117487117
The TEXONO research program on low-energy neutrino and astroparticle physics
AbstractThis article reviews the research program and efforts of the TEXONO Collaboration on neutrino and astroparticles. The main program is on reactor-based low-energy neutrino physics at the Kuo-Sheng Power Plant in Taiwan. The facilities of the laboratory are described. A limit on the neutrino magnetic moment of μν(
$$\bar \nu _e $$
) < 1.3 × 10−10 μB at 90% C.L. has been achieved from measurements with a high-purity germanium detector. Other research programs at Kuo-Sheng are surveyed.
16990556
Effective dynamic range in measurements with flash analog-to-digital convertor
Flash Analog-to-Digital Convertor (FADC) is frequently used in Nuclear and Particle Physics experiments, often as the major component in big multi-channel systems. The large data volume makes the optimization of operating parameters necessary. This article reports a study of a method to extend the dynamic range of an 8-bit FADC from the nominal 28 value. By comparing the integrated pulse area with that of a reference profile, good energy reconstruction and event identification can be achieved on saturated events from CsI(TI) crystal scintillators. The effective dynamic range can be extended by at least four more bits. The algorithm is generic and is expected to be applicable to other detector systems with FADC readout. (C) 2003 Elsevier B.V. All rights reserved.
119107308
Hadron spectra in p+p collisions at RHIC and LHC energies
We present the systematic analysis of transverse momentum (pT) spectra of identified hadrons in p+p collisions at Relativistic Heavy Ion Collider ( and 200 GeV) and at Large Hadron Collider (LHC) energies (, 2.76 and 7.0 TeV) using phenomenological fit functions. We review various forms of Hagedorn and Tsallis distributions and show their equivalence. We use Tsallis distribution which successfully describes the spectra in p+p collisions using two parameters, Tsallis temperature T which governs the soft bulk spectra and power n which determines the initial production in partonic collisions. We obtain these parameters for pions, kaons and protons as a function of center-of-mass energy . It is found that the parameter T has a weak but decreasing trend with increasing . The parameter n decreases with increasing which shows that production of hadrons at higher energies are increasingly dominated by point like qq scatterings. Another important observation is with increasing , the separation between the powers for protons and pions narrows down hinting that the baryons and mesons are governed by same production process as one moves to the highest LHC energy.
121929737
Factorization limit on photon-photon cross section
A lower bound on the photon-photon total cross section following from factorization of Regge singularities is presented. The bound seems to lie quite close to the recent PETRA measurements when the gamma-gamma c.m. energy is above 6 GeV.
121365081
UPPER BOUNDS ON THE ELASTIC DIFFERENTIAL CROSS SECTION.
We derive improved axiomatic upper bounds on the elastic unpolarized differential cross section, dσdΩ, at high energies for the scattering of particles with arbitrary spin. We prove that 
dσdω⩽s→∞σel4φ{(L+1)2[PL(cos θ)]2+sin2θ[PL′(cos θ)]2} 
with L=12Sto In sσel), where s and t are, respectively, the squares of the c.m. energy and the c.m. momentum transfer; θ is the c.m. scattering angle. Further to, is the mass of the lowest mass state that couples to the crossed t-channel (being equal to twice the pion mass for ππ and πN scattering). This result has the following important consequences: 
1. 
(i) for forward scattering, 
dσdtt=0⩽s→∞σel4t0Insσel2 
 
 
2. 
(ii) for fixed θ ≠ 0, π, 
dσdω(s;cosθ)⩽s→∞14φ2st0σelsinθInsσel 
and 
 
3. 
(iii) for fixed negative t, 
 
 
 
dσdω(s,t)⩽s→∞18φt0s−tσelInsσel 
 
 
We also give an upper bound on differential cross section involving the diffraction peak width but not having an explicit ln s dependence.
121540442
Unitarity bounds on elastic absorptive amplitudes involving total cross section, forward slope and curvature. II
For pt.I see Phys. Lett. vol.67B, no.3, p.327 (1977). Unitarity bounds on the shape of the diffraction peak obtained using only the positivity of the absorptive part of the partial waves are extended to include the boundedness restriction and are compared with data. A detailed explanation is given for a curious phenomenon that has recently been observed to arise in variational problems of this kind.
119421763
High precision study of the space distribution of the colour flux in the SU(2) lattice gauge theory
Abstract The work of the Cracow-LSU collaboration on the space structure of the colour fields around the static charges is reported. We find that the large cancellations between the electric and magnetic energy densities lead to a narrow tube.
123138859
Determination of shell correction energies at saddle point using pre-scission neutron multiplicities
Abstract Pre-scission neutron multiplicities have been measured for 12 C +  194, 198 Pt systems at matching excitation energies at near Coulomb barrier region. Statistical model analysis with a modified fission barrier and level density prescription have been carried out to fit the measured pre-scission neutron multiplicities and the available evaporation residue and fission cross sections simultaneously to constrain statistical model parameters. Simultaneous fitting of the pre-scission neutron multiplicities and cross section data requires shell correction at the saddle point.