-
G. Abbiendi, K. Ackerstaff,
P. F. Akesson,
G. Alexander,
J. Allison,
K. J. Anderson,
S. Arcelli,
S. Asai,
S. F. Ashby,
D. Axen, [......],
T. Wengler,
N. Wermes,
D. Wetterling,
J. S. White,
G. W. Wilson,
J. A. Wilson,
T. R. Wyatt,
S. Yamashita,
V. Zacek,
D. Zer-Zion
[show abstract]
[hide abstract]
ABSTRACT: The magnitude of the Cabibbo-Kobayashi-Maskawa matrix element
Vcb has been measured using
B¯0-->D*+l-ν¯ decays
recorded on the Z0 peak using the OPAL detector at LEP. The
D*+-->D0π+ decays were
reconstructed both in the particular decay modes
D0-->K-π+ and
D0-->K-π+π0 and via
an inclusive technique. The product of Vcb and the decay form
factor of the
B¯0-->D*+l-ν¯
transition at zero recoil /F(1) was measured to be
F(1)Vcb=(37.1+/-1.0+/-2.0)×10- 3, where the
uncertainties are statistical and systematic respectively. By using
Heavy Quark Effective Theory calculations for /F(1), a value
ofVcb=(40.7+/-1.1+/-2.2+/-1.6)×10- 3was
obtained, where the third error is due to theoretical uncertainties in
the value of /F(1). The branching ratio
Br(B¯0-->D*+l-ν¯) was
also measured to be /(5.26+/-0.20+/-0.46)%.
Physics Letters B 05/2000; 482:15-30. · 3.95 Impact Factor
-
OPAL Collaboration,
G. Abbiendi, K. Ackerstaff,
G. Alexander,
J. Allison,
N. Altekamp,
K. J. Anderson,
S. Anderson,
S. Arcelli,
S. Asai, [......],
P. S. Wells,
N. Wermes,
J. S. White,
G. W. Wilson,
J. A. Wilson,
T. R. Wyatt,
S. Yamashita,
G. Yekutieli,
V. Zacek,
D. Zer-Zion
[show abstract]
[hide abstract]
ABSTRACT: The branching ratio for the decay τ--->e-
ν¯eντ has been measured using
Z0 decay data collected by the OPAL experiment at LEP. In
total 33 073 τ--->e-
ν¯eντ candidates were
identified from a sample of 186 197 selected τ decays, giving a
branching ratio of B(τ--->e-
ν¯eντ)=(17.81+/-0.09
(stat)+/-0.06 (syst))%. This result is combined with other measurements
to test e - μ and μ - τ universality in charged-current weak
interactions. Additionally, the strong coupling constant
αs(mτ2) has been extracted
from B(τ--->e-
ν¯eντ) and evolved to the
Z0 mass scale, giving
αs(mZ2)=0.1204+/-0.0011
(exp)+/-0.0019 (theory).
Physics Letters B 01/1999; 447:134-146. · 3.95 Impact Factor
-
OPAL Collaboration, K. Ackerstaff,
G. Alexander,
J. Allison,
N. Altekamp,
K. J. Anderson,
S. Anderson,
S. Arcelli,
S. Asai,
S. F. Ashby, [......],
P. S. Wells,
N. Wermes,
J. S. White,
G. W. Wilson,
J. A. Wilson,
T. R. Wyatt,
S. Yamashita,
G. Yekutieli,
V. Zacek,
D. Zer-Zion
[show abstract]
[hide abstract]
ABSTRACT: A search for the resonant production of high mass photon pairs
associated with a leptonic or hadronic system has been performed using a
data sample of 57.7 pb-1 collected at an average
center-of-mass energy of 182.6 GeV with the OPAL detector at LEP. No
evidence for contributions from non-Standard Model physics processes was
observed. The observed candidates are used to place limits on
B(H0-->γγ) assuming a Standard Model
production rate for Higgs boson masses up to 92 GeV, and on the
production cross section for a scalar resonance decaying into di-photons
up to a mass of 170 GeV. Upper limits on the product of cross section
and branching ratios,
σ(e+e--->XY)xB(X-->γγ)xB(Y-
->ff¯), as low as 70 fb are obtained over the range
10<MX<170 GeV for the case where
10<MY<160 GeV and MX+MY>90
GeV, independent of the nature of Y provided it decays to a fermion pair
and has negligible width. Higgs scalars which couple only to gauge
bosons at Standard Model strength are ruled out up to a mass of 90.0 GeV
at the 95% confidence level. Limits are also placed on non-minimal Higgs
sectors having triplet representations.
Physics Letters B 09/1998; 437:218-230. · 3.95 Impact Factor
-
K. Ackerstaff,
G. Alexander,
J. Allison,
N. Altekamp,
K. J. Anderson,
S. Anderson,
S. Arcelli,
S. Asai,
S. F. Ashby,
D. Axen, [......],
P. S. Wells,
N. Wermes,
J. S. White,
G. W. Wilson,
J. A. Wilson,
T. R. Wyatt,
S. Yamashita,
G. Yekutieli,
V. Zacek,
D. Zer-Zion
[show abstract]
[hide abstract]
ABSTRACT: In e+e2212 collisions at centre-of-mass energies around 91 GeV, D*0 mesons have been reconstructed using data collected with the OPAL detector at LEP. The hadronisation fraction has been measured
to be f(c→D*0)=0.218±0.054±0.045±0.007, where the errors correspond to the statistical and systematic errors specific to this analysis,
and to systematic uncertainties from externally measured branching fractions, respectively. Together with previous OPAL measurements
of the hadronisation fractions of other charmed mesons, this value is used to investigate the relative production of observed
vector and pseudoscalar charmed mesons in Z0 ® c[`(c)]Z^0 \to c\bar c decays. The production ratio is determined to be P
effV = V/(V+P)=0.57±0.05. The relative primary production of vector and pseudoscalar mesons, P
vrim, is studied in the context of the production and decay of orbitally excited charmed resonances. The first measurement of
the inclusive Ds*+ production rate in hadronic Z0 decays is presented.
European Physical Journal C 04/1998; 5(1):1-17. · 3.63 Impact Factor
-
OPAL Collaboration, K. Ackerstaff,
G. Alexander,
J. Allison,
N. Altekamp,
K. J. Anderson,
S. Anderson,
S. Arcelli,
S. Asai,
D. Axen, [......],
J. S. White,
B. Wilkens,
G. W. Wilson,
J. A. Wilson,
G. Wolf,
T. R. Wyatt,
S. Yamashita,
G. Yekutieli,
V. Zacek,
D. Zer-Zion
[show abstract]
[hide abstract]
ABSTRACT: Deep inelastic electron-photon scattering is studied using
e+e- data collected by the OPAL detector at
centre-of-mass energies sqrt(see)~MZ0.
The photon structure function
F2γ(x,Q2) is explored in a
Q2 range of 1.1 to 6.6 GeV2 at lower x values than
ever before. To probe this kinematic region events are selected with a
beam electron scattered into one of the OPAL luminosity calorimeters at
scattering angles between 27 and 55 mrad. A measurement is presented of
the photon structure function
F2γ(x,Q2) at
=1.86 GeV2 and 3.76 GeV2 in
five logarithmic x bins from 0.0025 to 0.2.
Physics Letters B 09/1997; 412:225-234. · 3.95 Impact Factor
-
OPAL Collaboration, K. Ackerstaff,
G. Alexander,
J. Allison,
N. Altekamp,
K. J. Anderson,
S. Anderson,
S. Arcelli,
S. Asai,
D. Axen, [......],
J. S. White,
B. Wilkens,
G. W. Wilson,
J. A. Wilson,
G. Wolf,
T. R. Wyatt,
S. Yamashita,
G. Yekutieli,
V. Zacek,
D. Zer-Zion
[show abstract]
[hide abstract]
ABSTRACT: New measurements are presented of the photon structure function
F2γ(x,Q2) at four values of
Q2 between 9 and 59 GeV2 based on data collected
with the OPAL detector at centre-of-mass energies of 161-172 GeV, with a
total integrated luminosity of 18.1 pb-1. The evolution of
F2γ with Q2 in bins of x is
determined in the Q2 range from 1.86 to 135 GeV2
using data taken at centre-of-mass energies of 91 GeV and 161-172 GeV.
F2γ is observed to increase with
Q2 with a slope of α-
1dF2γ/dlnQ2=0.10+0.05-0.03
measured in the range 0.1<x<0.6.
Physics Letters B 09/1997; 411:387-401. · 3.95 Impact Factor
-
K. Ackerstaff,
G. Alexander,
J. Allison,
N. Altekamp,
K. Ametewee,
K. J. Anderson,
S. Anderson,
S. Arcelli,
S. Asai,
D. Axen, [......],
J. S. White,
B. Wilkens,
G. W. Wilson,
J. A. Wilson,
G. Wolf,
S. Wotton,
T. R. Wyatt,
S. Yamashita,
G. Yekutieli,
V. Zacek
[show abstract]
[hide abstract]
ABSTRACT: Searches for unstable neutral and charged heavy leptons (L0,
L+/-) have been performed using a data sample of 10.0
pb-1 at a centre-of-mass energy of √s = 161.3 GeV
collected with the OPAL detector at LEP during July and August 1996. Two
candidate events were observed after the selection, which is consistent
with the expected total background of 1.57 events, and lower limits have
been derived on heavy lepton masses for various models. If an unstable
Dirac neutral heavy lepton, L0, decays only into
eW*, μW* or τW*, the lower
limits on its mass at the 95% C.L. are 69.3 GeV, 72.0 GeV and 66.0 GeV,
respectively. The limits are modified for a Majorana L0 to
59.5 GeV, 60.5 GeV and 55.7 GeV, respectively. If an unstable heavy
charged lepton, L+/-, decays into a stable heavy neutrino,
and ifmL+/- - mνL > 13
GeV, a lower limit on its mass of 73.5 GeV is obtained. If the
L+/- decays through lepton flavour mixing into a massless
neutrino νl and W*+/-, the lower limit on
mL+/- was determined to be 76.7 GeV at 95% C.L.
Physics Letters B 01/1997; 393:217-230. · 3.95 Impact Factor
-
K. Ackerstaff,
G. Alexander,
J. Allison,
N. Altekamp,
K. Ametewee,
K. J. Anderson,
S. Anderson,
S. Arcelli,
S. Asai,
D. Axen, [......],
J. S. White,
B.. Wilkens,
G. W. Wilson,
J. A. Wilson,
G. Wolf,
S. Wotton,
T. R. Wyatt,
S. Yamashita,
G. Yekutieli,
V. Zacek
[show abstract]
[hide abstract]
ABSTRACT: We report a measurement of the Cabibbo-Kobayashi-Maskawa matrix element
Vcb. From approximately 4.2 million hadronic Z0
decays recorded with the OPAL detector, a sample is selected containing
1251 +/- 125 B0 ->
D*+L-vL candidates, where L is either
an electron or a muon. Using Heavy Quark Effective Theory calculations
for the decay form factor at zero recoil of the D*+ meson in
the B0 rest frame, we derive Vcb = [36.0 +/- 2.1
(stat) +/- 2.4 (syst) +/- 1.2 (theory)] × 10-3.
Physics Letters B 01/1997; 395:128-140. · 3.95 Impact Factor
-
K. Ackerstaff,
G. Alexander,
J. Allison,
N. Altekamp,
K. Ametewee,
K. J. Anderson,
S. Anderson,
S. Arcelli,
S. Asai,
D. Axen, [......],
B. Wilkens,
G. W. Wilson,
J. A. Wilson,
G. Wolf,
S. Wotton,
T. R. Wyatt,
S. Yamashita,
G. Yekutieli,
V. Zacek,
D. Zer-Zion
[show abstract]
[hide abstract]
ABSTRACT: This letter describes a measurement of one of the anomalous triple gauge
boson couplings using the first data recorded by the OPAL detector at
LEP2. A total of 28 W-pair candidates have been selected for an
integrated luminosity of 9.89+/-0.06 pb-1 recorded at a
centre-of-mass energy of 161 GeV. We use these data to place constraints
upon the coupling parameter αWφ. We analyse the
predicted variation of the total cross-section for all observed channels
and the distribution of kinematic variables in the semileptonic decay
channels. We measure αWφ to be
-0.61+0.73-0.61 +/- 0.35, which is consistent with
the Standard Model expectation of zero.
Physics Letters B 01/1997; 397:147-157. · 3.95 Impact Factor
-
K. Ackerstaff,
G. Alexander,
J. Allison,
N. Altekamp,
K. J. Anderson,
S. Anderson,
S. Arcelli,
S. Asai,
D. Axen,
G. Azuelos, [......],
J. S. White,
B. Wilkens,
G. W. Wilson,
J. A. Wilson,
G. Wolf,
T. R. Wyatt,
S. Yamashita,
G. Yekutieli,
V. Zacek,
D. Zer-Zion
[show abstract]
[hide abstract]
ABSTRACT: The process e+e– , () is studied using data recorded with the OPAL detector at LEP. The data sample corresponds to a total integrated luminosity of 25.38 pb–1 taken at centre-of-mass energies of 130–172 GeV. The measured cross-sections agree well with the expectation from QED. In a combined fit using data from all centre-of-mass energies, the angular distribution is used to obtain improved limits on the cut-off parameters: + > 195 GeV and – > 210 GeV (95% CL). In addition, limits on nonstandard e+e– couplings and contact interactions, as well as a 95% CL mass limit for an excited electron,Me*= > 194 GeV for an e+e– coupling = 1, are determined.
Zeitschrift für Physik C 02/1979; 1(1):21-30.
-
K. Ackerstaff,
G. Alexander,
J. Allison,
N. Altekamp,
K. J. Anderson,
S. Anderson,
S. Arcelli,
S. Asai,
D. Axen,
G. Azuelos, [......],
J. S. White,
B. Wilkens,
G. W. Wilson,
J. A. Wilson,
G. Wolf,
T. R. Wyatt,
S. Yamashita,
G. Yekutieli,
V. Zacek,
D. Zer-Zion
[show abstract]
[hide abstract]
ABSTRACT: A search for the resonant production of high mass photon pairs associated with a leptonic or hadronic system has been performed using a total data sample of 25.7 pb–1 taken at centre-of-mass energies between 130 GeV and 172 GeV with the OPAL detector at LEP. The observed number of events is consistent with the expected number from Standard Model processes. The observed candidates are combined with search results from s Mz to place limits onB(H0 within the Standard Model for Higgs boson masses up to 77 GeV, and on the production cross section of any scalar resonance decaying into di-photons. Upper limits onB(H0 4 x (e+e– HZ) of 290 – 830 fb are obtained over 40 M
H < 160="" gev.="" higgs="" scalars="" which="" couple="" only="" to="" gauge="" bosons="" with="" standard="" model="" strength="" are="" ruled="" out="" up="" to="" a="" mass="" of="" 76.5="" gev="" at="" the="" 95%="" confidence="">
Zeitschrift für Physik C 02/1979; 1(1):31-43.
-
OPAL Collaboration, K. Ackerstaff,
G. Alexander,
J. Allison,
N. Altekamp,
K. vJ. Anderson,
S. Anderson,
S. Arcellie,
S. Asai,
D. Axen, [......],
J. S. White,
B. Wilkens,
G. W. Wilson,
J. A. Wilson,
G. Wolf,
T. R. Wyatt,
S. Yamashita,
G. Yekutieli,
V. Zacek,
D. Zer-Zion
[show abstract]
[hide abstract]
ABSTRACT: We have searched for unstable neutral and charged heavy leptons, N and L, and for excited states of neutral and charged leptons, * e*, * and *, in e+e– collisions at centre-of-mass energies of 170 and 172 GeV using the OPAL detector at LEP. No evidence for their existence was found. From the analysis of charged-current decays of pair-produced unstable heavy leptons, and of charged-current and photonic decays of pair-produced excited leptons, lower limits on their masses are derived. From the analysis of charged-current and photonic decays of singly-produced excited leptons, upper limits on the ratio of the coupling to the compositeness scale, /, are determined for masses up to the kinematic limit.
Zeitschrift für Physik C 01/1979; 1(1):45-64.
-
G Abbiendi, K Ackerstaff,
P F Åkesson,
Gideon Alexander,
J Allison,
K J Anderson,
S Arcelli,
S Asai,
S F Ashby,
D A Axen, [......],
T Wengler,
N Wermes,
D Wetterling,
J S White,
G W Wilson,
J A Wilson,
T R Wyatt,
S Yamashita,
V Zacek,
D Zer-Zion
[show abstract]
[hide abstract]
ABSTRACT: A search for the decay B+- to K+-K+-pi-+ was performed using data collected by the OPAL detector at LEP. These decays are strongly suppressed in the Standard Model but could occur with a higher branching ratio in supersymmetric models, especially in those with R-parity violating couplings. No evidence for a signal was observed and a 90% confidence level upper limit of 1.29x10^-4 was set for the branching ratio.
-
G Abbiendi, K Ackerstaff,
Gideon Alexander,
J Allison,
N Altekamp,
K J Anderson,
S Anderson,
S Arcelli,
S Asai,
S F Ashby, [......],
P S Wells,
N Wermes,
D Wetterling,
J S White,
G W Wilson,
J A Wilson,
T R Wyatt,
S Yamashita,
V Zacek,
D Zer-Zion
[show abstract]
[hide abstract]
ABSTRACT: A sample of Z decays containing b-flavoured hadrons is tagged using leptons, and events having precise proper time measurements are selected. These events are used to study Bs oscillations. using the lepton to tag the decay b-flavour and jet charge or a second lepton, where available, to determine the produced b-flavour. The flavour (b or b-bar) at decay is determined from the lepton charge while the flavour at production is determined from jet charge or the charge of a second lepton, where available. The experiment was not able to resolve the oscillatory behaviour, and we deduce that the Bs oscillation frequency Delta(ms)> 5.2ps-1 at the 95% confidence level.
-
P Pfeifenschneider,
O Biebel,
P. A. Movilla Fernández,
G Abbiendi, K Ackerstaff,
P F Åkesson,
Gideon Alexander,
J Allison,
K J Anderson,
S Arcelli, [......],
T Wengler,
N Wermes,
D Wetterling,
J S White,
G W Wilson,
J A Wilson,
T R Wyatt,
S Yamashita,
V Zacek,
D Zer-Zion
[show abstract]
[hide abstract]
ABSTRACT: We employ data taken by the JADE and OPAL experiments for an integrated QCD study in hadronic e+e- annihilations at c.m.s. energies ranging from 35 GeV through 189 GeV. The study is based on jet-multiplicity related observables. The observables are obtained to high jet resolution scales with the JADE, Durham, Cambridge and cone jet finders, and compared with the predictions of various QCD and Monte Carlo models. The strong coupling strength, alpha_s, is determined at each energy by fits of O(alpha_s^2) calculations, as well as matched O(alpha_s^2) and NLLA predictions, to the data. Matching schemes are compared, and the dependence of the results on the choice of the renormalization scale is investigated. The combination of the results using matched predictions gives alpha_s(MZ)=0.1187+{0.0034}-{0.0019}. The strong coupling is also obtained, at lower precision, from O(alpha_s^2) fits of the c.m.s. energy evolution of some of the observables. A qualitative comparison is made between the data and a recent MLLA prediction for mean jet multiplicities.
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G Abbiendi, K Ackerstaff,
Gideon Alexander,
J Allison,
K J Anderson,
S Anderson,
S Arcelli,
S Asai,
S F Ashby,
D A Axen, [......],
P S Wells,
N Wermes,
D Wetterling,
J S White,
G W Wilson,
J A Wilson,
T R Wyatt,
S Yamashita,
V Zacek,
D Zer-Zion
[show abstract]
[hide abstract]
ABSTRACT: From an analysis of the ionisation energy loss of charged particles selected from a sample of 147926 e+e- -> tau+tau- candidates recorded in the OPAL detector at e+e- centre-of-mass energies near the Z0 resonance, we determine the branching ratios: BR(tau- -> nu_tau K- pi- pi+ (pi0)) = 0.343 +- 0.073 +- 0.031 % BR(tau- -> nu_tau K- pi- K+ (pi0)) = 0.159 +- 0.053 +- 0.020 % where the (pi0) notation refers to decay modes with or without an accompanying pizero. The tau- -> nu_tau K- pi- pi+ (pi0) final states occurring through tau- -> nu_tau K- K_s (pi0) are treated as background in this analysis. We also examine the resonant structure of tau- -> nu_tau K- pi- pi+ candidates. Under the assumption that the resonant structure is dominated by the K_1 resonances, we determine the ratio of the BR (tau- -> K_1(1270)) to the sum of the BRs (tau -> K_1(1270) and (tau -> K_1(1400)) to be 0.71 +- 0.16 +- 0.11. In all results, the first uncertainties are statistical and the second are systematic.
-
G Abbiendi, K Ackerstaff,
P F Åkesson,
Gideon Alexander,
J Allison,
K J Anderson,
S Arcelli,
S Asai,
S F Ashby,
D A Axen, [......],
T Wengler,
N Wermes,
D Wetterling,
J S White,
G W Wilson,
J A Wilson,
T R Wyatt,
S Yamashita,
V Zacek,
D Zer-Zion
[show abstract]
[hide abstract]
ABSTRACT: The inclusive production of D*+- mesons in photon-photon collisions has been measured using the OPAL detector at LEP at e+e- centre-of-mass energies of 183 and 189GeV. The D* mesons are reconstructed in their decay to D0pi+ with the D0 observed in the two decay modes Kpi+ and Kpi+pi-pi+. After background subtraction, 100.4+-12.6(stat) D*+- mesons have been selected in events without observed scattered beam electron ("anti-tagged") and 29.8+-5.9 (stat) D*+- mesons in events where one beam electron is scattered into the detector ("single-tagged"). Direct and single-resolved events are studied separately. Differential cross-sections as functions of the D* transverse momentum p_t and pseudorapidity \eta are presented in the kinematic region 2<p_t<12GeV and calculations. The total cross-section for the process (e+e- to e+e-ccbar), where the charm quarks are produced in the collision of two quasi-real photons, is measured to be 842+-97(stat)+-75(syst)+-196(extrapolation)pb. A first measurement of the charm structure function F2 of the photon is performed in the kinematic range 0.0014<x<0.87 and 5<Q^2<100 GeV^2, and the result is compared to a NLO perturbative QCD calculation.
-
G Abbiendi, K Ackerstaff,
P F Åkesson,
Gideon Alexander,
J Allison,
K J Anderson,
S Arcelli,
S Asai,
S F Ashby,
D A Axen, [......],
T Wengler,
N Wermes,
D Wetterling,
J S White,
G W Wilson,
J A Wilson,
T R Wyatt,
S Yamashita,
V Zacek,
D Zer-Zion
[show abstract]
[hide abstract]
ABSTRACT: The energy distribution and type of the particle with the highest momentum in quark jets are determined for each of the five quark flavours making only minimal model assumptions. The analysis is based on a large statistics sample of hadronic Z0 decays collected with the OPAL detector at the LEP e+e- collider. These results provide a basis for future studies of light flavour production at other centre-of-mass energies. We use our results to study the hadronisation mechanism in light flavour jets and compare the data to the QCD models JETSET and HERWIG. Within the JETSET model we also directly determine the suppression of strange quarks to be gamma_s=0.422+-0.049 (stat.)+-0.059 (syst.) by comparing the production of charged and neutral kaons in strange and non-strange light quark events. Finally we study the features of baryon production.
-
G Abbiendi, K Ackerstaff,
Gideon Alexander,
J Allison,
K J Anderson,
S Anderson,
S Arcelli,
S Asai,
S F Ashby,
D A Axen, [......],
P S Wells,
N Wermes,
D Wetterling,
J S White,
G W Wilson,
J A Wilson,
T R Wyatt,
S Yamashita,
V Zacek,
D Zer-Zion
[show abstract]
[hide abstract]
ABSTRACT: The rate of secondary charm-quark-pair production has been measured in 4.4 million hadronic Z0 decays collected by OPAL. By selecting events with three jets and tagging charmed hadrons in the gluon jet candidate using leptons and charged D* mesons, the average number of secondary charm-quark pairs per hadronic event is found to be (3.20+-0.21+-0.38)x10-2.
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K Ackerstaff,
Gideon Alexander,
J Allison,
N Altekamp,
K J Anderson,
S Anderson,
S Arcelli,
S Asai,
S F Ashby,
D A Axen, [......],
P S Wells,
N Wermes,
J S White,
G W Wilson,
J A Wilson,
T R Wyatt,
S Yamashita,
G Yekutieli,
V Zacek,
D Zer-Zion
[show abstract]
[hide abstract]
ABSTRACT: An upper limit for the tau-neutrino mass has been determined from the decay tau -> 5pi+- \nu_tau using data collected with the OPAL detector from 1991 to 1995 in e+e- collisions at \sqrt{s} ~ M_Z. A limit of 43.2 MeV at 95% CL is obtained using a two-dimensional method in the 5pi invariant mass and energy distribution from 22 selected events. Combining this result with OPAL's previously published measurement using tau+tau- -> 3h+- \bar{nu}_tau 3h-+ obtained.
