Motivated by recent experimental claims for the existence of a 17 keV neutrino and by the solar neutrino problem, we consider a class of models which contain in their low-energy spectrum a single light sterile neutrino and one or more Nambu–Goldstone bosons. In these models, the required pattern of small neutrino masses and Nambu–Goldstone-boson couplings are understood as the low-energy residu...

The spin fractions and deep inelastic lepton structure functions of the proton are analyzed using chiral field theory involving Goldstone bosons. A detailed comparison with recent chiral models sheds light on their successful description of the spin fractions of the proton as being due to neglecting helicity non-flip chiral transitions. This approximation is valid for zero mass but not for cons...

We perform an exhaustive analysis of the Equivalence Theorem both in the minimal Standard Model and in an Effective Electroweak Chiral Lagrangian up to O(p 4). We have considered the leading corrections to the usual prescription consisting in just replacing longitudinally polarized W or Z by the corresponding Goldstone bosons. The corrections appear through an overall constant multiplying the G...

We study the quantum phase transition occurring in an infinite homogeneous system of spin 1/2 fermions in a non-relativistic context. As an example we consider neutrons interacting through a simple spin-spin Heisenberg force. The two critical values of the coupling strength — signaling the onset into the system of a finite magnetization and of the total magnetization, respectively — are found a...

We study the stability of the pentaquarks uuddQ, uudsQ and udssQ (Q = c, b, or t) of positive parity in a constituent quark model based on Goldstone boson exchange interaction between quarks. The pentaquark parity is the antiquark parity times that of a quark excited to a p-shell. We show that the Goldstone boson exchange interaction favors these pentaquarks much more than the negative parity o...

Two paradigms for the origin of electroweak superconductivity are a weakly coupled scalar condensate, and a strongly coupled fermion condensate. The former suffers from a finetuning problem unless there are cancelations to radiative corrections, while the latter presents potential discrepancies with precision electroweak physics. Here we present a framework for electroweak symmetry breaking whi...

A complete characterization of all the possible effective interactions up to dimension 5 of the top and bottom quarks with the electroweak gauge bosons have been made within the context of the non-linear chiral Lagrangian. The dimension 5 operators (19 in total) can contribute to the V L V L → tt or tb amplitudes with a leading energy power of E 3 (E 2) for fermion pairs with same (opposite) si...

Abstract We review the boson transformation method to deal with spontaneous symmetry breaking in quantum field theory, focussing on how it describes emergence of extended and classical objects such context. then apply space itself, as an object resulting from evaporation a black hole. In particular, we show torsion curvature tensors can emerge effects inhomogeneous Nambu–Goldstone condensation ...