2V一阶波恩近似条件<<1(低能)或h?86.4分波方法2ml V。01n(ka)<1(高能)并不总能满足-h?k一、自由粒子态:平面波与球面波7k大上1(x /yr(+)[eikz +f(K',k)(2元)3/24元2m1(K'|T|K)f(k',k)T=V+VE-H+ieh?L22p2h?2aH=or22mr22m2mr or[H, P] = O, [H, L] = [H, L?] = O两种选择:hk,k)=|≤);球面波:[E,1,m>F平面波:2m对具确定角动量的态受散射的影响感兴趣分波法
§6.4 分波方法 一、自由粒子态:平面波与球面波 ◼ 两种选择: ◼ 平面波: ;球面波: |E, l, m> ◼ 对具确定角动量的态受散射的影响感兴趣→分波法 2 [ , ] 0, [ , ] [ , ] 0 z H p H L H L = = = 2 2 , 2 k E k k m = = 2 2 2 2 2 2 2 ( ) 2 2 2 p L H m m r r r mr = = − + + 2 2 4 ( ', ) ' m f k k k T k = − 大 ( ) 3/2 1 [ ( ', ) ]; (2 ) r ikr ikz e x e f k k r + → + 2 0 2 0 2 | | 一阶波恩近似条件 1(低能)或 2 | | ln( ) 1(高能)并不总能满足 m V a m V a ka k
、球面波的动量与坐标空间波函数:动量空间波函数(KE,1,m)=[(E,1,mK)][(E, 1, m|D(g, 0, 0)|k2))*=[Z[ dE'(Elm|D(0,0, 0)[E'1'm")(E'1'm'|k2)]D(0)*(p, 0, 0) [(Elm = 0| k2)]*4元Y"(h) [(Elm = O| k2)* = gie(k)Y"(k21+(K- E)(K[E, 1, m)(K[(H - E)|E, 1, m) = 0 :2mh~k2Eg1e(k)2m
二、球面波的动量与坐标空间波函数: ◼ 动量空间波函数 * * * ' ' ( )* * 0 * , , [ , , ] [ , , ( , ,0) ] ˆ [ ' ( , ,0) ' ' ' ' ' ' ] ˆ ( , ,0)[ 0 ] ˆ 4 ˆ ˆ ( )[ 0 ] ( ) ( ) ˆ 2 1 l m l m m m l lE l k E l m E l m k E l m D kz dE Elm D E l m E l m kz D Elm kz Y k Elm kz g k Y k l = = = = = = = = + 2 2 2 2 ( ) , , 0 ( ) , , 2 ( ) ( ) 2 lE kl k k H E E l m E k E l m m k g k N E m − = = − = −
据:S(E-E)S,.S'1'm'[Elm)=「dk(E'1'm'|k)(k|ElmHhk2h2k2= J dk [Nk s("- E)Y"(K)Y"**(K)2m2mmk= N s(E - E')Sh?h?k?h得:gie(k)H22 mVmkh8(E,- E)Y"(k)(k|Elm)=VmkhK)=Z[dE|Elm)(Elm|k)=ZZElmym*2h?k2mk1=0 m=-1FIm2m球面波对研究粒子衰变过程也特别有用(角动量守恒)
得: 据: ◼ 球面波对研究粒子衰变过程也特别有用(角动量守恒) ' ' 2 2 2 2 2 '* ' 2 2 ' ' ( ') ' ' ' ' ' ' ( ') ( ) ( ) ( ) ˆ ˆ 2 2 ( ') ll mm m m kl l l kl ll mm E E E l m Elm dk E l m k k Elm k k dk N E E Y k Y k m m mk N E E − = = = − − = − 2 2 ( ) ( ) 2 lE k g k E mk m = − 2 2 * 0 2 ˆ ( ) l m l k lm l m l E m k dE Elm Elm k Elm Y k mk = = − = = = ˆ ( ) ( ) m k l k Elm E E Y k mk = −
坐标空间波函数(x|Elm)=「dk(x|)《|Elm)hk- E)Y"(K)[2dkd(x|)2mmkY"(h) 2/4 m3/4E1/4exp(ik.x)oik.x= Z (21 + 1)i'j;(kr)P(k . x)[d?,福一h3/2(2元)3/21Z(21'+ 1)i'j,(kr) d2,P,(K.)(R)mk(2元)3/2h/Vmk4i'j,.(kr)[ d,**()y"(x)"(k)(2元)3/2 hmil2mk(k = 2mE /n)j,(kr)y"(x)h元h(k|Elm)S(E)-E)Y"(k)Vmk
◼ 坐标空间波函数 2 2 2 1/4 3/4 1/4 3/2 3/2 3/2 ' ' ' '* ' ' ' ' ' ' ˆ ( ) ( ) 2 exp( ) 2 ˆ ( ) (2 ) 1 ˆ ˆ (2 ' 1) ( ) ( ) ( ) ˆ (2 ) ˆ ˆ 4 ( ) ( ) ( ) ( ˆ m k l m k l l m l l l k l l m m m l l l l k l m x Elm dk x k k Elm k k dkd x k E Y k mk m ik x m E d Y k mk l i j kr d P k x Y k i j kr d Y k Y x Y = = − = = + = ( / ) 3/2 ) (2 ) 2 ( ) ( ) 2 ˆ l m l l mk k i mk j kr Y x k mE = = ( ) ( ) m ˆ k l k Elm E E Y k mk = − ˆ (2 1) ( ) ( )ˆ ik x l l l l e l i j kr P k x = +
h三、分波展开(对球心势)- E)Y"(kS(E.4lnVmk1T-V+V.1E-Ho+ie4元2m(K'|T|K)fCkh?4元2mZdEdE'《'[E'1'm")《E'I'm'|T|Elm)《Elm|)h?lm,1m24元ZT(E)Y"(K')Y"*(k) = f(0)k1m-T(E), =Z(k,')Z (21 + 1)f,(k)P(cos 0)(f(k) = -k
三、分波展开(对球心势) ( = 2 2 2 2 , ' ' 2 * 4 ( ', ) ' 4 ' ' ' ' ' ' ' ' 4 ˆ ˆ ( ) ( ') ( ) ( ) ˆ ˆ (2 1) ( ) (cos ) ( ) ( ), ( , ') lm l m m m l l l k lm l l l l l m f k k k T k m dEdE k E l m E l m T Elm Elm k T E Y k Y k f k l f k P f k T E k k k = − = − = − = = + = − ˆ ( ) ( ) m k l k Elm E E Y k mk = −