The neutron skin of 208Pb from coherent pion photoproduction

Crystal Ball MAMI A2 Collaboration; C. M. Tarbert; D. P. Watts; D. I. Glazier; P. Aguar; J. Ahrens; J. R. M. Annand; H. J. Arends; R. Beck; V. Bekrenev; B. Boillat; A. Braghieri; D. Branford; W. J. Briscoe; J. Brudvik; S. Cherepnya; R. Codling; E. J. Downie; K. Foehl; P. Grabmayr; R. Gregor; E. Heid; D. Hornidge; O. Jahn; V. L. Kashevarov; A. Knezevic; R. Kondratiev; M. Korolija; M. Kotulla; D. Krambrich; B. Krusche; M. Lang; V. Lisin; K. Livingston; S. Lugert; I. J. D. MacGregor; D. M. Manley; M. Martinez; J. C. McGeorge; D. Mekterovic; V. Metag; B. M. K. Nefkens; A. Nikolaev; R. Novotny; R. O. Owens; P. Pedroni; A. Polonski; S. N. Prakhov; J. W. Price; G. Rosner; S. Schumann

doi:10.1103/PhysRevLett.112.242502

The neutron skin of 208Pb from coherent pion photoproduction

Crystal Ball MAMI A2 Collaboration, C. M. Tarbert^*, D. P. Watts, D. I. Glazier, P. Aguar, J. Ahrens, J. R. M. Annand, H. J. Arends, R. Beck, V. Bekrenev, B. Boillat, A. Braghieri, D. Branford, W. J. Briscoe, J. Brudvik, S. Cherepnya, R. Codling, E. J. Downie, K. Foehl, P. GrabmayrR. Gregor, E. Heid, D. Hornidge, O. Jahn, V. L. Kashevarov, A. Knezevic, R. Kondratiev, M. Korolija, M. Kotulla, D. Krambrich, B. Krusche, M. Lang, V. Lisin, K. Livingston, S. Lugert, I. J. D. MacGregor, D. M. Manley, M. Martinez, J. C. McGeorge, D. Mekterovic, V. Metag, B. M. K. Nefkens, A. Nikolaev, R. Novotny, R. O. Owens, P. Pedroni, A. Polonski, S. N. Prakhov, J. W. Price, G. Rosner, S. Schumann

^*Corresponding author for this work

School of Physics and Astronomy

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

Abstract / Description of output

Information on the size and shape of the neutron skin on $^{208}$Pb has been extracted from coherent pion photoproduction cross sections measured using the Crystal Ball together with the Glasgow tagger at the MAMI electron beam facility. Exploiting an interpolated fit of a theoretical model to the measured cross sections the half-height radius and diffuseness of the neutron distribution are found to be 6.77$\pm 0.03(stat)$ fm and 0.55$\pm 0.01(stat)$$^{+0.00}_{-0.025}(sys)$ fm respectively, corresponding to a neutron skin thickness $\Delta r_{np}$=0.19$\pm 0.03(stat)$$^{+0.00}_{-0.03}(sys)$ fm. The results give the first successful extraction of a neutron skin with an electromagnetic probe and indicate the skin of $^{208}$Pb has a halo character. The measurement provides valuable new constraints on both the structure of nuclei and the equation of state for neutron rich matter.

Original language	English
Article number	242502
Number of pages	6
Journal	Physical Review Letters
Volume	112
Issue number	24
DOIs	https://doi.org/10.1103/PhysRevLett.112.242502
Publication status	Published - 18 Jun 2014

Keywords / Materials (for Non-textual outputs)

TAGGED PHOTON SPECTROMETER
NUCLEI
RADII
SCATTERING
MICROTRON
EQUATION
MESONS
PI(0)
STARS
STATE

Access to Document

10.1103/PhysRevLett.112.242502

Illuminating strongly interacting matter
Watts, D.
STFC
1/06/09 → 31/12/13
Project: Research

Cite this

Crystal Ball MAMI A2 Collaboration, Tarbert, C. M., Watts, D. P., Glazier, D. I., Aguar, P., Ahrens, J., Annand, J. R. M., Arends, H. J., Beck, R., Bekrenev, V., Boillat, B., Braghieri, A., Branford, D., Briscoe, W. J., Brudvik, J., Cherepnya, S., Codling, R., Downie, E. J., Foehl, K., ... Schumann, S. (2014). The neutron skin of 208Pb from coherent pion photoproduction. Physical Review Letters, 112(24), Article 242502. https://doi.org/10.1103/PhysRevLett.112.242502

@article{cfe7f062f00c4d458c1f27cd418cbb88,

title = "The neutron skin of 208Pb from coherent pion photoproduction",

abstract = "Information on the size and shape of the neutron skin on $^{208}$Pb has been extracted from coherent pion photoproduction cross sections measured using the Crystal Ball together with the Glasgow tagger at the MAMI electron beam facility. Exploiting an interpolated fit of a theoretical model to the measured cross sections the half-height radius and diffuseness of the neutron distribution are found to be 6.77$\pm 0.03(stat)$ fm and 0.55$\pm 0.01(stat)$$^{+0.00}_{-0.025}(sys)$ fm respectively, corresponding to a neutron skin thickness $\Delta r_{np}$=0.19$\pm 0.03(stat)$$^{+0.00}_{-0.03}(sys)$ fm. The results give the first successful extraction of a neutron skin with an electromagnetic probe and indicate the skin of $^{208}$Pb has a halo character. The measurement provides valuable new constraints on both the structure of nuclei and the equation of state for neutron rich matter.",

keywords = "TAGGED PHOTON SPECTROMETER, NUCLEI, RADII, SCATTERING, MICROTRON, EQUATION, MESONS, PI(0), STARS, STATE",

author = "{Crystal Ball MAMI A2 Collaboration} and Tarbert, {C. M.} and Watts, {D. P.} and Glazier, {D. I.} and P. Aguar and J. Ahrens and Annand, {J. R. M.} and Arends, {H. J.} and R. Beck and V. Bekrenev and B. Boillat and A. Braghieri and D. Branford and Briscoe, {W. J.} and J. Brudvik and S. Cherepnya and R. Codling and Downie, {E. J.} and K. Foehl and P. Grabmayr and R. Gregor and E. Heid and D. Hornidge and O. Jahn and Kashevarov, {V. L.} and A. Knezevic and R. Kondratiev and M. Korolija and M. Kotulla and D. Krambrich and B. Krusche and M. Lang and V. Lisin and K. Livingston and S. Lugert and MacGregor, {I. J. D.} and Manley, {D. M.} and M. Martinez and McGeorge, {J. C.} and D. Mekterovic and V. Metag and Nefkens, {B. M. K.} and A. Nikolaev and R. Novotny and Owens, {R. O.} and P. Pedroni and A. Polonski and Prakhov, {S. N.} and Price, {J. W.} and G. Rosner and S. Schumann",

note = "4 figures 5 pages",

year = "2014",

month = jun,

day = "18",

doi = "10.1103/PhysRevLett.112.242502",

language = "English",

volume = "112",

journal = "Physical Review Letters",

issn = "0031-9007",

publisher = "American Physical Society",

number = "24",

}

Crystal Ball MAMI A2 Collaboration, Tarbert, CM, Watts, DP, Glazier, DI, Aguar, P, Ahrens, J, Annand, JRM, Arends, HJ, Beck, R, Bekrenev, V, Boillat, B, Braghieri, A, Branford, D, Briscoe, WJ, Brudvik, J, Cherepnya, S, Codling, R, Downie, EJ, Foehl, K, Grabmayr, P, Gregor, R, Heid, E, Hornidge, D, Jahn, O, Kashevarov, VL, Knezevic, A, Kondratiev, R, Korolija, M, Kotulla, M, Krambrich, D, Krusche, B, Lang, M, Lisin, V, Livingston, K, Lugert, S, MacGregor, IJD, Manley, DM, Martinez, M, McGeorge, JC, Mekterovic, D, Metag, V, Nefkens, BMK, Nikolaev, A, Novotny, R, Owens, RO, Pedroni, P, Polonski, A, Prakhov, SN, Price, JW, Rosner, G & Schumann, S 2014, 'The neutron skin of 208Pb from coherent pion photoproduction', Physical Review Letters, vol. 112, no. 24, 242502. https://doi.org/10.1103/PhysRevLett.112.242502

TY - JOUR

T1 - The neutron skin of 208Pb from coherent pion photoproduction

AU - Crystal Ball MAMI A2 Collaboration

AU - Tarbert, C. M.

AU - Watts, D. P.

AU - Glazier, D. I.

AU - Aguar, P.

AU - Ahrens, J.

AU - Annand, J. R. M.

AU - Arends, H. J.

AU - Beck, R.

AU - Bekrenev, V.

AU - Boillat, B.

AU - Braghieri, A.

AU - Branford, D.

AU - Briscoe, W. J.

AU - Brudvik, J.

AU - Cherepnya, S.

AU - Codling, R.

AU - Downie, E. J.

AU - Foehl, K.

AU - Grabmayr, P.

AU - Gregor, R.

AU - Heid, E.

AU - Hornidge, D.

AU - Jahn, O.

AU - Kashevarov, V. L.

AU - Knezevic, A.

AU - Kondratiev, R.

AU - Korolija, M.

AU - Kotulla, M.

AU - Krambrich, D.

AU - Krusche, B.

AU - Lang, M.

AU - Lisin, V.

AU - Livingston, K.

AU - Lugert, S.

AU - MacGregor, I. J. D.

AU - Manley, D. M.

AU - Martinez, M.

AU - McGeorge, J. C.

AU - Mekterovic, D.

AU - Metag, V.

AU - Nefkens, B. M. K.

AU - Nikolaev, A.

AU - Novotny, R.

AU - Owens, R. O.

AU - Pedroni, P.

AU - Polonski, A.

AU - Prakhov, S. N.

AU - Price, J. W.

AU - Rosner, G.

AU - Schumann, S.

N1 - 4 figures 5 pages

PY - 2014/6/18

Y1 - 2014/6/18

N2 - Information on the size and shape of the neutron skin on $^{208}$Pb has been extracted from coherent pion photoproduction cross sections measured using the Crystal Ball together with the Glasgow tagger at the MAMI electron beam facility. Exploiting an interpolated fit of a theoretical model to the measured cross sections the half-height radius and diffuseness of the neutron distribution are found to be 6.77$\pm 0.03(stat)$ fm and 0.55$\pm 0.01(stat)$$^{+0.00}_{-0.025}(sys)$ fm respectively, corresponding to a neutron skin thickness $\Delta r_{np}$=0.19$\pm 0.03(stat)$$^{+0.00}_{-0.03}(sys)$ fm. The results give the first successful extraction of a neutron skin with an electromagnetic probe and indicate the skin of $^{208}$Pb has a halo character. The measurement provides valuable new constraints on both the structure of nuclei and the equation of state for neutron rich matter.

AB - Information on the size and shape of the neutron skin on $^{208}$Pb has been extracted from coherent pion photoproduction cross sections measured using the Crystal Ball together with the Glasgow tagger at the MAMI electron beam facility. Exploiting an interpolated fit of a theoretical model to the measured cross sections the half-height radius and diffuseness of the neutron distribution are found to be 6.77$\pm 0.03(stat)$ fm and 0.55$\pm 0.01(stat)$$^{+0.00}_{-0.025}(sys)$ fm respectively, corresponding to a neutron skin thickness $\Delta r_{np}$=0.19$\pm 0.03(stat)$$^{+0.00}_{-0.03}(sys)$ fm. The results give the first successful extraction of a neutron skin with an electromagnetic probe and indicate the skin of $^{208}$Pb has a halo character. The measurement provides valuable new constraints on both the structure of nuclei and the equation of state for neutron rich matter.

KW - TAGGED PHOTON SPECTROMETER

KW - NUCLEI

KW - RADII

KW - SCATTERING

KW - MICROTRON

KW - EQUATION

KW - MESONS

KW - PI(0)

KW - STARS

KW - STATE

U2 - 10.1103/PhysRevLett.112.242502

DO - 10.1103/PhysRevLett.112.242502

M3 - Article

SN - 0031-9007

VL - 112

JO - Physical Review Letters

JF - Physical Review Letters

IS - 24

M1 - 242502

ER -

The neutron skin of 208Pb from coherent pion photoproduction

Abstract / Description of output

Keywords / Materials (for Non-textual outputs)

Access to Document

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Projects

Illuminating strongly interacting matter

Cite this