Strong coupling from an improved t vector isovector spectral function.
BOITO, Diogo Rodrigues; GOLTERMAN, Maarten; MALTMAN, Kim; PERIS, Santiago; RODRIGUES, Marcus Vinícius Gonzalez; SCHAAF, Wilder.
BOITO, Diogo Rodrigues; GOLTERMAN, Maarten; MALTMAN, Kim; PERIS, Santiago; RODRIGUES, Marcus Vinícius Gonzalez; SCHAAF, Wilder.
Abstract: We combine ALEPH and OPAL results for the spectral distributions measured in t ? p-p0?t, t ? 2p-pþp0?t and t ? p-3p0?t decays with (i) recent BABAR results for the analogous t ? K-K0?t distribution and (ii) estimates of the contributions from other hadronic t-decay modes obtained using CVC and electroproduction data, to obtain a new and more precise nonstrange, inclusive vector, isovector spectral function. The BABAR K-K0 and CVC/electroproduction results provide us with alternate, entirely data-based input for the contributions of all exclusive modes for which ALEPH and OPAL employed Monte-Carlo-based estimates. We use the resulting spectral function to determine asðmtÞ, the strong coupling at the t mass scale, employing finite energy sum rules. Using the fixed-order perturbation theory (FOPT) prescription, we find asðmtÞ ¼ 0.3077 0.0075, which corresponds to the five-flavor result asðMZÞ ¼ 0.1171 0.0010 at the Z mass. While we also provide an estimate using contour-improved perturbation theory (CIPT), we point out that the FOPT prescription is to be preferred for comparison with other as determinations employing the MS scheme, especially given the inconsistency between CIPT and the standard operator product expansion recently pointed out in the literature. Additional experimental input on the dominant 2p and 4p modes would allow for further improvements to the current analysis.
@article={003024649,author = {BOITO, Diogo Rodrigues; GOLTERMAN, Maarten; MALTMAN, Kim; PERIS, Santiago; RODRIGUES, Marcus Vinícius Gonzalez; SCHAAF, Wilder.},title={Strong coupling from an improved t vector isovector spectral function},journal={Physical Review D},note={v. 103, n. 3, p. 034028-1-034028-24},year={2021}}