Flavio

New observables
- A large number of observables (decay widths and angular observables) of the decay Λ_b→Λ(1520)ll has been added, including two different form factor implementations (thanks to Felicia56)

Measurements
- The `LHCb B->ee 2020` measurement has been implemented using the Gaussian uncertainties provided in the LHCb paper instead of upper bounds, which allows it to be used in a `FastLikelihood` (thanks to alekssmolkovic)

Bug fixes
- In the computation of epsilon_K, an issue with the renormalization scales of quark masses has been resolved (thanks to MJKirk)
- An issue with labels in contour plots when using a `matplotlib` version >= 3.5.0 has been fixed (thanks to MJKirk)
- The complex phase in the CKM dependence of the K→πνν amplitude has been fixed
- Deprications in numpy that expired in numpy 1.23 and 1.24 have been fixed

This minor release adds the recent LHCb measurements of R(KS) and R(K*+) from [arXiv:2110.09501](https://arxiv.org/abs/2110.09501) (thanks to nsahoo).

This is a bug fix release that makes `flavio` compatible with the interface of `particle` v0.20.0.

This minor release adds the recent LHCb measurements of the B_s→φμμ angular observables FL, S3, S4, and S7 from [arXiv:2107.13428](https://arxiv.org/abs/2107.13428).

This release adds many new measurements and fixes several bugs.
New and updated measurements
- The new LHCb measurement of BR(Bs->mumu), `LHCb Bs->mumu 2021` and a combination with ATLAS and CMS data, `AS combination Bs->mumu 2021`
- The Bs->mumu effective lifetime measured by LHCb in 2017 and 2021 and by CMS in 2019
- The new LHCb measurement of RK, `LHCb RK 2021`
- The 2021 muon g-2 measurement by the "Muon g-2" experiment
- The 2021 BR(Bs->phimumu) measurement by LHCb
- Small typos have been fixed in `LHCb B+->Kmumu BR 2014` and `CDF B+>Kmumu 2012` (thanks jafuen for finding them)
- `LHCb KS->mumu 2019` has been updated to the published version (thanks to hoodyn)
- `LHCb B->ee 2020` has been added (thanks to hoodyn)
New observables
- The B0->K\*mumu - B0->K*ee LFU difference `D_AFB`
Bug fixes
- A wrong sign in the B->D(*) form factor correlation matrix that led to too large uncertainties has been fixed (thanks to Jorge-Alda)
- The subleading contributions to B->Vll at high q^2 had not been added correctly (thanks to langenbruch or fixing this)
- A wrong factor of 1/2 has been removed from the scalar Wilson coefficients used in semi-leptonic tree-level decays (thanks to whereforebound)

New features
- The new `flavio.citations` module provides a bibliography of theory papers (thanks to MJKirk)
- At the end of a flavio computation, the theory papers on which the computation is based can be obtained from `flavio.citations.set` in terms of a set of INSPIRE citation keys. The bibliography can be reset by calling `flavio.citations.reset()`.
- The new `theory_citations()` method of the `Observable` class returns the theory papers on which the prediction of a given observable is based.

New observable
- The ratio of the branching ratio of B⁰→K*γ and the time-integrated branching ratio of B_s →φγ, `BR(B0->K*gamma)/BR(Bs->phigamma)` (thanks to MartinoBorsato for the suggestion)

New measurements
- The B⁺→K*μμ angular observables by LHCb
- The combination of B_s→μμ by ATLAS, CMS, and LHCb
- Some LEP measurement (thanks to MJKirk)
- Some LHCb and ATLAS measurements (thanks to olcyr)

Bug fixes
- Some bugs in the implementation of mu-e conversion have been fixed (thanks to xmarcano for reporting the issue)
- A problem with the PyYAML loader `SafeIncludeLoader` on some Windows systems has been fixed

Other improvements
- flavio now supports Python 3.9
- The PyYAML loader `SafeIncludeLoader` now supports absolute file paths in the `!include` and `!include_merge_list` constructors
- The config files have been updated to avoid matplotlib deprecation warnings (thanks to MJKirk)
- The interface to iminuit has been upgraded to use iminuit v2.x

End of support for Python 3.5
This release requires at least Python 3.6. Python 3.5 has reached [end-of-life](https://devguide.python.org/devcycle/#end-of-life-branches) on 30 September 2020. If you are on an outdated system and cannot update Python, have a look at [conda](https://docs.conda.io/). It allows you to install the newest version of Python in a virtual environment without root privileges. Conda is also the best choice if you are on Windows.