Related papers: Gauged linear sigma model and pion-pion scattering
We report on an interesting realization of the QCD axion, with mass in the range $\mathcal{O}(10)$ MeV. It has previously been shown that although this scenario is stringently constrained from multiple sources, the model remains viable for…
Beyond Standard Model theories describing the electro-weak sector must exhibit a large separation of scales (or "walking") to account for a light, 125 GeV Higgs boson and the fact that so far no other resonances have been observed. Large…
We review two manifestations of chiral symmetry breaking in the pion sector. First, we examine the $\pi\pi$ scattering amplitude at threshold, which is completely determined by the chiral symmetry breaking part of the strong interaction,…
We introduce an effective lagrangian including negative and positive parity heavy mesons containing a heavy quark, light pseudoscalars, and light vector resonances, with their allowed interactions, using heavy quark spin-flavour symmetry,…
We begin a systematic study of how gaugino mass unification can be probed at the CERN Large Hadron Collider (LHC) in a quasi-model independent manner. As a first step in that direction we focus our attention on the theoretically…
In extensions of the Standard Model (SM) of particle physics a light scalar from a hidden sector can interact with known particles via mixing with the SM Higgs boson. If the scalar mass is of GeV scale, this coupling induces the scalar…
Using a ladder-rainbow kernel previously established for light quark hadron physics, we explore the extension to masses and electroweak decay constants of ground state pseudoscalar and vector quarkonia and heavy-light mesons in the c- and…
In absence of the Standard Model Higgs boson the interaction among the gauge bosons becomes strong at high energies and influences the couplings between them. Each trilinear and quartic gauge boson vertex is characterised by a set of…
Using a four fermion interaction Lagrangian, we demonstrate that the spontaneous breaking of vector symmetries requires the existence of a light (comparing with the heavy fermion mass) scalar particle and the low energy effective theory…
Stringent constraints from direct detection experiments and the Large Hadron Collider motivate us to consider models in which the dark matter does not directly couple to the Standard Model, but that instead annihilates into hidden sector…
The vector manifestation (VM) is a new pattern for realizing the chiral symmetry in QCD. In the VM, the massless vector meson becomes the chiral partner of pion at the critical point, in contrast with the restoration based on the linear…
We consider the impact of colored scalars that can couple directly to matter fields on the recently measured h to gamma gamma excess. Among all possible candidates only scalar states transforming as (8, 2,1/2) and (6,3,1/3) under the…
The pion properties in symmetric nuclear matter are investigated with the Quark-Meson Coupling (QMC) Model plus the light-front constituent quark model~(LFCQM). The LFCQM has been quite successful in describing the properties of…
Using holography, we study the low-lying mesonic spectrum of a range of asymptotically free gauge theories. First we revisit a simple top-down holographic model of QCD-like dynamics with predictions in the M_rho-M_pi plane. The meson masses…
We study nuclear matter and finite nuclei with a chiral Lagrangian which generalizes the linear $\sigma$ model and also accounts for the QCD trace anomaly by means of terms which involve the $\sigma$ and $\vmg{\pi}$ fields as well as the…
Nuclear matter and surface properties are carefully studied for a model based on an effective hadronic lagrangian with vector-vector and scalar-vector self-interactions. The results of the model are compared with those of the successful…
We explore the link between the chiral symmetry of QCD and the numerical results of the light-front quark model, analyzing both the two-point and three-point functions of the pion. Including the axial-vector coupling as well as the…
We discuss the relevance of a dedicated measurement of exclusive production of a pair of neutral pions in a hard gamma* gamma scattering at small momentum transfer. In this case, the virtuality of one photon provides us with a hard scale in…
A vector-like extension of the standard model for heavier quarks and leptons with $SU(2)\times U(1)$ gauge symmetry and only one Higgs doublet is examined. This scheme incorporates infinitely many fermions and avoids the appearance of a…
We analyse the excess in the $\gamma$-ray emission from the center of our galaxy observed by Fermi-LAT in terms of dark matter annihilation within the scalar Higgs portal model. In particular, we include the astrophysical uncertainties from…