119618633
Search for isosinglet neutral heavy leptons in Z0 decays
Abstract We search for neutral heavy leptons that are isosinglets under the standard SU (2) L gauge group. Such neutral heavy leptons are expected in many extensions of the standard model. Three types of heavy leptons N e , N μ , N τ associated with the three neutrino types v e , v μ , v τ have been directly searched for and no evidence for a signal has been found. We set the limit Br(N Su 0 → v l N l ) x 10 −5 at the 95% CL for mass range from 3 GeV up to M z .
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.
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.
125677069
TUBE CHAMBERS FOR THE MUON FILTER OF THE L3 DETECTOR
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.
119306498
Using multipoles of the correlation function to measure H(z), DA(z) and β(z) from Sloan Digital Sky Survey luminous red galaxies
Galaxy clustering data can be used to measure the cosmic expansion history H(z), the angular-diameter distance D_A(z), and the linear redshift-space distortion parameter beta(z). Here we present a method for using effective multipoles of the galaxy two-point correlation function (\xi_0(s), \xi_2(s), \xi}_4(s), and \xi_6(s), with s denoting the comoving separation) to measure H(z), D_A(z)$, and beta(z), and validate it using LasDamas mock galaxy catalogs. Our definition of effective multipoles explicitly incorporates the discreteness of measurements, and treats the measured correlation function and its theoretical model on the same footing. We find that for the mock data, \xi_0+\xi_2+\xi_4 captures nearly all the information, and gives significantly stronger constraints on H(z), D_A(z), and beta(z), compared to using only \xi_0+\xi_2. 
We apply our method to the sample of luminous red galaxies (LRGs) from the Sloan Digital Sky Survey (SDSS) Data Release 7 (DR7) without assuming a dark energy model or a flat Universe. We find that \xi}_4(s) deviates on scales of s<60Mpc/h from the measurement from mock data (in contrast to \xi_0(s), \xi_2(s), and \xi_6(s)), thus we only use \xi_0+\xi_2 for our fiducial constraints. We obtain {H(0.35), D_A(0.35), Omega_mh^2, beta(z)} = {79.6_{-8.7}^{+8.3} km/s/Mpc, 1057_{-87}^{+88}Mpc, 0.103\pm0.015, 0.44\pm0.15} using \xi_0+\xi_2. We find that H(0.35)r_s(z_d)/c and D_A(0.35)/r_s(z_d) (where r_s(z_d) is the sound horizon at the drag epoch) are more tightly constrained: {H(0.35)r_s(z_d)/c, D_A(0.35)/r_s(z_d)} = {0.0437_{-0.0043}^{+0.0041}, 6.48_{-0.43}^{+0.44}\} using \xi_0+\xi_2.
15577836
CENTRALITY, SYSTEM SIZE AND ENERGY DEPENDENCE OF CHARGED PARTICLE PSEUDORAPIDITY DISTRIBUTION
Utilizing the three-fireball picture within the quark combination model, we study systematically the charged particle pseudorapidity distributions in both Au + Au and Cu + Cu collision systems as a function of collision centrality and energy, , 62.4, 130 and 200 GeV, in the full pseudorapidity range. We find that: (i) the contribution from leading particles to dNch/dη distributions increases with the decrease of the collision centrality and energy respectively; (ii) the number of leading particles is almost independent of the collision energy, but it does depend on the nucleon participants Npart; (iii) if Cu + Cu and Au + Au collisions at the same collision energy are selected to have the same Npart, the resulting charged particle dN/dη distributions are nearly identical, in both the midrapidity particle density and the width of the distribution; this is true for both 62.4 GeV and 200 GeV data; (iv) the limiting fragmentation phenomenon is reproduced. We predict the total multiplicity and pseudorapidity distribution for the charged particles in Pb + Pb collisions at . Finally, we give a qualitative analysis of Nch/〈Npart/2〉 and dNch/dη/〈Npart/2〉|η≈0 as a function of and Npart from the RHIC to the LHC.
17823222
LHC reach for gauge mediated supersymmetry breaking models via prompt photon channels
Abstract We evaluate the supersymmetry reach of the Large Hadron Collider within the gauge-mediated low energy supersymmetry breaking framework, assuming that a neutralino is the second lightest sparticle and that it decays promptly into a gravitino which escapes detection. We find that the maximum reach is obtained via a search for inclusive γγ+ E / T events coming dominantly from chargino and neutralino production. Assuming an integrated luminosity of 10 fb −1 , we find that LHC experiments will be able to probe values of the model parameter Λ ≲400 TeV, corresponding to m g ≤2.8 TeV. A measure of the model parameter Λ may be possible from the photon p T spectrum.
122617218
Polarization transfer in quasifree (p, n) reactions at 495 MeV
A complete set of polarization-transfer observables has been measured for quasifree ([ital [rvec p]],[ital [rvec n]]) reactions on [sup 2]H, [sup 12]C, and [sup 40]Ca at a bombarding energy of 495 MeV and a laboratory scattering angle of 18[degree]. The data span an energy-loss range from 0 to 160 MeV, with a corresponding momentum transfer range of [ital q][sub c.m.]=1.7--1.9 fm[sup [minus]1]. The laboratory observables are used to construct partial cross sections proportional to the nonspin response and three orthogonal spin responses. These results are compared to the transverse spin response measured in deep inelastic electron scattering and to nuclear responses based on the random phase approximation. The polarization observables for all three targets are remarkably similar and reveal no evidence for an enhancement of the spin-longitudinal nuclear response relative to the spin-transverse response. These results suggest the need for substantial modifications to the standard form assumed for the residual particle-hole interaction.
1288334
Model-independent measurement of the primordial power spectrum
In inflationary models with minimal amount of gravity waves, the primordial power spectrum of density fluctuations, AS2(k), together with the basic cosmological parameters, completely specify the predictions for the cosmic microwave background (CMB) anisotropy and large scale structure. Here we show how we can strongly constrain both AS2(k) and the cosmological parameters by combining the data from the Microwave Anisotropy Probe (MAP) and the galaxy redshift survey from the Sloan Digital Sky Survey (SDSS). We allow AS2(k) to be a free function, and thus probe features in the primordial power spectrum on all scales. MAP and SDSS have scale-dependent measurement errors that decrease in opposite directions on astrophysically interesting scales; they complement each other and allow the measurement of the primordial power spectrum independent of inflationary models, giving us valuable information on physics in the early Universe, and providing clues to the correct inflationary model.