! " ! " v z # x' = x y'= y z ' = γ ( z − β ct ) t ' = γ (t − β= γ= β c z) v c 1 1− β 2 v S’ S t $ ! " % & # x' = x y ' = y cos α + z sin α z ' = − y sin α + z cos α ! " r 2 = ( x1 − x2 ) + ( y1 − y2 ) + ( z1 − z2 ) = ( x '1 − x '2 ) + ( y '1 − y '2 ) + ( z '1 − z '2 ) 2 2 2 2 2 2 invariante per rotazioni ' '$ $ $ s 2 = ( ct1 − ct2 ) − ( x1 − x2 ) + ( y1 − y2 ) + ( z1 − z2 ) = ( ct '1 − ct '2 ) − ( x '1 − x '2 ) − ( y '1 − y '2 ) − ( z '1 − z '2 ) 2 2 2 2 2 2 2 invariante per trasformazioni di Lorentz # $ $ $ ( ( ) '$ # $ ( 2 '$ $ $ '$ '$ ( & $ $ ' '$ ' * '$ ' + '$ ! " ! &$ " # ( v µ = v 0 , v1 , v 2 , v3 ) µ / , & , . - . ( ) − (v ) − (v ) − (v ) v 2 = v0 2 1 2 ! # 2 2 3 2 " 0 12 3 '$ ← ! ! " # # $ ## % ## & ## # ## ! ' ( ) # # ! # ! ! * # % & + # (v1 = vx , v2 = v y , v3 = vz , v4 = ivt ) v = v +v +v +v 2 . /0 / ' 2 1 2 2 2 3 2 4 , - ! 1 ! # v µ = v 0 , v1 , v 2 , v 3 = ( vt , vx , v y , vz ) ( ) vµ = ( v0 , v1 , v2 , v3 ) = ( vt , −vx , −v y , −vz ) µ / µ v = v vµ = vµ v 4 2 '$ vu = v µ uµ = vµ u µ '$ 5 # 1 g µν = g µν = 0 0 0 0 −1 0 0 0 0 −1 0 0 0 0 −1 vν = g µν v µ , vν = g µν vµ / &$ # ! " 2 - 2 - . ) % . $ 3 ) % 4 , 6 45 , % $ '$ '$ / '$ p µ = ( E , pc ) p ! ! " " 0 p = mγ v E = m 2c 4 + p 2 c 2 m '$ # p 2 = E 2 − p2c2 = m2c4 c 1 '$ # p⊥ ' = p⊥ p ' = γ ( p − β E) E ' = γ (E − β p ) - . β # p⊥ = p⊥ ' p = γ ( p '+ β E ') E = γ ( E '+ β p ' ) 4 p p⊥ p '$ 4 ! " 0 # N particelle i =1 piµ = costante 6 # 7 ## ! 85 # # ' ,. +9 ## ) v = βc # ) # # ' β= β8 p p E , γ = , βγ = E m m ,. +9 :β;8 +9 ,. ) 7 +9 # ! ! *4 # p = ( E p + mb , p p ) % < β= = 7 ,. p* = ( E *p + Eb* , 0 ) & < p E = mb + E p = % =m pb = E *p + Eb* < β + pp ,. β= # & pp mb + m 2p + p 2p ! * '$ 7 7 )1 )1 " 8 p* 7 p* ! : p ⊥* p* " p9 &$ # # *2 *2 2 p⊥*2 + p*2 = p*2 x + p y + pz = k ; z# )1 p⊥ = p⊥* ( E = γ (E ) +βp ) p = γ p* + β E * * * # p* = 1 γ p − β E* p →p + 2 ⊥ γ 2 −βE = k2 * ( p − βγ E * p2 → ⊥2 + k γ 2k 2 ) 2 =1 )1 7 ! γ β # " z β9 7 z )1 βγE*. ) ! ) 1" & ! 7" # !" β<β9 ! 7 )1 "4 = 4 7 )1 p⊥ 0 ! ! " β> β?β9 ! " "4 )1 7 7 )1 p⊥ ! " β>β9 ! "# p⊥ " 8 )1 cos θ = tan ϕ = φ p p +p 2 2 ⊥ p⊥ , sin θ = p + p⊥2 2 py px θ 7 p* cos θ * = p*2 + p⊥*2 , sin θ = p⊥* p*2 + p⊥*2 p*y tan ϕ = p*x : γ ( p − β E) cos θ * = γ ( p − β E ) 2 + p⊥2 py tan ϕ * = px ,sin θ * = p⊥ γ ( p − β E ) 2 + p⊥2 = tan ϕ # tan θ * = p sin θ sin θ = γ ( p cos θ − β E ) γ ( cos θ − β β part ) β part = )1 β 7 ) 1 @" / @% ! )1 " γ=5 7 ∗ β/β . β>β∗ )1 Theta LAB vs Theta CM 180 150 γ=5 β/β∗=1.5,1.,0.5 Theta LAB 120 90 60 30 0 0 30 60 90 120 Theta CM "/ )1 )1 7 150 p ! E 180 & p⊥ = p⊥* ( E = γ (E ) +βp ) p = γ p* + β E * * * E * = −γβ p + γ E → E * = −γβ p cos θ + γ E → E * = −γβ p cos θ + γ m 2 + p 2 p / ( ( cos θ β β * ± 1 + γ 2 1 − β β * p= p * γ (1 − β 2 cos 2 θ ) 2 2 θ )1 β/β∗ # ) ) tan # y ; ∗ β/β ? " ∗ ! 7 !β/β ≤ " ) 14 # " : - M '$ : '$ 7 . m m: # . ( M , 0, 0, 0 ) = ( E1 , p1 ) + ( E2 , p 2 ) M = E1 + E2 = m12 + p12 + m22 + p22 p1 + p 2 = 0 → p1 = −p 2 → p1 = p 2 = p 7 # 1 2M p= M 2 − ( m1 − m2 ) 2 M 2 − ( m1 + m2 ) 2 # 1 M 2 + m12 − m22 2M 1 E2 = m22 + p 2 = M 2 + m22 − m12 2M E1 = m12 + p 2 = ( ) ( ) 6 M ≥ m1 + m2 , p " :" 7 &" / & : 4 '" ; 4 A" B 7 B B B B ) 14 p* "4 ! p1 = (M 2 ) '$ + m12 − m22 p cos θ1 ± 2 E M 2 p*2 − m12 p 2 sin 2 θ1 ( 2 M 2 + p 2 sin 2 θ1 ) p1 C θ1 * Mp <1 m1 p )1 p1 : p2 sin θ1max = * Mp >1 m1 p Mp* 4 m1 p : p1 + * π, 3! > - %γ 0 π , ,.! M E 0 p 0 p 1 M E p 1 massa # 1 p 2 2 p 2 0 fotone 0 p p - p 1 E p p 2 1 M m2 p E p 2 2 p 0 2 # / π5 , ) # / ,. ! ? π0 p , ?' γ: 7 π0; 2γ 0 E p E *1 1 p 1 p p 1 M E *1 p* 1 * E 1 1 * 1 * 1 0 p*1 2 p* cos p* 1 p * 1 Casi estremi : cos * 1 1 p* 1 p* cos * 1 1 p* 1 p* M 0 2 M 0 2 M p 1 p 1 M 1 0 2 1 p 1 1 0 M M 1 0 2 val. min 2 1 0 2 M 0 2 M 1 p M 0 2 0 val.max. 2 1 ## 1 M 1 1 M 0 2 0 2 ) ?) ,. +9 !& ) # ! # π # ,. φ dN d * ) A , 5 # # dN d cos * d * A dN d cos * B θ # +9 θ@! E 1 p E *1 1 M 2 dE M 0 cos 2 M 1 dN dE 1 , 0 M p* 1 2 dN d cos 0 p* cos 2 M * 0 2 d cos 2 M * 0 1 * * cos * 0 2B M 0 # ! π5 %! ) A π5 < # γ = ) & % > # % ! - - π5 3 1 %! p 1 p* 1 E *1 p 2 p* 2 E*2 p p* 1 E *1 M E*2 0 * 1 p cos p* 2 p* cos * 2 cos * 1 sin * 1 1 2 * 1 min * 2 sin tan p 1 p 1 p* sin p* cos 1* p 2 p 2 * 2 sin 1* cos 1* p* sin 2* cos 2* sin cos * 1 * 1 1 0 m * 1 da' l'angolo minimo fra i due 2 2 arctan p p *1 * 2 cos tan p* 1 2 * 1 p * 1 2 arctan min 0 m 0 p 0 Bα π5 π ! ( π4 C C4 D! ?- K µ , (π ) Eµ = mµ + pµ ,π = 2 2 Eµ( ) = mµ2 + pµ2 , K = K ,. M π2 + mµ2 2M π M K2 + mµ2 2M K % (π ) → Eµ ( 0.139 ) + ( 0.106 ) = 2 2 0.110 GeV 2*0.139 → Eµ( ) = K ( 0.494 ) + ( 0.106 ) 2 2*0.494 2 0.258 GeV π , µ ! C & E% !" # π % C ## ! π # C 7 ,. p 1 2M 2 - M 2, K m 2 M 2, K 56.5 m2 248.2 ,K π % # MeV C 5! +9 dP d cos * E* E dP dE dP dE 1 2 p* cos 1 2 p* dP d cos * d cos * dE * p*d cos dE 1+ E * max 1- E * min * d cos * dE p* +9 # & p p p p p p m2 m2 2p p m2 m2 m2 2 E ) E m2 p 2 p p 2 p p 2 E E E p cos m E m2 m2 m2 m2 4 E sin 2 2 E 1 cos 2 ' E m2 E m2 2 θ " & 4 ) : 7 ! " 0 F ?: # ) 78 G G !& ! 787 8 # ← G ! ' G G N part i =1 piµ = P µ G # - # # * % * 8% →78H 8% θeφ # 8 →78I 8J # & ,. & ! ,. % % ! ,. 7 # 4 : p1 '$ # p2 P µ = p1µ + p2µ P B P 2 = ( E1 + E2 , p1 + p2 ) 2 = ( E1 + E2 ) − ( p1 + p2 ) = m12 + m22 + 2 E1 E2 − 2 p1 ⋅ p2 2 0 B B P P 2 '$ 4 P2 B ! & '$ # P = p1 + p2 + p3 # " s = P2 = M 2 s1 ≡ s23 = ( P − p1 ) = ( p2 + p3 ) 2 2 s2 ≡ s13 = ( P − p2 ) = ( p1 + p3 ) 2 s3 ≡ s12 = ( P − p3 ) = ( p1 + p2 ) 2 2 2 s B 4 s1, s2 e s3 & & B ! B " /& 4 B i si s1, s2 e s3 # s1 + s2 + s3 = M 2 + m12 + m22 + m32 si 0 s1 7 # s1 = M 2 + m12 − 2 ME1 E1≥m1 s1 ≤ ( M − m1 ) 2 D s1 ≡ s23 ≥ ( m2 + m3 ) s2 0 2 s3 # ( m2 + m3 ) ≤ s1 ≤ ( M − m1 ) 2 2 ( m1 + m3 ) ≤ s2 ≤ ( M − m2 ) 2 2 ( m1 + m2 ) ≤ s3 ≤ ( M − m3 ) 2 2 s2 4 0 s1 # 7 : & ! E 3 # "4 F p ^2 = −p 3^ p1^ = P ^ ( = (E ) ) s1 = E ^ − E1^ ^ 2 + E3^ 2 = ( M 2 + p12 − m12 + p12 ) 2 2 ( ) = λ (s ,m ,m ) = λ (s ,m ,m ) p1^2 = λ s1 , M 2 , m12 p2^2 p3^2 1 2 2 2 3 1 2 2 2 3 con λ ( x,y,z ) = x 2 + y 2 + z 2 − 2 xy − 2 yz − 2 zx s2# 6 ( s2 = ( p1 + p3 ) = m12 + m32 + 2 E1^ E3^ − p1^ ⋅ p 3^ 2 & !p2^ s2 ) p3^ " s2# s2± = m12 + m32 + 2 ( E1^ E3^ ± p1^ p3^ ) E1^ E3^ s2± = m12 + m22 + s1 1 2 s1 ( s − s − m )( s − m 1 2 1 2 2 ) ( ) ( + m12 ± λ1 2 s1 , s, m12 λ 1 2 s1 , m22 , m32 !s1 0 :" # s1 = M 2 + m12 − 2 ME1 E1max s1min ≡ s1− p1max E1 , p1 # p1max = 1 2M M 2 − ( m1 + m2 + m3 ) 2 M 2 − ( m2 + m3 − m1 ) 2 ) " D ! " !:" )1 !&" !'" : P / '$ : # )1 P + , , C G p1 7 p2 : p3 : , , , , , p4 & ' C& C' G& G' & ' 9 C9 G9 9 P 9 + 9: , , , p1 9 p2 9: p3 9& p4 9' , , 9 , , $ 9 9C 9G 9 $ 9C $ 9G $ 9 7 ! :" !& '" # " : '$ > 7 s = ( p1 + p2 ) = ( p3 + p3 ) = P 2 2 D 2 # ( s = (E ) +E ) s = E1* + E2* * 3 2 * 2 4 = m12 + m22 + 2m2 E1 = m32 + m42 + 2 ( E3 E4 − p3 ⋅ p 4 ) E1 = 1 s − m12 − m22 2m2 p1 = 1 12 λ s, m12 , m22 2m2 ( ) ( m2 s 1 * 2 = + m2 E1 E1,2 m1,2 s p* = p1 ( ) ) s, 7 # m1,m2, ..,mn 7 s≥ # n i =1 s " pLAB " mi ! : '$ # ( t = ( p1 − p3 ) = m12 + m32 − 2 ( E1 E3 − p1 ⋅ p3 ) = m12 + m32 − 2 E1* E3* − p* ⋅ p ' * 2 ( ) u = ( p1 − p4 ) = m12 + m42 − 2 ( E1 E4 − p1 ⋅ p 4 ) = m12 + m42 − 2 E1* E4* + p* ⋅ p ' * 2 D # cos θ3 = 1 1 t − m12 − m32 + E1 E3 p1 p 3 2 cos θ3* = 1 1 t − m12 − m32 + E1* E3* p * p '* 2 ( ) ( ) s + t + u = m12 + m22 + m32 + m42 / / # w ∝ d 3p1d 3p 2 ...d 3p nδ 4 ( P − p1 − p2 − ... − pn ) 1 1 1 ... Fin→out 2 E1 2 E2 2 En # • d 3p i 2 Ei • & 4 H ) • δ. ! # " 4 7 R2 ( E ) = d 3p1d 3p 2δ 4 ( P − p1 − p2 ) 1 1 2 E1 2 E2 D: D: ! " " : # B B : : B ! # B B 7 B B 4 7 " 7 5 δ B B # d3 p = d 4 pϑ ( E ) δ ( p 2 − m 2 ) 2E θ! " B ! " G δ f ( x) = δ ( x-x i ) zeri di f ∂f ∂x xi f ( x ) : p 2 − m2 = E 2 − p 2 − m 2 zeri : E± = ± p 2 + m 2 ∂f ∂E = 2E E± δ ( p 2 − m2 ) = ( d pϑ ( E ) δ p − m 4 2 2 δ ( E − E+ ) + δ ( E − E− ) 2E )=d 3 p dEϑ ( E ) δ ( E − E+ ) + δ ( E − E− ) 2E d3 p = 2E ) R2 ( E ) = : # d 3 p1 d 3 p2 4 δ ( P − p1 − p2 ) = δ 4 ( P − p1 − p2 ) δ p12 − m12 δ p22 − m22 d 4 p1d 4 p2 2 E1 2 E2 : δ# R2 ( E ) = δ 4 ( P − p1 − p2 ) δ p12 − m12 δ p22 − m22 d 4 p1d 4 p2 = δ p12 − m12 δ ( P − p1 ) − m22 d 4 p1 δ B B ! # '$ " 2 ! " 7 # δ ( P − p1 ) 2 (M − E ) (M + E − m22 = δ * 1 =δ 2 2 *2 1 − p1*2 − m22 ) − 2ME1* − p1*2 − m22 = δ M 2 − 2 ME1* + m12 − m22 ) # R2 ( E ) = δ p12 − m12 δ 6 2 − m22 d 4 p1 = d 3 p1* δ M 2 − 2 ME1* + m12 − m22 2 E1* = d 3 p1* δ M 2 − 2 ME1* + m12 − m22 * 2 E1 # E2 d 3p 0 ( P − p1 ) p2 m2 EdE p 2 dpd p2 pdp E dE p dp E dEd p pEdEd # R2 ( E ) = 1 * p1 δ M 2 − 2 ME1* + m12 − m22 dE1*d Ω1* 2 δ * # P1* d Ω1* 4M R2 ( E ) = M 2 + m12 − m22 λ = 2M λ 1 2 M 2 , m12 , m22 → R2 ( E ) = 8M 2 12 P1* = P2* = ( ) (M 2 , m12 , m22 ) 2M d Ω1* "* B # R2 ( E ) = P* B πλ 1 2 ( M 2 , m12 , m22 ) 7 2M 2 = π P* 2M " % B 7# dR2 ( E ) d Ω1* = λ 1 2 ( M 2 , m12 , m22 ) 8M 2 / 7# dw d 1* " 1 4 & # 3 R3 E i 1 / d 3 pi 2 Ei 4 P p1 p2 7# : d 3p1d 3p 3 8 E1 E2 E3 R3 E p3 E E1 E2 E3 # p2 p1 E22 E22 p3 p12 p32 p1 2 p3 2 p1 p3 cos m22 m22 13 # d 3p1d 3p3 p12 dp1d 1 E1 p1dE1d θ& φ& p32 dp3d 1 E3 p3 d 3 3 θ φ4 & ! " 6 E22 p12 p32 2 p1 p3 cos E2 cos 13 m22 13 p1 p3 E2 # E1 p1dE1d R3 E 1 E3 p3 dE3 d cos 13 d 3 E 8 E1 E2 E3 δ θ& E2 E3 θ& ! :"# E1 p1dE1d 1 E3 p3dE3d 8 E1 E2 E3 p1 p3 E2 R3 E E1 0 3 1 8 dE1d 1 4 4 # R3 E : dE1dE3 ! " / : d 2 R3 E dE1dE 2 6 0 p 7 n &I J % : # J dE3 d 3 4 ! > " / # * ! ! % .→ 34 % % → %4 % % + ,. 3 % E1* E2* E3* ! M2 M2 M2 m12 2M m22 2M m32 2M 2 m23 m132 m122 ,. ! % $ & 3 K 3 3 ! " / & ! # Ti 3 Ei* Ti m 3m M Q Q-valore del decadimento i 1 8 0# / !8 >8:>8&>0 K&" # T1 T2 T3 Q 1 r cos 3 Q 1 r cos 3 2 3 Q 1 r cos 3 2 3 7" # x r2 1 xr 3 cos 3 2 x 2 2 1 Q M , ε 4 K 0.17 0.23 0.47 0 ≅7 → ε≅ →C≅:4 / ! 0 <<7 → ε≅, →C≅, ; " # • # R L eventi al secondo area -1 tempo-1 area σ ! ; " 0 σ D # D ! " ' '$ $ ! "# 4 σ & 0 ! " T E L t dt 0 ! @" ) D σ σ ! " σ $ σ σ , ρ% ρ3 Ω # # # dN - β% # " F d d d Fd T 1" L 3" L 2" ! T 1" L 5" ! ! ! ! F 1 2 2 #N dN #V1#t dN #V1#t 2 0 2 0 2 d #N1#N 2 d 1 #V1 2 2 d #t 1 dN #V1 d 2 2 #t 1 2 ! 2 E2 effetto contrazione di Lorentz delle lunghezze m2 ) β3 :β3 # β% 7 #N #V #t dN ! + F 'd ' dN F' ' ' 1 2 ' 2 0 1 0 2 1 ' 2 ' 1 ' 2 A ' 2 " 8" " 2 1 1 1 2 σ • " 7 ! L # " 6 # : 7 # d3 d * dp * f * , * , p* / : 7 # d3 f d * dp ! * f * , * ,p * " &$ 4 φ θ / # p p* , * , p p* , * , * p, , E ! * p* , * , * p* , * , * : " # p* p J cos p* cos * p dp* d * * cos cos Jdpd D 7 )1 # J tg * p* cos * p cos 1 p sin p cos p* E E E ! cos p * E p cos p2 E J p* cos m2 2 2 p cos 2 p cos m2 2 0 " # 3 p f 3 1 f * J p * ' # ,. % 3 +9 1 1 1 J 4 p* 2 3 f 1 f * J p p * p* 0 3 f * * p ) p*0 # ,. ## ) # 3 1 1 4 p0*2 tutto lo spazio degli impulsi 1 1 4 p0*2 1 p0*2 p* p* p* p0* p*2 dp* d p0* p*2 dp* 7 p0* d 3 p* * 1 ## p* E p* E p cos p0* m2 2 E 2 !E p cos p0* " p cos p p F p * 0 p cos p 1 p0* p 1 cos cos p = zero di F p* p0* p ! !E p0* 1 1 cos p2 p J "1 p cos p p p cos ! 1 1 cos J # p0* " p cos 2 cos m2 2 " +9 p3 1 cos p3 1 cos 2 3 3 f 1 * J p f p 6 p0* 1 p 4 p0*2 ! * 1 cos " # f $ 0 p0* 1 p 4 p0*2 ! 1 p 2 dp " cos 1 4 1 2 1 cos Distribuzioni angolari 1.6 1.4 1.2 Distribuzione 1 0.8 β=0.9 0.6 0.4 0.2 β=0.1 0 -1 -0.5 0 0.5 1 cos θ 5 3! # % 5 I! # # ( % # 34%→ 4 s p1 p2 t p1 p3 u p1 p4 s t u 2 2 2 m12 m22 m32 m42 β 2 , % % % K L # % ) ,. & 2 t p1 p3 u p1 p4 m12 m32 2 E1 E3 p1 p3 m12 m42 2 E1 E4 p1 p 4 2 ,. cos * s t ! u m12 s, m12 , m22 m22 m32 s, m32 , m42 m42 12 " +9 cos 2m22 t m12 ! m32 s s, m12 , m22 m12 m22 u u , m22 , m32 m22 12 " # ) D # $ %D & M 8 // A &, N ) ; m32