Particle Correlation Results from the ALICE Experiment at LHC

Measurements of two-particle correlations of inclusive and identified charged particles performed with the ALICE detector in Pb--Pb collisions at $\sqrt{s_{NN}} = 2.76 TeV$ are presented. The near-side jet shape is analyzed in the low $p_{\rm T}$ regions ($1<$p_{\rm T}$<8GeV/c$). While the RMS of the peak in $\Delta\varphi$-direction is independent of centrality within uncertainties, we find significant broadening in $\Delta\eta$-direction from peripheral to central collisions. The near-side $p/\pi$ ratio of particles associated to a trigger particle from jet fragmentation in the central Pb--Pb collisions is consistent with vacuum fragmentation in the measured momentum region ($1.5<$p_{\rm T}<4.5GeV\c).Comment: 8 pages, 6 figures, proceeding for Physics at LHC 2012, vancouver, Canad

Pulsar Velocity with Three-Neutrino Oscillations in Non-adiabatic Processes

We have studied the position dependence of neutrino energy on the Kusenko-Segr\`{e} mechanism as an explanation of the proper motion of pulsars. The mechanism is also examined in three-generation mixing of neutrinos and in a non-adiabatic case. The position dependence of neutrino energy requires the higher value of magnetic field such as $B\sim 3\times 10^{15}$ Gauss in order to explain the observed proper motion of pulsars. It is shown that possible non-adiabatic processes decrease the neutrino momentum asymmetry, whereas an excess of electron neutrino flux over other flavor neutrino fluxes increases the neutrino momentum asymmetry. It is also shown that a general treatment with all three neutrinos does not modify the result of the two generation treatment if the standard neutrino mass hierarchy is assumed.Comment: 8 pages, REVTEX, no figure

Disassortativity of random critical branching trees

Random critical branching trees (CBTs) are generated by the multiplicative branching process, where the branching number is determined stochastically, independent of the degree of their ancestor. Here we show analytically that despite this stochastic independence, there exists the degree-degree correlation (DDC) in the CBT and it is disassortative. Moreover, the skeletons of fractal networks, the maximum spanning trees formed by the edge betweenness centrality, behave similarly to the CBT in the DDC. This analytic solution and observation support the argument that the fractal scaling in complex networks originates from the disassortativity in the DDC.Comment: 3 pages, 2 figure

Potential contributions of noncontact atomic force microscopy for the future Casimir force measurements

Surface electric noise, i.e., the non-uniform distribution of charges and potentials on a surface, poses a great experimental challenge in modern precision force measurements. Such a challenge is encountered in a number of different experimental circumstances. The scientists employing atomic force microscopy (AFM) have long focused their efforts to understand the surface-related noise issues via variants of AFM techniques, such as Kelvin probe force microscopy or electric force microscopy. Recently, the physicists investigating quantum vacuum fluctuation phenomena between two closely-spaced objects have also begun to collect experimental evidence indicating a presence of surface effects neglected in their previous analyses. It now appears that the two seemingly disparate science communities are encountering effects rooted in the same surface phenomena. In this report, we suggest specific experimental tasks to be performed in the near future that are crucial not only for fostering needed collaborations between the two communities, but also for providing valuable data on the surface effects in order to draw the most realistic conclusion about the actual contribution of the Casimir force (or van der Waals force) between a pair of real materials.Comment: The paper appeared in the Proceedings to the 12th International Conference on Noncontact Atomic Force Microscopy (NC-AFM 2009) and Casimir 2009 Satellite Worksho