Related papers: Electromagnetic effects on the light hadron spectr…
We investigate electromagnetic effects in the framework of chiral perturbation theory. Using a completely independent method, we confirm Urech's results for the divergences of the one--loop functional in the electromagnetic sector. We…
Electromagnetic reactions on light nuclei are fundamental to advance our understanding of nuclear structure and dynamics. The perturbative nature of the electromagnetic probes allows to clearly connect measured cross sections with the…
We present the current status of the MILC collaboration's calculations of the properties of the light pseudoscalar meson sector. We use asqtad staggered ensembles with 2+1 dynamical flavors down to $a \approx 0.045$ fm and light quark mass…
We analyze the electromagnetic scattering of massive particles with and without spin and, using the techniques of effective field theory, we isolate the leading long distance effects beyond one photon exchange, both classical and quantum…
Within the scenario of chiral freedom we compute the quark and lepton masses of the first two generations in terms of their chiral couplings. This allows us to make a rough estimate of the size of the chiral couplings, narrowing down the…
We present an update of the MILC investigation of the properties of light pseudoscalar mesons using three flavors of improved staggered quarks. Results are presented for the $\pi$ and $K$ leptonic decay constants, the CKM matrix element…
The interaction between free electrons and nanoscale optical fields has emerged as a unique platform to investigate ultrafast processes in matter and explore fundamental quantum phenomena. In particular, optically modulated electrons are…
We analyze the electromagnetic scattering of massive particles with and without spin wherein one particle (or both) is electrically neutral. Using the techniques of effective field theory, we isolate the leading long distance effects, both…
We present a factorisation formula for the dependence of light hadron masses and low energy hadronic scales on the mass $M$ of a heavy quark: apart from an overall factor $Q$, ratios such as $r_0(M)/r_0(0)$ are computable in perturbation…
We present results of lattice QCD simulations with mass-degenerate up and down and mass-split strange and charm (N_f = 2+1+1) dynamical quarks using Wilson twisted mass fermions at maximal twist. The tuning of the strange and charm quark…
The theory of heavy meson masses, in which the symmetries of heavy and light quarks are exploited, can be used to describe the low energy interaction among heavy mesons to a better extent. The spin-flavor symmetry leads to many interesting…
The low-energy light-by-light cross section as determined by the nonlinear Euler-Heisenberg QED Lagrangian is evaluated in the presence of constant magnetic fields in the center-of-mass system of the colliding photons. This cross section…
The photon self-energy from chirally imbalanced quark matter is evaluated at finite temperature and density using the real time formulation of thermal field theory. The analytic structure is explored in detail exposing the cut structure…
While electromagnetic and up-down quark mass difference effects on octet baryon masses are very small, they have important consequences. The stability of the hydrogen atom against beta decay is a prominent example. Here we include these…
Quenched lattice QCD simulations and quenched chiral perturbation theory are used together for this study of strangeness in the nucleon. Dependences of the matrix elements on strange quark mass, valence quark mass and momentum transfer are…
The low energy behaviour of Quantum Chromodynamics makes unreliable an expansion in terms of its coupling strength, since nothing guarantees the convergence of such expansion. To overcomer such difficulty one resorts to Lattice QCD or…
We determine the masses of the light and the strange quarks in the $\bar{MS}$-scheme using our high-statistics lattice simulation of QCD with dynamical Wilson fermions. For the light quark mass we find $m^{light}_{\bar{MS}}(2 GeV) = 2.7(2)…
We present the current status of our ongoing calculations of the light hadron spectrum with both Kogut-Susskind (KS) and Wilson quarks in the valence or quenched approximation. We discuss KS quarks first and find that the chiral…
Mixing effects on the mass spectrum of light neutral pseudoscalar and vector mesons in the presence of an external uniform magnetic field $\vec B$ are studied in the framework of a two-flavor NJL-like model. The model includes isoscalar and…
We study electromagnetic as well as strong isospin breaking effects in the isospin mass splittings of light pseudoscalar and vector mesons. To this end we employ a coupled system of quark Dyson-Schwinger and meson Bethe-Salpeter equations…