Current-current operator contribution to the decay matrix in $B$-meson mixing at next-to-next-to-leading order of QCD
Fuente:
arXiv
Enregistré dans:
| Auteurs principaux: | , , , , |
|---|---|
| Format: | Preprint |
| Publié: |
2025
|
| Sujets: | |
| Accès en ligne: | |
| Tags: |
Ajouter un tag
Pas de tags, Soyez le premier à ajouter un tag!
|
| _version_ | 1866918037579366400 |
|---|---|
| author | Gerlach, Marvin Nierste, Ulrich Reeck, Pascal Shtabovenko, Vladyslav Steinhauser, Matthias |
| author_facet | Gerlach, Marvin Nierste, Ulrich Reeck, Pascal Shtabovenko, Vladyslav Steinhauser, Matthias |
| contents | We compute next-to-next-to-leading order perturbative corrections to the decay width difference of mass eigenstates and the charge-parity asymmetry $a_{\rm fs}$ in flavour-specific decays of neutral $B$ mesons. In our calculation we take into account the full dependence on the charm and bottom quark masses for the current-current operator contributions up to three-loop order. Special emphasis is put on the proper construction of the so-called $|ΔB|=2$ theory such that Fierz symmetry is preserved. We provide updated phenomenological predictions, for $ΔΓ$, $ΔΓ/ΔM$ and $a_{\rm fs}$ for the $B_d$ and $B_s$ system, including a detailed analysis of the uncertainties of our predictions. The calculated NNLO correction reduce the perturbative uncertainty of the leading term of the $1/m_b$ expansion of the width difference $\dg_s$ in the $B_s$ system to the level of the current experimental error. The uncertainty of our prediction $\dg_s=({0.077}\pm 0.016)\,\mbox{ps}^{-1}$ is dominated by the sub-leading term of this expansion. We further illustrate how better future measurements of $\dg_d$ and $a_{\rm fs}^d$ will help to gain a better understanding of $B_d$-$\bar B_d$ mixing. |
| format | Preprint |
| id |
arxiv_https___arxiv_org_abs_2505_22740 |
| institution | arXiv |
| publishDate | 2025 |
| record_format | arxiv |
| spellingShingle | Current-current operator contribution to the decay matrix in $B$-meson mixing at next-to-next-to-leading order of QCD Gerlach, Marvin Nierste, Ulrich Reeck, Pascal Shtabovenko, Vladyslav Steinhauser, Matthias High Energy Physics - Phenomenology We compute next-to-next-to-leading order perturbative corrections to the decay width difference of mass eigenstates and the charge-parity asymmetry $a_{\rm fs}$ in flavour-specific decays of neutral $B$ mesons. In our calculation we take into account the full dependence on the charm and bottom quark masses for the current-current operator contributions up to three-loop order. Special emphasis is put on the proper construction of the so-called $|ΔB|=2$ theory such that Fierz symmetry is preserved. We provide updated phenomenological predictions, for $ΔΓ$, $ΔΓ/ΔM$ and $a_{\rm fs}$ for the $B_d$ and $B_s$ system, including a detailed analysis of the uncertainties of our predictions. The calculated NNLO correction reduce the perturbative uncertainty of the leading term of the $1/m_b$ expansion of the width difference $\dg_s$ in the $B_s$ system to the level of the current experimental error. The uncertainty of our prediction $\dg_s=({0.077}\pm 0.016)\,\mbox{ps}^{-1}$ is dominated by the sub-leading term of this expansion. We further illustrate how better future measurements of $\dg_d$ and $a_{\rm fs}^d$ will help to gain a better understanding of $B_d$-$\bar B_d$ mixing. |
| title | Current-current operator contribution to the decay matrix in $B$-meson mixing at next-to-next-to-leading order of QCD |
| topic | High Energy Physics - Phenomenology |
| url | https://arxiv.org/abs/2505.22740 |