To say that this is the best book on the quantum theory of fields is no praise, since to my knowledge it is the only book on this subject But it is a very good and most useful book The original was written in German and appeared in 1942 This is a translation with some minor changes A few remarks have been added, concerning meson theory and nuclear forces, also footnotes referring to modern work in this field, and finally an appendix on the symmetrization of the energy momentum tensor according to Belinfante Quantum Theory of Fields Prof Gregor Wentzel Translated from the German by Charlotte Houtermans and J M Jauch Pp ix + 224, (New York and London: Interscience Publishers, Inc, 1949) 36s

Quantum Theory of Fields

We review the present status of QCD corrections to weak decays beyond the leading-logarithmic approximation, including particle-antiparticle mixing and rare and $\mathrm{CP}$-violating decays. After presenting the basic formalism for these calculations we discuss in detail the effective Hamiltonians of all decays for which the next-to-leading-order corrections are known. Subsequently, we present the phenomenological implications of these calculations. The values of various parameters are updated, in particular the mass of the newly discovered top quark. One of the central issues in this review are the theoretical uncertainties related to renormalization-scale ambiguities, which are substantially reduced by including next-to-leading-order corrections. The impact of this theoretical improvement on the determination of the Cabibbo-Kobayashi-Maskawa matrix is then illustrated. [S0034-6861(96)00304-2]

Weak decays beyond leading logarithms

This article reports world averages of measurements of b-hadron, c-hadron, and tau-lepton properties obtained by the Heavy Flavor Averaging Group (HFAG) using results available through the end of 2011. In some cases results available in the early part of 2012 are included. For the averaging, common input parameters used in the various analyses are adjusted (rescaled) to common values, and known correlations are taken into account. The averages include branching fractions, lifetimes, neutral meson mixing parameters, CP violation parameters, parameters of semileptonic decays and CKM matrix elements.

/pdf/averages-of-b-hadron-c-hadron-and-tau-lepton-properties-as-29qrkk2j2g.pdf

Averages of b-hadron, c-hadron, and tau-lepton properties as of early 2012

THE subject of quantum electrodynamics is extremely difficult, even for the case of a single electron. The usual method of solving the corresponding wave equation leads to divergent integrals. To avoid these, Prof. P. A. M. Dirac* uses the method of redundant variables. This does not abolish the difficulty, but presents it in a new form, which may be dealt with in two ways. The first of these needs only comparatively simple mathematics and is directly connected with an elegant general scheme, but unfortunately its wave functions apply only to a hypothetical world and so its physical interpretation is indirect. The second way has the advantage of a direct physical interpretation, but the mathematics is so complicated that it has not yet been solved even for what appears to be the simplest possible case. Both methods seem worth further study, failing the discovery of a third which would combine the advantages of both.

http://ieeexplore.ieee.org/iel5/3/22993/01069961.pdf

Quantum electrodynamics

We update the profile of the CKM matrix. The apex (rhobar,etabar) of the Unitarity Triangle is given by means of a global fit. We propose to include therein sin2alpha from the CP-violating asymmetries in B0->rho+rho-, using isospin to discriminate the penguin contribution. The constraint from epsilon'/epsilon is briefly discussed. We study the impact from the measurement of the rare decay K+->pi+nunu-bar, and from a future observation of KL->pi0nunubar. The B system is investigated in detail, beginning with 2beta+gamma and gamma from B0->D(*)+-pi-+ and B+->D(*)0K+. A significant part of this paper is dedicated to B decays into pipi, Kpi, rhopi and rhorho. Various phenomenological and theoretical approaches are studied. Within QCD Factorization we find a remarkable agreement of the pipi and Kpi data with the other UT constraints. A fit of QCD FA to all pipi and Kpi data leads to precise predictions of the related observables. We analyze separately the B->Kpi decays, and in particular the impact of electroweak penguins in response to recent phenomenological discussions. We do not observe any unambiguous sign of New Physics, whereas there is some evidence for potentially large rescattering effects. Finally we use a model-independent description of a large class of New Physics effects in both BBbar mixing and B decays, namely in the b->d and b->s gluonic penguin amplitudes, to perform a new numerical analysis. Significant non-standard corrections cannot be excluded yet, however standard solutions are favored in most cases.

/pdf/cp-violation-and-the-ckm-matrix-assessing-the-impact-of-the-4cq2oi0v9w.pdf

CP Violation and the CKM Matrix : Assessing the Impact of the Asymmetric B Factories

We derive the lepton spectrum in semileptonic [ital b] decays from a nonperturbative treatment of QCD; it is based on an expansion in 1/[ital m][sub [ital Q]] with [ital m][sub [ital Q]] being the heavy flavor quark mass. The leading corrections arising on the 1/[ital m][sub [ital Q]] level are completely expressed in terms of the difference in the mass of the heavy hadron and the quark. Nontrivial effects appear in 1/[ital m][sub [ital Q]][sup 2] terms affecting mainly the end-point region; they are different for meson and baryon decays as well as for bottom and charm decays.

QCD predictions for lepton spectra in inclusive heavy flavor decays

The key quantity of the heavy quark theory is the quark mass mQ. Since quarks are unobservable one can suggest different definitions of mQ. One of the most popular choices is the pole quark mass routinely used in perturbative calculations and in some analyses based on heavy quark expansions. We show that no precise definition of the pole mass can be given in the full theory once non-perturbative effects are included. Any definition of this

/pdf/pole-mass-of-the-heavy-quark-perturbation-theory-and-beyond-5egeip7art.pdf

Pole mass of the heavy quark: Perturbation theory and beyond.

Nonperturbative corrections to inclusive beauty and charm decays. QCD versus phenomenological models

In previous papers we have pointed out that there exists a QCD analog of the phenomenological concept of the so-called Fermi motion for the heavy quark inside a hadron. Here we show in a more detailed way how this comes about and we analyze the limitations of this concept. Nonperturbative as well as perturbative aspects are included. We emphasize both similarities and differences to the well-known treatment of deep inelastic lepton-nucleon scattering. We derive a model-independent lower bound on the kinetic energy of the heavy quark inside the hadron.

On the motion of heavy quarks inside hadrons: universal distributions and inclusive decays

▪ Abstract Recent achievements in heavy-quark theory are critically reviewed. The emphasis is put on those aspects that either did not attract enough attention or cause heated debates in the current literature. Among other topics we discuss (a) basic parameters of the heavy-quark theory; (b) a class of exact QCD inequalities; (c) new heavy quark sum rules; (d) the virial theorem; (e) applications (|Vcb| from the total semileptonic width and from the B → D* transition at zero recoil). In some instances new derivations of previously known results are given, or new aspects addressed. In particular, we dwell on the exact QCD inequalities. Furthermore, a toy model is considered that may shed light on the controversy regarding the value of the kinetic energy of heavy quarks obtained by different methods.

Nikolai Uraltsev

Papers

QCD predictions for lepton spectra in inclusive heavy flavor decays

Pole mass of the heavy quark: Perturbation theory and beyond.

Nonperturbative corrections to inclusive beauty and charm decays. QCD versus phenomenological models

On the motion of heavy quarks inside hadrons: universal distributions and inclusive decays

Aspects of heavy-quark theory