Difference between revisions of "Differential Cross-Section"

From New IAC Wiki
Jump to navigation Jump to search
Line 82: Line 82:
  
  
<center><math>\frac{2s^2}{tu}=\frac{32E^{*4}}{4p^{*4}\left(1+\cos{\theta}\right)\left(1-\cos{\theta}\right)}=\frac{8E^{*4}}{p^{*4}\sin^2{\theta}}=\frac{8E^{*4}\sin^2{\theta}}{p^{*4}\sin^4{\theta}}</math></center>
+
<center><math>\frac{2s^2}{tu}=\frac{32E^{*4}}{4p^{*4}\left(1+\cos{\theta}\right)\left(1-\cos{\theta}\right)}=\frac{8E^{*4}}{p^{*4}\sin^2{\theta}}=\frac{8E^{*4}\sin^2{\theta}}{p^{*4}\sin^4=\frac{8E^{*4}\left(1-\cos^2{\theta}\right)}{p^{*4}\sin^4{\theta}}</math></center>
  
  

Revision as of 16:33, 1 January 2019

Navigation_

Differential Cross-Section

dσdΩ=164π2spfinalpinitial|M|2


Working in the center of mass frame

pfinal=pinitial


Determining the scattering amplitude in the center of mass frame


M=e2(ust+tsu)


M2=e4(ust+tsu)(ust+tsu)


M2=e4((us)2t2+(ts)2u2+2(us)t(ts)u)


M2=e4((u22us+s2)t2+(t22ts+s2)u2+2(utst+s2us)tu)


M2=e4((t2+s2)u2+2s2tu+22ust22st2tsu22su+(u2+s2)t2)


Using the fine structure constant (with c==ϵ0=1)

αe24π


dσdΩ=α22s((t2+s2)u2+2s2tu+22ust22st2tsu22su+(u2+s2)t2)


In the center of mass frame the Mandelstam variables are given by:

s4E2


t2p2(1cosθ)



u2p2(1+cosθ)


Calculating the parts to have common denominators:

2=2p4sin4θp4sin4θ


t2u2=4p2(1cosθ)24p2(1+cosθ)2=tan4θ2=p4(1cosθ)4p4sin4θ


s2u2=16E44p4(1+cosθ)2=E4sec4θ2p4=4E4p4(1+cosθ)2=4E4(1cosθ)2p4(1+cosθ)2(1cosθ)2=4E4(cos2θ2cosθ+1)p4sin4θ


u2t2=4p2(1+cosθ)24p2(1cosθ)2=cot4θ2=p4(1+cosθ)4p4sin4θ=p4(1+cosθ)4p4(1cos4θ)


s2t2=16E44p4(1cosθ)2=E4csc4θ2p4=4E4p4(1cosθ)2=4E4(1+cosθ)2p4(1cosθ)2(1+cosθ)2=4E4(cos2θ+2cosθ+1)p4sin4θ


\frac{2s^2}{tu}=\frac{32E^{*4}}{4p^{*4}\left(1+\cos{\theta}\right)\left(1-\cos{\theta}\right)}=\frac{8E^{*4}}{p^{*4}\sin^2{\theta}}=\frac{8E^{*4}\sin^2{\theta}}{p^{*4}\sin^4=\frac{8E^{*4}\left(1-\cos^2{\theta}\right)}{p^{*4}\sin^4{\theta}}


2st=8E22p2(1cosθ)=4E2p2(1cosθ)=4E2(1+cosθ)p2(1cosθ)(1+cosθ)=4E2(1+cosθ)p2sin2θ=4E2p2sin2θ(1+cosθ)p4sin4θ


2su=8E22p2(1+cosθ)=4E2p2(1+cosθ)=4E2(1cosθ)p2(1+cosθ)(1cosθ)=4E2(1cosθ)p2sin2θ=4E2p2sin2θ(1cosθ)p4sin4θ


2tsu2=4p2(1cosθ)4E24p2(1+cosθ)2=E2(1cosθ)sec4θ2p2=E2p2(1cosθ)p4(1+cosθ)2=E2p2(1cosθ)(1cosθ)2p4(1+cosθ)2(1cosθ)2=E2p2(cos3θ+3cos2θ3cosθ+1)p4sin4θ


2ust2=4p2(1+cosθ)4E24p2(1cosθ)2=E2(1+cosθ)csc4θ2p2=E2p2(1+cosθ)p4(1cosθ)2=E2p2(1+cosθ)(1+cosθ)2p4(1cosθ)2(1+cosθ)2=E2p2(cos3θ+3cos2θ+3cosθ+1)p4sin4θ

Navigation_