
Alarcon, J. M., Hiller Blin, A. N., Vicente Vacas, M. J., & Weiss, C. (2017). Peripheral transverse densities of the baryon octet from chiral effective field theory and dispersion analysis. Nucl. Phys. A, 964, 18–54.
Abstract: The baryon electromagnetic form factors are expressed in terms of twodimensional densities describing the distribution of charge and magnetization in transverse space at fixed lightfront time. We calculate the transverse densities of the spin1/2 flavoroctet baryons at peripheral distances b = O(Mpi(1)) using methods of relativistic chiral effective field theory (chi EFT) and dispersion analysis. The densities are represented as dispersive integrals over the imaginary parts of the form factors in the timelike region (spectral functions). The isovector spectral functions on the twopion cut t > 4 Mpi(2) are calculated using relativistic chi EFT including octet and decuplet baryons. The chi EFT calculations are extended into the rho meson mass region using an N / D method that incorporates the pion electromagnetic form factor data. The isoscalar spectral functions are modeled by vector meson poles. We compute the peripheral charge and magnetization densities in the octet baryon states, estimate the uncertainties, and determine the quark flavor decomposition. The approach can be extended to baryon form factors of other operators and the moments of generalized parton distributions.



Albaladejo, M., Daub, J. T., Hanhart, C., Kubis, B., & Moussallamd, B. (2017). How to employ (B)overbar(d)(0) > J/psi(pi eta, (K)overbarK) decays to extract information on pi eta scattering. J. High Energy Phys., 04(4), 010–28pp.
Abstract: We demonstrate that dispersion theory allows one to deduce crucial information on pi eta scattering from the finalstate interactions of the light mesons visible in the spectral distributions of the decays (B) over bar (0)(d) > J/psi(pi(0)eta, K+K, K0 (K) over bar (0)). Thus highquality measurements of these differential observables are highly desired. The corresponding rates are predicted to be of the same order of magnitude as those for (B) over bar (0)(d) > J/psi pi(+)pi() measured recently at LHCb, letting the corresponding measurement appear feasible.



Albaladejo, M., Oller, J. A., Oset, E., Rios, G., & Roca, L. (2012). Finite volume treatment of pi pi scattering and limits to phase shifts extraction from lattice QCD. J. High Energy Phys., 08(8), 071–22pp.
Abstract: We study theoretically the effects of finite volume for pi pi scattering in order to extract physical observables for infinite volume from lattice QCD. We compare three different approaches for pi pi scattering (lowest order BetheSalpeter approach, N/D and inverse amplitude methods) with the aim of studying the effects of the finite size of the box in the potential of the different theories, specially the lefthand cut contribution through loops in the crossed t, uchannels. We quantify the error made by neglecting these effects in usual extractions of physical observables from lattice ()CD spectrum. We conclude that for pi pi phaseshifts in the scalarisoscalar channel up to 800 MeV this effect is negligible for box sizes bigger than 2,5m(pi)(1) and of the order of 5% at around 1.5 – 2m(pi)(1). For isospin 2 the finite size effects can reach up to 10% for that energy. We also quantify the error made when using the standard Luscher method to extract physical observables from lattice QCD, which is widely used in the literature but is an approximation of the one used in the present work.



Baron, R., Boucaud, P., Carbonell, J., Deuzeman, A., Drach, V., Farchioni, F., et al. (2010). Light hadrons from lattice QCD with light (u, d), strange and charm dynamical quarks. J. High Energy Phys., 06(6), 111–31pp.



Bernard, V., & Passemar, E. (2010). Chiral extrapolation of the strangeness changing scalar K pi form factor. J. High Energy Phys., 04(4), 001–18pp.
Abstract: We perform a chiral extrapolation of lattice data on the scalar K pi form factor and the ratio of the kaon and pion decay constants within Chiral Perturbation Theory to two loops. We determine the value of the scalar form factor at zero momentum transfer, at the CallanTreiman point and at its soft kaon analog as well as its slope. Results are in good agreement with their determination from experiment using the standard couplings of quarks to the W boson. The slope is however rather large. A study of the convergence of the chiral expansion is also performed.



Bernardoni, F., Hernandez, P., & Necco, S. (2010). Heavylight mesons in the epsilonregime. J. High Energy Phys., 01(1), 070–30pp.
Abstract: We study the finitesize scaling of heavylight mesons in the static limit. We compute twopoint functions of chiral current densities as well as pseudoscalar densities in the epsilonregime of heavy meson Chiral Perturbation Theory (HMChPT). As expected, finite volume dependence turns out to be significant in this regime and can be predicted in the effective theory in terms of the infinitevolume lowenergy couplings. These results might be relevant for extraction of heavymeson properties from lattice simulations.



Chen, Y. H., Yao, D. L., & Zheng, H. Q. (2018). A Study of rhoomega Mixing in Resonance Chiral Theory. Commun. Theor. Phys., 69(1), 50–58.
Abstract: The strong and electromagnetic corrections to rhoomega mixing are calculated using an SU(2) version of resonance chiral theory up to nexttoleading orders in 1/NC expansion, respectively. Up to our accuracy, the effect of the momentum dependence of rhoomega mixing is incorporated due to the inclusion of loop contributions. We analyze the impact of rhoomega mixing on the pion vector form factor by performing numerical fit to the data extracted from e(+)e() > pi(+)pi() and tau > nu(tau)2 pi, while the decay width of omega > pi(+)pi() is taken into account as a constraint. It is found that the momentum dependence is significant in a good description of the experimental data. In addition, based on the fitted values of the involved parameters, we analyze the decay width of omega > pi(+)pi(), which turns out to be highly dominated by the rhoomega mixing effect.



Cirigliano, V., Gisbert, H., Pich, A., & RodriguezSanchez, A. (2020). Isospinviolating contributions to epsilon '/epsilon. J. High Energy Phys., 02(2), 032–44pp.
Abstract: The known isospinbreaking contributions to the K > pi pi amplitudes are reanalyzed, taking into account our current understanding of the quark masses and the relevant nonperturbative inputs. We present a complete numerical reappraisal of the direct CPviolating ratio is an element of(')/is an element of, where these corrections play a quite significant role. We obtain the Standard Model prediction Re (is an element of(')/is an element of) = (14 +/ 5) <bold> </bold>10(4), which is in very good agreement with the measured ratio. The uncertainty, which has been estimated conservatively, is dominated by our current ignorance about 1/NCsuppressed contributions to some relevant chiralperturbationtheory lowenergy constants.



de Blas, J., Eberhardt, O., & Krause, C. (2018). Current and future constraints on Higgs couplings in the nonlinear Effective Theory. J. High Energy Phys., 07(7), 048–45pp.
Abstract: We perform a Bayesian statistical analysis of the constraints on the nonlinear Effective Theory given by the Higgs electroweak chiral Lagrangian. We obtain bounds on the effective coefficients entering in Higgs observables at the leading order, using all available Higgsboson signal strengths from the LHC runs 1 and 2. Using a prior dependence study of the solutions, we discuss the results within the context of naturalsized Wilson coefficients. We further study the expected sensitivities to the different Wilson coefficients at various possible future colliders. Finally, we interpret our results in terms of some minimal composite Higgs models.



Filipuzzi, A., Portoles, J., & RuizFemenia, P. (2012). Zeros of the W(L)Z(L) > W(L)Z(L) amplitude: where vector resonances stand. J. High Energy Phys., 08(8), 080–22pp.
Abstract: A Higgsless electroweak theory may be populated by spin1 resonances around E similar to 1 TeV as a consequence of a new strong interacting sector, frequently proposed as a tool to smear the highenergy behaviour of scattering amplitudes, for instance, elastic gauge boson scattering. Information on those resonances, if they exist, must be contained in the lowenergy couplings of the electroweak chiral effective theory. Using the facts that: i) the scattering of longitudinal gauge bosons, WL, Z(L), can be well described in the highenergy region (E >> MW) by the scattering of the corresponding Goldstone bosons (equivalence theorem) and ii) the zeros of the scattering amplitude carry the information on the heavier spectrum that has been integrated out; we employ the O(p(4)) electroweak chiral Lagrangian to identify the parameter space region of the lowenergy couplings where vector resonances may arise. An estimate of their masses is also provided by our method.

