Neutron polarisation transfer, $C_{x'}^n$, in $π^+$ photoproduction off the proton

A2 Collaboration

Neutron polarisation transfer, $C_{x'}^n$, in $π^+$ photoproduction off the proton

A2 Collaboration

Physics

Research output: Working paper › Preprint

Abstract

We report a first measurement of the double-polarisation observable, $C_{x'}$, in $\pi^+$ photoproduction off the proton. The $C_{x'}$ double-polarisation observable represents the transfer of polarisation from a circularly polarised photon beam to the recoiling neutron. The MAMI circularly polarised photon beam impinged on a liquid deuterium target cell, with reaction products detected in the Crystal Ball calorimeter. Ancillary apparatus surrounding the target provided tracking, particle identification and determination of recoil nucleon polarisation. The $C_{x'}$ observable is determined for photon energies 800-1400 MeV, providing new constraints on models aiming to elucidate the spectrum and properties of nucleon resonances. This is the first determination of any polarisation observable from the beam-recoil group of observables for this reaction, providing a valuable constraint and systematic check of the current solutions of partial wave analysis based theoretical models.

Original language	Undefined/Unknown
Publisher	arXiv
Publication status	Published - 17 Nov 2022

Keywords

nucl-ex

Access to Document

2211.09688v1

Cite this

@techreport{4e281e08be934c92b67500b9d1b2b201,

title = "Neutron polarisation transfer, $C_{x'}^n$, in $π^+$ photoproduction off the proton",

abstract = "We report a first measurement of the double-polarisation observable, $C_{x'}$, in $\pi^+$ photoproduction off the proton. The $C_{x'}$ double-polarisation observable represents the transfer of polarisation from a circularly polarised photon beam to the recoiling neutron. The MAMI circularly polarised photon beam impinged on a liquid deuterium target cell, with reaction products detected in the Crystal Ball calorimeter. Ancillary apparatus surrounding the target provided tracking, particle identification and determination of recoil nucleon polarisation. The $C_{x'}$ observable is determined for photon energies 800-1400 MeV, providing new constraints on models aiming to elucidate the spectrum and properties of nucleon resonances. This is the first determination of any polarisation observable from the beam-recoil group of observables for this reaction, providing a valuable constraint and systematic check of the current solutions of partial wave analysis based theoretical models.",

keywords = "nucl-ex",

author = "{A2 Collaboration} and M. Bashkanov and Watts, {D. P.} and Kay, {S. J. D.} 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 R. Beck and M. Biroth and N. Borisov 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 S. Fegan and A. Fix and S. Gardner and D. Ghosal and Glazier, {D. I.} and I. Gorodnov and W. Gradl and D. Gurevich and L. Heijkenskj{\"o}ld and D. Hornidge and Huber, {G. M.} and Kashevarov, {V. L.} and M. Korolija and B. Krusche and A. Lazarev and K. Livingston and S. Lutterer and MacGregor, {I. J. D.} and Manley, {D. M.} and Martel, {P. P.} and R. Miskimen and E. Mornacchi and C. Mullen and A. Neganov and A. Neiser and M. Ostrick and Otte, {P. B.} and D. Paudyal and N. Zachariou",

year = "2022",

month = nov,

day = "17",

language = "Undefined/Unknown",

publisher = "arXiv",

type = "WorkingPaper",

institution = "arXiv",

}

TY - UNPB

T1 - Neutron polarisation transfer, $C_{x'}^n$, in $π^+$ photoproduction off the proton

AU - A2 Collaboration

AU - Bashkanov, M.

AU - Watts, D. P.

AU - Kay, S. J. D.

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 - Beck, R.

AU - Biroth, M.

AU - Borisov, N.

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 - Fegan, S.

AU - Fix, A.

AU - Gardner, S.

AU - Ghosal, D.

AU - Glazier, D. I.

AU - Gorodnov, I.

AU - Gradl, W.

AU - Gurevich, D.

AU - Heijkenskjöld, L.

AU - Hornidge, D.

AU - Huber, G. M.

AU - Kashevarov, V. L.

AU - Korolija, M.

AU - Krusche, B.

AU - Lazarev, A.

AU - Livingston, K.

AU - Lutterer, S.

AU - MacGregor, I. J. D.

AU - Manley, D. M.

AU - Martel, P. P.

AU - Miskimen, R.

AU - Mornacchi, E.

AU - Mullen, C.

AU - Neganov, A.

AU - Neiser, A.

AU - Ostrick, M.

AU - Otte, P. B.

AU - Paudyal, D.

AU - Zachariou, N.

PY - 2022/11/17

Y1 - 2022/11/17

N2 - We report a first measurement of the double-polarisation observable, $C_{x'}$, in $\pi^+$ photoproduction off the proton. The $C_{x'}$ double-polarisation observable represents the transfer of polarisation from a circularly polarised photon beam to the recoiling neutron. The MAMI circularly polarised photon beam impinged on a liquid deuterium target cell, with reaction products detected in the Crystal Ball calorimeter. Ancillary apparatus surrounding the target provided tracking, particle identification and determination of recoil nucleon polarisation. The $C_{x'}$ observable is determined for photon energies 800-1400 MeV, providing new constraints on models aiming to elucidate the spectrum and properties of nucleon resonances. This is the first determination of any polarisation observable from the beam-recoil group of observables for this reaction, providing a valuable constraint and systematic check of the current solutions of partial wave analysis based theoretical models.

AB - We report a first measurement of the double-polarisation observable, $C_{x'}$, in $\pi^+$ photoproduction off the proton. The $C_{x'}$ double-polarisation observable represents the transfer of polarisation from a circularly polarised photon beam to the recoiling neutron. The MAMI circularly polarised photon beam impinged on a liquid deuterium target cell, with reaction products detected in the Crystal Ball calorimeter. Ancillary apparatus surrounding the target provided tracking, particle identification and determination of recoil nucleon polarisation. The $C_{x'}$ observable is determined for photon energies 800-1400 MeV, providing new constraints on models aiming to elucidate the spectrum and properties of nucleon resonances. This is the first determination of any polarisation observable from the beam-recoil group of observables for this reaction, providing a valuable constraint and systematic check of the current solutions of partial wave analysis based theoretical models.

KW - nucl-ex

M3 - Preprint

BT - Neutron polarisation transfer, $C_{x'}^n$, in $π^+$ photoproduction off the proton

PB - arXiv

ER -