We include two loop, relativistic one loop and second order tree level corrections, plus leading nonperturbative contributions, to obtain a calculation of the lower states in heavy quarkonium spectrum correct up to, including, $O(\alpha_s^4)$ $\Lambda^4/m^4$ terms. This allows us, particular, model independent determination pole masses $b, c$ quarks, $$m_b=5 015^{+110}_{-70} mev; m_c=1 884^{+222}_{-133} mev$$ which correspond $\bar{\hbox{MS}}$ masses, $$\bar{m}_b(\bar{m}_b^2)=4...

In the framework of potential NRQCD, we obtain next-to-leading-log renormalization-group running matching coefficients for heavy quarkonium production currents near threshold. This allows to S-wave heavy-quarkonium production/annihilation observables with accuracy within perturbative QCD. particular, give expressions decays e^+e^- and two photons. We also compute O(m\alpha^8\ln^3\alpha) corrections Hydrogen spectrum.

We compute the hyperfine splitting in a heavy quarkonium composed of different flavors next-to-leading logarithmic approximation using nonrelativistic renormalization group. predict mass difference vector and pseudoscalar charm-bottom mesons to be M(B∗c)−M(Bc)=65±24 (th)+19−16(δαs) MeV.

We study the effect of resumming large logarithms in determination bottom quark mass through a nonrelativistic sum rule analysis. Our result is complete at next-to-leading-logarithmic accuracy and includes some known contributions next-to-next-to-leading logarithmic accuracy. Compared to finite order computations, reliability theoretical evaluation greatly improved, resulting substantially reduced scale dependence faster convergent perturbative series. This allows us significantly improve...

We study the hydrogen and muonic within an effective field theory framework. perform matching between heavy baryon coupled to photons leptons relevant at atomic scales. This can be performed in a perturbative expansion $\ensuremath{\alpha},{1/m}_{p},$ chiral counting. then compute ${O(m}_{{l}_{i}}^{3}{\ensuremath{\alpha}}^{5}{/m}_{p}^{2}\ifmmode\times\else\texttimes\fi{}\mathrm{logarithms})$ contribution (including leading logarithms) hyperfine splitting compare with experiment. They explain...

We have mesured the polarization of 375-GeV/c ${\mathrm{\ensuremath{\Sigma}}}^{+}$ and \ensuremath{\Sigma}\ifmmode\bar\else\textasciimacron\fi{} $^{\mathrm{\ensuremath{-}}}$ hyperons produced by 800-GeV/c protons incident on a Cu target. find that rises with increasing ${\mathit{p}}_{\mathit{t}}$ to maximum 16% at ${\mathit{p}}_{\mathit{t}}$=1.0 GeV/c then decreases 10% ${\mathit{p}}_{\mathit{t}}$=1.8 GeV/c. compare this data lower energies. The has been measured for first time. It same sign...

Whey in large quantities can cause environmental problems when discarded, because it reduces dissolved oxygen and aquatic life. Nonetheless, could be used as an easily available economical alternative to reduce culture medium costs microbially induced calcium carbonate precipitation (MICP). In this work, a native Sporosarcina pasteurii was isolated then cultured by using different proportions of whey (W) nutrient broth (NB). The solids were characterized XRD, FT-IR, TGA, SEM. potential...

We compute the energy of a static hybrid, i.e., hybrid quarkonium with quark and antiquark, at short distances in $D=4,3$, dimensions. The soft contribution to this is potential color-octet quark-antiquark pair distances, which known two loops for arbitrary $D$. have checked expression employing thermal field theory methods. Using effective nonrelativistic QCD we calculate ultrasoft contributions (and singlet) two-loop level. then present new results energy/potential decay width three four...

We update our perturbative determination of MSbar bottom quark mass mb(mb), by including the recently obtained four-loop coefficient in relation between pole and mass. First renormalon subtracted (RS or RS') is determined from known Upsilon(1S) meson, where we use residue Nm asymptotic behavior 3-loop static singlet potential. then using 4-loop renormalon-free RS (RS') argue that effects charm are accounted for effectively Nf=3 relations. The extracted value mb(mb) = 4222(40) MeV,...

We study the large order behaviour in perturbation theory of Bjorken, Ellis-Jaffe and Gross-Llewellyn-Smith sum rules. In particular, we consider their first infrared renormalons, for which obtain analytic structure with logarithmic accuracy also an approximate determination normalization constant. Estimates higher terms perturbative series are given. The Renormalon subtracted scheme is worked out these observables compared experimental data. Overall, good agreement experiment found. This...

We show that perturbation theory may give reasonable numbers for the decays of bottomonium and charmonium ground states to $e^+e^-$ $γγ$. To reach this conclusion it is important perform resummation logs. In particular, we obtain value $Γ(η_b (1S) \to γγ)=0.35 \pm 0.1 ({\rm th.}) 0.05 (\lQ)$ KeV.

Recently the muonic hydrogen lamb shift has been measured with unprecedented accuracy, allowing for a precise determination of proton radius. This is 5 sigma away from previous CODATA value obtained (mainly) and electron-proton scattering. Within an effective field theory formalism, I will define radius briefly review some aspects theoretical prediction shift, studying both pure QED-like computation hadronic effects.

Journal Article Alejandro García-Rivera (1951–2010): Un recordatorio Get access Cecilia González-Andrieu, González-Andrieu hgonzal4@lmu.edu Search for other works by this author on: Oxford Academic Google Scholar Ana María Pineda of the American Academy Religion, Volume 79, Issue 2, June 2011, Pages 280–286, https://doi.org/10.1093/jaarel/lfr015 Published: 01 2011