E. Megias

On dilatons and the LHC diphoton excess

A bstractWe study soft wall models that can embed the Standard Model and a naturally light dilaton. Exploiting the full capabilities of these models we identify the parameter space that allows to pass Electroweak Precision Tests with a moderate Kaluza-Klein scale, around 2 TeV. We analyze the coupling of the dilaton with Standard Model (SM) fields in the bulk, and discuss two applications: i) Models with a light dilaton as the first particle beyond the SM pass quite easily all observational tests even with a dilaton lighter than the Higgs. However the possibility of a 125 GeV dilaton as a Higgs impostor is essentially disfavored; ii) We show how to extend the soft wall models to realize a 750 GeV dilaton that could explain the recently reported diphoton excess at the LHC.

A natural origin for the LHCb anomalies

A bstractThe anomalies recently found by the LHCb collaboration in B-meson decays seem to point towards the existence of new physics coupled non-universally to muons and electrons. We show that a beyond-the-Standard-Model dynamics with these features naturally arises in models with a warped extra-dimension that aim to solve the electroweak Hierarchy Problem. The attractiveness of our set-up is the fact that the dynamics responsible for generating the flavor anomalies is automatically present, being provided by the massive Kaluza-Klein excitations of the electroweak gauge bosons. The flavor anomalies can be easily reproduced by assuming that the bottom and muon fields have a sizable amount of compositeness, while the electron is almost elementary. Interestingly enough, this framework correlates the flavor anomalies to a pattern of corrections in the electroweak observables and in flavor-changing processes. In particular the deviations in the bottom and muon couplings to the Z-boson and in ΔF = 2 flavor-changing observables are predicted to be close to the present experimental bounds, and thus potentially testable in near-future experiments.

The quark-antiquark potential at finite temperature and the dimension two gluon condensate

A recently proposed phenomenological model, which includes non perturbative effects from dimension two gluon condensates, is applied to analyze the available lattice data for the heavy quark free energy in the deconfined phase of quenched QCD. For large

Time evolution of entanglement for holographic steady state formation

q\bar{q}

Non-extensive thermodynamics and neutron star properties

separations we recover previous results for the Polyakov loop, exhibiting unequivocal condensate contributions. For the

Polyakov loop in various representations in the confined phase of QCD

q\bar{q}

From chiral quark dynamics with Polyakov loop to the hadron resonance gas model

potential at finite temperature and finite separation we find that a good overall description of the lattice data can be achieved once the condensate is properly accounted for. In addition, the model predicts a duality between the zero temperature potential as a function of the

Fractal aspects of hadrons

q\bar{q}

g μ − 2 from Vector-like leptons in warped space

separation, on the one hand, and the quark selfenergy as a function of the temperature, on the other, which turns out to be satisfied to a high degree by the lattice data.

Nonextensive thermodynamics with finite chemical potential, hadronic matter and protoneutron stars

A bstractWithin gauge/gravity duality, we consider the local quench-like time evolution obtained by joining two 1+1-dimensional heat baths at different temperatures at time t = 0. A steady state forms and expands in space. For the 2+1-dimensional gravity dual, we find that the “shockwaves” expanding the steady-state region are of spacelike nature in the bulk despite being null at the boundary. However, they do not transport information. Moreover, by adapting the time-dependent Hubeny-Rangamani-Takayanagi prescription, we holographically calculate the entanglement entropy and also the mutual information for different entangling regions. For general temperatures, we find that the entanglement entropy increase rate satisfies the same bound as in the ‘entanglement tsunami’ setups. For small temperatures of the two baths, we derive an analytical formula for the time dependence of the entanglement entropy. This replaces the entanglement tsunami-like behaviour seen for high temperatures. Finally, we check that strong subadditivity holds in this time-dependent system, as well as further more general entanglement inequalities for five or more regions recently derived for the static case.