| Full text | |
| Author(s): |
Boito, Diogo
;
Golterman, Maarten
;
Maltman, Kim
;
Peris, Santiago
;
Rodrigues, Marcus, V
;
Schaaf, Wilder
Total Authors: 6
|
| Document type: | Journal article |
| Source: | PHYSICAL REVIEW D; v. 103, n. 3, p. 24-pg., 2021-02-26. |
| Abstract | |
We combine ALEPH and OPAL results for the spectral distributions measured in tau -> pi(-) pi(0)nu(tau), tau -> 2 pi(-) pi(+) pi(0)nu(tau) and tau -> pi(-) 3 pi(0)nu(tau) decays with (i) recent BABAR results for the analogous tau -> K- K-0 nu(tau) distribution and (ii) estimates of the contributions from other hadronic tau-decay modes obtained using CVC and electroproduction data, to obtain a new and more precise nonstrange, inclusive vector, isovector spectral function. The BABAR K- K-0 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 alpha(s)(m(tau)), the strong coupling at the tau mass scale, employing finite energy sum rules. Using the fixed-order perturbation theory (FOPT) prescription, we find alpha(s)(m(tau)) = 0.3077 +/- 0.0075, which corresponds to the five-flavor result alpha(s)(M-Z) = 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 alpha(s) determinations employing the (MS) over bar 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 2 pi and 4 pi modes would allow for further improvements to the current analysis. (AU) | |
| FAPESP's process: | 15/20689-9 - Precise determination of fundamental QCD parameters |
| Grantee: | Diogo Rodrigues Boito |
| Support Opportunities: | Research Grants - Young Investigators Grants |
| FAPESP's process: | 19/16957-9 - Precise determination of the C quark mass |
| Grantee: | Marcus Vinícius Gonzalez Rodrigues |
| Support Opportunities: | Scholarships in Brazil - Master |