108905088
A 32 channels charge integrating ADC based on digital signal integration
Abstract A digital charge integrator with programmable gate width and range has been designed for use in the KLOE drift chamber front-end chain. The system has a resolution of 9 bits ranging from 600 fC / count up to ≈ 76  pC and integration time ranging from 100 ns to about 13 μ s . Thirty-two channels have been packaged in a single VME 9U board.
109329842
Improved Particle Identification Using Cluster Counting in a Full-Length Drift Chamber Prototype
Single-cell prototype drift chambers were built at TRIUMF and tested with a ~210MeV/c beam of positrons, muons, and pions. A cluster-counting technique is implemented which improves the ability to distinguish muons and pions when combined with a traditional truncated-mean charge measurement. Several cluster-counting algorithms and equipment variations are tested, all showing significant improvement when combined with the traditional method. The results show that cluster counting is a feasible option for any particle physics experiment using drift chambers for particle identification. The technique does not require electronics with an overly high sampling rate. Optimal results are found with a signal smoothing time of ~5ns corresponding to a ~100MHz Nyquist frequency.
16384620
CKM-UT Angles: Mixing And CP Violation at the B Factories
We review the experimental status of the angles of the Unitarity Triangle of the CKM matrix, as measured by the BABAR and Belle experiments. The B Factories have demonstrated since the beginning of this decade that CP violation in the B meson system is consistent with the Standard Model (SM) description in terms of the complex phase in the three-by-three Cabibbo-Kobayashi-Maskawa (CKM) matrix. With one single phase, the SM predicts clear patterns for quark mixing and CP violations, to be satisfied by all processes.
56098294
Review of measurements of the angles of the CKM matrix from the BaBar experiment
Experimental results on CP violation measurements in the B meson system from the BABAR experiment at the PEP-II asymmetric B Factory are reviewed.
123565774
Alpha and Beta at the B Factories
We review recent experimental results on time-dependent CP asymmetries in the B system from the BABAR and Belle experiments. Measurements of the {alpha} and {beta} angles of the Unitarity Triangle of the CKM matrix are discussed. These measurements constitute stringent tests of the Standard Model, and are also used to search for new physics.
120063494
High precision limited streamer drift tubes
Abstract A tracking telescope employing six layers of Al drift tubes 50 cm long, with diameter d = 3 cm and wall thickness 500 μm, has been built and successfully operated with a 40% Ar-60% iC 4 H 10 gas mixture at atmospheric pressure. The tube cells, with a 100 μm thick CuBe wire strung along the axis, enter streamer mode operation at V = 4.6 kV, and feature full efficiency and local resolution of ≤60 μm.
120513565
Measurement of inclusive two-particle rapidity correlations at the ISR
Abstract We present data on two-particle distributions in the approximate rapidity variable η = −1n tan θ /2 for secondaries produced in proton-proton collisions at the CERN Intersecting Storage Rings (ISR). The data at centre-of-mass energies of 23 and 62 GeV show the existence of energy-independent positive, short-range correlations between secondaries within the central region. Deviations from short-range correlation exist when one (or both) of the particles is near the boundary of the available phase space. In part, such deviations are interpreted as the effect of a diffractive-like component in multiparticle production.
120709377
Measurement of B-meson semileptonic decay
Using the Columbia University-Stony Brook detector we have measured the production of energetic electrons (E>1 GeV) in e/sup +/e/sup -/ annihilations in the center-of-mass energy range 10.4 to 11.4 GeV. We observe an enhanced electron signal at the UPSILON'''(4S) resonance, which we interpret as evidence for the ..beta.. decay of a new flavor of quark, b, bound within a new flavor meson, B. We derive a branching ratio for B..-->..Xe..nu.. of (13.6 +- 2.5 +- 3)%. The observed energy spectrum of the electrons favors the decay b..-->..ce..nu.. over b..-->..uev.
121618537
SEARCH FOR NARROW RESONANCES IN THE R REGION.
118729839
Measurement of two-particle semi-inclusive rapidity distributions at the CERN ISR
SummaryWe present data on the semi-inclusive distributions of rapidities of secondary particles produced in pp collisions at very high energies. Our experiment was performed at the CERN Intersecting Storage Rings (ISR). The data given here, at centre-of-mass energies of √s=23 and 62 GeV, include the single-particle distributions and two-particle correlations. The semi-inclusive correlations show pronounced short-range correlation effects which have a width considerably narrower than in the case of inclusive correlations. We show that these short-range effects can be understood empirically in terms of three parameters whose energy and multiplicity dependence are studied. The data support the picture of multiparticle production in which clusters of small multiplicity and small dispersion are emitted with subsequent decay into hadrons.RiassuntoVengono presentati dati sulle distribuzioni inclusive in rapidità dei secondari carichi prodotti nelle collisioni protone-protone ad altissime energie. L’esperimento è stato eseguito agli Anelli ad Intersezione (ISR) del CERN. I dati, ad una energia √s=23 e 62 GeV nel centro di massa, comprendono le distribuzioni di particella singola e le correlazioni a due particelle per fissa molteplicità carica, come anche le correlazioni inclusive a due particelle. Le correlazioni semi inclusive mostrano forti effetti di correlazione a breve distanza, che hanno una larghezza molto più piccola che nel caso delle correlazioni inclusive. Nel lavoro si fa vedere che questi effetti a breve distanza possono essere capiti empiricamente in funzione di tre parametri di cui si studia la dipendenza dall’energia e dalla molteplicità. I dati favoriscono la descrizione della produzione a molti corpi in cui vengono emessi agglomerati di piccola molteplicità e piccola dispersione, che successivamente decadono in adroni.РеэюмеВ работе приводятся данные для полуинклюэивных распределений вторичных частиц, рожденных в рр соударениях при очень высоких знергиях. Нащ зксперимент был проиэведен на встречных накопительных кольцах в ЦЕРНе. Полученные в работе данные при знергиях в системе центра масс √s=23 и 62 ГзВ включают одночастичные распределения и двухчастичные корреляции при фиксированной множественности эаряженных частиц п, а также инклюэивные двухчастичные корреляции. Полуинклюэивные корреляции обнаруживают явно выраженные зффекты короткодействуюших корреляций, которые обладают щириной эначительно меньщей, чем в случае инклюэивных корреляций. Мы покаэываем, что зти короткодействуюшие зффекты могут быть общяснены змпрически в терминах трех параметров. Обсуждается эависимость зтих параметров от знергии и множественности. Полученные данные подтверждают картину множественного рождения, в которой испускаются кластеры с малой множественностью и малой дисперсией с последуюшим распадом в адроны.
7668411
The High Voltage Feedthroughs for the ATLAS Liquid Argon Calorimeters
The purpose, design specifications, construction techniques, and testing methods are described for the high voltage feedthrough ports and filters of the ATLAS Liquid Argon calorimeters. These feedthroughs carry about 5000 high voltage wires from a room temperature environment (300 K) through the cryostat walls to the calorimeters cells (89 K) while maintaining the electrical and cryogenic integrity of the system. The feedthrough wiring and filters operate at a maximum high voltage of 2.5 kV without danger of degradation by corona discharges or radiation at the Large Hadron Collider.