-
Y Ishi,
M Inoue,
Y Kuriyama,
Y Mori,
T Uesugi,
JB Lagrange,
T Planche, M Takashima,
E Yamakawa,
H Imazu,
others
Proc. of IPAC10, Kyoto. 01/2010;
-
Consumer Electronics, 1997. Digest of Technical Papers. ICCE., International Conference on; 07/1997
-
[show abstract]
[hide abstract]
ABSTRACT: Microstructural changes that occur in a GeSbTe film during repetitious overwriting in phase‐change optical recording were investigated. The GeSbTe active layer was melted by a focused laser diode (LD) beam during each overwriting process over amorphous mark formation. The repetitious solidification and liquefaction process in such a short time as 50–200 ns resulted in microstructural changes in the active layer: a segregation, sink, and void formations. The sink was formed in the low‐density active layer due to the shrinking of the volume during the resolidification process. Sink formation could be suppressed when a high‐density active layer, having more than 80% of the bulk density, was used. Such a high‐density GeSbTe film, however, resulted in a void formation of the size of 0.1 μm. The voids were thought to be nucleated by residual vacancies and Ar precipitation, since the active layer contained a high concentration of Ar impurities, due to the atomic peening effect. The subsequent void coalescence and migration processes across the beam scanning direction could result in the formation of thermally discontinuous grooves at the edges of the written marks. The voids could also migrate along the LD beam scanning direction, accompanied by a material flow of the active layer in the opposite direction. These phenomena were also found to depend on the material used to fabricate the protective layers which sandwiched the active layer. A TaO x protective layer enhanced the void migration across the track, resulting in the removal of voids from the center of the track. Use of the ZnS:SiO 2 compound protective layer confined voids to the center of the track. The ZnS:SiO 2 protective layer also promoted the formation of thermally discontinuous grooves at the edges of amorphous marks. The material flow along the track resulted in a thicker active layer at the start of the consecutive LD irradiation,-
and also in a high void density region at the final edge of the irradiation having a length on the order of 10 μm. This tendency was found for both the ZnS:SiO 2 and TaO x sandwiching media. © 1995 American Institute of Physics.
Journal of Applied Physics 01/1996; · 2.17 Impact Factor
-
D. Decamp,
B. Deschizeaux,
C. Goy,
J. -P. Lees,
M. -N. Minard,
R. Alemany,
J. M. Crespo,
M. Delfino,
E. Fernandez,
V. Gaitan, [......],
Y. Saadi,
V. Sharma,
Z. H. Shi,
Y. H. Tang,
A. M. Walsh,
J. A. Wear,
F. V. Weber,
M. H. Whitney,
Sau Lan Wu,
G. Zobernig
[show abstract]
[hide abstract]
ABSTRACT: Using the data accumulated at LEP in 1989 and 1990 with the ALEPH detector, the inclusive and exclusive branching ratios of the lepton have been measured assuming lepton universality inZ
0 decays. The inclusive branching fractions for the decay into one, three, and five charged particles have been determined to be (85.450.97)%, (14.350.48)%, and (0.100.05)%, respectively, in agreement with the world averages. New undetected decay modes are determined to have a branching fraction of less than 2.1% at 95% CL. The measured branching ratios for quasi-exclusive channels are slightly larger than, but consistent with the world averages, except for the modes 3 hadrons+v
andhadron+20
v
, which are significantly larger. These latter branching ratios have been found to be (9.50.7)% and (10.21.1)%, respectively. The sum of all the measured quasi-exclusive branching ratios is (100.41.8)%. A fully exclusive analysis of modes with neutral pions shows no evidence for new photonic decay modes with a branching fraction limit of 3.4% at 95% CL.
Zeitschrift für Physik C 05/1992; 54(2):211-228.
-
ALEPH Collaboration,
D. Decamp,
B. Deschizeaux,
C. Goy,
J. -P. Lees,
M. -N. Minard,
R. Alemany,
J. M. Crespo,
M. Delfino,
E. Fernandez, [......],
Y. Saadi,
V. Sharma,
Z. H. Shi,
Y. H. Tang,
A. M. Walsh,
J. A. Wear,
F. V. Weber,
M. H. Whitney,
Sau Lan Wu,
G. Zobernig
[show abstract]
[hide abstract]
ABSTRACT: The properties of theZ resonance are measured on the basis of 190 000Z decays into fermion pairs collected with the ALEPH detector at LEP. Assuming lepton universality,M
z
=(91.1820.009exp0.020Lb[`(b)]b\bar b
asymmetries, and polarization, sin2
W
(M
Z
2
). In the contex of the Minimal Standard Model, limits are placed on the top-quark mass.
Zeitschrift für Physik C 02/1992; 53(1):1-20.
-
D. Decamp,
B. Deschizeaux,
C. Goy,
J. -P. Lees,
M. -N. Minard,
R. Alemany,
J. M. Crespo,
M. Delfino,
E. Fernandez,
V. Gaitan, [......],
Y. Saadi,
V. Sharma,
Z. H. Shi,
Y. H. Tang,
A. M. Walsh,
J. A. Wear,
F. V. Weber,
M. H. Whitney,
Sau Lan Wu,
G. Zobernig
[show abstract]
[hide abstract]
ABSTRACT: This paper describes a study of Bose-Einstein correlations made using the ALEPH detector at LEP. The correlations are found to enhance the two particle differential cross section for pairs of identical pions by a factor which can be roughly parametrized byR(Q)=1+ exp(-Q22), whereQ is the difference in the 3-momenta of the two pions in their centre of mass frame, =0.510.040.11 and =3.30.20.8 GeV–1, which corresponds to a source size of 0.650.040.16 fm. The large systematic errors on these results reflect their strong dependence on the choice of the reference sample used in the analysis. This problem is believed to occur primarily because of uncertainties in the rates of resonance production and a lack of knowledge about the pion-pion strong interaction. No significant correlations are seen amongst like-charged pion-kaon pairs.
Zeitschrift für Physik C 02/1992; 54(1):75-85.
-
D. Decamp,
B. Deschizeaux,
C. Goy,
J. -P. Lees,
M. -N. Minard,
R. Alemany,
J. M. Crespo,
M. Delfino,
E. Fernandez,
V. Gaitan, [......],
Y. Saadi,
V. Sharma,
Z. H. Shi,
Y. H. Tang,
A. M. Walsh,
J. A. Wear,
F. V. Weber,
M. H. Whitney,
Sau Lan Wu,
G. Zobernig
[show abstract]
[hide abstract]
ABSTRACT: We report on the absolute luminosity measurement performed with the ALEPH detector at LEP. The systematic errors of the measurements in 1990 are estimated to be 0.6% (experimental) and 0.3% (theoretical).
Zeitschrift für Physik C 01/1992; 53(3):375-390.
-
D. Buskulic,
D. Decamp,
C. Goy,
J. P. Lees,
M. N. Minard,
B. Mours,
R. Alemany,
F. Ariztizabal,
P. Comas,
J. M. Crespo, [......],
V. Sharma,
M. Schmitt,
Z. H. Shi,
Y. H. Tang,
A. M. Walsh,
F. V. Weber,
M. H. Whitney,
Sau Lan Wu,
X. Wu,
G. Zobernig
[show abstract]
[hide abstract]
ABSTRACT: Distributions are presented of event shape variables, jet roduction rates and charged particle momenta obtained from 53 000 hadronicZ decays. They are compared to the predictions of the QCD+hadronization models JETSET, ARIADNE and HERWIG, and are used to optimize several model parameters. The JETSET and ARIADNE coherent parton shower (PS) models with running s and string fragmentation yield the best description of the data. The HERWIG parton shower model with cluster fragmentation fits the data less well. The data are in better agreement with JETSET PS than with JETSETO(
S
2
) matrix elements (ME) even when the renormalization scale is optimized.
Zeitschrift für Physik C 01/1992; 55(2):209-234.
-
W.B. Atwood,
T. Barczewski,
L.A.T. Bauerdick,
L. Bellantoni,
E. Blucher,
W. Blum,
J. Boudreau,
O. Boyle,
D. Cinabro,
J. Conway, [......],
F. Steeg,
G. Stefanini, M. Takashima,
W. Tejessy,
J. Thomas,
A. Vayaki,
J. Wear,
W. Wiedenmann,
W. Witzeling,
S.L. Wu
[show abstract]
[hide abstract]
ABSTRACT: The tracking performance of the ALEPH time projection chamber
(TPC) has been studied using the data taken during the LEP (Large
Electron-Positron Collider) running periods in 1989 and 1990. After
careful correction of residual distortions and optimization of
coordinate reconstruction algorithms, a single coordinate resolution of
173 μm in the azimuthal and 740 μm in the longitudinal direction
is achieved. This results in a momentum resolution for the TPC alone of
Δ p / p <sup>2</sup>=0.0012 (GeV/c)<sup>-1</sup>. In
combination with the ALEPH inner tracking chamber (ITC), a total
momentum resolution of Δ p / p <sup>2</sup>=0.0008
(GeV/c)<sup>-1</sup>, close to the design specifications, is reached
IEEE Transactions on Nuclear Science 05/1991; · 1.45 Impact Factor
-
D. Decamp,
B. Deschizeaux,
C. Goy,
J. -P. Lees,
M. -N. Minard,
R. Alemany,
J. M. Crespo,
M. Delfino,
E. Fernandez,
V. Gaitan, [......],
B. W. LeClaire,
Y. B. Pan,
T. Parker,
J. R. Pater,
Y. Saadi,
V. Sharma,
J. A. Wear,
F. V. Weber,
Sau Lan Wu,
G. Zobernig
[show abstract]
[hide abstract]
ABSTRACT: We report on the properties of theZ resonance from 62 500Z decays into fermion pairs collected with the ALEPH detector at LEP, the Large Electron-Positron storage ring at CERN. We findM
Z=(91.1930.016exp0.030LEP) GeV,
Z
=(249731) MeV,
had
0
=(41.860.66)nb, and for the partial widths inv=(48924) MeV, had(175427) MeV,
ee
=(85.01.6)MeV,
=(80.02.5) MeV, and =(81.32.5) MeV, all in good agreement with the Standard Model. Assuming lepton universality and using a lepton sample without distinction of the final state we measure u=(84.31.3) MeV. The forward-backward asymmetry in leptonic decays is used to determine the vector and axial-vector weak coupling constants of leptors,g
v
2
(M
Z
2
)=(0.120.12)10–2 andg
A
2
(M
Z
2
)=0.25280.0040. The number of light neutrino species isN
=2.910.13; the electroweak mixing angle is sin2W(M
Z
2
)=0.22910.0040.
Zeitschrift für Physik C 08/1990; 48(3):365-391.
-
E. Blucher,
J. Fagerstrom,
S. Haywood,
U. Larsson,
I. Lehraus,
B. Loefstedt,
T. Lohse,
J. May,
A. Minten,
J. Richstein, [......],
J. Conway,
M. Conwery,
D.F. Cowen,
R.C. Jared,
R. Johnson,
B. LeClaire,
J. Pater,
J. Wear,
S.L. Wu,
S. Xue
[show abstract]
[hide abstract]
ABSTRACT: The Aleph detector is installed on the LEP electron-positron
storage ring. Its central tracking detector, a time projection chamber
(TPC), has about 50000 channels of sampling electronics. The digitized
signals are processed by 72 double-width Fastbus modules built around an
MC 68020 processor. The time projection processor is described, and the
solutions, both hardware and software, adopted to run and manage such a
complex system in a Fastbus-VAX environment are discussed. Practical
experience with the system is reported
IEEE Transactions on Nuclear Science 07/1990; · 1.45 Impact Factor
-
W. Braunschweig,
R. Gerhards,
F. J. Kirschfink,
H. -U. Martyn,
H. M. Fischer,
H. Hartmann,
J. Hartmann,
E. Hilger,
A. Jocksch,
R. Wedemeyer, [......],
A. Shapira,
N. Wainer,
G. Yekutieli,
A. Caldwell,
D. Muller,
S. Ritz,
D. Strom, M. Takashima,
Sau Lan Wu,
G. Zobernig
[show abstract]
[hide abstract]
ABSTRACT: The full TASSO data have been used to study the orientation of three-jet events ine
+
e
– annihilation. The polar angle distributions of the normal to the three-jet plane as well as the polar angle distribution of the most energetic jet have been measured as a function of the thrust cut-off used to select the three-jet sample. The data corrected for radiation and detector effects are compared to QCD predictions and fair agreement is found. As a consistency check we also present measurements of the azimuthal correlations between the lepton and hadron planes. A significant azimuthal dependence is found, consistent again with the QCD predictions.
Zeitschrift für Physik C 05/1990; 47(2):181-186.
-
W. Braunschweig,
R. Gerhards,
F. J. Kirschfink,
H. -U. Martyn,
H. M. Fischer,
H. Hartmann,
J. Hartmann,
E. Hilger,
A. Jocksch,
R. Wedemeyer, [......],
A. Shapira,
N. Wainer,
G. Yekutieli,
A. Caldwell,
D. Muller,
S. Ritz,
D. Strom, M. Takashima,
Sau Lan Wu,
G. Zobernig
[show abstract]
[hide abstract]
ABSTRACT: The full TASSO data have been used to study the inclusive production of strange mesons ine
+
e
– annihilations. Differential and total cross sections have been measured in the centre of mass energy range 14 to 44 GeV forK
0,
[`(K)]0\bar K^0
and 34.5 to 44 GeV forK
* (892). We have investigated the strange meson production properties in jets by studying the rapidity andp
t
2
distributions as well as the evolution of the multiplicities as a function of the event sphericity. We find no evidence that the strange meson yields increase with increasing sphericity faster than the total charged multiplicity.
Zeitschrift für Physik C 05/1990; 47(2):167-179.
-
W. Braunschweig,
R. Gerhards,
F. J. Kirschfink,
H. -U. Martyn,
B. Bock,
H. M. Fischer,
H. Hartmann,
J. Hartmann,
E. Hilger,
A. Jocksch, [......],
A. Montag,
D. Revel,
E. E. Ronat,
N. Wainer,
D. Muller,
S. Ritz,
D. Strom, M. Takashima,
Sau Lan Wu,
G. Zobernig
[show abstract]
[hide abstract]
ABSTRACT: Production of charmed mesons in D0 [`(D)]0D^0 \bar D^0
production have been measured. Neutral and charged meson pairs are estimated to be produced with comparable cross sections, and their sum seems to account for a sizeable fraction of c[`(c)]c\bar c
threshold.
Zeitschrift für Physik C 01/1990; 47(4):499-504.
-
W. Braunschweig,
R. Gerhards,
F. J. Kirschfink,
H. -U. Martyn,
H. M. Fischer,
H. Hartmann,
J. Hartmann,
E. Hilger,
A. Jocksch,
R. Wedemeyer, [......],
D. Revel,
E. Ronat,
N. Wainer,
A. Caldwell,
D. Muller,
S. Ritz,
D. Strom, M. Takashima,
Sau Lan Wu,
G. Zobernig
[show abstract]
[hide abstract]
ABSTRACT: The forward-backward asymmetry in the reaction e+e-[`(A)] b = - 0.21 ±0.08\overline A _b = - 0.21 \pm 0.08
ignoring
B0 [`(B)]0B^0 \bar B^0
mixing. Taking mixing into account leads to a corrected asymmetry of
[`(Abcor )] = - 0.28 ±0.11\overline {A_b^{cor} } = - 0.28 \pm 0.11
. The axial vector coupling constant of theb quark as calculated from the corrected asymmetry isa
b=–1.20.5 to be compared with the valuea
b
SM
=–1 from the standard model.
Zeitschrift für Physik C 01/1990; 48(3):433-444.
-
W. Braunschweig,
R. Gerhards,
F. J. Kirschfink,
H. -U. Martyn,
H. M. Fischer,
H. Hartmann,
J. Hartmann,
E. Hilger,
A. Jocksch,
R. Wedemeyer, [......],
D. Revel,
E. Ronat,
N. Wainer,
A. Caldwell,
D. Muller,
S. Ritz,
D. Strom, M. Takashima,
Sau Lan Wu,
G. Zobernig
[show abstract]
[hide abstract]
ABSTRACT: Jet properties ine
+
e
– annihilation at center of mass energies of 14, 22, 35 and 43.7 GeV were studied with the data collected in the TASSO detector at PETRA, using the same evaluation procedures for all the energies. The total hadronic cross section ratio for the center of mass energy interval 39–47 GeV was determined to be áÖs ñ = 43 - 7\langle \sqrt s \rangle = 43 - 7
GeV. Corrected distributions of global shape variables are presented as well as the inclusive charged particle distributions for scaled momentum and transverse momentum. The center of mass energy evolution of the average sphericity, thrust, aplanarity and particle momentum is shown.
Zeitschrift für Physik C 01/1990; 47(2):187-198.
-
W. Braunschweig,
R. Gerhards,
F. J. Kirschfink,
H. -U. Martyn,
H. M. Fischer,
H. Partmann,
J. Hartmann,
E. Hilger,
A. Jocksch,
R. Wedemeyer, [......],
A. Montag,
D. Revel,
E. Ronat,
A. N. Wainer,
G. Yekutieli,
D. Muller,
S. Ritz, M. Takashima,
Sau Lan Wu,
G. Zobernig
[show abstract]
[hide abstract]
ABSTRACT: We report on total cross section and forward backward charge asymmetry measurements of the reactione
+
e
– +– at centre of mass energies of 35.0 GeV and 42.4 GeV using the TASSO detector. Including previous data an analysis in terms of electroweak parameters of the standard model is presented, and lower limits on mass scale parameters of residual contact interactions are given. A combined analysis of electroweak couplings using all our results on leptonic reactionse
+
e
–l
+
l
– has been performed.
Zeitschrift für Physik C 11/1989; 43(4):549-555.
-
S.R. Amendolia,
T. Barczewski,
L.A.T. Bauerdick,
E. Blucher,
W. Blum,
J. Boudreau,
D. Cinabro,
M.A. Ciocci,
J. Conway,
D.F. Cowen, [......],
G. Stefanini,
F. Steeg, M. Takashima,
W. Tejessy,
J. Thomas,
A. Vayaki,
J. Wear,
W. Witzeling,
S.L. Wu,
S. Xue
[show abstract]
[hide abstract]
ABSTRACT: The readout of the Aleph time projection chamber (TPC) relies on a
set of 72 time projection processors (TPPs), which are based on a
Motorola 68020 microprocessor running a real-time operating system. The
advanced processing capabilities of the TPPs allow them to perform in
parallel a number of tasks, both during and outside of data acquisition,
which are outlined. The management and control of such a large number of
intelligent devices is presented. The discussion covers the hardware
configuration of the TPPs; the software running the TPPs; their
management, status, and control; exception handling and message logging;
and the TPP monitoring tasks
IEEE Transactions on Nuclear Science 11/1989; · 1.45 Impact Factor
-
S.R. Amendolia,
T. Barczewski,
L.A.T. Bauerdick,
E. Blucher,
J. Boudreau,
W. Blum,
D. Cinabro,
J. Conway,
M. Convery,
M.A. Ciocci, [......],
G. Stefanini,
F. Steeg, M. Takashima,
W. Tejessy,
J. Thomas,
A. Vayaki,
J. Wear,
W. Witzeling,
S.L. Wu,
S. Xue
[show abstract]
[hide abstract]
ABSTRACT: The readout system for the Aleph central tracking detector, a
large time projection chamber (TPC), consists of more than 100 FASTBUS
crates with approximately 1000 FASTBUS modules. The detector and its
associated electronics are briefly presented, followed by a more
detailed description of the readout and control system. The discussion
covers the sector readout, electronics calibration, front-end data
acquisition, data pipelining, and service request handling. Experiences
with the system are discussed
IEEE Transactions on Nuclear Science 11/1989; · 1.45 Impact Factor
-
TASSO Collaboration,
W. Braunschweig,
R. Gerhards,
F. J. Kirschfink,
H. -U. Martyn,
H. M. Fischer,
H. Hartmann,
J. Hartmann,
E. Hilger,
A. Jocksch, [......],
A. Shapira,
N. Wainer,
G. Yekutieli,
A. Caldwell,
D. Muller,
S. Ritz,
D. Strom, M. Takashima,
Sau Lan Wu,
G. Zobernig
[show abstract]
[hide abstract]
ABSTRACT: We report on a study of inclusive production ofD
* mesons ine
+
e
– annihilation at c.m. energies between 28 and 46.8 GeV using the TASSO detector at the PETRA storage ring. A hardD
* energy spectrum is measured with a maximum nearE
D
*
(sD* + + sD* - )/smm = 1.28 ±0.09 ±0.18(\sigma _{D^{* + } } + \sigma _{D^{* - } } )/\sigma _{\mu \mu } = 1.28 \pm 0.09 \pm 0.18
indicates thatD
* production accounts for a large fraction of the observed charm production. Two complementary methods have been used to determine the forward-backward asymmetry of charm pair production due to electroweak interference. Combining both measurements the product of the axial vector couplings of the electron and the charm quark to the weak neutral current was determined to beg
A
e
g
A
c
=–(0.2760.073), in agreement with the standard model prediction of –0.25. Using a sample of reconstructedD
* mesons, the relative strength of the strong interaction coupling of thec quark compared to that of an average of all flavours is measured as tD0 = (4.8 ±0.9 - 0.71.0 + 0.5 )10 - 13 s\tau _{D^0 = } (4.8 \pm _{0.9 - 0.7}^{1.0 + 0.5} )10^{ - 13} s
.
Zeitschrift für Physik C 08/1989; 44(3):365-378.
