Squaw Mark Numbers for E852
							JMB, 9/19/95

Note that Squaw will try all permutations of duplicate tracks (except when
it gets confused by identical intermediate particles at different vertices, 
which we have deliberately programmed around).  These additional permutations
will add 1000 for each permutation to the assigned mark number.  The actual
mark number, including permutation part is included in the Squaw output
block for E852.  MM means missing mass.  For intermediate eta, omega,
or etaprime, mark may not be unique.  Also, the mark is not unique across
topologies: marks for pi- pi+ 4 gamma (0-2-2) will be the same as for 4 gamma 
(0-0-0) events.

Mark	Reaction

15	MM --> gamma gamma
10	pi0 --> gamma gamma
20	eta --> gamma gamma
30	etaprime --> gamma gamma

If main vertex fits are not selected, this is the end of fitting.
If none of these fits, only mark 900 is tried.
If the event has 2 or 3 charged pions, the following will be tried:

100	eta --> pi- pi+ pi0, pi0 --> gamma gamma
105	MM --> pi- pi+ pi0, pi0 --> gamma gamma
110	omega --> pi- pi+ pi0, pi0 --> gamma gamma
120	etaprime --> pi- pi+ eta, eta --> gamma gamma
125	MM --> pi- pi+ eta, eta --> gamma gamma

Main Vertex fits:
Individual permutations are killed early if the corresponding gamma-gamma
fit above failed.

2nm	pi- p --> (pi- pi+) + m (pi0/eta/etaprime) + neutron 
		pi0/eta/etaprime --> gamma gamma
	if 3 charged pions, pi-, pi-, pi+, then neutron replaced by proton.
	m is always the number of 2 gamma neutrals at the main vertex.
	n is the number of etas in the fit, n=1-3, the rest are pi0.
	n=5-7 means 1-3 etaprimes with the rest pi0.
	n=8-9 means 1 or 2 etaprimes with the rest etas.
	e.g.:	202 is 2 pi0s
		212 is 1 eta + 1 pi0
		222 is 2 eta, no pi0
		252 is 1 etaprime + 1 pi0
		282 is 1 etaprime + 1 eta

4nm	pi- p --> (pi- pi+) + m (pi0/eta/etaprime) + MM
		pi0/eta/etaprime --> gamma gamma
	m and n as above

Marks 300 and 500 are not tried unless mark 200 gives at least one good fit.
Marks 300 and 500 are not tried unless mark 100-120 give at least one good fit.

3nm	pi- p --> (pi-) eta/omega/etaprime + m (pi0/eta/etaprime) + neutron
		eta/omega --> 3pi or etaprime --> eta pi pi
		pi0/eta/etaprime --> gamma gamma
		neutron replaced by proton if 3 charged pions at MV.
	m is always the number of 2 gamma neutrals at the main vertex only.
	n is the number of etas in the fit, as above, including 3 pi etas.
	e.g.:	321 is 2 etas, one to 3pi, 1 to 2 gammas, 
			pi0 to 2 gamma at secondary vertex only.
		361 is 2 etaprimes, one to eta 2pi, 1 to 2 gammas,
			eta to 2 gamma at secondary vertex only.
		381 may be 1 etaprime to eta 2pi, 1 eta to 2 gammas,
			eta to 2 gamma at secondary vertex only.
	    or	381 may be 1 eta to 3pi, 1 etaprime to 2 gammas,
			pi0 to 2 gamma at secondary vertex only.

5nm	pi- p --> (pi-) eta/omega/etaprime + m (pi0/eta/etaprime) + MM
		eta/omega --> 3pi or etaprime --> eta pi pi
		pi0/eta/etaprime --> gamma gamma
	m and n as above

900	pi- p --> (pi- pi+) + all gammas + MM
		All at main vertex missing mass fit, no pi0s, etas, etc.