56456381
Mass limits for excited electrons and muons from Z0 decay
Abstract We searched for excited electrons and muons from Z 0 decay in the channels ee→eeγ, ee→eeγγ, ee→(e)eγ, ee→μμγ, ee→μμγγ. using the L3 detector at LEP. The lower mass limit for e ∗ is 45.0 GeV and for μ ∗ 45.3 GeV. The upper limits of ll ∗ Z 0 and ll ∗ γ couplings at 95% CL have been determined up to m l∗ close to the Z 0 mass.
125677069
TUBE CHAMBERS FOR THE MUON FILTER OF THE L3 DETECTOR
118039047
Physics of tau and charm
The physics of tau and charm started in early 70's after J/$\psi$ and $\tau$ were discovered. Since then several dedicated accelerators and experiments were built with increasing luminosities and studies on light hadron spectroscopy, charmonium, electroweak and QCD were never interupted. New interests and surprises are not rare in this area. With the newly built BEPCII/BESIII, an even brighter future is foreseen.
122214277
A water Cherenkov calorimeter for long baseline neutrino oscillation experiments
Abstract We propose a water-based large homogeneous calorimeter as the next generation neutrino detector for ν factories and/or conventional ν beams. The Cherenkov light produced in water is sufficient to have good energy resolution, and the pattern recognition is realized by a modular water tank structure. Monte Carlo simulations show that the detector performance is excellent for identifying neutrino CC events while rejecting backgrounds.
56005177
Inclusive J production in Z0 decays
Abstract Inclusive J production in Z0 decays is observed via the leptonic decay mode J → l+l− (l = e,μ). We measure the branching ratio Br(Z0 → J + X) = (4.1 ± 0.7 (stat.) ± 0.3 (sys.)) × 10−3. We have calculated the fraction of the J mesons from b-hadron decay and find a branching ratio of Br(b → J + X)= (1.3±0.2(stat.)±0.2(sys.)) × 10−2. We determine the average fractional energy of bottom hadrons 〈XE > = 0.70±0.03 (stat.)+0.02−0.01 (sys.) using the momentum spectrum of the J mesons. From a study of the angle between the J and the most energetic jet, we set an upper limit on the branching ratio Br ( Z 0 → q q g ∗ ; g ∗ → J + X ) −4 at 90% confidence level.
18893994
The mass production and quality control of RPCs for the Daya Bay experiment
Abstract Resistive plate chambers will be used in the Daya Bay reactor neutrino experiment to help veto backgrounds created by cosmic-ray muons. The mass production of RPCs began in 2008 and by the end of 2009, 1600 RPCs (3500 m 2 ) had been produced and tested. This paper describes the production and quality control procedures, and quality assurance using cosmic-ray testing.
121107871
Electron-pion discrimination with a scintillating fiber calorimeter
Abstract We report on an experimental study of a variety of techniques for discriminating between (isolated) electrons and pions in a lead and scintillating fiber calorimeter without longitudinal segmentation. Using information from the lateral shower development, from a pre-shower detector, from the time structure of the signals, or from a combination of these we measure pion rejection factors of up to several thousand while maintaining electron efficiencies of 95% or higher.
119727400
A conformally broken system as the constrained SL(2,R) WZNW model, its integrability and dressing symmetry
This paper is devoted to the study of the conformally broken system related to the conformally invariant SL(2,R) WZNW model. Our starting point is such an action that is similar in form to the action of gauged WZNW theories developed by Balog et al. (1990). However, the Lagrangian multipliers in our case are assumed to take their values on the mixing of upper and lower Borel subalgebras of sl(2). The system obtained turns out to be an off-conformal extension of the sinh-Gordon model. Its integrability is displayed by the Lax formalism with an arbitrary spectral parameter, the classical r-matrix, and the hidden dressing symmetry.
126327724
New determination of the proton spectroscopic factor in Be-9 from the C-13 (Be-9, Li-8) N-14 angular distribution
121984352
The BES detector
Abstract The Beijing Spectrometer (BES) is a general purpose solenoidal detector at the Beijing Electron Positron Collider (BEPC). It is designed to study exclusive final states in e + e − annihilations at the center of mass energy from 3.0 to 5.6 GeV. This requires large solid angle coverage combined with good charged particle momentum resolution, good particle identification and high photon detection efficiency at low energies. In this paper we describe the construction and the performance of BES detector.
119226794
Observational constraints to Ricci dark energy model by using: SN, BAO, OHD, fgas data sets
We perform a global constraint on the Ricci dark energy model with both the flat case and the non-flat case, using the Markov Chain Monte Carlo (MCMC) method and the combined observational data from the cluster X-ray gas mass fraction, Supernovae of type Ia (397), baryon acoustic oscillations, current Cosmic Microwave Background, and the observational Hubble function. In the flat model, we obtain the best fit values of the parameters in 1σ,2σ regions: Ωm0 = 0.2927+0.0420+0.0542−0.0323−0.0388, α = 0.3823+0.0331+0.0415−0.0418−0.0541, Age/Gyr = 13.48+0.13+0.17−0.16−0.21, H0 = 69.09+2.56+3.09−2.37−3.39. In the non-flat model, the best fit parameters are found in 1σ,2σ regions:Ωm0 = 0.3003+0.0367+0.0429−0.0371−0.0423, α = 0.3845+0.0386+0.0521−0.0474−0.0523, Ωk = 0.0240+0.0109+0.0133−0.0130−0.0153, Age/Gyr = 12.54+0.51+0.65−0.37−0.49, H0 = 72.89+3.31+3.88−3.05−3.72. Compared to the constraint results in the ΛCDM model by using the same datasets, it is shown that the current combined datasets prefer the ΛCDM model to the Ricci dark energy model.