Rescattering Effects in the HadronicLightbyLight Contribution to the Anomalous Magnetic Moment of the Muon
We present a first modelindependent calculation of ππ intermediate states in the hadroniclightbylight (HLBL) contribution to the anomalous magnetic moment of the muon (g  2) _{μ} that goes beyond the scalar QED pion loop. To this end, we combine a recently developed dispersive description of the HLBL tensor with a partialwave expansion and demonstrate that the known scalarQED result is recovered after partialwave resummation. Using dispersive fits to highstatistics data for the pion vector form factor, we provide an evaluation of the full pion box a ^{π} _{μ} ^{box} = –15.9(2) x 10 ^{11}. We then construct a suitable input for the γ*γ* → ππ helicity partial waves, based on a pionpole lefthand cut and show that for the dominant chargedpion contribution, this representation is consistent with the twoloop chiral prediction and the COMPASS measurement for the pion polarizability. This allows us to reliably estimate Swave rescattering effects to the full pion box and leads to our final estimate for the sum of these two contributions a ^{π} _{μ} ^{box} + a ^{ππ,πpole} _{μ,J=0} ^{LHC} = –24(1) x 10 ^{11}.
 Authors:

^{[1]};
^{[2]};
^{[3]};
^{[4]}
 Univ. of Bern (Switzerland). Albert Einstein Center for Fundamental Physics. Inst. for Theoretical Physics
 Univ. of Washington, Seattle, WA (United States). Inst. for Nuclear Theory; Univ. of California, Santa Barbara, CA (United States). Kavli Inst. for Theoretical Physics
 European Organization for Nuclear Research (CERN), Geneva (Switzerland). Theoretical Physics Dept.
 Univ. of Bonn (Germany). Helmholtz Inst. for Radiation and Nuclear Physics. Bethe Center for Theoretical Physics; Univ. of California, San Diego, CA (United States). Dept. of Physics
 Publication Date:
 Grant/Contract Number:
 FG0200ER41132; PHY1125915; SFB/TR 16; SFB/TR 110; P300P2_167751; PIEFGA2013622527
 Type:
 Published Article
 Journal Name:
 Physical Review Letters
 Additional Journal Information:
 Journal Volume: 118; Journal Issue: 23; Journal ID: ISSN 00319007
 Publisher:
 American Physical Society (APS)
 Research Org:
 Univ. of Washington, Seattle, WA (United States); Univ. of Bern (Switzerland); Univ. of Bonn (Germany); European Organization for Nuclear Research (CERN), Geneva (Switzerland)
 Sponsoring Org:
 USDOE Office of Science (SC), Nuclear Physics (NP) (SC26); National Science Foundation (NSF); German Research Foundation (DFG); Swiss National Science Foundation (SNSF); European Union (EU)
 Country of Publication:
 United States
 Language:
 English
 Subject:
 72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS; particle interactions; strong interaction; muons; photons; pions; form factors; gyromagnetic ratio; magnetic moment
 OSTI Identifier:
 1372583
 Alternate Identifier(s):
 OSTI ID: 1429071
Colangelo, Gilberto, Hoferichter, Martin, Procura, Massimiliano, and Stoffer, Peter. Rescattering Effects in the HadronicLightbyLight Contribution to the Anomalous Magnetic Moment of the Muon. United States: N. p.,
Web. doi:10.1103/PhysRevLett.118.232001.
Colangelo, Gilberto, Hoferichter, Martin, Procura, Massimiliano, & Stoffer, Peter. Rescattering Effects in the HadronicLightbyLight Contribution to the Anomalous Magnetic Moment of the Muon. United States. doi:10.1103/PhysRevLett.118.232001.
Colangelo, Gilberto, Hoferichter, Martin, Procura, Massimiliano, and Stoffer, Peter. 2017.
"Rescattering Effects in the HadronicLightbyLight Contribution to the Anomalous Magnetic Moment of the Muon". United States.
doi:10.1103/PhysRevLett.118.232001.
@article{osti_1372583,
title = {Rescattering Effects in the HadronicLightbyLight Contribution to the Anomalous Magnetic Moment of the Muon},
author = {Colangelo, Gilberto and Hoferichter, Martin and Procura, Massimiliano and Stoffer, Peter},
abstractNote = {We present a first modelindependent calculation of ππ intermediate states in the hadroniclightbylight (HLBL) contribution to the anomalous magnetic moment of the muon (g  2)μ that goes beyond the scalar QED pion loop. To this end, we combine a recently developed dispersive description of the HLBL tensor with a partialwave expansion and demonstrate that the known scalarQED result is recovered after partialwave resummation. Using dispersive fits to highstatistics data for the pion vector form factor, we provide an evaluation of the full pion box aπμbox = –15.9(2) x 1011. We then construct a suitable input for the γ*γ* → ππ helicity partial waves, based on a pionpole lefthand cut and show that for the dominant chargedpion contribution, this representation is consistent with the twoloop chiral prediction and the COMPASS measurement for the pion polarizability. This allows us to reliably estimate Swave rescattering effects to the full pion box and leads to our final estimate for the sum of these two contributions aπμbox + aππ,πpoleμ,J=0 LHC = –24(1) x 1011.},
doi = {10.1103/PhysRevLett.118.232001},
journal = {Physical Review Letters},
number = 23,
volume = 118,
place = {United States},
year = {2017},
month = {6}
}