TY - GEN
T1 - Precise measurement of hyperfine splitting of positronium using the Zeeman effect
AU - Ishida, Akira
AU - Akimoto, Ginga
AU - Sasaki, Yuichi
AU - Suehara, Taikan
AU - Namba, Toshio
AU - Asai, Shoji
AU - Kobayashi, Tomio
AU - Saito, Haruo
AU - Yoshida, Mitsuhiro
AU - Tanaka, Kenichi
AU - Yamamoto, Akira
PY - 2011
Y1 - 2011
N2 - The ground state hyperfine splitting of positronium, ΔHFS, is sensitive to high order corrections of QED. A new calculation up to O(α 3 lnα ) has revealed a 3.9 σ discrepancy between the QED prediction and the experimental results. This discrepancy might either be due to systematic problems in the previous experiments or to contributions beyond the Standard Model. We propose an experiment to measure ΔHFS employing new methods designed to remedy the possible systematic errors which may have affected the previous experiments. Our experiment will provide an independent check of the discrepancy. The prototype run has been performed and a result of ΔHFS = 203.3804 ± 0.0022 (stat., 11 ppm) ± 0.0081 (sys., 40 ppm) GHz has been obtained. Compensation magnets to obtain O(ppm) magnetic field uniformity has been developed. The final run will start soon and a measurement with a precision of O(ppm) is expected within a few years.
AB - The ground state hyperfine splitting of positronium, ΔHFS, is sensitive to high order corrections of QED. A new calculation up to O(α 3 lnα ) has revealed a 3.9 σ discrepancy between the QED prediction and the experimental results. This discrepancy might either be due to systematic problems in the previous experiments or to contributions beyond the Standard Model. We propose an experiment to measure ΔHFS employing new methods designed to remedy the possible systematic errors which may have affected the previous experiments. Our experiment will provide an independent check of the discrepancy. The prototype run has been performed and a result of ΔHFS = 203.3804 ± 0.0022 (stat., 11 ppm) ± 0.0081 (sys., 40 ppm) GHz has been obtained. Compensation magnets to obtain O(ppm) magnetic field uniformity has been developed. The final run will start soon and a measurement with a precision of O(ppm) is expected within a few years.
KW - Hyperfine splitting (HFS)
KW - Positronium
KW - Quantum electrodynamics (QED)
UR - http://www.scopus.com/inward/record.url?scp=79951835641&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=79951835641&partnerID=8YFLogxK
U2 - 10.4028/www.scientific.net/MSF.666.129
DO - 10.4028/www.scientific.net/MSF.666.129
M3 - Conference contribution
AN - SCOPUS:79951835641
SN - 9780878492084
T3 - Materials Science Forum
SP - 129
EP - 132
BT - Progress in Positron Annihilation
PB - Trans Tech Publications Ltd
ER -