Mass Spectra of Heavy-Light Mesons in Heavy Hadron Chiral Perturbation Theory

We study the masses of the low-lying charm and bottom mesons within the framework of heavy- hadron chiral perturbation theory (HHChPT). We work to third order in the chiral expansion, where meson loops contribute. In contrast to previous approaches, we use physical meson masses in evaluating these loops. This ensures that their imaginary parts are consistent with the observed widths of the D-mesons. The lowest odd- and even-parity, strange and nonstrange charm mesons provide enough constraints to determine only certain linear combinations of the low-energy constants (LECs) in the effective Lagrangian. We comment on how lattice QCD could provide further information to disentangle these constants. Then we use the results from the charm sector to predict the spectrum of odd- and even-parity of the bottom mesons. The predicted masses from our theory are in good agreement with experimentally measured masses for the case of the odd-parity sector. For the even-parity sector, the B-meson states have not yet been observed; thus, our results provide useful information for experimentalists investigating such states. The near degeneracy of nonstrange and strange scalar B mesons is confirmed in our predictions using HHChPT. We show why previous approaches of using HHChPT in studying the mass degeneracy in the scalar states of charm and bottom meson sectors gave unsatisfactory results.Comment: 16 pages, LATEX2e, 6 figure

Graph-Based Decoding in the Presence of ISI

We propose an approximation of maximum-likelihood detection in ISI channels based on linear programming or message passing. We convert the detection problem into a binary decoding problem, which can be easily combined with LDPC decoding. We show that, for a certain class of channels and in the absence of coding, the proposed technique provides the exact ML solution without an exponential complexity in the size of channel memory, while for some other channels, this method has a non-diminishing probability of failure as SNR increases. Some analysis is provided for the error events of the proposed technique under linear programming.Comment: 25 pages, 8 figures, Submitted to IEEE Transactions on Information Theor

Collaborative Downloading in VANET using Network Coding

Data downloading on the fly is the base of commercial data services in vehicular networks, such as office-onwheels and entertainment-on-wheels. Due to the sparse spacial distribution of roadside Base Stations (BS) along the road, downloading through Roadside-to-Vehicle (R2V) connections is intermittent.When multiple vehicles with geographical proximity have common interest in certain objects to download, they can collaborate to reduce significantly their overall download time. In this paper, we investigate application of Network Coding (NC) in collaborative downloading (CD). We focus on the R2V part of CD, and analytically derive probability distribution and expected value of amount of time needed to deliver all information to the vehicles with and without NC. Our results show that using NC slightly improves the downloading time in addition to removing any need for having any sort of uplink communications from vehicles to the infrastructure.Comment: conference, 7 Pages, 3 Figures; Published, in Proceedings of IEEE International Conference on Communications (ICC'12) 201

The comparison of hearing loss among diabetic and non-diabetic patients

Introduction: The prevalence of Diabetes Mellitus is steadily increasing. This is a multi- systemic abnormality, causing side- effects which are mainly irreversible. Hearing loss is one of the common symptoms, and there are many studies, with contradictory results. Aim of this study was to compare the hearing loss among diabetic with non- diabetic patients. Material and Methods: In this study 50 diabetic patients were chosen randomly from those overt diabetic patients referred to the Diabetes clinic in Gorgan hospital northern Iran, 50 other patients who referred to the 5th Azar hospital, with any other ENT complaint were also randomly chosen as control group. The case and control groups were matched. Demographic questionnaires were filled for each subjects in case and control groups, and those with intervening factors were omitted from this study. Data were analyzed using SPSS. Results: In this study 66% and 34% of participants were men and women respectively. The age distribution of the patient were 15-75 years. The hearing loss among diabetic patients and non- diabetic subjects were 16% and 5% respectively, which showed that the diabetic patient has3.2 times more possibility to acquire hearing problem. It was also shown, that there was a direct correlation between increasingage and hearing loss. More women are at risk, of getting hearingloss than men. The hearing loss also has a correlation with the duration of disease onset and the consumption of Glibanclamid. Conclusion The careful periodical assessment of hearing loss, and the application of hearing facilities to improve the qualityof diabetic patients life is recommended due to chronic and irreversible Symptom of the disease

Entropy production in a photovoltaic cell

We evaluate entropy production in a photovoltaic cell that is modeled by four electronic levels resonantly coupled to thermally populated field modes at different temperatures. We use a formalism recently proposed, the so-called multiple parallel worlds, to consistently address the nonlinearity of entropy in terms of density matrix. Our result shows that entropy production is the difference between two flows: a semiclassical flow that linearly depends on occupational probabilities, and another flow that depends nonlinearly on quantum coherence and has no semiclassical analog. We show that entropy production in the cells depends on environmentally induced decoherence time and energy detuning. We characterize regimes where reversal flow of information takes place from a cold to hot bath. Interestingly, we identify a lower bound on entropy production, which sets limitations on the statistics of dissipated heat in the cells.Comment: 7 pages, 2 figure