Looking up the parameters of a theory
The parameters for all of the theories can be found in the theory_cards folder.
The theory_cards folder is installed together, with the data, as part of the validphys package.
This is an sqlite database file. The information contained within this file can also be
viewed [within the docs](theory-indexes).
The tools required to extract the parameters for a given theory are already in the validphys framework:
from validphys.loader import Loader
l = Loader()
# replace 53 with the relevant theoryID
tinfo = l.check_theoryID(53)
print(tinfo.get_description())
{'ID': 53, 'PTO': 2, 'FNS': 'FONLL-C', 'DAMP': 0, 'IC': 1, 'ModEv': 'TRN',
'XIR': 1.0, 'XIF': 1.0, 'NfFF': 5, 'MaxNfAs': 5, 'MaxNfPdf': 5, 'Q0': 1.65,
'alphas': 0.118, 'Qref': 91.2, 'QED': 0, 'alphaqed': 0.007496252,
'Qedref': 1.777, 'SxRes': 0, 'SxOrd': 'LL', 'HQ': 'POLE', 'mc': 1.51,
'Qmc': 1.51, 'kcThr': 1.0, 'mb': 4.92, 'Qmb': 4.92, 'kbThr': 1.0, 'mt': 172.5,
'Qmt': 172.5, 'ktThr': 1.0, 'CKM': '0.97428 0.22530 0.003470 0.22520 0.97345 0.041000 0.00862 0.04030 0.999152',
'MZ': 91.1876, 'MW': 80.398, 'GF': 1.1663787e-05, 'SIN2TW': 0.23126, 'TMC': 1,
'MP': 0.938, 'Comments': 'NNPDF3.1 NNLO central', 'global_nx': 0, 'EScaleVar': 1}
Given that printing a dictionary in a python terminal is a bit cumbersome, the above
method for checking theory parameters has been added to a command line
script vp-checktheory which essentially does the same thing but prints the
table in a nicer format.
The usage is simple:
$ vp-checktheory 53
Info for theory 53
ID 53
PTO 2
FNS FONLL-C
DAMP 0
IC 1
ModEv TRN
XIR 1
XIF 1
NfFF 5
MaxNfAs 5
MaxNfPdf 5
Q0 1.65
alphas 0.118
Qref 91.2
QED 0
alphaqed 0.00749625
Qedref 1.777
SxRes 0
SxOrd LL
HQ POLE
mc 1.51
Qmc 1.51
kcThr 1
mb 4.92
Qmb 4.92
kbThr 1
mt 172.5
Qmt 172.5
ktThr 1
CKM 0.97428 0.22530 0.003470 0.22520 0.97345 0.041...
MZ 91.1876
MW 80.398
GF 1.16638e-05
SIN2TW 0.23126
TMC 1
MP 0.938
Comments NNPDF3.1 NNLO central
global_nx 0
EScaleVar 1
Some of the entries of the table have been truncated to fit in the terminal, for
example the CKM matrix elements. If you want to see the
full output or wish to keep a permanent copy of the table then you can use the
command line option -d, which stands for --dumptable which will save the
table in your current working directory as theory_<id>_info.csv:
$vp-checktheory --fit FIT
where FIT is a valid fit name. If the fit cannot be found locally, the script
will attempt to download it.
The parameters in the above are defined [here](./theoryparamsdefinitions).