arXiv subjects

T. Kinoshita

Publications and source records attributed to T. Kinoshita.

45 records · Page 3Linked to original sources

arXiv1999

Sixth-Order Vacuum-Polarization Contribution to the Lamb Shift of the Muonic Hydrogen

The sixth-order electron-loop vacuum-polarization contribution to the $2P_{1/2} - 2S_{1/2}$ Lamb shift of the muonic hydrogen ($μ^{-} p^+$ bound state) has been evaluated numerically. Our result is 0.007608(1) meV. This eliminates the largest uncertainty in the theoretical calculation. Combined with the proposed precision measurement of the Lamb shift it will lead to a very precise determination of the proton charge radius.

hep-ph↗

arXiv1998

NRQED Approach to the Hyperfine Structure of the Muonium Ground State

The method of NRQED is an adaptation of QED to bound systems. While it is fully equivalent to QED, it enables us to explore the QED bound states systematically as an expansion in the fine structure constant $α$ and velocity ($\sim Zα$) of the bound electron. I describe how to construct the NRQED Hamiltonian choosing recent works on the $α(Zα)$, $α^2 (Zα)$,$α(Zα)^2$, $α(Zα)^3$, and $α^2 (Zα)^2$ radiative corrections to the hyperfine structure of the muonium ground state as examples.

hep-ph↗

arXiv1997

Pseudoscalar pole terms in the hadronic light-by-light scattering contribution to muon $ g - 2 $

The pseudoscalar pole contribution is the dominant source of the $ {\cal O}(α^3) $ hadronic light-by-light scattering effect in muon $g - 2$. We have examined this contribution taking account of the off-shell structure of the pseudoscalar-photon-photon anomaly vertex deduced from available experimental data. Our work leads to an improved estimate, $ -79.2 (15.4) \times 10^{-11}$, for the total hadronic light-by-light scattering contribution to the muon $g - 2$.

hep-ph↗

arXiv1997

Radiative Corrections to the Muonium Hyperfine Structure. II. The $α(Zα)^2 $ Correction

This is the second of a series of papers on the radiative corrections of order $α^2 (Zα)$, $α(Zα)^2$, and various logarithmic terms of order $α^4$, to the hyperfine structure of the muonium ground state. This paper deals with the $α(Zα)^2$ correction. Based on the NRQED bound state theory, we isolated the term of order $α(Zα)^2$ exactly. Our result $+16.904 2 (11) α(Zα)^2 E_F / π$ for the non-logarithmic part is consistent with the $α(Zα)^2$ part of Sapirstein's calculation and the recent result of Pachucki, and reduces the numerical uncertainty in the $α(Zα)^2$ term by two orders of magnitude.

hep-ph↗

arXiv1996

Magnetoresistance and magnetic breakdown in the quasi-two-dimensional conductors (BEDT-TTF)$_2$MHg(SCN)$_4$[M=K,Rb,Tl]

The magnetic field dependence of the resistance of (BEDT-TTF)$_2$MHg(SCN)$_4$[M=K,Rb,Tl] in the density-wave phase is explained in terms of a simple model involving magnetic breakdown and a reconstructed Fermi surface. The theory is compared to measurements in pulsed magnetic fields up to 51 T. The value implied for the scattering time is consistent with independent determinations. The energy gap associated with the density-wave phase is deduced from the magnetic breakdown field. Our results have important implications for the phase diagram.

cond-mat↗

arXiv1996

Radiative Corrections to the Muonium Hyperfine Structure. I. The $α^2 (Zα)$ Correction

This is the first of a series of papers on a systematic application of the NRQED bound state theory of Caswell and Lepage to higher-order radiative corrections to the hyperfine structure of the muonium ground state. This paper describes the calculation of the $α^2 (Zα)$ radiative correction. Our result for the complete $α^2 (Zα)$ correction is 0.424(4) kHz, which reduces the theoretical uncertainty significantly. The remaining uncertainty is dominated by that of the numerical evaluation of the nonlogarithmic part of the $α(Zα)^2$ term and logarithmic terms of order $α^4$.

hep-ph↗

arXiv1996

Hadronic Light-by-light Scattering Contribution to Muon $ g - 2 $

The hadronic light-by-light scattering contribution to muon $g-2$ is examined based on the low energy effective theories of QCD, the Nambu-Jona-Lasinio model and hidden local symmetry approach, supplemented by a general information concerning the asymptotic behavior of QCD. Our result is $- 52 \times 10^{-11}$ with an uncertainty of $\pm 18 \times 10^{-11}$, which includes our best estimate of model dependence. This is within the expected measurement uncertainty of $40\times 10^{-11}$ in the forthcoming experiment at Brookhaven National Laboratory. Our result removes one of the main theoretical obstacles in verifying the existence of the weak contribution to the muon $g-2$.

hep-ph↗

arXiv1995

Hadronic Light-by-light Scattering Effect on Muon g-2

The hadronic light-by-light scattering contribution to muon $g-2$ is examined using low energy effective theories of QCD, the Nambu-Jona-Lasinio model and hidden local chiral symmetry, as guides. Our result is $- 36 \times 10^{-11}$ with an uncertainty of $\pm 16 \times 10^{-11}$, which includes our best estimate of model dependence. This is within the expected measurement uncertainty of $40\times 10^{-11}$ in the forthcoming experiment at Brookhaven National Laboratory. Our result removes one of the main theoretical obstacles in verifying the existence of the weak contribution to the muon $g-2$.

hep-ph↗

arXiv1994

Improved Theory of the Muonium Hyperfine Structure

Terms contributing to the hyperfine structure of the muonium ground state at the level of few tenths of kHz have been evaluated. The $α^2 (Zα)$ radiative correction has been calculated numerically to the precision of 0.02 kHz. Leading $\ln (Zα)$ terms of order $α^{4-n} (Zα)^n , n=1,2,3,$ and some relativistic corrections have been evaluated analytically. The theoretical uncertainty is now reduced to 0.17 kHz. At present, however, it is not possible to test QED to this precision because of the 1.34 kHz uncertainty due to the muon mass.

hep-ph↗