The Positron Annihilation to Dark Matter Experiment (PADME) uses the positron beam of the DA
\Phi
Φ
NE Beam-Test Facility, at the Laboratori Nazionali di Frascati (LNF) to search for a Dark Photon ...A’. The search technique studies the missing mass spectrum of single-photon final states in
e^+e^-\rightarrow A'\gamma
e
+
e
−
→
A
′
γ
annihilation in a positron-on-thin-target experiment. This approach facilitates searches for new particles such as long lived Axion-Like-Parti-cles, protophobic X bosons and Dark Higgs. This talk illustrated the scientific program of the experiment and its first physics results. In particular, the measurement of the cross-section of the SM process
e^+e^-\rightarrow \gamma\gamma
e
+
e
−
→
γ
γ
at
\sqrt{s}
s
=21 MeV was shown.
In this work we consider a model including dark sector bosons interacting through tensor currents with Standard Model leptons. We show that for certain values of the interaction constant this model ...has the potential of providing an explanation for the discrepancy between theory and experiment, regarding the anomalous magnetic moment of the muon. The effect on the already established measurements for the electron are small and the lepton universality violation is naturally incorporated. Possible experimental searches together with systematic approach to characteristic properties of the final states are discussed.
Abstract
The great success of the Standard Model has reached its maximum with the Higgs boson discovery. However, several anomalies observed in the universe when applying the gravitational theory, ...lead to believe that the visible matter is not the only constituent of the universe. A new matter component, called dark matter, must be introduced through an extension of the Standard Model. A simple scenario consisting in adding a new gauge symmetry
U
D
(1) and, as a consequence, a new (massive) gauge boson, the dark photon A′. PADME is a new experiment of the Laboratori Nazionali di Frascati searching for the A′, decaying invisibly, produced in the fixed target annihilation
e+e
−
→ γA′. The technique used by the experiment to probe the dark photon hypothesis is the missing mass method. The PADME experiment took data in two runs. Some preliminary highlights from the ongoing data analysis effort are presented.
Nucl. Phys. B, Volume 978, 2022, 115723 The phenomenological implications to the decay of the neutral pion from the
introduction of new dark particles are discussed. We calculate the contribution
to ...the $\pi^0$ decay width and then we extend the theory by adding dark sector
vector particles which interact through $\gamma^\mu$, $\sigma^{\mu\nu}$ and
$\sigma^{\mu\nu}\gamma^5$. We calculate the total decay width of
$\pi^0\rightarrow \gamma e^+ e^-$ where the electron-positron pair is produced
through a decay of a dark meson. The implication of the presented model on the
present and future searches for new dark particles is also discussed.
PADME (Positron Annihilation into Dark Matter Experiment) is searching for the production of a dark photon from positron-electron annihilation e^+e^−→γA′ using the positron beam of the Beam Test ...Facility (BTF) of the DAΦNE Linac at Laboratori Nazionali di Frascati (LNF). This work presents the assembly and the performance of the charged particle veto system required to identify Bremsstrahlung processes which are the main source of background events.
A measurement of the form factors of charged kaon semileptonic decays is presented, based on 4.4 × 106K± → π0e±νe (K e3 ± ) and 2.3 × 106K± → π0μ±νμ (K μ3 ±) decays collected in 2004 by the NA48/2 ...experiment. The results are obtained with improved precision as compared to earlier measurements. The combination of measurements in the K e3 ± and K μ3 ± modes is also presented.
The NA62 experiment recorded a large sample of K+→μ+νμ decays in 2007. A peak search has been performed in the reconstructed missing mass spectrum. In the absence of a signal, limits in the range ...2×10−6 to 10−5 have been set on the squared mixing matrix element |Uμ4|2 between muon and heavy neutrino states, for heavy neutrino masses in the range 300–375 MeV/c2. The result extends the range of masses for which upper limits have been set on the value of |Uμ4|2 in previous production search experiments.
Abstract The NA48/2 experiment at CERN reports the first observation of the K ± → π 0 π 0 μ ± ν decay based on a sample of 2437 candidates with 15% background contamination collected in 2003–2004. ...The decay branching ratio in the kinematic region of the squared dilepton mass above 0.03 GeV2/c 4 is measured to be (0.65 ± 0.03) × 10 −6. The extrapolation to the full kinematic space, using a specific model, is found to be (3.45 ± 0.16) × 10 −6, in agreement with chiral perturbation theory predictions.
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