2024-03-28T21:39:40Z
https://nagoya.repo.nii.ac.jp/oai
oai:nagoya.repo.nii.ac.jp:00004825
2023-01-16T03:49:27Z
336:635:636
Belle実験におけるタウレプトンの電気双極子モーメントの精密測定
Precise measurement of the electric dipole moment of the τ lepton at Belle
Inami, Kenji
12061
居波, 賢二
12062
名古屋大学
Nagoya University
博士(理学)
To search for CP-violation(CPV)signatures in the lepton sector, an electric dipole moment, dr, of the τ lepton was measured using the e+e-→τ+τ-reaction collected with the Belle detector at the KEKB collider at s=10.58GeV. This is a good probe of new physics beyond the Standard Model (SM), since such physics produce the CPV in the lepton sector, though the SM does not predict any appreciable effect, and such effect is expected to be enhanced for t leptons due to their large mass. An optimal observable method was adopted to extract, dr, which uses all experimentally available information of the spin and momenta of the τdecays, and maximizes the sensitivity to dr. By extracting the conversion parameters from the observables to dr using a full Monte Carlo simulation with the electric dipole moment effect, the systematic uncertainties arising from the detector acceptance effect were successfully suppressed. All of the results are consistent with zero-EDM within the errors. Using 29.5fb-1data, which correspond to 26.8 million generated τ-pair events, the following result was obtained:and the 95% confidence level limits was set to be This investigation has successfully improved the sensitivity to the τlepton's electric dipole moment by an order of magnitude over previous measurements.It is not only due to a 100 times larger statistics but also due to well-controlled systematic uncertainties.
名古屋大学博士学位論文 学位の種類:博士(理学) (課程) 学位授与年月日:平成15年3月25日
doctoral thesis
2003-03-25
application/pdf
甲第5777号
http://hdl.handle.net/2237/6360
https://nagoya.repo.nii.ac.jp/record/4825/files/ko5777.pdf
eng