Amplitude
is a database of Feynman amplitudes. Amplitude["name"]
returns the amplitude corresponding to the string "name"
. A list of all defined names is obtained with Amplitude[]
. New amplitudes can be added to the file "Amplitude.m"
. It is strongly recommended to use names that reflect the process.
The option Gauge -> 1
means `t Hooft Feynman gauge;
Polarization -> 0
gives unpolarized OPE-type amplitudes, Polarization -> 1
the polarized ones.
[] // Length Amplitude
98
This is the amplitude of a gluon self-energy diagram:
["se1g1"]
Amplitude
[%]
Explicit
\text{SUNDeltaContract}\left(f^{\text{FCGV}(\text{a})\text{FCGV}(\text{c})\text{FCGV}(\text{e})} f^{\text{FCGV}(\text{b})\text{FCGV}(\text{d})\text{FCGV}(\text{f})} \Pi _{\text{FCGV}(\text{e})\text{FCGV}(\text{f})}^{\text{FCGV}(\beta )\text{FCGV}(\sigma )}(\text{FCGV}(\text{q})) V^{\text{FCGV}(\mu )\text{FCGV}(\alpha )\text{FCGV}(\beta )}(\text{FCGV}(\text{p})\text{, }\;\text{FCGV}(\text{q})-\text{FCGV}(\text{p})\text{, }-\text{FCGV}(\text{q})) V^{\text{FCGV}(\nu )\text{FCGV}(\rho )\text{FCGV}(\sigma )}(-\text{FCGV}(\text{p})\text{, }\;\text{FCGV}(\text{p})-\text{FCGV}(\text{q})\text{, }\;\text{FCGV}(\text{q})) \Pi _{\text{FCGV}(\text{c})\text{FCGV}(\text{d})}^{\text{FCGV}(\alpha )\text{FCGV}(\rho )}(\text{FCGV}(\text{p})-\text{FCGV}(\text{q}))\right)
-\frac{1}{\text{FCGV}(\text{q})^2 (\text{FCGV}(\text{p})-\text{FCGV}(\text{q}))^2}g_s^2 g^{\text{FCGV}(\alpha )\text{FCGV}(\rho )} g^{\text{FCGV}(\beta )\text{FCGV}(\sigma )} f^{\text{FCGV}(\text{a})\text{FCGV}(\text{d})\text{FCGV}(\text{f})} f^{\text{FCGV}(\text{b})\text{FCGV}(\text{d})\text{FCGV}(\text{f})} \left(g^{\text{FCGV}(\beta )\text{FCGV}(\mu )} \left(-\text{FCGV}(\text{p})^{\text{FCGV}(\alpha )}-\text{FCGV}(\text{q})^{\text{FCGV}(\alpha )}\right)+g^{\text{FCGV}(\alpha )\text{FCGV}(\mu )} \left(2 \;\text{FCGV}(\text{p})^{\text{FCGV}(\beta )}-\text{FCGV}(\text{q})^{\text{FCGV}(\beta )}\right)+g^{\text{FCGV}(\alpha )\text{FCGV}(\beta )} \left(2 \;\text{FCGV}(\text{q})^{\text{FCGV}(\mu )}-\text{FCGV}(\text{p})^{\text{FCGV}(\mu )}\right)\right) \left(g^{\text{FCGV}(\rho )\text{FCGV}(\sigma )} \left(\text{FCGV}(\text{p})^{\text{FCGV}(\nu )}-2 \;\text{FCGV}(\text{q})^{\text{FCGV}(\nu )}\right)+g^{\text{FCGV}(\nu )\text{FCGV}(\sigma )} \left(\text{FCGV}(\text{p})^{\text{FCGV}(\rho )}+\text{FCGV}(\text{q})^{\text{FCGV}(\rho )}\right)+g^{\text{FCGV}(\nu )\text{FCGV}(\rho )} \left(\text{FCGV}(\text{q})^{\text{FCGV}(\sigma )}-2 \;\text{FCGV}(\text{p})^{\text{FCGV}(\sigma )}\right)\right)