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E. Nakano

Publications and source records attributed to E. Nakano.

111 records · Page 7Linked to original sources

AFM pictures of the surfaces of glass RPC electrodes damaged by water vapor contamination

We present surface pictures of the damaged electrodes from the Glass Resistive Plate Chambers (GRPCs) taken by an Atomic Force Microscope (AFM). For the test, a set of chambers were operated with freon mixed gas (damaged) and freonless gas (not damaged), contaminated with 1000 to 2000 ppm of water vapor. In the AFM pictures, clear differences in damage are seen between the electrodes in the chambers with the freon mixed gas and the freonless gas; a combination of freon and water vapor caused the damage.

hep-ex↗

Color-SU(3)-Ginzburg-Landau Effective Potential for Order Parameter with ${\bf 3} \times {\bf 3}$ Symmetry

Ginzburg-Landau effective potential is studied for the order parameter that transforms in the $(3,3)$ representation under the color SU(3) group. All the SU(3) terms to the fourth-order of the order parameter are classified and the effective potential is constructed in its most general form. The conditions which stabilize the condensed phases are also obtained. As simple applications, the classification of the condensed phase is discussed in some special cases and the Higgs phenomenon associated with symmetry breaking is studied by introducing a coupling to the gauge boson.

hep-ph↗

Measurement of the forward-backward asymmetries for charm- and bottom-quark pair productions at $<\sqrt{s}>$=58GeV with electron tagging

We have measured, with electron tagging, the forward-backward asymmetries of charm- and bottom-quark pair productions at $<\sqrt{s} >$=58.01GeV, based on 23,783 hadronic events selected from a data sample of 197pb$^{-1}$ taken with the TOPAZ detector at TRISTAN. The measured forward-backward asymmetries are $A_{FB}^c = -0.49 \pm 0.20(stat.) \pm 0.08 (sys.)$ and $A_{FB}^b = -0.64 \pm 0.35(stat.) \pm 0.13 (sys.)$, which are consistent with the standard model predictions.

hep-ex↗