We report on a search for the excited leptons e
∗,
μ
∗
,
τ
∗
and
ν
∗
in e
+e
− collisions at
s
= 130-140
GeV
using the L3 detector at LEP. No evidence has been found for their existence. From an ...analysis of the expected pair produced
ℓ
∗ℓ
∗
in the channels eeγγ, μμγγ, ττγγ, eeWW, and ννγγ, we determine the lower mass limits at 95% C.L. of 64.7 GeV for e
∗, 64.9 GeV for
μ
∗
, 64.2 GeV for
τ
∗
, 57.3 GeV (eW decay mode) and 61.4 GeV (νγ decay mode) for
ν
∗
. From an analysis of the expected singly produced
ℓℓ
∗
in the channels eeγ, μμγ, ττγ, νeW and ννγ, we determine upper limits on the couplings
λ
m
ℓ
∗
up to
m
ℓ
∗
= 130
GeV
.
Total and differential cross sections for the process e
+e
− →
γγ(
γ), and the total cross section for the process e
+e
− →
γγγ, are measured at energies around 91 GeV using the data collected with ...the L3 detector from 1991 to 1993. We set lower limits, at 95% CL, on a contact interaction energy scale parameter
Λ > 602 GeV, on the mass of an excited electron
m
e
∗
>146
GeV
and on the QED cut-off parameters
Λ
+ > 149 GeV and
Λ_ > 143 GeV. Upper limits are also set o branching fractions of Z decaying into
γγ,
π° and
ηγ of 5.2 × 10
−5, 5.2 × 10
−5 and 7.6 × 10
−5 respectively. The reactions e
+e
− → ℓ
+ℓ
−
nγ (ℓ =
e,
μ,
τ) are studied using the data collected from 1990 to 1994. The data are consistent with the QED expectations.
A search for the decays B
d,s
0 → γγ in 2.95 million hadronic Z decays has been performed using the L3 detector at LEP. No candidates are found in the signal region and upper limits have been set on ...the branching ratios: Br(B
d
0→
γ)<3.9×10
−5 and Br(B
s
0 →
γγ) < 14.8 × 10
−5 at 90% CL. These are the first limits set on these exclusive rare decays.
The reaction
e
+e
−
→
e
+e
−
γ
∗γ
∗ →
e
+e
−K
S
0K
S
0
is studied with the L3 detector at LEP and the formation of the f
2′(1525) resonance is observed. For an integrated luminosity of 114 pb
−1, ...31±6 f
2′ events are found. Their angular distribution is consistent with a pure helicity two. The radiative width times the branching ratio is measured to be
Γ
γγ
(f
2′)×Br(f
2′ → K
K)
=(0.093±0.018±0.022)
keV. Only three events are found in the f
2(1270)−a
2(1320) mass region, consistent with destructive f
2−a
2 interference in the K
S
0K
S
0 final state. The mixing angle of the tensor meson nonet is determined to the
θ = (29.4
−1.6
+1.4)°.
Prise en charge d’un améloblastome mandibulaire Bouletreau, P.; Paranque, A.-R.; Steve, M. ...
Revue de stomatologie et de chirurgie maxillo-faciale,
2006, 2006-1-00, Letnik:
107, Številka:
1
Journal Article
A search for a diffuse flux of astrophysical muon neutrinos, using data collected by the ANTARES neutrino
telescope is presented. A (0.83 × 2π) sr sky was monitored for a total of 334 days of ...equivalent live
time. The searched signal corresponds to an excess of events, produced by astrophysical sources, over the
expected atmospheric neutrino background. The observed number of events is found compatible with the
background expectation. Assuming an E−2 flux spectrum, a 90% c.l. upper limit on the diffuse νμ flux
of E2Φ90% = 5.3 × 10−8 GeVcm−2 s−1 sr−1 in the energy range 20 TeV–2.5 PeV is obtained. Other signal
models with different energy spectra are also tested and some rejected.
Peer Reviewed
Management of mandibular ameloblastoma Bouletreau, P; Paranque, A-R; Steve, M ...
Revue de stomatologie et de chirurgie maxillo-faciale
107, Številka:
1
Journal Article
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