We extract |V cb | from the available data in the decay B → D ( * ) ν . B → D * ν , the unfolded binned differential decay rates of four kinematic variables including the q 2 bins have been used. In the CLN and BGL parameterizations of the form factors, the combined fit to all the available data along with their correlations yields |V cb | = (39.77 ± 0.89) × 10 −3 and (40.90 ± 0.94) × 10 −3 respectively. In these fits, we have used the inputs from lattice and light cone sum rule (LCSR) along with the data. Using our fit results and the HQET relations (with the known corrections included) amongst the form factors, and parameterizing the unknown higher order corrections (in the ratios of HQET form factors) with a conservative estimate of the normalizing parameters, we obtain R(D * ) = 0.259 ± 0.006 (CLN) and R(D * ) = 0.257 ± 0.005 (BGL).

The physics programme and the design are described of a new collider for particle and nuclear physics, the Large Hadron Electron Collider (LHeC), in which a newly built electron beam of 60 GeV, to possibly 140 GeV, energy collides with the intense hadron beams of the LHC. Compared to the first ep collider, HERA, the kinematic range covered is extended by a factor of twenty in the negative four-momentum squared, Q 2 , and in the inverse Bjorken x, while with the design luminosity of 10 33 cm −2 s −1 the LHeC is projected to exceed the integrated HERA luminosity by two orders of magnitude. The physics programme is devoted to an exploration of the energy frontier, complementing the LHC and its discovery potential for physics beyond the Standard Model with high precision deep inelastic scattering measurements. These are designed to investigate a variety of fundamental questions in strong and electroweak interactions. The LHeC thus continues the path of deep inelastic scattering (DIS) into unknown areas of physics and kinematics. The physics programme also includes electron-deuteron and electron-ion scattering in a (Q 2 1/x) range extended by four orders of magnitude as compared to previous lepton-nucleus DIS experiments for novel investigations of neutron's and nuclear structure, the initial conditions of Quark-Gluon Plasma formation and further quantum chromodynamic phenomena. The LHeC may be realised either as a ring-ring or as a linac-ring collider. Optics and beam dynamics studies are presented for both versions, along with technical design considerations on the interaction region, magnets including new dipole prototypes, cryogenics, RF, and further components. A design study is also presented of a detector suitable to perform high precision DIS measurements in a wide range of acceptance using state-ofthe art detector technology, which is modular and of limited size enabling its fast installation. The detector includes tagging devices for electron, photon, proton and neutron detection near to the beam pipe. Civil engineering and installation studies are presented for the accelerator and the detector. The LHeC can be built within a decade and thus be operated while the LHC runs in its high-luminosity phase. It so represents a major opportunity for progress in particle physics exploiting the investment made in the LHC.

We extract the magnitude of the Cabibbo-Kobayashi-Maskawa matrix element V(c)} and the most relevant parameters of the heavy quark expansion from data of inclusive semileptonic B decays. Our calculation includes the recently computed O(α(s)Λ(QCD)(2)/m(b)(2)) corrections and a careful estimate of the residual theoretical uncertainty. Using a recent determination of the charm quark mass, we obtain |V(cb)|=(42.21±0.78)×10(-3) and m(b)(kin)(1  GeV)=(4.553±0.020)  GeV.

We construct a class of two Higgs doublets models with a 4th sequential generation of fermions that may effectively accommodate the low energy characteristics and phenomenology of a dynamical electroweak symmetry breaking scenario which is triggered by the condensates of the 4th family fermions. In particular, we single out the heavy quarks by coupling the "heavier" Higgs doublet (Φ h ) which possesses a much larger VEV only to them while the "lighter" doublet (Φ ℓ ) couples only to the light fermions. We study the constraints on these models from precision electroweak data as well as from flavor data. We also discuss some distinct new features that have direct consequences on the production and decays of the 4th family quarks and leptons in high energy colliders; in particular the conventional search strategies for t ′ and b ′ may need to be significantly revised.

We extend our recent work and study implications of the Standard Model with four generations (SM4) for rare B and K decays. We again take seriously the several 2-3 σ anomalies seen in B, B s decays and interpret them in the context of this simple extension of the SM. SM4 is also of course of considerable interest for its potential relevance to dynamical electroweak symmetry breaking and to baryogenesis. Using experimental information from processes such as B → X s γ, B d and B s mixings, indirect CP-violation from K L → ππ etc along with oblique corrections, we constrain the relevant parameter space of the SM4, and find m t ′ of about 400-600 GeV with a mixing angle |V * t ′ b V t ′ s | in the range of about (0.05 to 1.4)×10 −2 and with an appreciable CP-odd associated phase, are favored by the current data. Given the unique role of the CP asymmetry in B s → ψφ due to its gold-plated nature, correlation of that with many other interesting observables, including the semileptonic asymmetry (A SL ) are studied in SM4. We also identify several processes, such as B → X s νν, K L → π 0 νν etc, that are significantly different in SM4 from the SM. Experimentally the very distinctive process B s → µ + µ − is also discussed; the branching ratio can be larger or smaller than in SM, (3.2 → 4.2) × 10 −9 , by a factor of O(3).