Employing a sample presented by Kaneko et al. (2006) and Kocevski et al. (2003), we select 42 individual tracking pulses (here we defined tracking as the cases in which the hardness follows the same pattern as the flux or count rate time profile) within 36 Gamma-ray Bursts (GRBs) containing 527 time-resolved spectra and investigate the spectral hardness, Epeak (where Epeak is the maximum of the...

The CCD magnitudes in Johnson V and Cousins R and I photometric passbands are determined for GRB 000301C afterglow starting ∼ 1.5 day after the γ−ray burst. In fact we provide the earliest optical observations for this burst. Light curves of the afterglow emissions are obtained by combining the published data with the present measurements in B,V,R, I, J and K ′ passbands. Flux decay shows a ver...

One of the folk theorems in quantum lattice models claims the equivalence of the existence of a nonvanishing spectral gap and exponential decay of spatial correlations in the ground state. It has been known for some time that there are exceptions to one direction of this equivalence. There are models with a unique ground state with exponential decay of correlations but without a gap in the exci...

Planar quantum dot clusters (QDCs) consisting of six InGaAs quantum dots (QDs) formed around a GaAs nanomound are the most sophisticated self-assembled QDCs grown by molecular beam epitaxy thus far. We present the first photoluminescence measurements on individual hexa-QDCs with high spatial, spectral, and temporal resolution. In the best QDCs, the excitons confined in individual QDs are remark...

We show that all X-ray decay curves of -ray bursts (GRBs) measured by Swift can be fitted using one or two components, both of which have exactly the same functional form comprised of an early falling exponential phase followed by a power-law decay. The first component contains the prompt -ray emission and the initial X-ray decay. The second component appears later, has a much longer duration, ...

The CCD magnitudes in Johnson V and Cousins R and I photometric passbands are determined for GRB 000301C afterglow starting ∼ 1.5 day after the γ−ray burst. In fact we provide the earliest optical observations for this burst. Light curves of the afterglow emissions in U, B, V, R, I, J and K ′ passbands are obtained by combining the present measurements with the published data. Flux decay shows ...

We present a chirally symmetric hadronic model for the vector and axial-vector correlators in vacuum. The dominant contributions to these correlators come from intermediate pions, ρ and a 1 mesons which are calculated in one-loop approximation. The resulting spectral functions are compared with the data obtained by the ALEPH collaboration from τ decay. In the vector channel we find good agreeme...

The radiative decay φ → γππ in a coupled channel model and the structure of f 0 (980) Abstract A coupled channel model is used to study the nature of the scalar mesons produced in the decay φ → γππ. The K ¯ K molecular picture of f 0 (980) is found to be in a good agreement with the recent experimental data from SND and CMD-2. The structure of the light scalar mesons is elucidated by investigat...