The Bc→ψ(2S)πB_c\rightarrow \psi(2S)\pi, ηc(2S)π\eta_c(2S)\pi decays in the perturbative QCD approach

Nonleptonic two body $B_c$ decays including radially excited $\psi(2S)$ or $\eta_c(2S)$ mesons in the final state are studied using the perturbative QCD approach based on $k_T$ factorization. The charmonium distribution amplitudes are extracted from the $n = 2, l = 0$ Schr$\ddot{o}$dinger states for the harmonic oscillator potential. Utilizing these distribution amplitudes, we calculate the numerical results of the $B_c\rightarrow \psi(2S),\eta_c(2S)$ transition form factors and branching fractions of $B_c\rightarrow \psi(2S)\pi, \eta_c(2S)\pi$ decays. The ratio between two decay modes $B_c\rightarrow \psi(2S)\pi$ and $B_c\rightarrow J/\psi\pi$ is compatible with the experimental data within uncertainties, which indicate that the harmonic oscillator wave functions for $\psi(2S)$ and $\eta_c(2S)$ work well. It is found that the branching fraction of $B_c\rightarrow \eta_c(2S)\pi$, which is dominated by the twist-3 charmonium distribution amplitude, can reach the order of $10^{-3}$. We hope it can be measured soon in the LHCb experiment.Comment: 9 pages, 3 figures,3 Table

Enhancing high-order-harmonic generation by time delays between two-color, few-cycle pulses

Use of time delays in high-order-harmonic generation (HHG) driven by intense two-color, few-cycle pulses is investigated in order to determine means of optimizing HHG intensities and plateau cutoff energies. Based upon numerical solutions of the time-dependent Schrõdinger equation for the H atom as well as analytical analyses, we show that introducing a time delay between the two-color, few-cycle pulses can result in an enhancement of the intensity of the HHG spectrum by an order of magnitude (or more) at the cost of a reduction in the HHG plateau cutoff energy. Results for both positive and negative time delays as well as various pulse carrier-envelope phases are investigated and discussed

Enhancing high-order harmonic generation by sculpting waveforms with chirp

We present a theoretical analysis showing how chirp can be used to sculpt two-color driving laser field waveforms in order to enhance high-order harmonic generation (HHG) and/or extend HHG cutoff energies. Specifically, we consider driving laser field waveforms composed of two ultrashort pulses having different carrier frequencies in each of which a linear chirp is introduced. Two pairs of carrier frequencies of the component pulses are considered: (ω, 2ω) and (ω, 3ω). Our results show how changing the signs of the chirps in each of the two component pulses leads to drastic changes in the HHG spectra. Our theoretical analysis is based on numerical solutions of the time-dependent Schrödinger equation and on a semiclassical analytical approach that affords a clear physical interpretation of how our optimized waveforms lead to enhanced HHG spectra

Enhancing high-order-harmonic generation by time delays between two-color, few-cycle pulses

Use of time delays in high-order-harmonic generation (HHG) driven by intense two-color, few-cycle pulses is investigated in order to determine means of optimizing HHG intensities and plateau cutoff energies. Based upon numerical solutions of the time-dependent Schrõdinger equation for the H atom as well as analytical analyses, we show that introducing a time delay between the two-color, few-cycle pulses can result in an enhancement of the intensity of the HHG spectrum by an order of magnitude (or more) at the cost of a reduction in the HHG plateau cutoff energy. Results for both positive and negative time delays as well as various pulse carrier-envelope phases are investigated and discussed

Utilizing the C2Maps Platform for Characterizing Drug-Protein Relations, Generating Mobile Games, and Constructing Integrated Pathway Models

poster abstractThe C2Maps platform is a collection of genome-wide data that display the connections between drugs, diseases and genes. The C2Maps is used as a tool to compare and extrapolate known map data into unknown areas. By using C2Maps, researchers can compare genetic, sequential and physical information about disease specific proteins. Manual curation is important for the C2Maps platform in order to validate the literature mining approach and to overcome high levels of data noise generated from molecular networks. Currently we are examining specific drug-protein relationships in several diseases. In this research, the C-Maps website is being used to manually curate abstracts about disease specific drugprotein relations and then it is determined whether a drug “Up Regulates”, “Down Regulates”, or “Indirectly” affects a specific protein. Presently, more than 2000 specific protein-drug relations have been examined through the platform. We theorize that new drug-protein relations will be discovered through curation efforts. To broaden the scope of curation data generated, a C2Maps mobile game is in the process of being developed. This game takes advantage of novel technology in mobile development to create a game that will allow several researchers to contribute to the curation process. The data generated from the manual curation approach can be used to validate various protein-drug relationships in pharmacology and can determine the best possible drugs targeting specific proteins in cancer. Optimal drugs and their respective targets for a specific disease can then be incorporated into an integrative pathway model to analyze the mechanism of the drug. Specific properties of the drug, including chemical structure, can then be examined to determine how a specific drug acts on particular target proteins