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- Schoonschip manual examples.
- *end
-
- C Example 1
-
- Z XX = (a + b)^2
-
- *begin
-
- B a
-
- Z XX= (a + b)^2
-
- *end
-
- C Example 2.
-
- P output !Only the first two characters of 'output' are significant.
-
- Digits 3
- Rationalization 3 ! 0 leads to no rationalization attempt.
-
- Z XX=3.14 + 1/3*a1 + 7.1357689E20*a2 !E20 or E+20 implies 10^20.
-
- *yep
-
- Digits !This restores to the default option, 5 digits.
- Rationalization !Default: 22 digits, with check.
-
- *end
-
- C Example 3.
-
- BLOCK text{xx,yy}
- C This argument is substituted in a call: 'xx'.
- This not: xx.
- Arguments can be glued together: 'xx''yy'.
- ENDBLOCK
-
- BLOCK lines{A,B}
- 'A'C line 1
- 'A' line 2
- 'B' line 3
- ENDBLOCK
-
- C Calling block text:
-
- text{yes,sir}
-
- DELETE text
-
- C Calling lines twice:
-
- lines{,~}
- lines{~,}
-
- DO var=1,3,2
- P input !Normally only the first DO round is printed.
- C value of var: 'var'
- ENDDO
-
- DO var=-1,0 !The third number is 1 by default.
- P input
- C value of var: 'var'.
- C This may be part of a name, for example XX'var', or an index,
- for example YY(3+'var'). In the last case Schoonschip will interpret
- the % sign as minus if not on a C line and correctly work out the
- number.
- ENDDO
-
- *end
-
- C Example 4.
-
- A a1,a2,a3 !Algebraic symbol list.
- F f1,f2,f3 !Functions.
- I mu,nu !Indices.
- V p,q,k !Vectors.
-
- Z XX = p(mu)*{ a3^-20*a1*q(mu) + a2*a1^7*D(mu,nu)*k(nu)
-
- + a3*f2(mu,k,q)*f1} !Note the use of {}.
-
- + q(mu)*{a3*a2*a1 + f3*f2*f1}
-
- *end
-
- C Example 5.
-
- A a1,a2=i,a3=c,a4=c,a5=i=3
- V p,q=z,k
-
- Z XX = Conjg(a1 + a2 + a3 + a4 + a5)
- Z YY = Conjg(a3C + a4C)
- Z ZZ = (a1 + a5)^5
- Z AA = p(mu)*{p(mu) + q(mu)} + D(mu,3)*{p(mu) + q(mu)} + pDk
-
- Oldnew a4C=b4,k=K
-
- *end
-
- C Example 6.
-
- I mu,nu,la,ka
-
- Z XX = D(mu,nu)*f1(a1,a2,mu)*f2(a3,a4,nu)
- + f1(a1,a2,mu)*f2(a3,a4,nu)*D(mu,nu)
-
- Z YY = D(la,ka)*f1(a1,a2,la)*f2(a3,a4,ka)
- + f1(a1,a2,la)*f2(a3,a4,ka)*D(la,ka)
-
- Sum,la,ka
-
- *end
-
- C Example 7.
-
- A a1,a2=i,a3=c
- F f1,f2=i,f3=c,f4=u
-
- Z xx=Conjg{ f1(a1,a2,a3)*f2(a1,a2,a3,f3)*f4(a1,a2,a3) }
-
- *end
-
- C Example 8.
-
- Digits 20
- Ratio 0
-
- Z xx= DS(J,0,20,(1.),(1/J))
-
- *begin
-
- Digits
- Ratio
-
- Z yy = DS(J,0,5,(X^J),(1/J))
-
- *end
-
- C Example 9.
-
- X EXP(y) = DS(J,0,6,(y^J),(1/J))
-
- Z COS = { EXP{ (i*x) } + EXP{ -(i*x) } }/2
-
- *end
-
- C Example 10.
-
- B a11,a21,a31
-
- D rc(n)=a11,a12,a13,
- a21,a22,a23,
- a31,a32,a33
-
- X matrix(n,m)=rc(3*n+m-3)
-
- Z xxx = DS{J1,1,3,(DS{J2,1,3,(DS{J3,1,3,
- { DP(J1,J2,J3)*matrix(J1,1)*matrix(J2,2)*matrix(J3,3) }
- } ) } ) }
-
- *begin
-
- B a11,a21,a31,b11,b21,b31
-
- D ra(n)=a11,a12,a13,
- a21,a22,a23,
- a31,a32,a33
-
- D rb(n)=b11,b12,b13,
- b21,b22,b23,
- b31,b32,b33
-
- X matrix(n,m,ra)=ra(3*n+m-3)
-
- X DET(ra) = DS{J1,1,3,(DS{J2,1,3,(DS{J3,1,3,
- { DP(J1,J2,J3)*matrix(J1,1,ra)*matrix(J2,2,ra)*matrix(J3,3,ra) }
- } ) } ) }
-
- Z detb=DET(rb)
-
- Z deta=DET(ra)
-
- *begin
-
- F f1
-
- B b11,b21,b31
-
- D ra(n)=(a1-a2),0,
- 0,(a1+a2)
-
- D rb(n)=b11,b12,b13,
- b21,b22,b23,
- b31,b32,b33
-
- D rc(n)=c11
- X matrix(k,n,m,f1)=f1(k*n+m-k)
-
- D DET(n,f1) = f1(1),
- DS{J1,1,2,(DS{J2,1,2,
- { DP(J1,J2)*matrix(n,J1,1,f1)*matrix(n,J2,2,f1) }
- } ) }
- ,
- DS{K1,1,3,(DS{K2,1,3,(DS{K3,1,3,
- { DP(K1,K2,K3)*matrix(n,K1,1,f1)*matrix(n,K2,2,f1)*matrix(n,K3,3,f1) }
- } ) } ) }
-
- Z deta=DET(2,ra)
-
- Z detb=DET(3,rb)
-
- Z detc=DET(1,rc)
-
- *end
-
- C Example 11.
-
- T List(n)=a,b,c
-
- F f
-
- Z compl = DS(J,1,3,{ f(List(J)) } )
-
- *begin
-
- A x=c
-
- T r1(n)=a11,a12,a13
- T r2(n)=a21,a22,a23
- T r3(n)=a31,a32,a33
-
- T matr(n,m)=r1,r2,r3
-
- T weird(n,a1,a2)=Conjg(a1+a2),Integ(3*a2)
-
- X XX(a1,a2)=a2*a1
-
- Z sqa13 = DS(J,1,3,{f1(matr(1,J))*f1(matr(J,3))} )
-
- Z weirdo=XX(weird(1,x,7),weird(2,x,7))
-
- *end
-
- C Example 12.
-
- P lists
-
- Common yyy,ccc(0)
-
- Z xxx(a,b)=(a+b)^2
- Z ccc(3,a,b)=(a+b)^3
- Z ccc(4,a,b)=(a+b)^4
-
- Keep xxx
-
- *next
-
- F f1,f2
- V p
-
- Z yyy(p)=xxx(c,d) + p(nu)*f2(mu)
-
- Sum mu,nu
-
- *begin
- Write fileC
- *begin
-
- V q
-
- Z zzz=a1*yyy(q)
-
- Z Abc=xxx(a,b)
-
- Delete ccc,yyy !The actual delete when this section is done.
-
- *begin
-
- Z xyz=ccc(3,e,f)
-
- *end !The reader may want to delete fileC at this point.
-
- C Example 13.
-
- Z integr = a*x^2 +b*x
-
- Id,x^n~ = x2^(n+1)/(n+1) - x1^(n+1)/(n+1)
-
- *begin
-
- Z integr = (a*x^2 + b*x + c)*dx
-
- Id,x^n~*dx = x2^(n+1)/(n+1) - x1^(n+1)/(n+1)
-
- Al,dx = x2 - x1
-
- *begin
-
- C Method to integrate expressions of the form x^n*sin(x) or x^n*cos(x).
- C The method is based on the equation (n even):
- C Integral( x^n*sin(x)) = - n! * cos(x)
- + Integral( sin(x) * n * { x^(n-1) - (n-2)*(n-1)*x^(n-3) + ...} )
- + Integral( -cos(x) * { x^n - (n-1)*n*x^(n-2) + ...} )
- and similar equations for odd n and also cos(x).
- The X-expressions Coefa and Coefb corresponds to the above sums enclosed
- in curly brackets.
- Below the function DK is used to separate even and odd n cases. Remember
- that Integ converts and truncates its argument to a short integer in the
- range -128, 127.
-
- X Coefa(n,m,x)=DS(j,0,m,{ x^(n-2*j-1) } , { -(n-2*j)*(n-2*j+1) } )
- X Coefb(n,m,x)=DS(k,0,m,{ x^(n-2*k) } , { -(n-2*k+2)*(n-2*k+1) } )
-
- X Icos(n,x) =
- DK(2*Integ(n/2),n)*{
- - DB(n)*sin(x) ! n even.
- + cos(x)*n*Coefa(n,(n-1)/2,x)
- + sin(x)*Coefb(n,(n-1)/2-1,x) }
-
- + DK(2*Integ(n/2),n+1)*{
- DB(n)*cos(x) ! n odd.
- + cos(x)*n*Coefa(n,(n-1)/2-1,x)
- + sin(x)*Coefb(n,(n-1)/2,x) }
-
- X Isin(n,x) =
- DK(2*Integ(n/2),n)*{
- DB(n)*cos(x) ! n even.
- + sin(x)*n*Coefa(n,(n-1)/2,x)
- - cos(x)*Coefb(n,(n-1)/2-1,x) }
-
- + DK(2*Integ(n/2),n+1)*{
- + DB(n)*sin(x) ! n odd.
- + sin(x)*n*Coefa(n,(n-1)/2-1,x)
- - cos(x)*Coefb(n,(n-1)/2,x) }
-
- Z xx = x^8*cos(x)
-
- Id,x^n~*cos(x) = Icos(n,x2) - Icos(n,x1)
- Al,x^n~*sin(x) = Isin(n,x2) - Isin(n,x1)
-
- *end
-
- C Example 14.
-
- V p,q
- A a,b,c,d,e,f,g,h
- I mu,nu
- F f1,f2,f3
-
- X expr=f1(a,b,p)*f2(a,c,q)*f3(d,e)*f1(g,h)*
- { a^7 + a^-7 + a^2 + pDq^2 + pDp + p(mu) + p(nu) }
-
- *fix
-
- C Class 0, no keyword.
-
- Z xxx=expr
-
- Id,f1(a1~,a2~)=a1^10*a2^20
-
- *begin
-
- C Class 0, keyword Always.
-
- Z xxx=expr
-
- Id,Always,f1(a1~,a2~)=a1^10*a2^20
-
- *begin
-
- C Class 1, keyword Multi.
-
- Z xxx=expr
-
- Id,Multi,a^3 = xyz + hij
-
- *begin
-
- C Class 2, exponent 1, no keyword.
-
- Z xxx=expr
-
- Id,pDq = XYZ + HIJ
-
- *begin
-
- C Class 3, no keyword.
-
- Z xxx=expr
-
- Id,a^2 = a1^7/15
-
- *begin
-
- C Class 5.
-
- Z xxx=expr
-
- Id,p(mu) = - q(mu)
-
- *begin
-
- C Class 6.
-
- Z xxx=expr
-
- Id,p(mu~) = - q(mu)
-
- *begin
-
- C Class 7, keyword Funct.
-
- Z xxx=expr
-
- Id,Funct,a = a27
-
- Id,f1(a1~,a2~,a3~) = 200*a1*a2*a3
- Al,f2(a1~,a2~,a3~) = a1^10*a2^11*a3^12
-
- *begin
-
- C Class 8, keyword Once.
-
- Z xxx=expr
-
- Id,Once,a^2 = XXX
-
- *begin
-
- C Class 9.
-
- Z xxx=expr
-
- Id,a^2*f2(a1~,c,p~) = F2(a1,c,p)
-
- *begin
-
- C Class 10.
-
- Z xxx=expr
-
- Id,f1~(a,b~,p~) = F(a,b,p)
-
- *begin
-
- C Class 11, keyword Adiso.
-
- Z xxx = expr
-
- Id,Adiso,f1(g,h)*f1(a~,b~,c~) = F1(a,b,c,g,h)
-
- *begin
-
- C Class 12, keyword Ainbe.
-
- Z xxx=expr
-
- Id,Ainbe,f1(g,h)*f1(a~,b~,c~) = F1(a,b,c,g,h)
- Id,Ainbe,f1(a~,b~,c~)*f1(g,h) = F2(a,b,c,g,h)
-
- *begin
-
- C Class 13.
-
- Z xxx=expr
-
- Id,f1(x~,b,p)*f2(x~,c,q) = F(x,b,p,c,q)
-
- *begin
-
- C Class 15, keyword Dotpr.
-
- Z xxx=expr
-
- Id,Dotpr,p(mu~) = - q(mu)
-
- *begin
-
- C Class 16, keyword Funct.
-
- Z xxx=expr
-
- Id,Funct,p(mu~) = - F1(a,b,mu)
-
- *end
-
- C Example 15.
-
- Integration of polynomium.
-
- A a,b,c,d,e,x
-
- Z xxx = a*x^2 + b*x + c + d/x + e/x^2
-
- IF NOT x^-1=[Log(x)]
- AND NOT x^n~=x^(n+1)/(n+1)
- Al,Addfa,x
- ENDIF
-
- *end
-
- C Example 16.
-
- V p,q
- F F
- I mu=N,nu=N
-
- Z xx= pDp^2 * pDq^3 * F1(p,p,q,p) * p(mu) * q(nu)
-
- Id,All,p,N,F
- P output
- *yep
- C Showing the dimensionality of the created indices:
-
- Id,F(i1~,i2~,i3~,i4~,i5~,i6~,i7~,i8~,i9~,i10~,i11~)=
- F(i1,i2,i3,i6,i7,i8,i9,i10,i11)*D(i4,i5)
- *begin
-
- C A more realistic example.
-
- I al,be,mu,nu
- A N,N_
- V p,k
- F F,F20,F22
-
- Z xx = G(1,1,al,be,p,al,be,p)
-
- Id,All,p,N,F
- P output
- *yep
- Id,F(i1~,i2~) = D(i1,i2)*F20(k) + k(i1)*k(i2)*F22(k)
- *end
-
- C Example 17.
-
- V p,q,k
- I mu
- A a,b,c,d,e,f,g,h
- F F1,F2,F3
-
- Z xx = F1(e,d,c,b,a) + F2(e,d,c,b,a) + F3(e,d,c,b,a)
- + F2(-125,-30,-1,0,30,125)
- + F2(pDq,pDk,kDq,p(3),q(2),F2,7,mu,p,a)
- + f1(e,f,g,d,a,b,c,h,k)
-
- Id,Asymm,F1,2,3,4,F2,F3,4,5
- Al,Asymm,f1:1-3:5-7:
-
- *end
-
- C Example 18.
-
- A a1,a2,a3,a4,alt1,agt2,aeq15,ai12
-
- Z xxx= 0.5*a1 + 1.5*a2 + 2.5*a3 + 1.E-20*a4
-
- IF Coef,lt,1.
- Al,Addfa,alt1
- ENDIF
-
- IF Coef,gt,2.
- Al,Addfa,agt2
- ENDIF
-
- IF Coef,eq,1.5
- Al,Addfa,aeq15
- ENDIF
-
- IF Coef,ib,1,2
- Al,Addfa,ai12
- ENDIF
-
- IF Coef,lt,1E-15 !Delete the term if coefficient < 1E-15.
- Al,Addfa,0
- ENDIF
-
- *end
-
- C Example 19.
-
- A a1,a2,a3,a4,a5
- F F1,F2,F3
-
- Z xx= F3(a1,a2)*F1(a1,a2,a3)*F1(a4,a5)
- + F1(a1,a2,a4)*F2(a1,a2,a3)*F1(a1,a2,a3)
- + F3(a1,a4)*F2(a1,a2,a3)*F1(a1,a2,a4)*F2(a3,a4,a5)
-
- Id,Commu,F1,F3
-
- *end
-
- C Example 20.
-
- F F1,F2
- A a,b,c,d
-
- Z xx = F1("c,"b,"a,/,"e,*,a1)
- + F1("c,"b,"a,/,"e,*,a1,*,xy)
- + F1("c,"b,"a,/,"e,*,a1,*,xy,*,a2)
- + F1("c,"b,"a,/,"e,*,a1,*,xy,*,a2,*,xz)
-
- + F2("a,"b,/,"F,*,x,*,y,*,z1)
- + F2("b,"a,/,"F,*,x,*,y,*,z1)
- + F2("F,"c,"b,"a,*,*,z,*,y,*,x)
- + F2("F,"c,"b,"a,*,*,z,*,yp,*,x)
-
-
- Id,Compo,<AVIFXA>,F1,<FF>,F2
- Id,Always,F2(F1~,a~,b~,c~,d~,e~) = F1(a,b,c)
- Id,F1~(a~,b~,z1) = F1(a,b)
- *begin
- C
- j1
- i1 ---0-------0--- i3
- j4 | |j2
- | |
- i2 ---0-------0--- i4
- j3
-
-
- T Ch(n)="A,"B,"C
- T Cg(n)="A,"C,"B
-
- F BC,ABC
- A i1,i2,i3,i4,j1,j2,j3,j4
-
- Z solu = square("A,"A,"A,"A)
-
- Id,square(c1~,c2~,c3~,c4~) = DS{L1,1,3,(DS{L2,1,3,
- (DS{L3,1,3,(DS{L4,1,3,(
- v3(c1,Ch(L1),Cg(L4),*,i1,*,-j1,*,j4)*
- con(Ch(L1),Cg(L1),*,j1,*,-j1)*
- v3(c3,Cg(L1),Ch(L2),*,-i3,*,j1,*,-j2)*
- con(Ch(L2),Cg(L2),*,j2,*,-j2)*
- v3(c4,Cg(L2),Ch(L3),*,-i4,*,j2,*,-j3)*
- con(Ch(L3),Cg(L3),*,j3,*,-j3)*
- v3(c2,Cg(L3),Ch(L4),*,i2,*,j3,*,-j4)*
- con(Ch(L4),Cg(L4),*,j4,*,-j4)
- ) } ) } ) } ) }
-
- Id,Compo,<F>,v3,con
- Id,v3(f1~,a1~,a2~,a3~) = f1(a1,a2,a3)
- Al,con(f1~,a1~,a2~) = f1(a1)
-
- *end
-
- C Example 20.
-
- A x,y
- T tt(n) = "1,"2,"3,"4,"5
-
- C Here a complicated way to make
- C pow(x) = a1*x + a2*x^2 + a3*x^3 + a4*x^4 + a5*x^5.
-
- Z pow(x) = DS(J,1,5,{f1(/,"a,tt(J))*x^J})
-
- Id,Compo,f1
- Id,f1(y~) = y
-
- Keep pow
- *next
-
- Z xx = pow(x)
-
- Id,Count,3,x,1
-
- Keep pow
- *next
-
- Z xx = pow(y)
-
- Id,Count,f1,y,2,a3,10
-
- Keep pow
- *next
- V p,q
- A AA
-
- Z xx = pow(y)*f1(a2,a3)*pDq^2
-
- Id,Count,AA,y,2,f1,-4,p,1,q,3
-
- *end
-
- C Example 22.
-
- A a,b,c,d,e
-
- Z xxx = F1(e,d,c,b,a) + F2(e,d,c,b,a) +F3(e,d,c,b,a)
-
- Id,Cyclic,F1,2,5,4
- Id,Symme,F2,F3,2,3,4
-
- *end
-
- C Example 23.
-
- V p,q,k,pp,qp,kp
-
- Z xxx = Epf(k,p,q)*Epf(kp,pp,qp) + Epf(i1,i2,i3,i4)*Epf(i1,i2,j3,j4)
-
- Id,Epfred
-
- *end
-
- C Example 24.
-
- F f1,f2,f3,f4
-
- Z xxx = f1(-a1,-a2,a3,-a4) + f2(-a1,-a2,a3,-a4) + f3(-a1,-a2,a3,-a4)
- + f4(-a1,-a2,a3,-a4)
-
- Id,Even,f1,2,3,f2
- Id,Odd,f3,2,3,f4
-
- *end
-
- C Example 25.
-
- V p,q
-
- Z xxx = a1^2*pDq^3/p(4)
-
- Id,Numer,a1,2,pDq,1.E10,p(4),1.E5
-
- *end
-
- C Example 26.
-
- A a1,a2,a2ma1
- F f1
- B b2,b3,b4,b5
-
- Z xx=f1(8,4)
-
- Id,f1(n~,m~)=
- { b2*a1^n*a2^m
- + b3*a1^-n*a2^m
- + b4*a1^n*a2^-m
- + b5*a1^-n*a2^-m
- }
-
- Id,Ratio,a1,a2,a2ma1
- *begin
-
- C Here the use of Ratio with [] names.
-
- B [b-a]
-
- Z xxx = 1/[x+a]^3 * 1/[x+b]^2
-
- Id,Ratio,[x+a],[x+b],[b-a]
- P output
- *yep
- C Just checking...
-
- Id,[x+a]^n~ = (x+a)^(3+n)*(x+b)^2/[x+a]^3/[x+b]^2
- Al,[x+b]^n~ = (x+a)^3*(x+b)^(2+n)/[x+a]^3/[x+b]^2
- Id,b = [b-a] + a
- *end
-
- C Example 27. Muon decay.
-
- Masses and momenta: muon Mm,k; electron Me,p;
- anti-e-neutrino qp; mu-neutrino q.
- The length of the 3-dimensional parts of p, q and qp are
- denoted by pl, ql and qpl. The variable z is the cosine
- of the angle between p and q (3-dimensional parts).
- Also k0, p0 etc are the energies of the particles. Note
- that k4=i*k0 etc. Note also that q0=ql, qp0=qpl since
- the neutrino masses are taken to be zero.
-
- C Further quantities: Pi=3.14... and Mpr is the proton mass.
-
- C The evaluation is in the muon rest-system, thus kl=0 and
- k0=Mm.
-
- A Me,Mm,ql,qpl,pl,p0,Pi,b,z,bp,Mpr,Al
- V p,q,qp,k
- I mu,mup,i1,i2
- F Dia=u
-
- Z Rate = Dia(mu,1)*Conjg(Dia(mup,10))/2
-
- C Factor 1/2 for averaging over muon polarizations.
-
- Id,Dia(mu~,n~) = Ubg(n,Me,p)*G(n,n+1,mu,G6)*Ug(n+1,0,qp)
- *Ubg(n+2,0,q)*G(n+2,n+3,mu,G6)*Ug(n+3,Mm,k)
- Id,Spin,p,q,k,qp
-
- C There are two separate traces here. They may be unified to
- advantage as they have two indices in common (mu and mup).
-
- Id,Gammas,"U
-
- C Apply conservation of four-momentum qp=k-p-q and
- the mass-shell relations kDk=-Mm^2, pDp=-Me^2 and
- qDq=qpDqp=0.
-
- Id,qpDq=kDq-pDq
- Al,qpDk=-Mm^2-pDk-qDk
- Al,qpDp=pDk+Me^2-qDp
- Id,Funct,qp(mu~) = k(mu) - p(mu) - q(mu)
-
- *yep
-
- Id,pDq=pl*ql*z-p0*ql
- Al,pDk=-Mm*p0
- Al,qDk=-ql*Mm
- Al,kDk=-Mm^2
- Al,pDp=-Me^2
-
- C Integration over all angles of the vector p
- gives a factor 4*Pi:
-
- Id,Addfa,4*Pi
-
- C The integration over the azimuthal angle of q
- gives a factor 2*Pi. Including the various factors
- 1/(2k0)..., a factor (2*Pi)^4/{(2*Pi)^3)}^3
- and the factors from going to polar coordinates
- for q and p gives:
-
- Id,Addfa,2*Pi/16/Mm/p0/ql/qpl*pl^2*ql^2/32/Pi^5
-
- C The remaining delta function is delta(k0-p0-q0-qp0).
- For given p0=Sqrt(pl^2+Me^2) and q0=ql this may be
- solved for z using qp0=qpl=length(p+q)=
- Sqrt(pl^2+ql^2+2*pl*ql*z) where z is the cosine of
- the angle of q with the third axis, taken along p.
- In this last comment p and q are three-vectors.
-
- C Note that integration over the delta-function gives
- a factor 1/Abs(F), where F is the derivative of the
- argument of the delta function with respect to z.
- This F is equal to ql*pl/qpl.
-
- Id,z=(0.5*Me^2+0.5*Mm^2-Mm*p0-ql*Mm+ql*p0)/pl/ql
- Al,Addfa,qpl/ql/pl
-
- *yep
-
- B Pi
-
- C The next integration is over the length ql. The
- endvalues are denoted by qma and qmi, with
- qma=(Mm-p0+pl)/2 and qmi=(Mm-p0-pl)/2. These
- values obtain for configurations where the electron
- and both neutrinos are aligned. The maximum value
- obtains if the momentum qp is in the direction
- of the electron momentum, while q is pointed in the
- opposite direction. Then pl+qpl=ql and q0=Mm-p0-qp0,
- and one solves ql(=q0)=(Mm-p0+pl)/2.
-
- C Actually, ql^-1 is not occurring here, but for
- completeness we include it in the integration.
-
- IF NOT ql^-1=[Log(qa/qb)]
- AND NOT ql^n~=qma^(n+1)/(n+1)-qmi^(n+1)/(n+1)
- Al,Addfa,qma-qmi
- ENDIF
-
- Id,qma=0.5*Mm-0.5*p0+0.5*pl
- Al,qmi=0.5*Mm-0.5*p0-0.5*pl
-
- *yep
-
- Id,Multi,p0^2 = pl^2+Me^2
- Id,p0 = (pl^2+Me^2)/p0
-
- C The answer contains essentially one kinematic variable,
- namely pl (or p0). The spectrum that follows from this
- equation is typical for a V-A theory. Using a variable
- x (shown below) this spectrum follows an equation derived
- by Michel provided a parameter ro in that equation, called
- Michel parameter, is set to 3/4.
-
- P output
- *yep
-
- C The final integration is over pl. A new variable
- x defined by x=pl+p0, with p0=Sqrt(pl^2+Me^2)
- is used in the following. One has dx/d(pl)=1+p/p0
- and this may be rewritten as d(pl)/p0 = dx/x.
- Note that pl=(x+Me^2/x)/2.
- There are terms with and without p0^-1, and they
- are treated separately.
- The variable plmx is the maximum value of pl, i.e.
- plmx=(Mm-Me^2/Mm)/2. This is achieved if both neutrinos
- are aligned and opposite to the electron. The
- energy of the neutrinos is then simply pl, since
- the sum of the momenta must be equal to the electron
- momentum. In that case therefore Mm=p0+pl, which gives
- the stated value for plmx. Note that Mm is the endpoint
- value for x, corresponding to maximum pl.
- The minimum value for pl is 0, for x it is Me.
-
- IF p0^-1=1/x
- Al,pl^n~=(x/2-Me^2/x/2)^n
- Id,x^-1=[Log(Mm/Me)]
- Al,x^n~=Mm^(n+1)/(n+1)-Me^(n+1)/(n+1)
- ELSE
- ..IF NOT pl^n~=plmx^(n+1)/(n+1)
- ..Al,Addfa,plmx
- ..ENDIF
- ENDIF
-
- Id,plmx=Mm/2-Me^2/Mm/2
-
- P output
- *yep
-
- Digits 7
-
- C Numerical evaluation. One usually introduces the coupling
- constant g/Sqrt(2)/Mpr^2, and then g is to be taken such
- that the muon lifetime comes out to be 2.197134E-6.
- Note also the factor (h/(2*Pi))^-1 to convert Mev to 1/seconds.
-
- Id,Addfa,g^2/6.582173E-22/2/Mpr^4
- Id,Numer,Mm,105.65946,Me,0.5110034,[Log(Mm/Me)],5.33160,Mpr,938.2796
- Al,Numer,Pi,3.141592653589793238
-
- C Multiply the Rate (= inverse lifetime) with the experimental
- lifetime. Then g can be solved from the requirement that
- the result must be one. This gives g = 1.024E-5, which
- corresponds to the well-known result for the fermi-coupling
- constant:
- Gf = 1.02 * 10^-5 /Sqrt(2) /Mpr^2 .
-
- Id,Addfa,2.197134E-6
-
- P output
- *yep
-
- Id,g = 1.0246275E-5
-
- *end
-
- C Example 28.
-
- C The problem is to make a series expansion of a
- complicated expression in terms of quantities a and b.
- The expression was given in terms of the quantities
- called X1,X2,Omx1a,X2b,Bmx2a,Fac1 and Fac2 here below.
-
- C The problem was solved in two separate runs. Here the
- first run is shown. The object is to give the series
- expansion for the quantities mentioned. Up to order 7
- in a and/or b is required. The quantity ep is an expansion
- parameter, essentially counting the order in a and b.
- Terms ep^8 and higher are to be ignored, the sooner the
- better. For this the assignment ep=8 in the A-list is
- the best tool.
-
- C The calculation proceeds by building up one quantity
- after the next, step by step.
-
- Common X1,X2,Omx1a,X2b,Bmx2a,Fac1,Fac2
-
- A ep=8,a,b
- X X(a)=ep^2*(a^2+b^2-2*a*b)-2*ep*(a+b)
-
- *fix
-
- C First certain roots called WO and WOI are needed.
- These are of the form Sqrt(1+XX) and 1/Sqrt(1+XX).
- The quantity XX itself is a function of a and b,
- given above as X(a). In the following DO-loop the
- powers of X(a) are computed:
- XX(1)=X(a), XX(2)=X(a)^2 etc.
-
- Z XX(0)=1.
-
- Keep XX
- *next
-
- DO K1=1,7
- B ep
- Z XX('K1')=X(a)*XX('K1'-1)
- Nprint XX('K1')
- Keep XX
- *next
- ENDDO
-
- C Now the roots WO and WOI can be computed. The expansions
- used here are simply the expansions for Sqrt(1+x) and
- 1/Sqrt(1+x).
-
- B ep
-
- Z WO = 1 + XX(1)/2 - XX(2)/8 + XX(3)/16 - 5*XX(4)/128
- + 7*XX(5)/256 - 21*XX(6)/1024 + 33/2048*XX(7)
- Z WOI = 1 - XX(1)/2 + 3*XX(2)/8 - 5*XX(3)/16 + 35*XX(4)/128
- - 63*XX(5)/256 + 231*XX(6)/1024 - 429/2048*XX(7)
-
- Keep WO,WOI
- *next
-
- B ep
-
- Z X1=0.5+0.5*b*ep-0.5*a*ep+0.5*WO
- Z X2=0.5+0.5*b*ep-0.5*a*ep-0.5*WO
-
- Keep WOI
- *next
-
- B ep
-
- Z Omx1a=1/a/ep-X1/a/ep
- Z X2b=X2/b/ep
- Z Bmx2a=b/a-X2/a/ep
-
- Keep WOI
- *next
-
- B ep
- A ep=7
-
- C For Fac1 and Fac2 only up to ep^6 is needed.
-
- Z Fac1=(b*ep-X1)*WOI
- Z Fac2=(X2-b*ep)*WOI
-
- *begin
-
- C Wrinting of common files. The printed list shows which
- common files were in existence here; a common file
- has =C after its name. The X-expression X uses two
- levels and has =X2 after its name. It is not written.
-
- P lists
- Write expP
- *end
-
- C Example 29.
-
- C In this second part (Example 28 is first part)
- we will not show the whole calculation of all
- expressions as they were needed, but just
- the evaluation of the first one, which is
- enough to clarify the procedure. First the
- output of example 27 must be entered.
-
- Enter expP
- A ep=7,a,b
- *fix
-
- B ep
-
- Z Arg(1) = X2
- Z Arg(3) = (b-a)*X2/b
- Z Arg(4) = 1 - X2b
- Z Arg(5) = Omx1a*X2b - 1
- Z Arg(6) = (b-a)*(1-X1)/a
- Z Arg(7) = (a-b)*ep*Omx1a
- Z Arg(8) = Bmx2a
-
- Keep Arg
- *next
-
- B ep
-
- C The Sp are certain functions of a variable x.
- Sp(1) = Log(1-x)/x, higher Sp are obtained by
- iteration, involving differentiation.
- In the end x must be set to (a-b)/a.
- The XX2 are powers of -Arg(1).
-
- Z Sp(1) = - Lomx/x
- Z XX2(1) = - Arg(1)
-
- Nprint Sp,XX2
- Keep Sp,XX2,Arg
- *next
-
- B ep
-
- DO K1=2,6
- Z Sp('K1') = Difx*Sp('K1'-1)/'K1'
- Z XX2('K1') = - XX2('K1'-1)*Arg(1)
-
- Id,Difx*Lomx = - 1/Omx + Lomx*Difx
- Id,Difx*Omx^n~ = - n*Omx^(n-1) + Omx^n*Difx
- Id,Difx*x^n~ = n*x^(n-1) + x^n*Difx
- Id,Difx = 0
-
- C Note that only negative exponents of x occur here.
- Id,x^n~*Omx^-1 = DS(J1,1,-n,(x^-J1)) + 1/Omx
-
- Nprint Sp,XX2
- Keep Sp,XX2,Arg
- *next
- ENDDO
-
- B Lga,Lgb
-
- DO K2=1,6
- Z Sp('K2') = Sp('K2')*x^'K2'
- ENDDO
-
- C Omx = 1-x appears only with negative exponent. It
- is rewritten in terms of x/(1-x) = Xomx, which
- is possible here since the exponent of x is here
- always larger than minus the exponent of Omx.
-
- Id,x^n~*Omx^m~ = Xomx^-m*x^(n+m)
- Id,x = (a-b)/a
- Al,Xomx = (a-b)/b
- Id,Lomx = Lgb - Lga
-
- Nprint Sp
- Keep Sp,XX2,Arg
- *next
-
- C Now finally the first of the desired expressions
- is worked out.
-
- B ep,Lga,Lgb
-
- Z Exp(1) = DS(J3,1,6,{Sp(J3)*XX2(J3)})
-
- *end
- ə