Meeting XI Bevatron Research Conference Page: 2 of 3
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(2) UCRL - 2464
orbital angular moment involved in the production.)
(2) There is a strong tendency toward coplanarity between production and
decay planes of A\.,' .
(2), if confirmed; shoes that /\0 remembers its production plane. -ow if
J t 1/2; the A0 has to decay spherically symmetricaly in itsswn rest system
Classically the plane of decay is perpendicular to I because J " xt. Quantum
mechanically, if 9 is the angle between and decay plane, the angular distribution
is (1 - cos 9)/ . Therefore the data imply that \0 is produced with high spin
perpendicular to the reaction plane. (Even if data were more extensive they could
give only a lover limit, on J since the Ao is not made with 100 percent polarization.,
It seems feasible to change orientation of .A..A spin between production and
decay by a strong magnetic field appropriately directed in the production plane.
If A has a gyromagnetic ratio about that of a proton; then in 3 x 110 seG
(lifetime of .A,) a field of 50,00C gauss can change the decay plane by half a
radian. If data like that in table I continues, this change and its sign is easily
detected. Magnetic fields of order 75,000 gauss will be available for plate work.
Because A-o's are relatively slow in the laboratory, there is no time dilitation;
it may be possible to select only longer lived ( > 3 x 10-10 sec) jAy to increase
For this effect to be measured, one should have much greater numbers of J\R
than made at Brookhaven. Solid targets will certainly increase number. Will pro-
duction and passage through matter spoil coplanarity: This is also important if
plates are used to detect the decay.
1) Passage through matter:
Calculation shows negligible depolarization in passing through matter
for any reasonable gyromagnetic ratio. Also, even an unreasonably large
A 0 quadrapole moment will not jepelarize. Positively charged polarized
particles (except positrons) will come to rest in matter without losing
their polarization. Negatives may be depolarized when they come to rest and
are captured into atomic levels, especially if they have quadrapole moments,
2) Production of f\Q in C by n-
The n- can scatter on a nucleon of carbon before J production.
Experiments at 1.5 Bov give a n- - p cross section of 30 mb. About 15 mb
is diffraction and therefore small angle ( < 6'), Carbon has too few nucleons
for more than one scatter to bo probable with this cross section. Therefore
the direction of a n- is most probably almost not altered in a C nucleus If
/\ does not interact with a nucleon of C much more strongly than n or p
(this would seem to be the case if current interpretation of delayed n's from
nuclear fragments is correct) then the polarization of ,frO from n- + p and
n" + C should be similar.
Since the cross section for _/\O production in H at 1.5 Bov is ", 1 mb,
higher energy mesons incident on C should produce enough /\ c mesons to make the
above experiment feasible. Similar experiments could be suggested for other mesons
if they have a spin > 1/2 and are produced polarized.
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Wenzel, William A. Meeting XI Bevatron Research Conference, article, January 12, 1954; Berkeley, California. (digital.library.unt.edu/ark:/67531/metadc876331/m1/2/: accessed October 21, 2018), University of North Texas Libraries, Digital Library, digital.library.unt.edu; crediting UNT Libraries Government Documents Department.