TY - JOUR AU - NA64 Collaboration (Andreev, Y. M. et al AU - Molina Bueno, L. AU - Tuzi, M. PY - 2024 DA - 2024// TI - First constraints on the Lμ – Lτ explanation of the muon g-2 anomaly from NA64-e at CERN T2 - J. High Energy Phys. JO - Journal of High Energy Physics SP - 212 - 15pp VL - 07 IS - 7 PB - Springer KW - Beyond Standard Model KW - Fixed Target Experiments KW - Dark Matter AB - The inclusion of an additional U(1) gauge L-mu – L-tau symmetry would release the tension between the measured and the predicted value of the anomalous muon magnetic moment: this paradigm assumes the existence of a new, light Z ' vector boson, with dominant coupling to μand tau leptons and interacting with electrons via a loop mechanism. The L-mu – L-tau model can also explain the Dark Matter relic abundance, by assuming that the Z ' boson acts as a "portal" to a new Dark Sector of particles in Nature, not charged under known interactions. In this work we present the results of the Z ' search performed by the NA64-e experiment at CERN SPS, that collected similar to 9 x 10(11) 100 GeV electrons impinging on an active thick target. Despite the suppressed Z ' production yield with an electron beam, NA64-e provides the first accelerator-based results excluding the g – 2 preferred band of the Z ' parameter space in the 1 keV < m(Z ') less than or similar to 2 MeV range, in complementarity with the limits recently obtained by the NA64-mu experiment with a muon beam. SN - 1029-8479 UR - https://arxiv.org/abs/2404.06982 UR - https://doi.org/10.1007/JHEP07(2024)212 DO - 10.1007/JHEP07(2024)212 LA - English N1 - WOS:001276265700010 ID - NA64CollaborationAndreev_etal2024 ER -