Related papers: Field Theory of the Fermi Function
We develop an effective field theory (EFT) for nuclear vibrations. The key ingredients - quadrupole degrees of freedom, rotational invariance, and a breakdown scale around the three-phonon level - are taken from data. The EFT is developed…
Prompted by the level of accuracy now being achieved in tests of the unitarity of the CKM matrix, we consider the possible modification of the Fermi matrix element for the $\beta$-decay of a neutron, including possible in-medium and isospin…
The geometry of field space governs on-shell scattering amplitudes. We formulate a geometric description of effective field theories which extends previous results for scalars and gauge fields to fermions. The field-space geometry…
Quantum corrections to Thomas-Fermi (TF) theory are investigated for noninteracting one-dimensional fermions with known uniform semiclassical approximations to the density and kinetic energy. Their structure is analyzed, and contributions…
In this article, we consider the propagation of QED fermions in the presence of a classical background magnetic field with white-noise stochastic fluctuations. The effects of the magnetic field fluctuations are incorporated into the fermion…
New \textit{ab initio} calculations of the isotopic reactor antineutrino fluxes are provided with exact numerical calculations of the lepton wave functions, assuming all the decay branches are allowed GT transitions. We illustrate that the…
Using effective field theory techniques we discuss the QCD corrections to the large-$m_t$ contributions to the process $Z\rightarrow b \bar b$. In particular we obtain the $\a$ correction to the non-universal $\log m_t$ contribution to the…
A fully analytical description of the allowed $\beta$ spectrum shape is given in view of ongoing and planned measurements. Its study forms an invaluable tool in the search for physics beyond the standard electroweak model and the weak…
A method for determining the leading quantum contributions to the effective action for both zero and finite temperatures is presented. While it is described in the context of a scalar field theory, it can be straight-forwardly extended to…
We determine the fermionic corrections to the nucleation rate of bubbles at the electroweak phase transition. The fermion determinant is evaluated exactly and by using the gradient expansion. The gradient expansion is found to be a reliable…
We review an effective field theory for the non-Fermi liquid regime of dense QCD matter. Non-Fermi liquid effects arise due the presence of unscreened magnetic gluon exchanges. We show that there is a systematic low energy expansion in…
Using soft-collinear effective theory (SCET), we examine the 1/m_b corrections to the factorization formulas for inclusive semi-leptonic B decays in the endpoint region, where the hadronic final state consists of a single jet. At tree…
We investigate fermionic quantum field theories using functional renormalisation. In the limit of many fermion flavours $N$, we demonstrate that theories have exact solutions for their quantum effective actions given by quasi-local…
The cross section for massive fermion production in two-photon collisions was examined at next-to-leading order in QCD/QED for general photon helicity. The delta function (virtual+soft) part of the differential cross section was…
We compute the QED beta function using a new method of functional integration. It turns out that in this procedure the beta function contains only the first two orders coefficients and thus corresponds to a new renormalization scheme, long…
Most previous calculations of the annihilation decay rates of heavy quarkonium were based on factorization assumptions that were unproven and, in some cases, even incorrect. The recent development of a general factorization formula for…
We discuss the calculation of fermion self energy correction in Light Front QED using a coherent state basis. We show that if one uses coherent state basis instead of fock basis to calculate the transition matrix elements, the true infrared…
In the in-out formalism we advance a new method to represent the gamma function for QED actions in supercritical fields, which is complementary to the proper-time integral representation in Phys. Rev. D 78, 105013 (2008) and Phys. Rev. D…
We present the first combined analysis of the statistical rate function f in superallowed beta decays with ab initio calculations and data. We focus on C10 to 10B, 14O to 14N and 26mAl to 26Mg, all of which are important channels for the…
We derive a factorization theorem for the structure-dependent QED effects in the weak exclusive process $B^-\to\ell^-\bar\nu_\ell$, i.e., effects probing the internal structure of the $B$ meson. The derivation requires a careful treatment…