In this paper we explore interactions between neutrinos and dark matter. In particular, we study how the propagation of astrophysical neutrinos can be modified by computing the most general potential ...generated by the galactic DM background. We use on-shell techniques to compute this potential in a completely model independent way and obtain an expression valid for any dark matter mass and spin. Afterwards, we use this expression to analyse under what circumstances such potential can be important at the phenomenological level, and we find that under some assumptions only ultra light scalar dark matter could be of any relevance to oscillation experiments.
ALPs, the on-shell way Bertuzzo, Enrico; Grojean, Christophe; Salla, Gabriel M.
The journal of high energy physics,
05/2024, Letnik:
2024, Številka:
5
Journal Article
Recenzirano
Odprti dostop
A
bstract
We study how the coupling between axion-like particles (ALPs) and matter can be obtained at the level of on-shell scattering amplitudes. We identify three conditions that allow us to ...compute amplitudes that correspond to shift-symmetric Lagrangians, at the level of operators with dimension 5 or higher, and we discuss how they relate and extend the Adler’s zero condition. These conditions are necessary to reduce the number of coefficients consistent with the little-group scaling to the one expected from the Lagrangian approach. We also show how our formalism easily explains that the dimension-5 interaction involving one ALP and two massless spin-1 bosons receive corrections from higher order operators only when the ALP has a non-vanishing mass. As a direct application of our results, we perform a phenomenological study of the inelastic scattering
ℓ
+
ℓ
−
→
ϕh
(with
ℓ
±
two charged leptons,
ϕ
the ALP and
h
the Higgs boson) for which, as a result of the structure of the 3-point and 4-point amplitudes, dimension-7 operators can dominate over the dimension-5 ones well before the energy reaches the cutoff of the theory.
A
bstract
In this paper we study the present and future sensitivities of the rare meson decay facilities KOTO, LHCb and Belle II to a light dark sector of the minimal dark abelian gauge symmetry ...where a dark Higgs
S
and a dark photon
Z
D
have masses ≲ 10 GeV. We have explored the interesting scenario where
S
can only decay to a pair of
Z
D
’s and so contribute to visible or invisible signatures, depending on the life-time of the latter. Our computations show that these accelerator experiments can access the dark Higgs (mass and scalar mixing) and the dark photon (mass and kinetic mixing) parameters in a complementary way. We have also discussed how the CMS measurement of the SM Higgs total decay width and their limit on the Higgs invisible branching ratio can be used to extend the experimental reach to dark photon masses up to ~ 10 GeV, providing at the same time sensitivity to the gauge coupling associated with the broken dark abelian symmetry.
Dark photon bounds in the dark EFT Barducci, Daniele; Bertuzzo, Enrico; Grilli di Cortona, Giovanni ...
The journal of high energy physics,
12/2021, Letnik:
2021, Številka:
12
Journal Article
Recenzirano
Odprti dostop
A
bstract
Dark photons are massive abelian gauge bosons that interact with ordinary photons via a kinetic mixing with the hypercharge field strength tensor. This theory is probed by a variety of ...different experiments and limits are set on a combination of the dark photon mass and kinetic mixing parameter. These limits can however be strongly modified by the presence of additional heavy degrees of freedom. Using the framework of dark effective field theory, we study how robust are the current experimental bounds when these new states are present. We focus in particular on the possible existence of a dark dipole interaction between the Standard Model leptons and the dark photon. We show that, under certain assumptions, the presence of a dark dipole modifies existing supernovæ bounds for cut-off scales up to
O
(10–100 TeV). On the other hand, terrestrial experiments, such as LSND and E137, can probe cut-off scales up to
O
(3 TeV). For the latter experiment we highlight that the bound may extend down to vanishing kinetic mixing.
In this paper we explore interactions between neutrinos and Dark Matter. In particular, we study how the propagation of astrophysical neutrinos can be modified by computing the most general potential ...generated by the galactic DM background. We use on-shell techniques to compute this potential in a completely model independent way and obtain an expression valid for any Dark Matter mass and spin. Afterwards, we use this expression to analyse under what circumstances such potential can be important at the phenomenological level, and we find that under some assumptions only ultra light scalar Dark Matter could be of any relevance to oscillation experiments.
ALPs, the on-shell way Bertuzzo, Enrico; Grojean, Christophe; Salla, Gabriel M
arXiv.org,
11/2023
Paper, Journal Article
Odprti dostop
We study how the coupling between axion-like particles (ALPs) and matter can be obtained at the level of on-shell scattering amplitudes. We identify three conditions that allow us to compute ...amplitudes that correspond to shift-symmetric Lagrangians, at the level of operators with dimension 5 or higher, and we discuss how they relate and extend the Adler's zero condition. These conditions are necessary to reduce the number of coefficients consistent with the little-group scaling to the one expected from the Lagrangian approach. We also show how our formalism easily explains that the dimension-5 interaction involving one ALP and two massless spin-1 bosons receive corrections from higher order operators only when the ALP has a non-vanishing mass. As a direct application of our results, we perform a phenomenological study of the inelastic scattering \(\ell^+\ell^- \to \phi h\) (with \(\ell^\pm\) two charged leptons, \(\phi\) the ALP and \(h\) the Higgs boson) for which, as a result of the structure of the 3-point and 4-point amplitudes, dimension-7 operators can dominate over the dimension-5 ones well before the energy reaches the cutoff of the theory.
We investigate the renormalization of the radiative decays of the Higgs to two gauge bosons in the Standard Model Effective Field Theory at mass dimension eight. Given that these are loop-level ...processes, their one-loop renormalization can be phenomenologically important when triggered by operators generated through the tree-level exchange of heavy particles (assuming a weakly coupled UV model). By computing the tree-level matching conditions of all relevant extensions of the Standard Model, we demonstrate that this effect is indeed present in the \(h\to \gamma Z\) decay at dimension eight, even though it is absent at dimension six. In contrast, the \(h\to gg\) and \(h\to \gamma\gamma\) decays can only be renormalized by operators generated by one-loop processes. For UV models with heavy vectors, this conclusion hinges on the specific form of their interaction with massless gauge bosons which is required for perturbative unitarity. We study the quantitative impact of the possible logarithmic enhancement of \(h\to \gamma Z\), and we propose an observable to boost the sensitivity to this effect. Given the expected increased precision of next-generation high-energy experiments, this dimension-eight contribution could be large enough to be probed and could therefore give valuable clues about new physics by revealing some of its structural features manifesting first at dimension eight.
In this paper we study the present and future sensitivities of the rare meson decay facilities KOTO, LHCb and Belle II to a light dark sector of the minimal dark abelian gauge symmetry where a dark ...Higgs \(S\) and a dark photon \(Z_D\) have masses \(\lesssim 10\) GeV. We have explored the interesting scenario where \(S\) can only decay to a pair of \(Z_D\)'s and so contribute to visible or invisible signatures, depending on the life-time of the latter. Our computations show that these accelerator experiments can access the dark Higgs (mass and scalar mixing) and the dark photon (mass and kinetic mixing) parameters in a complementary way. We have also discussed how the CMS measurement of the SM Higgs total decay width and their limit on the Higgs invisible branching ratio can be used to extend the experimental reach to dark photon masses up to \(\sim 10\) GeV, providing at the same time sensitivity to the gauge coupling associated with the broken dark abelian symmetry.
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