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Related papers: Flavor constraints on electroweak ALP couplings

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The weak decays $K^\pm\to\pi^\pm a$ offer a powerful probe of axion-like particles (ALPs). In this work, we provide a comprehensive analysis of these processes within chiral perturbation theory, extending existing calculations by including…

High Energy Physics - Phenomenology · Physics 2024-08-16 Claudia Cornella , Anne Mareike Galda , Matthias Neubert , Daniel Wyler

We analyze the three-body decays of the long-lived neutral kaon $K_L \to \pi\pi a$, where $a$ is an axion-like particle (ALP), and compare them to the two-body decay $K_L \to \pi^0 a$. While the latter requires both flavor violation (FV)…

High Energy Physics - Phenomenology · Physics 2026-04-09 Reuven Balkin , Stefania Gori , Christiane Scherb

We derive the one-loop contributions to ALP-SM effective couplings, including all finite corrections. The complete leading-order -- dimension five -- effective linear Lagrangian is considered. The ALP is left off-shell, which is of…

High Energy Physics - Phenomenology · Physics 2021-12-08 J. Bonilla , I. Brivio , M. B. Gavela , V. Sanz

The theoretical calculation of pseudo-scalar leptonic decay widths into an invisible ALP, $M \to \ell\, \nu_\ell\, a$, is reviewed. Assuming generic flavour-conserving ALP couplings to SM fermions and a generic ALP mass, $m_a$, the latest…

High Energy Physics - Phenomenology · Physics 2022-05-11 Jorge Alda Gallo , Alfredo Walter Mario Guerrera , Siannah Peñaranda , Stefano Rigolin

Axion-like particles (ALPs) with lepton-flavor violating couplings can be probed in exotic muon and tau decays. The sensitivity of different experiments depends strongly on the ALP mass and its couplings to leptons and photons. For ALPs…

High Energy Physics - Phenomenology · Physics 2020-06-24 Martin Bauer , Matthias Neubert , Sophie Renner , Marvin Schnubel , Andrea Thamm

We explore the potential of the Mu2e experiment to probe the lepton-flavor-violating process $\mu^- e^- \to e^- e^-$ in a muonic atom within a simplified axion-like particle (ALP) framework featuring flavor-violating $e$-$\mu$ couplings and…

High Energy Physics - Phenomenology · Physics 2026-04-10 Girish Kumar , Alexey A. Petrov

Axions and axion-like particles (ALPs) are well-motivated low-energy relics of high-energy extensions of the Standard Model, which interact with the known particles through higher-dimensional operators suppressed by the mass scale $\Lambda$…

High Energy Physics - Phenomenology · Physics 2021-04-28 Martin Bauer , Matthias Neubert , Sophie Renner , Marvin Schnubel , Andrea Thamm

Pseudo-scalar particles, often referred to as axion-like-particles (ALPs), arise in a variety of theoretical contexts. The phenomenology of such states is typically studied assuming flavor-conserving interactions, yet they can in principle…

High Energy Physics - Phenomenology · Physics 2023-08-08 Hooman Davoudiasl , Roman Marcarelli , Nicholas Miesch , Ethan T. Neil

Axion-like particles (ALPs), which are gauge-singlets under the Standard Model (SM), appear in many well-motivated extensions of the SM. Describing the interactions of ALPs with SM fields by means of an effective Lagrangian, we discuss ALP…

High Energy Physics - Phenomenology · Physics 2018-01-17 Martin Bauer , Matthias Neubert , Andrea Thamm

In hidden-sector models, axion-like particles (ALPs) can couple to heavy neutral leptons (HNLs), leading to rich phenomenologies. We study ALPs produced from $D$- and $B$-meson decays via quark-flavor-violating couplings, and decaying…

High Energy Physics - Phenomenology · Physics 2025-01-29 Zeren Simon Wang , Yu Zhang , Wei Liu

In this paper we study axion-like particles (ALPs) with lepton-flavour-violating (LFV) couplings in the mass regime above the muon threshold, $m_a>m_\mu$, where the strong bound from the exotic muon decay $\mu\to ea$ no longer apply and the…

High Energy Physics - Phenomenology · Physics 2026-04-15 Marco Ardu , Lorenzo Calibbi , Marco Fedele , Federico Mescia

We study the possibility of finding the axion-like particles (ALPs) through the leptonic decays of heavy mesons. The Standard Model (SM) predictions of the branching ratios of the leptonic decays of heavy mesons are less than the…

High Energy Physics - Phenomenology · Physics 2024-12-03 Gang Yang , Tianhong Wang , Guo-Li Wang

We investigate the most interesting decay processes involving axions, photons and the lightest pseudoscalar mesons, making use of a chiral effective Lagrangian model with $L=3$ light quark flavors, which also includes the flavor-singlet…

High Energy Physics - Phenomenology · Physics 2020-04-08 Giacomo Landini , Enrico Meggiolaro

Axions and axion-like particles emerge in many models for physics beyond the Standard Model. Thus, they have gained increasing research interest in both experimental and theoretical physics apart from their original proposition as a…

High Energy Physics - Phenomenology · Physics 2024-06-07 Matthias Neubert , Marvin Schnubel

Possible non-standard tuZ and tcZ interactions, which induce flavor-changing neutral-current decays of the top quark, are studied in the effective-Lagrangian framework. The corresponding Lagrangian consists of four kinds of non-standard…

High Energy Physics - Phenomenology · Physics 2019-11-11 Zenro Hioki , Kazumasa Ohkuma , Akira Uejima

Neutrino experiments lie at the edge of the intensity frontier and therefore can be exploited to search for new light particles weakly coupled to the visible sector. In this work we derive new constraints on axion-like particles (ALPs)…

High Energy Physics - Phenomenology · Physics 2023-10-17 Pilar Coloma , Pilar Hernández , Salvador Urrea

Leptonic and semileptonic meson decays that proceed via flavour-changing neutral currents provide excellent probes of physics of the standard model and beyond. We present explicit results for the Wilson coefficients of the weak effective…

High Energy Physics - Phenomenology · Physics 2021-11-01 Fady Bishara , Joachim Brod , Martin Gorbahn , Ulserik Moldanazarova

We consider the complete leading-order -- dimension five -- effective linear Lagrangian for ALPs. The full set of one-loop contributions to ALP-SM effective couplings are derived, including all finite corrections. A few phenomenological…

High Energy Physics - Phenomenology · Physics 2022-05-20 Jesús Bonilla

New pseudoscalars, axion-like particles (ALPs), provide the exciting target for present and future collider-based experiments. Search for ALPs is performed in this paper via the $W^{+}W^{-}$ fusion process…

High Energy Physics - Phenomenology · Physics 2023-12-08 Chong-Xing Yue , Han Wang , Yue-Qi Wang

We study the production of axion-like particles (ALPs) in association with electrons and neutrinos in the muon decay process. For this purpose, we compute the decay width of the muon to a four-body channel using a $d=7$ effective operator…

High Energy Physics - Phenomenology · Physics 2024-07-12 Ankita Budhraja , Samadrita Mukherjee , Sahana Narasimha