2 (parallel spins) components to be measured for quasi-free production of π0η pairs off protons and neutrons. The main finding is that the two helicity components contribute identically, within uncertainties, for both participant protons and neutrons. The absolute couplings for protons and neutrons are also identical. This means that nucleon resonances contributing to this reaction in the investigated energy range have almost equal electromagnetic helicity couplings, A1/2 n,p and A3/2 n,p. Identical couplings for protons and neutrons are typical for Δ resonances and identical A1/2 and A3/2 components are only possible for J≥3/2 states, which constrains possible contributions of nucleon resonances.",

author = "A. K{\"a}ser and M. Dieterle and L. Witthauer and S. Abt and P. Achenbach and P. Adlarson and F. Afzal and Z. Ahmed and J. Ahrens 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 F. Cividini and C. Collicott and S. Costanza and A. Denig and Downie, {E. J.} and P. Drexler and A. Fix and S. Garni and Glazier, {D. I.} and I. Gorodnov and W. Gradl and M. G{\"u}nther and Gurevich, {G. M.} and L. Heijkenskj{\"o}ld and D. Hornidge and Huber, {G. M.} and Kashevarov, {V. L.} and S. Kay and I. Keshelashvili and R. Kondratiev and M. Korolija and B. Krusche and Lazarev, {A. B.} and V. Lisin and K. Livingston and S. Lutterer and MacGregor, {I. J.D.} 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 G. Reicherz and G. Ron and T. Rostomyan and A. Sarty and C. Sfienti 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 = "Publisher Copyright: {\textcopyright} 2018",

year = "2018",

month = nov,

day = "10",

doi = "10.1016/j.physletb.2018.10.006",

language = "אנגלית",

volume = "786",

pages = "305--312",

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

issn = "0370-2693",

publisher = "Elsevier",

}

Käser, A, Dieterle, M, Witthauer, L, Abt, S, Achenbach, P, Adlarson, P, Afzal, F, Ahmed, Z, Ahrens, J, Annand, JRM, Arends, HJ, Bashkanov, M, Beck, R, Biroth, M, Borisov, NS, Braghieri, A, Briscoe, WJ, Cividini, F, Collicott, C, Costanza, S, Denig, A, Downie, EJ, Drexler, P, Fix, A, Garni, S, Glazier, DI, Gorodnov, I, Gradl, W, Günther, M, Gurevich, GM, Heijkenskjöld, L, Hornidge, D, Huber, GM, Kashevarov, VL, Kay, S, Keshelashvili, I, Kondratiev, R, Korolija, M, Krusche, B, Lazarev, AB, Lisin, V, Livingston, K, Lutterer, S, MacGregor, IJD, 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, Reicherz, G, Ron, G, Rostomyan, T, Sarty, A, Sfienti, C, 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 2018, 'First measurement of helicity-dependent cross sections in π⁰η photoproduction from quasi-free nucleons', Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics, vol. 786, pp. 305-312. https://doi.org/10.1016/j.physletb.2018.10.006

TY - JOUR

T1 - First measurement of helicity-dependent cross sections in π0η photoproduction from quasi-free nucleons

AU - Käser, A.

AU - Dieterle, M.

AU - Witthauer, L.

AU - Abt, S.

AU - Achenbach, P.

AU - Adlarson, P.

AU - Afzal, F.

AU - Ahmed, Z.

AU - Ahrens, J.

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 - Cividini, F.

AU - Collicott, C.

AU - Costanza, S.

AU - Denig, A.

AU - Downie, E. J.

AU - Drexler, P.

AU - Fix, A.

AU - Garni, S.

AU - Glazier, D. I.

AU - Gorodnov, I.

AU - Gradl, W.

AU - Günther, M.

AU - Gurevich, G. M.

AU - Heijkenskjöld, L.

AU - Hornidge, D.

AU - Huber, G. M.

AU - Kashevarov, V. L.

AU - Kay, S.

AU - Keshelashvili, I.

AU - Kondratiev, R.

AU - Korolija, M.

AU - Krusche, B.

AU - Lazarev, A. B.

AU - Lisin, V.

AU - Livingston, K.

AU - Lutterer, S.

AU - MacGregor, I. J.D.

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 - Reicherz, G.

AU - Ron, G.

AU - Rostomyan, T.

AU - Sarty, A.

AU - Sfienti, C.

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.

PY - 2018/11/10

Y1 - 2018/11/10

N2 - The helicity-dependent cross sections for the photoproduction of π0η pairs have been measured for the first time. The experiment was performed at the tagged photon facility of the Mainz MAMI accelerator with the combined Crystal Ball – TAPS calorimeter. The experiment used a polarized deuterated butanol target and a circularly polarized photon beam. This arrangement allowed the σ1/2 (photon and target spin antiparallel) and σ3/2 (parallel spins) components to be measured for quasi-free production of π0η pairs off protons and neutrons. The main finding is that the two helicity components contribute identically, within uncertainties, for both participant protons and neutrons. The absolute couplings for protons and neutrons are also identical. This means that nucleon resonances contributing to this reaction in the investigated energy range have almost equal electromagnetic helicity couplings, A1/2 n,p and A3/2 n,p. Identical couplings for protons and neutrons are typical for Δ resonances and identical A1/2 and A3/2 components are only possible for J≥3/2 states, which constrains possible contributions of nucleon resonances.

AB - The helicity-dependent cross sections for the photoproduction of π0η pairs have been measured for the first time. The experiment was performed at the tagged photon facility of the Mainz MAMI accelerator with the combined Crystal Ball – TAPS calorimeter. The experiment used a polarized deuterated butanol target and a circularly polarized photon beam. This arrangement allowed the σ1/2 (photon and target spin antiparallel) and σ3/2 (parallel spins) components to be measured for quasi-free production of π0η pairs off protons and neutrons. The main finding is that the two helicity components contribute identically, within uncertainties, for both participant protons and neutrons. The absolute couplings for protons and neutrons are also identical. This means that nucleon resonances contributing to this reaction in the investigated energy range have almost equal electromagnetic helicity couplings, A1/2 n,p and A3/2 n,p. Identical couplings for protons and neutrons are typical for Δ resonances and identical A1/2 and A3/2 components are only possible for J≥3/2 states, which constrains possible contributions of nucleon resonances.

UR - http://www.scopus.com/inward/record.url?scp=85054879201&partnerID=8YFLogxK

U2 - 10.1016/j.physletb.2018.10.006

DO - 10.1016/j.physletb.2018.10.006

M3 - ???researchoutput.researchoutputtypes.contributiontojournal.article???

AN - SCOPUS:85054879201

SN - 0370-2693

VL - 786

SP - 305

EP - 312

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 helicity-dependent cross sections in π⁰η photoproduction from quasi-free nucleons

Abstract

Bibliographical note

Access to Document

Other files and links

Fingerprint

Cite this