Skip to content

Latest commit

 

History

History
33 lines (31 loc) · 2.73 KB

File metadata and controls

33 lines (31 loc) · 2.73 KB

Objects in C++

Object Example Description
Symbol Symbol("s") a real variable s.
Index Index("mu",Type::VD) a Lorentz index mu with dimension d.
Index("mu",Type::CA) a color index a with dimension NA.
Index("mu",Type::CF) a color index i with dimension NF.
Vector Vector("p") a vector/momentum p.
Pair Pair(mu,nu) a Kronecker delta $$\delta_{\mu\nu}$$ with Index mu and nu.
Pair(p,mu) a Vector p with Lorentz Index mu, $$p^\mu$$, p.mu.
Pair(p,q) a scalar product $$p\cdot q$$ between Vector p and q.
SUNT SUNT(a,i,j) a T-matrix element $$T^a_{ij}$$ for SU(N) group.
SUNT(lst{a,b,c},i,j) a matrix element of a product of T, $$(T^aT^bT^c)_{ij}$$.
SUNF SUNF(a,b,c) a structure constant $$f^{abc}$$ of SU(N) group.
SUNF4 SUNF4(a,b,c,d) a contract of two SUNF, $$f^{abe} f^{ecd}$$.
Eps Eps(mu1,mu2,mu3,mu4) a Levi-Civita tensor $$\varepsilon_{\mu_1\mu_2\mu_3\mu_4}$$.
Eps(p1,p2,mu1,mu2) a partially contracted Levi-Civita tensor $$\varepsilon_{p_1p_2\mu_1\mu_2}$$.
Eps(p1,p2,p3,p4) a fully contracted Levi-Civita tensor $$\varepsilon_{p_1p_2p_3p_4}$$.
DGamma DGamma(mu,l) a Dirac-$$\gamma$$ matrix $$\gamma_\mu$$ for a fermion line l.
DGamma(p,l) a Dirac slash $$p!!!/=p^\mu\gamma_\nu$$ for a fermion line l.
DGamma(1/5/6/7,l) a unit matrix, $$\gamma_5$$, $$\gamma_6$$, $$\gamma_7$$ for a fermion line l.
SP SP(mu,nu) evaluated to $$\delta_{\mu\nu}$$.
SP(p+s*q,mu) evaluated to $$p^\mu+sq^\mu$$.
SP(2*p+q,p+s*q) evaluated to $$2p^2+(2s+1)p\cdot q+sq^2$$.
GAS GAS(mu) evaluated to $$\gamma_\mu$$.
GAS(3*p+s*q) evaluated to $$3p!!!/+sq!!!/$$.
GAS(1/5/6/7) evaluated to a unit matrix, $$\gamma_5$$, $$\gamma_6$$, $$\gamma_7$$, respectively.
LC LC(p,mu,p+s*q,k) evaluated to $$s\varepsilon_{kph\mu}$$.
TR TR(expr) a wrapper for the Dirac trace of expression expr.
TTR TTR(lst{a,b,c,d}) a wraaper for the SU(N) trace of $$T^aT^bT^cT^d$$.
form form(expr) evaluate the expression expr using FORM program.