Measurement of the Scaling Property of Factorial Moments in Hadronic Z Decay

Both three- and one-dimensional studies of local multiplicity fluctuations in hadronic Z decay are performed using data of the L3 experiment at LEP. The normalized factorial moments in three dimensions exhibit power-law scaling, indicating that the fluctuations are isotropic, which correspends to a self-similar fractal. A detailed study of the corresponding one-dimensional moments confirms this conclusion. However, two-jet subsamples have anisotropic fluctuations, correspending to a self-affine fractal. These features are, at least qualitatively, reproduced by the Monte Carlo models \JETSET and \HERWIG.Comment: 4 pages, 4 figures in eps, talk given at XXXI International Symposium on Multiparticle Dynamics, Sept 1-7, 2001, Datong China. see http://ismd31.ccnu.edu.cn

On the direct evaluation of the equilibrium distribution of clusters by simulation

An expression is derived that relates the average population of a particular type of cluster in a metastable vapor phase of volume Vtot to the probability, estimated by simulation, of finding this cluster in a system of volume V taken inside Vtot, where V<<Vtot. Correct treatment of the translational free energy of the cluster is crucial for this purpose. We show that the problem reduces to one of devising the proper boundary condition for the simulation. We then verify the result obtained previously for a low vapor density limit [J. Chem. Phys. 108, 3416 (1998)]. The difficulty implicit in our recent calculation [J. Chem. Phys. 110, 5249 (1999)], in which the approach in the former was generalized to higher vapor densities, is shown to be resolved by a method already suggested in that paper

Geometric Mean Neutrino Mass Relation

Present experimental data from neutrino oscillations have provided much information about the neutrino mixing angles. Since neutrino oscillations only determine the mass squared differences $\Delta m^2_{ij} = m^2_i - m^2_j$, the absolute values for neutrino masses $m_i$ can not be determined using data just from oscillations. In this work we study implications on neutrino masses from a geometric mean mass relation $m_2=\sqrt{m_1 m_3}$ which enables one to determined the absolute masses of the neutrinos. We find that the central values of the three neutrino masses and their $2\sigma$ errors to be $m_1 = (1.58\pm 0.18){meV}$, $m_2 = (9.04\pm 0.42){meV}$, and $m_3 = (51.8\pm 3.5){meV}$. Implications for cosmological observation, beta decay and neutrinoless double beta decays are discussed.Comment: 7 pages. Talk given at COSPA06. A reference adde

On the direct evaluation of the equilibrium distribution of clusters by simulation. II

We clarify some of the subtle issues surrounding the observational cluster method, a simulation technique for studying nucleation. The validity of the method is reaffirmed here. The condition of the compact cluster limit is quantified and its implications are elucidated in terms of the correct enumeration of configuration space

Magnitude of Magnetic Field Dependence of a Possible Selective Spin Filter in ZnSe/Zn_{1-x}Mn_{x}Se Multilayer Heterostructure

Spin-polarized transport through a band-gap-matched ZnSe/Zn_{1-x}Mn_{x} Se/ZnSe/Zn_{1-x}Mn_{x}Se/ZnSe multilayer structure is investigated. The resonant transport is shown to occur at different energies for different spins owing to the split of spin subbands in the paramagnetic layers. It is found that the polarization of current density can be reversed in a certain range of magnetic field, with the peak of polarization moving towards a stronger magnetic field for increasing the width of central ZnSe layer while shifting towards an opposite direction for increasing the width of paramagnetic layer. The reversal is limited in a small-size system. A strong suppression of the spin up component of the current density is present at high magnetic field. It is expected that such a reversal of the polarization could act as a possible mechanism for a selective spin filter device

Bulk metallic glass formation in binary Cu-rich alloy series – Cu100−xZrx (x=34, 36, 38.2, 40 at.%) and mechanical properties of bulk Cu64Zr36 glass

The compositional dependence of a glass-forming ability (GFA) was systematically studied in a binary alloy series Cu100−xZrx (x=34, 36, 38.2, 40 at.%) by the copper mold casting method. Our results show the critical casting thickness jumps from below 0.5 mm to above 2 mm when x changes from 34 to 36 while further increase in x reduces the critical casting thickness. The best glass former Cu64Zr36 does not correspond to either the largest undercooled liquid region (ΔT=Tx1−Tg, where Tg is the glass transition temperature, and Tx1 is the onset temperature of the first crystallization event upon heating) or the highest reduced glass transition temperature (Trg=Tg/Tl, where Tl is the liquidus temperature). Properties of bulk amorphous Cu64Zr36 were measured, yielding a Tg ~ 787 K, Trg ~ 0.64, ΔT ~ 46 K, Hv (Vicker's Hardness) ~ 742 kg/mm^2, Young's Modulus ~ 92.3 GPa, compressive fracture strength ~ 2 GPa and compressive strain before failure ~ 2.2%