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Related papers: One-loop contributions in the EFT for the $\Lambda…

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We reconsider the complete set of four-quark operators in the Weak Effective Theory (WET) for non-leptonic $\Delta F=1$ decays that govern $s\to d$ and $b\to d, s$ transitions in the Standard Model (SM) and beyond, at the Next-to-Leading…

High Energy Physics - Phenomenology · Physics 2021-12-22 Jason Aebischer , Christoph Bobeth , Andrzej J. Buras , Jacky Kumar , Mikołaj Misiak

We derive in detail the transition potential for nonmesonic lambda-hypernuclear decay in a one-meson-exchange model involving the full pseudoscalar and vector meson octets and including two effects that have been systematically omitted in…

Nuclear Theory · Physics 2009-11-07 C. Barbero , C. De Conti , A. P. Galeao , F. Krmpotic

We present new results on the summation of nonpower-series expansions in QCD Analytic Perturbation Theory (APT) in the one-loop approximation. We show how to generalize the approach suggested by one of us earlier to the cases of APT and…

High Energy Physics - Phenomenology · Physics 2008-03-27 A. P. Bakulev , S. V. Mikhailov

We report Quantum Monte Carlo calculations of weak transitions in $A\leq 10$ nuclei, based on the Norfolk two- and three-nucleon chiral interactions, and associated one- and two-body axial currents. We find that the contribution from…

Nuclear Theory · Physics 2020-08-26 G. B. King , L. Andreoli , S. Pastore , M. Piarulli , R. Schiavilla , R. B. Wiringa , J. Carlson , S. Gandolfi

We evaluate the one-loop prefactor in the false vacuum decay rate in a theory of a self interacting scalar field in 3+1 dimensions. We use a numerical method, established some time ago, which is based on a well-known theorem on functional…

High Energy Physics - Theory · Physics 2009-11-10 Jurgen Baacke , George Lavrelashvili

The non--mesonic weak decay of double--$\Lambda$ hypernuclei is studied within a microscopic diagrammatic approach. Besides the nucleon--induced mechanism, $\Lambda N\to nN$, widely studied in single--$\Lambda$ hypernuclei, additional…

Nuclear Theory · Physics 2015-03-23 E. Bauer , G. Garbarino , C. A. Rodriguez Peña

We provide a compendium of techniques that can be used to compute $O(N_f\alpha^2)$ corrections to low-energy electroweak processes. Specifically, these are the 2-loop electroweak corrections containing a light fermion loop. It is shown that…

High Energy Physics - Phenomenology · Physics 2007-05-23 R. Akhoury , Paresh Malde , Robin G. Stuart

We discuss the effective field theory (EFT) for nuclear beta decay. The general quark-level EFT describing charged-current interactions between quarks and leptons is matched to the nucleon-level non-relativistic EFT at the O(MeV) momentum…

High Energy Physics - Phenomenology · Physics 2024-04-29 Adam Falkowski , Martín González-Alonso , Ajdin Palavrić , Antonio Rodríguez-Sánchez

We present a theroretical treatment of electric dipole (E1) transitions of heavy quarkonia based on effective field theories. Within the framework of potential nonrelativistic QCD (pNRQCD) we derive the complete set of relativistic…

High Energy Physics - Phenomenology · Physics 2013-01-08 Piotr Pietrulewicz

We revisit the contributions of order $\alpha^2(Z\alpha)^5m$ and $\alpha^2(Z\alpha)E_F$, respectively, to the Lamb shift and to the hyperfine splitting from mixed self-energy-vacuum-polarization diagrams, involving fermionic loop. We use…

High Energy Physics - Phenomenology · Physics 2023-08-16 Petr A. Krachkov , Roman N. Lee

We show that constraints from perturbative QCD calculations play a role in the nucleon to Delta(1232) electromagnetic transition even at moderate momentum transfer scales. The pQCD constraints, tied to real photoproduction data and…

High Energy Physics - Phenomenology · Physics 2009-10-31 Carl E. Carlson , Nimai C. Mukhopadhyay

We recently developed a Bayesian framework for parameter estimation in general effective field theories. Here we present selected results from using that framework to estimate parameters with a nucleon-nucleon (NN) potential derived using…

Nuclear Theory · Physics 2019-03-15 S. Wesolowski , R. J. Furnstahl , J. A. Melendez , D. R. Phillips

We perform a complete calculation of the next-to-next-to-leading order (NNLO) electroweak fermionic corrections to fermion-pair production processes, where "fermionic" refers to contributions with closed fermion loops. We did this via a…

High Energy Physics - Phenomenology · Physics 2026-05-26 Ayres Freitas , E. Jackson Wallace

The non--mesonic weak decay of polarized $\Lambda$-hypernuclei is studied with a microscopic diagrammatic formalism in which one- and two-nucleon induced decay mechanisms, $\vec{\Lambda} N \to NN$ and $\vec{\Lambda} NN \to NNN$, are…

Nuclear Theory · Physics 2015-06-03 E. Bauer , G. Garbarino , A. Parreño , A. Ramos

We present an effective field theory (EFT) at leading order to describe light single-$\Lambda$ hypernuclei. Owing to the weak $\Lambda$ binding and to the $\Lambda N$ short interaction range, meson exchange forces are approximated by…

Nuclear Theory · Physics 2019-09-04 Lorenzo Contessi , Nir Barnea , Avraham Gal

We investigate the $\Lambda_c \to \Lambda \ell^{+} \nu_\ell$ decay with a focus on potential new physics (NP) effects in the $\ell = \mu$ channel. We employ an effective Hamiltonian within the framework of the Standard Model Effective Field…

High Energy Physics - Phenomenology · Physics 2024-09-16 Fernando Alvarado , Luis Alvarez-Ruso , Eliecer Hernandez , Juan Nieves , Neus Penalva

The one-loop self-energy correction to the hyperfine splitting of the 1s and 2s levels in H-like low-Z atoms is evaluated to all orders in Z\alpha. The results are compared to perturbative calculations. The residual higher-order…

High Energy Physics - Phenomenology · Physics 2009-11-07 V. A. Yerokhin , V. M. Shabaev

We evaluate the Fermi and Gamow-Teller (GT) matrix elements in tritium $\beta$-decay by including in the charge-changing weak current the corrections up to one loop recently derived in nuclear chiral effective field theory ($\chi$ EFT). The…

Nuclear Theory · Physics 2017-01-06 A. Baroni , L. Girlanda , A. Kievsky , L. E. Marcucci , R. Schiavilla , M. Viviani

Theoretical descriptions of the non-mesonic weak decay of Lambda-hypernuclei are unable to reproduce the experimental values of the ratio Gn/Gp=G(Lambda n -> nn)/G(Lambda p -> np). In this contribution we discuss a new approach to this…

Nuclear Theory · Physics 2009-11-10 G. Garbarino , A. Parreno , A. Ramos

We calculate one loop contributions to $\Gamma(h \rightarrow \gamma \, \gamma)$ from higher dimensional operators, in the Standard Model Effective Field Theory (SMEFT). Some technical challenges related to determining Electroweak one loop…

High Energy Physics - Phenomenology · Physics 2017-07-12 Christine Hartmann , Michael Trott