DIZET v. 6.45

The Fortran package DIZET, a library for the calculation of electroweak
radiative corrections, is part of the ZFITTER distribution. It can also
be used in a standalone mode.

The homepage of the ZFITTER project and collaboration is 
http://sanc.jinr.ru/users/zfitter/

Implemented in v 6.45 new features are:

IHVP=4  -- Hadronic vacuum polarization using Jegerlehner 2016 public code

IHVP=5  -- Hadronic vacuum polarization using Jegerlehner 2017 public code

For references see
F. Jegerlehner, The Anomalous Magnetic Moment of the Muon, Springer Tracts Mod.
Phys. 274, pp.1 (2017), doi:10.1007/978-3-319-63577-4
http://arxiv.org/abs/1711.06089v1


IAMT4=7  -- Complete two-loop electroweak corrections to sin^2\theta^b_eff
according to I. Dubovyk, A. Freitas, J. Gluza, T. Riemann and J. Usovitsch,  
``The two-loop electroweak bosonic corrections to
$\sin^2\theta^\mbox{b}_\mbox{eff}$,'' Phys. Lett. B 762, 184 (2016),
arXiv:1607.08375 [hep-ph]
and complete two-loop electroweak corrections to sin^2\theta^f_eff according
M. Awramik, M. Czakon and A. Freitas, ``Electroweak two-loop corrections to 
the effective weak mixing angle,'' JHEP 0611, 048 (2006), hep-ph/0608099.


IAMT4=8  -- Two-loop electroweak corrections from
I. Dubovyk, A. Freitas, J. Gluza, T. Riemann and J. Usovitsch, 
``Electroweak pseudo-observables and Z-boson form factors at two-loop accuracy''
JHEP {\bf 1908}, 113 (2019), arXiv:1906.08815 [hep-ph]
In comparison with arXiv:1607.08375 (IAMT4=7), it gives almost the same result
(but the fitting formula works in a larger range of input parameters). 
In comparison with hep-ph/0608099 (IAMT4=7), it includes additonally
alpha_t*alpha_s^3 corrections to the rho parameters.

So, option IAMT4=8 is the preferred one.

Concerning default options of DIZET (except IHVP and IAMT4), it is recommended
to start with the ones suggested in paper
A.B. Arbuzov, M. Awramik, M. Czakon, A. Freitas, M.W. Grünewald, K. Mönig,
S. Riemann, T. Riemann, ZFITTER: a semi-analytical program for fermion pair 
production in e+e− annihilation, from version 6.21 to version 6.42,
Computer Physics Communications, Volume 174, Issue 9, 2006, Pages 728-758 

