To investigate the momentum distribution of nucleons inside the nuclei of light el?ments of emulsion using nucelar emution techniques

Abstract

This projer::t r a l e t e s to the u l t Lo.a t.e structure of all matter. .Ju s t .:::-: the aL01n is a srna Ll soler- ?1':j: -: n with tiny electrons going around its central part known as the nucleus, s l m iLn r l y , the nucleus Lts e l f is a complex structure. It i? maJe up of n?utrc11s and protons, two particles which ;;ire ci:.,out 1,840 times more rne s s.l ve than ti1e electron. fhey ?;re, spoken of col 1 ec ti v e l y as nucleons .. f-,ucl eons ar e not stationary bu c mo vo w i cr. tr erne nc.o ua s pe ed s w i t h Ln the nuc Le L of the a torns , Our pr ob.l er., is to find out tl e morne n t a (products of mn ss ;3.nd velocity) of these: mov ing nuc l eons. The straigh?forward approach to studying the v a ri ous properties of t h e nucleus is to shoot the probing particles at them and measure the effects pro?uced. There is, r.owe ve r , one we l 1 known 1 irri t e t i on in this endeavour: the v1r1v01 cngth of the probi nCJ p s r t i c l e must be of the o r o c r of thr-, s I z e of the nuclei bo Lnq studied. Ord i.n a r y Li qh t for ex?m?le, has a wavcl?nqth ahout 10-7m, which is many order? -14 larger than the nuclAar size (10 mJ, and is no l: s u i t Ab 1 e for th i s ?1 tud y • I t is therefore n e c es s a r y to cm p I oy parti cl es such ;-.\s e 1-.?c tr...)n s, protons, an ti p r o tons a. ,d nout.r oris as pr obe s since their wav e Len qt.h s a r e much srna i ler. In this project v•e e:n!.1loy a very effective probe ( the an t I>- proton) which goes in:::idr_ the nucleus of an a t.orn anc Ln t e r= act? with the nucleons. 7hese interactions, known ?s ;..! nr. i h i l c! t i c n ?.:; , revca l t n E uc h a vi o 1 r of the inhar i - t: n ts of the nucleus, that is, of ?rotons and neutrons individually, as ·,;?11 a s the:l.r c o l Lric t.Lv e ber1aviour. By studying large nur.ue r of a n n Lh i La ti.oris , the d i.s tr Lbu ti on of momenta can be d:?t·::rt"incd. Once the rno.nr-?nta of the nucleons are known, ,.any other properties of the nucleus

I.. ,

f?ler,1..;.nt can be k nown , Th( s t a t e of the nuc Le i. a f t e r ' ;-_rnnihilation c an al so t h r ow llght on nuclear energy levels and tne whole science of nuclear spectroscopy, but there are better techniques availa?le for this study than the nuclear ornu I sions. The p r o j ec t h a s great be a r I ng on many r-robLerns of nucle2r physics. The rnomcn t ur-r.

, d i o tr i bu t Lon of nuclei of light 8lements was found by measurin? the lengths of tr2cks of recoil of these nuclei and wc-:is c ornp ar ed with the d Ls tr Lbtr t.-« ions predicted for sand p-state nucleons of carbon ?iven by Garron et al. It is f oun.I that the distribution closely c o rr e s po nd s with the s-:3tate nucleons. It is, therefore,

concluded ?hat annihilation takes place chiefly on the s- nucle?ns of the light elements of emulsion. This result

s i.ows an Ln h i.b i. tion of interactions w.i th r-state nucleons the t L:-;, with nucleus po s s e ss ing higher angular momenta. Similar inhibition has Le e n r er-ort eo by Go od i.nc, 2r: .... hJgh for

s how s that the upper Li m i t of nucleonic momentum extends up to 5 5 0 t': e v I c • CtJr results a r e different from the earlier work done by the Durham grcup usi.nc; the same technique.