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Complete Measurement of the Λ Electromagnetic Form Factors. / BESIII Collaboration.

In: Physical Review Letters, Vol. 123, No. 12, 122003, 20.09.2019.

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

Harvard

BESIII Collaboration 2019, 'Complete Measurement of the Λ Electromagnetic Form Factors', Physical Review Letters, vol. 123, no. 12, 122003. https://doi.org/10.1103/PhysRevLett.123.122003

APA

BESIII Collaboration (2019). Complete Measurement of the Λ Electromagnetic Form Factors. Physical Review Letters, 123(12), [122003]. https://doi.org/10.1103/PhysRevLett.123.122003

Vancouver

BESIII Collaboration. Complete Measurement of the Λ Electromagnetic Form Factors. Physical Review Letters. 2019 Sept 20;123(12):122003. doi: 10.1103/PhysRevLett.123.122003

Author

BESIII Collaboration. / Complete Measurement of the Λ Electromagnetic Form Factors. In: Physical Review Letters. 2019 ; Vol. 123, No. 12.

BibTeX

@article{a201095cdecf4b299d14e6715c993895,
title = "Complete Measurement of the Λ Electromagnetic Form Factors",
abstract = "The exclusive process e+e-→Λ{\=Λ}, with Λ→pπ- and {\=Λ}→{\=p}π+, has been studied at s=2.396 GeV for measurement of the timelike Λ electric and magnetic form factors, GE and GM. A data sample, corresponding to an integrated luminosity of 66.9 pb-1, was collected with the BESIII detector for this purpose. A multidimensional analysis with a complete decomposition of the spin structure of the reaction enables a determination of the modulus of the ratio R=|GE/GM| and, for the first time for any baryon, the relative phase Δφ=φE-φM. The resulting values are R=0.96±0.14(stat)±0.02(syst) and Δφ=37°±12°(stat)±6°(syst), respectively. These are obtained using the recently established and most precise value of the asymmetry parameter αΛ=0.750±0.010 measured by BESIII. In addition, the cross section is measured with unprecedented precision to be σ=118.7±5.3(stat)±5.1(syst) pb, which corresponds to an effective form factor of |G|=0.123±0.003(stat)±0.003(syst). The contribution from two-photon exchange is found to be negligible. Our result enables the first complete determination of baryon timelike electromagnetic form factors.",
keywords = "OBSERVABLES",
author = "{BESIII Collaboration} and M. Ablikim and Achasov, {M. N.} and P. Adlarson and S. Ahmed and M. Albrecht and M. Alekseev and A. Amoroso and An, {F. F.} and Q. An and Y. Bai and O. Bakina and {Baldini Ferroli}, R. and Y. Ban and K. Begzsuren and Bennett, {J. V.} and N. Berger and M. Bertani and D. Bettoni and F. Bianchi and J. Biernat and J. Bloms and I. Boyko and Briere, {R. A.} and H. Cai and X. Cai and A. Calcaterra and Cao, {G. F.} and N. Cao and Cetin, {S. A.} and J. Chai and Chang, {J. F.} and Chang, {W. L.} and G. Chelkov and Chen, {D. Y.} and G. Chen and Chen, {H. S.} and Chen, {J. C.} and Chen, {M. L.} and Chen, {S. J.} and Chen, {Y. B.} and W. Cheng and G. Cibinetto and F. Cossio and Cui, {X. F.} and Dai, {H. L.} and Dai, {J. P.} and Dai, {X. C.} and A. Dbeyssi and Muchnoi, {N. Yu} and Nikolaev, {I. B.}",
note = "Publisher Copyright: {\textcopyright} 2019 authors. Published by the American Physical Society. Published by the American Physical Society under the terms of the https://creativecommons.org/licenses/by/4.0/ Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article's title, journal citation, and DOI. Funded by SCOAP . Copyright: Copyright 2019 Elsevier B.V., All rights reserved.",
year = "2019",
month = sep,
day = "20",
doi = "10.1103/PhysRevLett.123.122003",
language = "English",
volume = "123",
journal = "Physical Review Letters",
issn = "0031-9007",
publisher = "American Physical Society",
number = "12",

}

RIS

TY - JOUR

T1 - Complete Measurement of the Λ Electromagnetic Form Factors

AU - BESIII Collaboration

AU - Ablikim, M.

AU - Achasov, M. N.

AU - Adlarson, P.

AU - Ahmed, S.

AU - Albrecht, M.

AU - Alekseev, M.

AU - Amoroso, A.

AU - An, F. F.

AU - An, Q.

AU - Bai, Y.

AU - Bakina, O.

AU - Baldini Ferroli, R.

AU - Ban, Y.

AU - Begzsuren, K.

AU - Bennett, J. V.

AU - Berger, N.

AU - Bertani, M.

AU - Bettoni, D.

AU - Bianchi, F.

AU - Biernat, J.

AU - Bloms, J.

AU - Boyko, I.

AU - Briere, R. A.

AU - Cai, H.

AU - Cai, X.

AU - Calcaterra, A.

AU - Cao, G. F.

AU - Cao, N.

AU - Cetin, S. A.

AU - Chai, J.

AU - Chang, J. F.

AU - Chang, W. L.

AU - Chelkov, G.

AU - Chen, D. Y.

AU - Chen, G.

AU - Chen, H. S.

AU - Chen, J. C.

AU - Chen, M. L.

AU - Chen, S. J.

AU - Chen, Y. B.

AU - Cheng, W.

AU - Cibinetto, G.

AU - Cossio, F.

AU - Cui, X. F.

AU - Dai, H. L.

AU - Dai, J. P.

AU - Dai, X. C.

AU - Dbeyssi, A.

AU - Muchnoi, N. Yu

AU - Nikolaev, I. B.

N1 - Publisher Copyright: © 2019 authors. Published by the American Physical Society. Published by the American Physical Society under the terms of the https://creativecommons.org/licenses/by/4.0/ Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article's title, journal citation, and DOI. Funded by SCOAP . Copyright: Copyright 2019 Elsevier B.V., All rights reserved.

PY - 2019/9/20

Y1 - 2019/9/20

N2 - The exclusive process e+e-→ΛΛ̄, with Λ→pπ- and Λ̄→p̄π+, has been studied at s=2.396 GeV for measurement of the timelike Λ electric and magnetic form factors, GE and GM. A data sample, corresponding to an integrated luminosity of 66.9 pb-1, was collected with the BESIII detector for this purpose. A multidimensional analysis with a complete decomposition of the spin structure of the reaction enables a determination of the modulus of the ratio R=|GE/GM| and, for the first time for any baryon, the relative phase Δφ=φE-φM. The resulting values are R=0.96±0.14(stat)±0.02(syst) and Δφ=37°±12°(stat)±6°(syst), respectively. These are obtained using the recently established and most precise value of the asymmetry parameter αΛ=0.750±0.010 measured by BESIII. In addition, the cross section is measured with unprecedented precision to be σ=118.7±5.3(stat)±5.1(syst) pb, which corresponds to an effective form factor of |G|=0.123±0.003(stat)±0.003(syst). The contribution from two-photon exchange is found to be negligible. Our result enables the first complete determination of baryon timelike electromagnetic form factors.

AB - The exclusive process e+e-→ΛΛ̄, with Λ→pπ- and Λ̄→p̄π+, has been studied at s=2.396 GeV for measurement of the timelike Λ electric and magnetic form factors, GE and GM. A data sample, corresponding to an integrated luminosity of 66.9 pb-1, was collected with the BESIII detector for this purpose. A multidimensional analysis with a complete decomposition of the spin structure of the reaction enables a determination of the modulus of the ratio R=|GE/GM| and, for the first time for any baryon, the relative phase Δφ=φE-φM. The resulting values are R=0.96±0.14(stat)±0.02(syst) and Δφ=37°±12°(stat)±6°(syst), respectively. These are obtained using the recently established and most precise value of the asymmetry parameter αΛ=0.750±0.010 measured by BESIII. In addition, the cross section is measured with unprecedented precision to be σ=118.7±5.3(stat)±5.1(syst) pb, which corresponds to an effective form factor of |G|=0.123±0.003(stat)±0.003(syst). The contribution from two-photon exchange is found to be negligible. Our result enables the first complete determination of baryon timelike electromagnetic form factors.

KW - OBSERVABLES

UR - http://www.scopus.com/inward/record.url?scp=85072785332&partnerID=8YFLogxK

U2 - 10.1103/PhysRevLett.123.122003

DO - 10.1103/PhysRevLett.123.122003

M3 - Article

C2 - 31633986

AN - SCOPUS:85072785332

VL - 123

JO - Physical Review Letters

JF - Physical Review Letters

SN - 0031-9007

IS - 12

M1 - 122003

ER -

ID: 23380033