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

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

Inclusive Decays of Bottom Hadrons in New Formulation of Heavy Quark Effective Field Theory

We apply the new formulation of heavy quark effective field theory (HQEFT) to the inclusive decays of bottom hadrons. The long-term ambiguity of using heavy quark mass or heavy hadron mass for inclusive decays is clarified within the framework of the new formulation of HQEFT. The $1/m_b$ order corrections are absent and contributions from $1/m_b^2$ terms are calculated in detail. This enables us to reliably extract the important CKM matrix element $|V_{cb}|$ from the inclusive semileptonic decay rates. The resulting lifetime ratios $\tau(B^0_s)/\tau(B^0)$ and $\tau(\Lambda_b)/\tau(B^0)$ are found to well agree with the experimental data. We also calculate in detail the inclusive semileptonic branching ratios and the ratios of the $\tau$ and $\beta$ decay rates as well as the charm countings in the $B^0$, $B^0_s$ and $\Lambda_b$ systems. For $B^0$ decays, all the observables are found to be consistent with the experimental data. More precise data for the $B^0$ decays and further experimental measurements for the $B^0_s$ and $\Lambda_b$ systems will be very useful for testing the framework of new formulation of HQEFT at the level of higher order corrections.Comment: 20 pages, RevTex, 8 figures, 3 tables, revised version with `dressed heavy quark' being addressed, to be published in Int. J. Mod. Phys.

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

|V_ub| and |V_cb|, Charm Counting and Lifetime Differences in Inclusive Bottom Hadron Decays

Inclusive bottom hadron decays are analyzed based on the heavy quark effective field theory (HQEFT). Special attentions in this paper are paid to the b\to u transitions and nonspectator effects. As a consequence, the CKM quark mixing matrix elements |V_ub| and |V_cb| are reliably extracted from the inclusive semileptonic decays B\to X_u e \nu and B\to X_c e \nu. Various observables, such as the semileptonic branch ratio B_SL, the lifetime differences among B^-, B^0, B_s and \Lambda_b hadrons, the charm counting n_c, are predicted and found to be consistent with the present experimental data.Comment: 20 pages, Revtex, 4 figures and 2 table

Large Component QCD and Theoretical Framework of Heavy Quark Effective Field Theory

Based on a large component QCD derived directly from full QCD by integrating over the small components of quark fields with $|{\bf p}| < E + m_Q$, an alternative quantization procedure is adopted to establish a basic theoretical framework of heavy quark effective field theory (HQEFT) in the sense of effective quantum field theory. The procedure concerns quantum generators of Poincare group, Hilbert and Fock space, anticommutations and velocity super-selection rule, propagator and Feynman rules, finite mass corrections, trivialization of gluon couplings and renormalization of Wilson loop. The Lorentz invariance and discrete symmetries in HQEFT are explicitly illustrated. Some new symmetries in the infinite mass limit are discussed. Weak transition matrix elements and masses of hadrons in HQEFT are well defined to display a manifest spin-flavor symmetry and $1/m_Q$ corrections. A simple trace formulation approach is explicitly demonstrated by using LSZ reduction formula in HQEFT, and shown to be very useful for parameterizing the transition form factors via $1/m_Q$ expansion. As the heavy quark and antiquark fields in HQEFT are treated on the same footing in a fully symmetric way, the quark-antiquark coupling terms naturally appear and play important roles for simplifying the structure of transition matrix elements, and for understanding the concept of `dressed heavy quark' - hadron duality. In the case that the `longitudinal' and `transverse' residual momenta of heavy quark are at the same order of power counting, HQEFT provides a consistent approach for systematically analyzing heavy quark expansion in terms of $1/m_Q$. Some interesting features in applications of HQEFT to heavy hadron systems are briefly outlined.Comment: 59 pages, RevTex, no figures, published versio

Spin and Orbital Splitting in Ferromagnetic Contacted Single Wall Carbon Nanotube Devices

We observed the coulomb blockade phenomena in ferromagnetic contacting single wall semiconducting carbon nanotube devices. No obvious Coulomb peaks shift was observed with existing only the Zeeman splitting at 4K. Combining with other effects, the ferromagnetic leads prevent the orbital spin states splitting with magnetic field up to 2 Tesla at 4K. With increasing magnetic field further, both positive or negative coulomb peaks shift slopes are observed associating with clockwise and anticlockwise orbital state splitting. The strongly suppressed/enhanced of the conductance has been observed associating with the magnetic field induced orbital states splitting/converging

A Consistent Calculation of Heavy Meson Decay Constants and Transition Wave Functions in the Complete HQEFT

Within the complete heavy quark effective field theory (HQEFT), the QCD sum rule approach is used to evaluate the decay constants including 1/m_Q corrections and the Isgur-Wise function and other additional important wave functions concerned at 1/m_Q for the heavy-light mesons. The 1/m_Q corrections to the scaling law f_M \sim F/\sqrt{m_M} are found to be small in HQEFT, which demonstrates again the validity of 1/m_Q expansion in HQEFT. It is also shown that the residual momentum v.k of heavy quark within hadrons does be around the binding energy \bar{\Lambda} of the heavy hadrons. The calculations presented in this paper provide a consistent check on the HQEFT and shows that the HQEFT is more reliable than the usual HQET for describing a slightly off-mass shell heavy quark within hadron as the usual HQET seems to lead to the breakdown of 1/m_Q expansion in evaluating the meson decay constants. It is emphasized that the introduction of the `dressed heavy quark' mass is useful for the heavy-light mesons (Qq) with m_Q >> \bar{\Lambda} >> m_q, while for heavy-heavy bound states (\psi_1\psi_2) with masses m_1, m_2 >> \bar{\Lambda}, like bottom-charm hadrons or similarly for muonium in QED, one needs to treat both particles as heavy effective particles via 1/m_1 and 1/m_2 expansions and redefine the effective bound states and modified `dressed heavy quark' masses within the HQEFT.Comment: 20 pages, revtex, 22 figures, axodraw.sty, two irrelevant figures are moved awa