R & D proposal: Proposal for research and development of a hadron calorimeter for high magnetic fields

title: First results on the Spaghetti Calorimeter projective prototype
abstract: The performances of a projective lead/scintillating fibres (“spaghetti”) calorimeter made out of rectangular cross-section (32 × 32 mm 2 ) straight modules alternated with tapering modules at 2.5° are described. Beam test results on energy resolution, constant term suppression, lineshape, uniformity of response, shower position resolution, and electron-pion discrimination are presented. The readout of the fibres in the straight modules, which are sensitive to most of the electromagnetic showers and to part of the hadronic showers, is kept separate from the readout of the fibres of the wedged sections, which are sensitive only to hadronic showers. The lead-to-fibre volume ratio is kept at about 4 to 1 in order to obtain an equal-amplitude response from electrons and hadrons (usually called “compensation”). The origin of the energy resolution constant term has been better understood. This allowed the reduction of the constant term to 0.5%, down from 1.2% measured in older prototypes. The probability of faking abnormally large signals because of channelling effects is also discussed. The position resolution has been measured to range from 0.5 to 1 mm depending on the hit position of the particle. A comparison with the larger hexagonal module design is also made. The efficiency of a hardware thresholding of the wedges' signal as a level one trigger pion veto is discussed along with off-line electron/pion discrimination performances. Since the wedges start at 26 X 0 from the calorimeter front face they should show no signal for electromagnetic showers. It was found that electromagnetic showers of 50 GeV generate wedge signals of a maximum of a few tens of MeV. It was also found that the discriminating power is angle dependent, mainly because at small particle-to-fibre angles (≤ 1°) some electrons can penetrate the calorimeter through channeling, thus exciting a signal in the wedges. At slightly higher tilt angle it is possible to use a lower wedge threshold without loss in electron efficiency. With a beam-to-fibre angle of 3°, 99.6% of pions are rejected with a 98.5% electron efficiency. More recent and preliminary results on energy resolution at energies up to 100 GeV, and on radiation damage of scintillating fibres are also presented.

title: 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.

title: Proton branching ratios in the beta-delayed proton decay of Mo-87
abstract: The nuclide Mo-87 With A = 4n+3 and T-z=3/2 was reinvestigated via its The nuclide Mo-87 With A = 4n+3 and T-z=3/2 was reinvestigated via its

title: beta-delayed proton decay of Kr-69
abstract: The nuclide Kr-69 With T-z=-3/2, A=4n+1 produced in the Ca-40(S-32,3n) The nuclide Kr-69 With T-z=-3/2, A=4n+1 produced in the Ca-40(S-32,3n)

title: Further evidences for enhanced nuclear cross-sections observed in 44 GeV carbon ion interactions with copper

title: The Palo Verde neutrino oscillation experiment
abstract: A new long baseline neutrino oscillation experiment1 is being built at the Palo Verde Nuclear Generating Station near Phoenix, Arizona. Its sensitivity is Δm 2 ~ 10−3 eV 2 and sin 2(2θ) ~ 0.1. The lab construction has been finished, the detector installation is almost completed and we are about to take data soon.

title: Guidelines for a supercollider experiment: the magnetic system
abstract: We try to give some general guidelines for optimizing the magnetic system of a general-purpose detector with a high momentum resolution for muons at a supercollider experiment. Solenoidal and toroidal schemes are investigated, with the possibility of using calorimeter material as the coil.

title: FERMIONIC ZERO MODES IN SELF-DUAL VORTEX BACKGROUND
abstract: We study fermionic zero modes in the background of self-dual vortex on a two-dimensional non-compact extra space in 5+1 dimensions. In the Abelian Higgs model, we present a unified description of the topological and non-topological self-dual vortex on the extra two dimensions. Based on it, we study the localization of bulk fermions on a brane with the inclusion of Yang–Mills and gravity backgrounds in six dimensions. Through two simple cases, it is shown that the vortex background contributes a phase shift to the fermionic zero mode, this phase is actually origin from the Aharonov–Bohm effect.

title: Neutral hadron production at LEP with the L3 detector