On the smallness of charm loop effects in $B\to K^{(*)} \ell\ell$ at low $q^2$: light meson Distribution Amplitude analysis
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arXiv
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| Autori principali: | , |
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| Natura: | Preprint |
| Pubblicazione: |
2024
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| _version_ | 1866910585957908480 |
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| author | Mahajan, Namit Mishra, Dayanand |
| author_facet | Mahajan, Namit Mishra, Dayanand |
| contents | The non-local effects originating from the charm quark loops at dilepton invariant masses smaller than the charmonium threshold in $B\to K \ell\ell$ are evaluated with light meson distribution amplitudes. The revised estimates with B-meson distribution amplitude within a Light Cone Sum Rule approach yielded results about three orders smaller than the original computation. In view of the importance of these non-factorizable soft gluon effects, both conceptually and phenomenologically, an independent evaluation is necessary. It is found that to twist-4 accuracy, these soft gluon effects vanish when evaluated employing the kaon distribution amplitude. Similar results hold for $B\to K^* \ell\ell$ to the leading twist. This eliminates one of the major sources of potential uncertainty which usually makes it difficult for a clear case of new physics, should the data show deviations from the standard model. |
| format | Preprint |
| id |
arxiv_https___arxiv_org_abs_2409_00181 |
| institution | arXiv |
| publishDate | 2024 |
| record_format | arxiv |
| spellingShingle | On the smallness of charm loop effects in $B\to K^{(*)} \ell\ell$ at low $q^2$: light meson Distribution Amplitude analysis Mahajan, Namit Mishra, Dayanand High Energy Physics - Phenomenology The non-local effects originating from the charm quark loops at dilepton invariant masses smaller than the charmonium threshold in $B\to K \ell\ell$ are evaluated with light meson distribution amplitudes. The revised estimates with B-meson distribution amplitude within a Light Cone Sum Rule approach yielded results about three orders smaller than the original computation. In view of the importance of these non-factorizable soft gluon effects, both conceptually and phenomenologically, an independent evaluation is necessary. It is found that to twist-4 accuracy, these soft gluon effects vanish when evaluated employing the kaon distribution amplitude. Similar results hold for $B\to K^* \ell\ell$ to the leading twist. This eliminates one of the major sources of potential uncertainty which usually makes it difficult for a clear case of new physics, should the data show deviations from the standard model. |
| title | On the smallness of charm loop effects in $B\to K^{(*)} \ell\ell$ at low $q^2$: light meson Distribution Amplitude analysis |
| topic | High Energy Physics - Phenomenology |
| url | https://arxiv.org/abs/2409.00181 |