First lattice calculation of the QED corrections to leptonic decay rates
| Autor: | Giusti, D., Lubicz, V., Martinelli, G., Sachrajda, C. T., Sanfilippo, F., Simula, S., Tantalo, N., Tarantino, C. |
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| Rok vydání: | 2017 |
| Předmět: | |
| Zdroj: | Phys. Rev. Lett. 120, 072001 (2018) |
| Druh dokumentu: | Working Paper |
| DOI: | 10.1103/PhysRevLett.120.072001 |
| Popis: | The leading-order electromagnetic and strong isospin-breaking corrections to the ratio of $K_{\mu 2}$ and $\pi_{\mu 2}$ decay rates are evaluated for the first time on the lattice, following a method recently proposed. The lattice results are obtained using the gauge ensembles produced by the European Twisted Mass Collaboration with $N_f = 2 + 1 + 1$ dynamical quarks. Systematics effects are evaluated and the impact of the quenched QED approximation is estimated. Our result for the correction to the tree-level $K_{\mu 2} / \pi_{\mu 2}$ decay ratio is $-1.22\,(16) \%$ to be compared to the estimate $-1.12\,(21) \%$ based on Chiral Perturbation Theory and adopted by the Particle Data Group. Comment: 5 pages, 6 figures; extended supplemental material with 1 table and 1 figure, results unchanged |
| Databáze: | arXiv |
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