S.C. Lee

The versatile link, a common project for super-LHC

A common project to develop a bi-directional, radiation tolerant, high speed (4.8 Gb/s) optical link for future high energy physics experiments is described. Due to be completed in 2012, it targets the upgrade programs of detectors installed at CERNs Large Hadron Collider (LHC). The development of radiation and magnetic field tolerant opto-electronic devices, fibre and connectors is described. Both Single-Mode and Multi-Mode versions of the system operating respectively at 850 nm and 1310 nm wavelength are proposed. First results at component and system level are presented, based mostly on commercially available devices.

Search of neutrino magnetic moments with a high-purity germanium detector at the Kuo-Sheng nuclear power station

A search of neutrino magnetic moments was carried out at the Kuo-Sheng nuclear power station at a distance of 28 m from the 2.9 GW reactor core. With a high purity germanium detector of mass 1.06 kg surrounded by scintillating NaI(Tl) and CsI(Tl) crystals as anti-Compton detectors, a detection threshold of 5 keV and a background level of 1 kg{sup -1} keV{sup -1} day{sup -1} near threshold were achieved. Details of the reactor neutrino source, experimental hardware, background understanding, and analysis methods are presented. Based on 570.7 and 127.8 days of Reactor ON and OFF data, respectively, at an average Reactor ON electron antineutrino flux of 6.4x10{sup 12} cm{sup -2} s{sup -1}, the limit on the neutrino magnetic moments of {mu}{sub {nu}{sub e}}<7.4x10{sup -11}{mu}{sub B} at 90% confidence level was derived. Indirect bounds on the {nu}{sub e} radiative decay lifetimes were inferred.

Limit on the Electron Neutrino Magnetic Moment from the Kuo-Sheng Reactor Neutrino Experiment

A search of neutrino magnetic moment was carried out at the Kuo-Sheng Nuclear Power Station at a distance of 28 m from the 2.9 GW reactor core. With a high purity germanium detector of mass 1.06 kg surrounded by scintillating NaI(Tl) and CsI(Tl) crystals as anti-Compton detectors, a detection threshold of 5 keV and a background level of 1 kg(-1) keV(-1) day(-1) at 12-60 keV were achieved. Based on 4712 and 1250 h of reactor ON and OFF data, respectively, the limit on the neutrino magnetic moment of mu(nu;(e))<1.3x10(-10)mu(B) at 90% confidence level was derived. An indirect bound of the nu;(e) radiative lifetime of m(3)(nu)tau(nu)>2.8x10(18) eV(3) s can be inferred.

Measurement of Nu(e)-bar -Electron Scattering Cross-Section with a CsI(Tl) Scintillating Crystal Array at the Kuo-Sheng Nuclear Power Reactor

The {nu}{sub e}-e{sup -} elastic scattering cross section was measured with a CsI(Tl) scintillating crystal array having a total mass of 187 kg. The detector was exposed to an average reactor {nu}{sub e} flux of 6.4x10{sup 12} cm{sup -2} s{sup -1} at the Kuo-Sheng Nuclear Power Station. The experimental design, conceptual merits, detector hardware, data analysis, and background understanding of the experiment are presented. Using 29882/7369 kg-days of Reactor ON/OFF data, the standard model (SM) electroweak interaction was probed at the squared 4-momentum transfer range of Q{sup 2{approx}}3x10{sup -6} GeV{sup 2}. The ratio of experimental to SM cross sections of {xi}=[1.08{+-}0.21(stat){+-}0.16(sys)] was measured. Constraints on the electroweak parameters (g{sub V},g{sub A}) were placed, corresponding to a weak mixing angle measurement of sin{sup 2{theta}}{sub W}=0.251{+-}0.031(stat){+-}0.024(sys). Destructive interference in the SM {nu}{sub e}-e process was verified. Bounds on anomalous neutrino electromagnetic properties were placed: neutrino magnetic moment at {mu}{sub {nu}{sub e}} <3.3x10{sup -32} cm{sup 2}, both at 90% confidence level.

The starting up of a neutrino project in Taiwan

Abstract There may be a unique opportunity to perform a long baseline reactor neutrino oscillation experiment in Taiwan, profiting from the power reactors which provide an abundant supply of neutrinos and the local mountainuous geography where an underground laboratory can be built. A Taiwan-based Collaboration has been built up to intensely pursue a detector R&D program in preparation for a pilot experiment at the power reactors, the first step towards this goal. Our current efforts and future plans are presented.

Soliton transformations for axially symmetric higher‐dimensional gravity. II. Belinskii–Zakharov N‐soliton transformations

The solutions of vacuum Einstein equations in 4+K dimensions with 2+K commuting Killing vectors under the Abelian Kaluza–Klein ansatz are considered. This system admits Belinskii–Zakharov‐type soliton transformations. The explicit formulas for general N‐soliton transformations are obtained by iterating the formulas for one‐soliton transformation.

Soliton transformations for axially symmetric higher-dimensional gravity. I. Generalized Neugebauer--Kramer transformations

The field equations for axially symmetric gravitational fields in 4+K dimensions with K‐dimensional toroidal compatification can be reduced to those of a generalized nonlinear sigma model. The dual symmetry of this model is considered first. Then the soliton transformations for these equations are derived using the method of Belinskii and Zakharov consequently generalizing their results to the higher‐dimensional case. From the result of one‐soliton transformation, a series of discrete symmetries generalizing the Neugebauer–Kramer transformation in the four‐dimensional case are obtained. The basic properties of these new transformations are studied.

Lagrangian dynamics on higher-dimensional spaces with applications to Kaluza--Klein theories

We review and apply the method of Lagrangian dynamics to particle motion in higher‐dimensional spaces. We discuss in detail the case of a Kaluza–Klein theory with coset spaces as fiber. While the total metric we use in general need not allow for Killing vectors, we require that the restriction to the fiber does. We find that for general Jordan–Thiry scalar fields, the geodesic motion in total space is not describable in terms of particle motion in the base manifold with the usual internal charges. The cases when this is possible are discussed. We also consider the geodesic motion in the Sorkin–Gross–Perry Kaluza–Klein monopoles. We find all the conserved quantities and the equations can be integrated by quadrature.