- Email: [email protected]
Recent Ψ′ results from Mark III
Nuclear Physics B (Proc. Suppl.) 16 (1990) 326-330 North-Holland
326
cent
DS
is from
III*
onen MIR University of Washington, Seattle, WA 95195 representing the Mark III Collaboration* at the Stanford Linear Accelerator Center, Stanford University, Stanford, CA 94309. Abstract Results on y/decays from Mark III are presented. With a data sample of 240,E W'-+y c, W'-->ont, V'-+,y6at, and V events, we measurer--~rc*tc-yi, perform a search for V'-+pn. Implications ofour measurements are discussed. 1. Introduction Fifteen years after its discovery, the charmonium system (Fig. 1) still poses many unanswered experimental and theoretical questions.
reported by the ISR experiment R7042), but have not been seen at e+e- machines. It is important to verify the Tlr, , which has only been observed as the recoil mass of a photon coming from Vdecays3}, and measure its exclusive decays . Little is known about hadronic and radiative decays of the Xc and 71c states.
From ey' --3n+n- Vt decays one can study the all neutral Videcays, and also normalize the current Mark III yr data. In addition, an accurate measurement of V- .U+juwill reduce the error on as through the relation4}: F(W-~8g8)
2.8L FIGURE 1 :
JPC
-+ 0
The charmonium system.
The V' 1) is the 2351 cc vector meson. It is the only well established radial excitation of the yr. There are many measurements to be made at the ty'. Two of the low-lying charmonium states are still unconfirmed, although there is evidence for both. Indications for the 1P1 state, hc, were * Work supported by
_5 M2 (IC2-y)(as(mc)}3 (1+ 1 .6ocs) . 18 4mc nag2 n
The error on yi-*yf.u - is currently 13ß'o . One can also search for vector glueball candidates, which might be near the yi Their possible mixing with the Vi will be discussed below. Several experiments have previously studied the W' Most results come from Mark I with 0.4x106 yi'events, Mark II with 1.0x106 yi'events, and Crystal Ball with 1.8x106 Vf'events. These events were all collected at the SPEAR e+e- storage ring at SLAC.
E contract DE-AC03-76SFOO515 and by the National Science Foundation.
0920-5632/90/$3 .50 © Elsevier Science Publishers BY. North-Holland
R. Mir, Mark III Collaboration /Recent V results from Mark III Mark III at SPEAR has recently completed a data taking run at the yf' energy . Our results are based on a sample of (236t35)x 103 yr' events. Approximately 400 of this data
was taken in a five day run in 1982, and the remainder in a three month run in the fall of 1988 . In this paperwe present results on yf'-+ n+a - yf,
11r-~ yxc, V'-+Y4nt, W'-+76n±, and perform a search for yf-~px.
2. Inclusive yr'-+n+n - yf decays .
327
The Mx +x- is shown in Fig. 2b. The shape of the x+x- spectrum peaks at high masses, as observed in previous experiments . No hints of resonance structure is seen. A theoretical discussion of this shape can be found in 6)
In the second method, V-+neutrals+yf, yf-+It+It-
was detected and PDG values for yf' -+neutrals+Vrand yf-~u+It- were used to measure the number of Wevents.
The two methods agree to within 1% . The weighted average of events found is: (236±35)x103. 3. vf'-+,yYVY-Yïe + e'(lt+ ;L-) decays.
3.05 3.10 3.15 GeV/c 2 recoil mass from x+x-
> F Mark III
ïau
300
preliminary
r
200
r i
100
r
0.4
0.5
M(x+x-)
GeV/c
FIGURE 2: yr' -~x+x-vy, a) recoil mass from x+ a- ; b) M(X+Z-).
_
The yf'--~n+n-yf decay is used to determine the
number of yf'events in two independent ways . In the first,
inclusive yr production from yf' -~n+tt- yf is measured. Events were selected with at least two charged tracks,
assumed to be pions. The recoil mass from the x+n- system is shown in Fig. 2a. A clear Vf peak is seen . No hints of resonance structure other than the yf are seen. To estimate the number of 'events, the PDGS) value for V'-+x+x- yf was used .
(YY) 5
GeV/c2
FIGURE 3: f' --~yyyf-+yNe +e-(~+It-) ; a) scatter plot of M(yy)2 Vs. Mhigh(7VV)2 ; b) M(yy); c) Mhigh(yV)2 after an anti il cut.
Events were selected with two charged tracks and two or more photons. Tree events were fit to yf -~ Yt e+e- or yf'--+ yy g*A-, with the mass of the two charged tracks constrained to the W mass . The fit with the best probability
R. Mir, Mark III Collaboration /Recent V results from Mark III
328
was kept . Fig. 3a shows a scatter plot of M(Yy)2 vs. high(Y )2, where Mhigh(YVf) is the high mass y combination.
Fig. 3b shows the M(yy) distribution . A clear T1
signal is seen . The Monte Carlo efficiency is 56%, and the
mass resolution 3 MeV. We measure a preliminary branching ratio of: B(W'~-4rl0 = (2 .5±0.2_+0.7)% .
Fig. 3c shows the Mhigh(y1V; distribution after cutting away the area 0.540
region). We observe the Xc 1 and Xc2 states . The Monte Carlo efficiency is 54%, and the mass resolution 7 MeV.
3.3
3.4 3.5 M(4n±)
3.6GeV/c2
We measure preliminary branching ratios of: (~4yw) _ (9 .4±0.5±2.5)%
and
(oV` 411M2) _ (11 .0±0.7±2.9)%, where the first error is statistic and the second systematic . . Vf'-->y4nt, V'-+y6n± . To study the y4nf final state, events were selected with four charged tracks and one or more photons. The
events were fit to vy'-+y4n±. The fit with the best probability was kept. Events were rejected if the recoil
mass from any n+n- pair was equal to Mq. The mass of the 4n+ system is shown in Fig. 4a . The Xc states are clearly seen . The Monte Carlo efficiency is 23%, and the mass
FIGURE 4: a) W' ~y4 e-, b) Vi-->y4 At 5. The pu puzzle .
resolution 13 MeV.
2 .0
For the 760 final state, events were selected with six charged tracks and one or more photons . The events were fit to W~-+
rtk The fit with the best probability was kept. Events were rejected if the recoil mass from any n+n-
1.01~ ..... .... ...... ..... ... .....4 ............................
pair was equal to Mly . The mass of the 6n+ system is shown in Fig. 4b. Again, clear xc states are seen, though
the Xcl and Xc2 are not as well resolved. The Monte Carlo
.0L 0
efficiency is 24%, and the mass resolution 17 MeV. We measure preliminary branching ratios of. B(
-4
c)(Xc-44n+):
B(11r-4yxc)(Xc-46n±):
.c0=(2 .4±0 .2±0.7)x 10-3 7
Xc0=(l .46±0.15±0.43)x10 -3
.c1=(0 .93±0.13±0.28)x10-3 7
Xc1=(0.44±0.10±0.15)x10-3
Xc2=(l .9±0 .2±0.6)x10-3
Xc2=(0.88±0.20±0.27)x10 -3 .
R=B -~X)/o.13B (y r-~X) (Nt Mark I Mark II Crystal Ball PPS lin e+e- PPnn 1
KK*
FIGURE 5: R=B(yi'-4X)l0 .13B(yi-4X) . The hadronic decay rate of the yrrelative to the W should scale as the ratio of the three gluon widths, which are proportional to the leptonic widths divided by the full widths :
R. Mir, Mark III Collaboration /Recent V results from Mark III B(V'->hadrons) _ B(V'-4ggg) _ ï(yr-~e+e')I'( B(Vr-+hadoons)
B(yr-+ggg)
I'(yf-+e+e-)I'(yr)
=(12 .2±2 .4)% .
329
The, Mark III data is used to search for W~-4p .
Events were selected with two charged tracks and two more photons. The events were fit to The fat with the best probability was kept. Events were rejected if
the recoil mass from the it+n- pair was consistent with The yy mass is shown in Fig. 6a. A small no signal is seen, providing evidence for VV' sic+ft-ico. A handscan is
~N 20
pe ormed to remove events with extra photons. The dalitz plot of the it+irito events is shown in Fig. 6b . Twenty
10
it+it-no events remain, two of which fall in the pit bands (770.±150 MeV/c2).There is no evidence for the triangular pit bands observed in yr-apO). We therefore set an up 0.1
0.2 M(YY)
0.3
c
Gev/
v
limit for these two events . The Monte Carlo efficiency is 32%. We obtain :
B(yf'-+pit ) < 7.0 x 10-5 (90% C.L.) . Assuming all three pion events are non-resonant, we obtain:
B(yf~~+rc-n~) = (0.26±0.05±0.05)x10-3. 6
2
Our results confirm the Mark II measurement. It is not understood whether the VV' decay is unexpectedly suppressed or the if decay enhanced. Because of the well
defined nature of this puzzle, there have been a number of theoretical attempts to explain it .
FIGURE 6: yf-4yyrc+xc; a) M(yo; b) M(n +no)2 vs .
Previous experiments (Mark I, Mark II and Crystal
Ball) have measured several hadronic decay modes of the Vi'that scale to 13% of the off rate, but did not observe any of the vector-pseudoscalar (VP) combinations! In particular, the pit decay of the V has a large branching ratio
(1 .3%), while the pit decay of the Vis not seen (<0.008%
at 90% C.L.7)) . The comparison between observed and predicted V decay rates is shown in Fig. 5, where R, the ratio of the measured B(V-4X) divided by the expected 0.13.B(yf-->X), is shown for various hadronic final states.
Freund and Nambu9), and later hlou and Soni 10) suggested that a vector glueball near the o fcouples strongly
to VP pairs, but not to e+e-, thus enhancing the rate at the oY Brodsky, Lepage and Tuan 11 ) refined this notion with the observation that VP final states are suppressed by the QCD theorem for yf decays, but not for the decays of the
glueball . Another model is that of Chaichian and Torngvist12 ) who propose that the effect is due to form factors. A recent model by Pinsky13), relates the VP decays of the V and yf to their decays into yqc, and observes that V-arlc is a hindered M1 transition .
R. Mir, Mark III Collaboration/Recent V results from Mark III
330
eferences :
. Conclusions. Our results are summarized and compared to other k U14) results were experiments in Table I. Many of the tincluded in the P average, and are therefore included in Table I. TABLE I. P
r
branching ratios. average Mark 11(thesis) °
:-+Vcl-->Y4± °47X-c-2-+ W'-41Xco-4î-
Yr-4 pre
(8.7±0.8)% (11 .0±0.7±2 .9)% (7.8±0.8)% (2.4±0.12±0.7)x -3 (3.4±0 .6>10-3 (2 .140.2)x10-3 (0.93±0.13±0.28)x -3 (1.4±0.4)x10'3 (0.840.1)x10-3 (1 .9±0.2±0.6)x10-3 (1 .7±0.4)xl0 -3 (1 .340.1)x10-3 (1 .46±0.15±0.43)x 10-3 (1.4±0.5)x 10-3 (1.840.3)x10-3 (0.44±0 .1 ±0.15)x10-3 (1.9±03)x10 -3 (0.9±0 2)x10-3 (0.88±0.20±0.27)x 10-3 (0.94±0.62)x10-3 (1.710.3)x10-3 4x -s (90% cl) <8.3x10-5 (90%cl)
In summary, Mark III has obtained a rather small yr data sample. With this data, precise measurements of V' branching ratios have been obtained. The px puzzle persists . New theoretical models try to explain the discrepancy between grand Videcays to VP mesons. More data is clearly needed to unveil the other experimental questions that remain unsolved. I wish to thank the SPEAR and SLAC Technical staff. I sincerely thank Gary Gladding who presented these results on my behalf at Madrid.
D. Coffma, G. Dubois, F. DeJongh, G. Eigen, J. Hausee, D. Hidin, A. Mincer, C. Matthews, J. : J. Adler, J. Richman, W. Wisniewski, Y. Zhu . rient, T. Browder, K. Bunnell, R. Cassell, D. Coward, . Einsweiler, C. Grab, P. Kim, J. Labs, A. Odian, D. Pitman, R. Schindler, W. Tok±, F. Villa, S. Wasserbaech, D. Wisinski. Banta Cr z: Z. Bai, M. Burchell, D. Dorfan, J. ' ard, C. Gatto, C. Heusch, L. Kopke, W. Lockman, R. Partridge, H. Sadrozinski, M. Scarlatella, T Schalk, A. Seiden, A. Weinstein, S. Weseler, R. Xu. G. Blaylock, B. Eisenstein, T. Freese, G. Gladding, J. Izen, S. Plaetzer, C. S±mopoulos, I. Stockdale, B. Tripsas, A. Wattenberg. : U. allik, . Roco, M. Wang. ashi ton : J. Brown, T. Burnett, V. Cook, A. Li, R. Mir, P. Mockelt, B. Nemati, L. Parrish, H. Willutzki . 1) The gris also called 3685) and ip(2s) . 2) C. Baglin et al., Phys. Lett. B171, 135 (1986). 3) C. Edwards et al., Phys. Rev. Lett. 8, 70 (1982). 4) W. Kwong and P. Mackenzie, Phys. Rev. 37, 3210 (1988) . 5) Particle Data Group, G.P. Yost et al., Phys. Lett. 204. 1 (1988). 6) T.N. Truong, Proc. of the 3rd Int . Conf. on Hadron Spectroscopy, Ajaccio, France, Sept. 23-27, 1989. 7) M. Franklin et al., Phys. Rev. Lett. 51, 963 (1983) . 8) D. Coffman et al., Phys. Rev . D38, 2695 (1988) . 9) P. Freund and Y. Nambu, Phys. Rev. Lett. 34, 1645 (1975 ;. 10) W. Hon and A. Soni, Phys. Rev. Lett. 50, 569 (1983) 11) S . Brodsky, P. Lepage and S.F. Tuan, Phys. Rev. Lett. 59, 621 (1987. 12) M. Chaichian and N. Tomqvist, preprint HU-tft-8811, 1988. 13) S. Pinsky, Ohio State Univ. Preprint (1989) . 14) T. Himmel, Ph.D. Thesis, SLAG-223, 1979.
326
cent
DS
is from
III*
onen MIR University of Washington, Seattle, WA 95195 representing the Mark III Collaboration* at the Stanford Linear Accelerator Center, Stanford University, Stanford, CA 94309. Abstract Results on y/decays from Mark III are presented. With a data sample of 240,E W'-+y c, W'-->ont, V'-+,y6at, and V events, we measurer--~rc*tc-yi, perform a search for V'-+pn. Implications ofour measurements are discussed. 1. Introduction Fifteen years after its discovery, the charmonium system (Fig. 1) still poses many unanswered experimental and theoretical questions.
reported by the ISR experiment R7042), but have not been seen at e+e- machines. It is important to verify the Tlr, , which has only been observed as the recoil mass of a photon coming from Vdecays3}, and measure its exclusive decays . Little is known about hadronic and radiative decays of the Xc and 71c states.
From ey' --3n+n- Vt decays one can study the all neutral Videcays, and also normalize the current Mark III yr data. In addition, an accurate measurement of V- .U+juwill reduce the error on as through the relation4}: F(W-~8g8)
2.8L FIGURE 1 :
JPC
-+ 0
The charmonium system.
The V' 1) is the 2351 cc vector meson. It is the only well established radial excitation of the yr. There are many measurements to be made at the ty'. Two of the low-lying charmonium states are still unconfirmed, although there is evidence for both. Indications for the 1P1 state, hc, were * Work supported by
_5 M2 (IC2-y)(as(mc)}3 (1+ 1 .6ocs) . 18 4mc nag2 n
The error on yi-*yf.u - is currently 13ß'o . One can also search for vector glueball candidates, which might be near the yi Their possible mixing with the Vi will be discussed below. Several experiments have previously studied the W' Most results come from Mark I with 0.4x106 yi'events, Mark II with 1.0x106 yi'events, and Crystal Ball with 1.8x106 Vf'events. These events were all collected at the SPEAR e+e- storage ring at SLAC.
E contract DE-AC03-76SFOO515 and by the National Science Foundation.
0920-5632/90/$3 .50 © Elsevier Science Publishers BY. North-Holland
R. Mir, Mark III Collaboration /Recent V results from Mark III Mark III at SPEAR has recently completed a data taking run at the yf' energy . Our results are based on a sample of (236t35)x 103 yr' events. Approximately 400 of this data
was taken in a five day run in 1982, and the remainder in a three month run in the fall of 1988 . In this paperwe present results on yf'-+ n+a - yf,
11r-~ yxc, V'-+Y4nt, W'-+76n±, and perform a search for yf-~px.
2. Inclusive yr'-+n+n - yf decays .
327
The Mx +x- is shown in Fig. 2b. The shape of the x+x- spectrum peaks at high masses, as observed in previous experiments . No hints of resonance structure is seen. A theoretical discussion of this shape can be found in 6)
In the second method, V-+neutrals+yf, yf-+It+It-
was detected and PDG values for yf' -+neutrals+Vrand yf-~u+It- were used to measure the number of Wevents.
The two methods agree to within 1% . The weighted average of events found is: (236±35)x103. 3. vf'-+,yYVY-Yïe + e'(lt+ ;L-) decays.
3.05 3.10 3.15 GeV/c 2 recoil mass from x+x-
> F Mark III
ïau
300
preliminary
r
200
r i
100
r
0.4
0.5
M(x+x-)
GeV/c
FIGURE 2: yr' -~x+x-vy, a) recoil mass from x+ a- ; b) M(X+Z-).
_
The yf'--~n+n-yf decay is used to determine the
number of yf'events in two independent ways . In the first,
inclusive yr production from yf' -~n+tt- yf is measured. Events were selected with at least two charged tracks,
assumed to be pions. The recoil mass from the x+n- system is shown in Fig. 2a. A clear Vf peak is seen . No hints of resonance structure other than the yf are seen. To estimate the number of 'events, the PDGS) value for V'-+x+x- yf was used .
(YY) 5
GeV/c2
FIGURE 3: f' --~yyyf-+yNe +e-(~+It-) ; a) scatter plot of M(yy)2 Vs. Mhigh(7VV)2 ; b) M(yy); c) Mhigh(yV)2 after an anti il cut.
Events were selected with two charged tracks and two or more photons. Tree events were fit to yf -~ Yt e+e- or yf'--+ yy g*A-, with the mass of the two charged tracks constrained to the W mass . The fit with the best probability
R. Mir, Mark III Collaboration /Recent V results from Mark III
328
was kept . Fig. 3a shows a scatter plot of M(Yy)2 vs. high(Y )2, where Mhigh(YVf) is the high mass y combination.
Fig. 3b shows the M(yy) distribution . A clear T1
signal is seen . The Monte Carlo efficiency is 56%, and the
mass resolution 3 MeV. We measure a preliminary branching ratio of: B(W'~-4rl0 = (2 .5±0.2_+0.7)% .
Fig. 3c shows the Mhigh(y1V; distribution after cutting away the area 0.540
region). We observe the Xc 1 and Xc2 states . The Monte Carlo efficiency is 54%, and the mass resolution 7 MeV.
3.3
3.4 3.5 M(4n±)
3.6GeV/c2
We measure preliminary branching ratios of: (~4yw) _ (9 .4±0.5±2.5)%
and
(oV` 411M2) _ (11 .0±0.7±2.9)%, where the first error is statistic and the second systematic . . Vf'-->y4nt, V'-+y6n± . To study the y4nf final state, events were selected with four charged tracks and one or more photons. The
events were fit to vy'-+y4n±. The fit with the best probability was kept. Events were rejected if the recoil
mass from any n+n- pair was equal to Mq. The mass of the 4n+ system is shown in Fig. 4a . The Xc states are clearly seen . The Monte Carlo efficiency is 23%, and the mass
FIGURE 4: a) W' ~y4 e-, b) Vi-->y4 At 5. The pu puzzle .
resolution 13 MeV.
2 .0
For the 760 final state, events were selected with six charged tracks and one or more photons . The events were fit to W~-+
rtk The fit with the best probability was kept. Events were rejected if the recoil mass from any n+n-
1.01~ ..... .... ...... ..... ... .....4 ............................
pair was equal to Mly . The mass of the 6n+ system is shown in Fig. 4b. Again, clear xc states are seen, though
the Xcl and Xc2 are not as well resolved. The Monte Carlo
.0L 0
efficiency is 24%, and the mass resolution 17 MeV. We measure preliminary branching ratios of. B(
-4
c)(Xc-44n+):
B(11r-4yxc)(Xc-46n±):
.c0=(2 .4±0 .2±0.7)x 10-3 7
Xc0=(l .46±0.15±0.43)x10 -3
.c1=(0 .93±0.13±0.28)x10-3 7
Xc1=(0.44±0.10±0.15)x10-3
Xc2=(l .9±0 .2±0.6)x10-3
Xc2=(0.88±0.20±0.27)x10 -3 .
R=B -~X)/o.13B (y r-~X) (Nt Mark I Mark II Crystal Ball PPS lin e+e- PPnn 1
KK*
FIGURE 5: R=B(yi'-4X)l0 .13B(yi-4X) . The hadronic decay rate of the yrrelative to the W should scale as the ratio of the three gluon widths, which are proportional to the leptonic widths divided by the full widths :
R. Mir, Mark III Collaboration /Recent V results from Mark III B(V'->hadrons) _ B(V'-4ggg) _ ï(yr-~e+e')I'( B(Vr-+hadoons)
B(yr-+ggg)
I'(yf-+e+e-)I'(yr)
=(12 .2±2 .4)% .
329
The, Mark III data is used to search for W~-4p .
Events were selected with two charged tracks and two more photons. The events were fit to The fat with the best probability was kept. Events were rejected if
the recoil mass from the it+n- pair was consistent with The yy mass is shown in Fig. 6a. A small no signal is seen, providing evidence for VV' sic+ft-ico. A handscan is
~N 20
pe ormed to remove events with extra photons. The dalitz plot of the it+irito events is shown in Fig. 6b . Twenty
10
it+it-no events remain, two of which fall in the pit bands (770.±150 MeV/c2).There is no evidence for the triangular pit bands observed in yr-apO). We therefore set an up 0.1
0.2 M(YY)
0.3
c
Gev/
v
limit for these two events . The Monte Carlo efficiency is 32%. We obtain :
B(yf'-+pit ) < 7.0 x 10-5 (90% C.L.) . Assuming all three pion events are non-resonant, we obtain:
B(yf~~+rc-n~) = (0.26±0.05±0.05)x10-3. 6
2
Our results confirm the Mark II measurement. It is not understood whether the VV' decay is unexpectedly suppressed or the if decay enhanced. Because of the well
defined nature of this puzzle, there have been a number of theoretical attempts to explain it .
FIGURE 6: yf-4yyrc+xc; a) M(yo; b) M(n +no)2 vs .
Previous experiments (Mark I, Mark II and Crystal
Ball) have measured several hadronic decay modes of the Vi'that scale to 13% of the off rate, but did not observe any of the vector-pseudoscalar (VP) combinations! In particular, the pit decay of the V has a large branching ratio
(1 .3%), while the pit decay of the Vis not seen (<0.008%
at 90% C.L.7)) . The comparison between observed and predicted V decay rates is shown in Fig. 5, where R, the ratio of the measured B(V-4X) divided by the expected 0.13.B(yf-->X), is shown for various hadronic final states.
Freund and Nambu9), and later hlou and Soni 10) suggested that a vector glueball near the o fcouples strongly
to VP pairs, but not to e+e-, thus enhancing the rate at the oY Brodsky, Lepage and Tuan 11 ) refined this notion with the observation that VP final states are suppressed by the QCD theorem for yf decays, but not for the decays of the
glueball . Another model is that of Chaichian and Torngvist12 ) who propose that the effect is due to form factors. A recent model by Pinsky13), relates the VP decays of the V and yf to their decays into yqc, and observes that V-arlc is a hindered M1 transition .
R. Mir, Mark III Collaboration/Recent V results from Mark III
330
eferences :
. Conclusions. Our results are summarized and compared to other k U14) results were experiments in Table I. Many of the tincluded in the P average, and are therefore included in Table I. TABLE I. P
r
branching ratios. average Mark 11(thesis) °
:-+Vcl-->Y4± °47X-c-2-+ W'-41Xco-4î-
Yr-4 pre
(8.7±0.8)% (11 .0±0.7±2 .9)% (7.8±0.8)% (2.4±0.12±0.7)x -3 (3.4±0 .6>10-3 (2 .140.2)x10-3 (0.93±0.13±0.28)x -3 (1.4±0.4)x10'3 (0.840.1)x10-3 (1 .9±0.2±0.6)x10-3 (1 .7±0.4)xl0 -3 (1 .340.1)x10-3 (1 .46±0.15±0.43)x 10-3 (1.4±0.5)x 10-3 (1.840.3)x10-3 (0.44±0 .1 ±0.15)x10-3 (1.9±03)x10 -3 (0.9±0 2)x10-3 (0.88±0.20±0.27)x 10-3 (0.94±0.62)x10-3 (1.710.3)x10-3 4x -s (90% cl) <8.3x10-5 (90%cl)
In summary, Mark III has obtained a rather small yr data sample. With this data, precise measurements of V' branching ratios have been obtained. The px puzzle persists . New theoretical models try to explain the discrepancy between grand Videcays to VP mesons. More data is clearly needed to unveil the other experimental questions that remain unsolved. I wish to thank the SPEAR and SLAC Technical staff. I sincerely thank Gary Gladding who presented these results on my behalf at Madrid.
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