122691076
Localized electrons in a magnetic field
We briefly review recent developments on the response of localized electrons to an external magnetic field. They originate from subtle interference effects between forward-scattered paths which, in the localized regime, make the dominant contribution to the transition amplitude. On a lattice the correlations between the paths produce self-similar (quasiperiodic) spatial interference patterns for commensurate (incommensurate) ratios of the applied magnetic flux per plaquette with the flux quantum. If localization is due to strong disorder (as in lightly doped semiconductors), this is augmented by a logarithmic averaging. They give rise to striking quantum interference phenomena observed in mesoscopic and macroscopic insulators: Aharonov-Bohm oscillations with periods of one and one half flux-quantum, the Hall effect, pronounced conductance fluctuations, and anomalous negative (and positive in presence of spin-orbit scattering) magnetoresistance. The theoretical works based on the “directed paths” approach ...
44875732
Interference of directed paths in disordered systems.
43040755
Localized electrons on a lattice with incommensurate magnetic flux.
The magnetic-field effects on lattice wave functions of Hofstadter electrons strongly localized at boundaries are studied analytically and numerically. The exponential decay of the wave function is modulated by a field-dependent amplitude J(t)=Π r=0 t-1 2cos(παr), where a is the magnetic flux per plaquette (in units of a flux quantum) and t is the distance from the boundary (in units of the lattice spacing). The behavior of |J(t)| is found to depend sensitively on the value of a
118156864
Fermi Hyper-Netted Chain Theory on a Lattice: The Hubbard Model
We review a new lattice version of Fermi Hyper-Netted Chain method for the study of strongly interacting electrons. The ordinary paramagnetic and the spin density wave functions have been correlated with Jastrow-type and e — d correlations, and the corresponding FHNC equations for the pair distribution function, the one body density matrix and the staggered magnetization are discussed. Results for the 1D chain and 2D square lattice models are presented and compared with the available results obtained within Quantum Monte Carlo, variational Monte Carlo and exact diagonalization of a 4x4 Hubbard cluster. Particularly interesting are the strong effects of e — d correlations on E/Nt and on the momentum distribution as well as antiferromagnetic behavior away from half filling found in our FHNC calculations in agreement with other studies.
18303820
Quark-quark Double Scattering and Modified Quark Fragmentation Functions in Nuclei
Abstract Quark-quark double scattering in eA DIS and its contribution to quark and anti-quark fragmentation functions are investigated with the generalized factorization of the relevant twist-four processes in pQCD. It is shown that the resulting modifications to quark and anti-quark fragmentation functions are different. While the numerical size of these effects cannot be determined from pQCD, the structure of our result leads to a number of qualitative predictions for the relative size of the effect for different hadrons. These qualitative predictions agree with the multiplicity ratios for positive and negative hadrons as observed by HERMES.
14706541
Punch-through jets in A + A collisions at RHIC/LHC
High pT single and dihadron production is studied within a NLO pQCD parton model with jet quenching in high energy A + A collisions at RHIC/LHC energy. A simultaneous χ2-fit to both single and dihadron spectra can be achieved within a narrow range of the energy loss parameter. Punch-through jets are found to result in a dihadron suppression factor slightly more sensitive to medium properties than the single hadron suppression factor at RHIC. Such jets at LHC are found to dominate high pT dihadron production and the resulting dihadron spectra are more sensitive to the initial parton distribution functions than the single hadron spectra.
117095291
Preparation of a silicon micro-strip nuclear radiation detector by a two-step annealing process
The annealing process for boron implantation is a crucial step during large size nuclear radiation detector fabrication. It can reduce the lattice defects and the projection straggling. A two-step annealing process for boron implantation was developed instead of a one-step annealing process, and the reverse body resistance of a silicon micro-strip detector was significantly increased, which means that the performance of the detector was improved.
118402964
Higgs boson decays and production in the left–right twin Higgs model
The left-right twin Higgs model predicts one neutral Higgs boson �0 and it acquires mass m�0 � µr with the µ term, which can be lighter than half the SM-like Higgs boson mass in a portion of parameter space. Thus, the SM-like Higgs boson h can dominantly decay into a pair of light neutral Higgs bosons especially when mh is below the WW threshold. First, we examine the branching ratios of the SM-like Higgs boson decays and find that the new decay mode h ! �0�0 is dominant for the case of mh > 2m�0 . Then we study the production via gluon fusion followed by the decay into two photons or two weak gauge bosons and found that the production rate can be significantly suppressed for some