A More Precise Extraction of |V_{cb}| in HQEFT of QCD

The more precise extraction for the CKM matrix element |V_{cb}| in the heavy quark effective field theory (HQEFT) of QCD is studied from both exclusive and inclusive semileptonic B decays. The values of relevant nonperturbative parameters up to order 1/m^2_Q are estimated consistently in HQEFT of QCD. Using the most recent experimental data for B decay rates, |V_{cb}| is updated to be |V_{cb}| = 0.0395 \pm 0.0011_{exp} \pm 0.0019_{th} from B\to D^{\ast} l \nu decay and |V_{cb}| = 0.0434 \pm 0.0041_{exp} \pm 0.0020_{th} from B\to D l \nu decay as well as |V_{cb}| = 0.0394 \pm 0.0010_{exp} \pm 0.0014_{th} from inclusive B\to X_c l \nu decay.Comment: 7 pages, revtex, 4 figure

Exclusive B-meson Rare Decays and General Relations of Form Factors in Effective Field Theory of Heavy Quarks

B meson rare decays ($B\to K(K^{*})l\bar l$ and $B\to K^*\gamma$) are analyzed in the framework of effective field theory of heavy quarks. The semileptonic and penguin type form factors for these decays are calculated by using the light cone sum rules method at the leading order of $1/m_Q$ expansion. Four exact relations between the two types of form factors are obtained at the leading order of $1/m_Q$ expansion. Of particular, the relations are found to hold for whole momentum transfer region. We also investigate the validity of the relations resulted from the large energy effective theory based on the general relations obtained in the present approach. The branching ratios of the rare decays are presented and their potential importance for extracting the CKM matrix elements and probing new physics is emphasized.Comment: 23 pages, Revtex, 32 figures, published version with the errors of numerical results caused by the computer program are correcte

Qualitative Analysis of Plant-Derived Samples by Liquid Chromatography-Electrospray Ionization-Quadrupole-Time of Flight-Mass Spectrometry

Purpose: Currently, mass spectrometry has become an effective method for the qualitative analysis of plant-derived samples. Precursor and product ions can be obtained by tandem mass spectrometry, supplying rich information for determining the structural formulas of compounds. In this work, we review the optimization of qualitative methods using liquid chromatography-electrospray ionization-quadrupoletime of flight (LC-ESI-Q-TOF), coupled with ultraviolet and infrared spectroscopy, nuclear magnetic resonance, and mass  spectrometry. This paper provides a systemic reference for researchers engaged in the qualitative analysis of plant-derived samples using LC-ESI-Q-TOF.Keywords: Qualitative analysis, Liquid chromatography-electrospray ionization-quadrupole-time of flight (LC-ESI-Q-TOF), Mass spectrometry, Optimizatio

B(s),D(s)→π,K,η,ρ,K∗,ω,ϕB_{(s)},D_{(s)} \to \pi, K, \eta, \rho, K^*, \omega, \phi Transition Form Factors and Decay Rates with Extraction of the CKM parameters ∣Vub∣|V_{ub}|, ∣Vcs∣|V_{cs}|, ∣Vcd∣|V_{cd}|

A systematic calculation for the transition form factors of heavy to light mesons ($B,B_s,D,D_s \to \pi, K, \eta, \rho, K^*, \omega, \phi$) is carried out by using light-cone sum rules in the framework of heavy quark effective field theory. The heavy quark symmetry at the leading order of $1/m_Q$ expansion enables us to reduce the independent wave functions and establish interesting relations among form factors. Some relations hold for the whole region of momentum transfer. The meson distribution amplitudes up to twist-4 including the contributions from higher conformal spin partial waves and light meson mass corrections are considered. The CKM matrix elements $|V_{ub}|$, $|V_{cs}|$ and $|V_{cd}|$ are extracted from some relatively well-measured decay channels. A detailed prediction for the branching ratios of heavy to light meson decays is then presented. The resulting predictions for the semileptonic and radiative decay rates of heavy to light mesons ($B,B_s,D,D_s \to \pi, K, \eta, \rho, K^*, \omega, \phi$) are found to be compatible with the current experimental data and can be tested by more precise experiments at B-factory, LHCb, BEPCII and CLEOc.Comment: 23 pages, 32 figures, 25 tables,published version, minor corrections and references adde