We consider weak decays of heavy hadrons (bottom and charmed) where the heavy quark acts as a spectator. These decays are heavily phase-space suppressed but may become experimentally accessible in the near future. These decays may be interesting as a QCD laboratory to study the behaviour of the light quarks in the colour-background field of the heavy spectator.

We study the semileptonic b -> u transition in the decay mode B- -> pi(+)pi(-)l(-)(nu) over bar (l). We define B -> pi pi form factors in the helicity basis, and study their properties in various kinematic limits, including form factor relations in the heavy-mass and large-energy limits, the decomposition into partial waves of the dipion system, and the resonant contribution of vector and scalar mesons. We show how angular observables in B- -> pi(+)pi(-)l(-)(nu) over bar (l) can be used to measure dipion form factors or to perform null tests of the Standard Model.

Top-quark physics at the LHC may open a window to physics beyond the Standard Model and even lead us to an understanding of the phenomenon of "flavor." However, current flavor data is a strong hint that no "new physics" with a generic flavor structure can be expected at the TeV scale. In turn, if there is "new physics" at the TeV scale, it must be "minimally flavor violating." This has become a widely accepted assumption for "new physics" models. In this paper we propose a model-independent scheme to test minimal flavor violation for the anomalous charged Wtq, q∈{d,s,b} and flavor-changing Vtq, q∈{u,c} and V∈{Z,γ,g} couplings within an effective field theory framework, i.e., in a model-independent way. We perform a spurion analysis of our effective field theory approach and calculate the decay rates for the anomalous top-quark decays in terms of the effective couplings for different helicities by using a two-Higgs doublet model of type II, under the assumption that the top-quark is produced at a high-energy collision and decays as a quasi-free particle.

We consider the exclusive decays $B\ensuremath{\rightarrow}{D}^{(*)}\ensuremath{\ell}\overline{\ensuremath{\nu}}$ and study the effect of non-$V\ensuremath{-}A$ structures on the observables. We extend the standard model hadronic current by additional right-handed vector as well as left- and right-handed scalar and tensor contributions and calculate the decay rates including the perturbative corrections up to order ${\ensuremath{\alpha}}_{s}$. Using the data of the exclusive semileptonic $b\ensuremath{\rightarrow}c$ decays and recent calculations of the form factors at the nonrecoil point, we discuss the constraints to the wrong-helicity admixtures in the hadronic current.

We consider the exclusive decays B -> D(*) l (nu) over bar and study the effect of non-V - A structures on the observables. We extend the standard model hadronic current by additional right-handed vector as well as left-and right-handed scalar and tensor contributions and calculate the decay rates including the perturbative corrections up to order alpha(s). Using the data of the exclusive semileptonic b -> c decays and recent calculations of the form factors at the nonrecoil point, we discuss the constraints to the wrong-helicity admixtures in the hadronic current.

CP violation is a major challenge of contemporary particle physics. It has been discovered in kaon decays and appears also in B decays, where the B ! J=cKS;L channels are considered to be clean probes of this phenomenon. Recent B-factory data challenge the description of CP violation in the standard model of particle physics, showing some ‘‘tension’’ with theoretical predictions. We take a detailed look at certain standard-model contributions, which are usually neglected, and point out that they can be included unambiguously through measurements of the B ! J=c 0 observables. Using the most recent data, we show that the tension with the standard model is softened, and we constrain a possible new-physics phase in B B mixing. Our strategy is crucial to fully exploit the accuracy of the search for this kind of new physics at the LHC and future super-flavor factories.

CP violation is a major challenge of contemporary particle physics. It has been discovered in kaon decays and appears also in B decays, where the B-0 -> J / psi K-S,K-L channels are considered to be clean probes of this phenomenon. Recent B-factory data challenge the description of CP violation in the standard model of particle physics, showing some ``tension'' with theoretical predictions. We take a detailed look at certain standard-model contributions, which are usually neglected, and point out that they can be included unambiguously through measurements of the B-0 -> J / psi pi(0) observables. Using the most recent data, we show that the tension with the standard model is softened, and we constrain a possible new-physics phase in B-0 - (B) over bar (0) mixing. Our strategy is crucial to fully exploit the accuracy of the search for this kind of new physics at the LHC and future super-flavor factories.

CP-violating effects in the time-dependent angular distribution of the B-s(0) -> J / psi[-> l(+)l(-)]phi[-> K+K-] decay products play a key role for the search of new physics. The hadronic standard-model uncertainties are related to doubly Cabibbo-suppressed penguin contributions and are usually assumed to be negligibly small. In view of recent results from the Tevatron and the quickly approaching start of the data taking at the LHC, we have a critical look at the impact of these terms, which could be enhanced through long-distance QCD phenomena, and explore the associated uncertainty for the measurement of the CP-violating B-s(0) - (B) over bar (0)(s) mixing phase. We point out that these effects can actually be controlled by means of an analysis of the time-dependent angular distribution of the B-s(0) -> J / psi[-> l(+)l(-)](K) over bar*(0)[-> pi K-+(-)] decay products and illustrate this through numerical studies. Moreover, we discuss SU(3)-breaking effects, which limit the theoretical accuracy of our method, and suggest internal consistency checks of SU(3).

In this paper we consider general relativity and its combination with scalar quantum electrodynamics (QED) as an effective quantum field theory at energies well below the Planck scale. This enables us to compute the one-loop quantum corrections to the Newton and Coulomb potentials induced by the combination of graviton and photon fluctuations. We derive the relevant Feynman rules and compute the nonanalytical contributions to the one-loop scattering matrix for charged scalars in the nonrelativistic limit. In particular, we derive the post-Newtonian corrections of order Gm/c(2)r from general relativity and the genuine quantum corrections of order Gh/c(3)r(2).

The B0 ! J= KS;L channels are outstanding probes of CP violation. We have a detailed look at the associated Standard-Model uncertainties, which are related to doubly Cabibbo-suppressed penguin contributions, and point out that these usually neglected eects can actually be taken into account unambiguously through the CP asymmetries and the branching ratio of the B0 ! J= 0 decay. Using