Top-Quark Mass Measurement in the Dilepton Channel Using {\it in situ} Jet Energy Scale Calibration

We employ a top-quark mass measurement technique in the dilepton channel with {\it in situ} jet energy scale calibration. Three variables having different jet energy scale dependences are used simultaneously to extract not only the top-quark mass but also the energy scale of the jet from a single likelihood fit. Monte Carlo studies with events corresponding to an integrated luminosity of 5 fb$^{-1}$ proton-proton collisions at the Large Hadron Collider $\sqrt{s} = 7$ TeV are performed. Our analysis suggests that the overall jet energy scale uncertainty can be significantly reduced and the top-quark mass can be determined with a precision of less than 1 GeV/c$^2$, including jet energy scale uncertainty, at the Large Hadron Collider.Comment: Submitted to Phys. Rev.

Resonant Raman scattering of quantum wire in strong magnetic field

The resonant Raman scattering of a quantum wire in a strong magnetic field is studied, focused on the effect of long range Coulomb interaction and the spin-charge separation. The energy-momentum dispersions of charge and spin excitation obtained from Raman cross-section show the characteristc cross-over behaviour induced by inter-edge Coulomb interaction. The "SPE" peak near resonance in polarized spectra becomes broad due to the momentum dependence of charge velocity. The broad peak in the depolarized spectra is shown to originate from the disparity between charge and spin excitation velocity.Comment: RevTex file, 6 pages, no figure: To appear in Int. Jour. Mod. Phys.

Theoretical study of X-ray absorption of three-dimensional topological insulator Bi2Se3\mathrm{Bi}_2\mathrm{Se}_3

X-ray absorption edge singularity which is usually relevant for metals is studied for the prototype topological insulator $\mathrm{Bi}_2\mathrm{Se}_3$. The generalized integral equation of Nozi\`eres and Dominicis type for X-ray edge singularity is derived and solved. The spin texture of surfaces states causes a component of singularity dependent on the helicity of the spin texture. It also yields another component for which the singularity from excitonic processes is absent.Comment: RevTeX 4.1. 4 pages, no figur

Effect of ferromagnetic contacts on spin accumulation in an all-metallic lateral spin-valve system: Semiclassical spin drift-diffusion equations

We study the effect of the ferromagnetic (FM) contacts on the spin accumulation in the lateral spin valve system for the collinear magnetization configurations. When an additional FM electrode is introduced in the all-metallic lateral spin-valve system, we find that the transresistance can be fractionally suppressed or very weakly influenced depending on the position of the additional FM electrode, and relative magnitudes of contact resistance and the bulk resistance defined over the spin diffusion length. Nonlocal spin signals such as nonlocal voltage drop and leakage spin currents are independent of the magnetization orientation of the additional FM electrode. Even when the additional contact is nonmagnetic, nonlocal spin signals can be changed by the spin current leaking into the nonmagnetic electrode.Comment: 13 pages, 1 figure, revised versio