A dark leptophilic scalar (φL) is a hypothetical particle that couples only to leptons rather than quarks. We report on a search for φL in the e+e-→τ+τ-φL, φL→ℓ+ℓ-(ℓ=e,μ) process using 626 fb-1 of data collected by the Belle experiment near the ϒ(4S) resonance. We validate the backgrounds with multiple control regions in data, using a novel multiclass multivariate event classifier. In absence of a signal, we quote upper limits at the 90% confidence level on the coupling between φL and leptons. Our bounds, obtained in a blinded approach, are 19% more constraining than the previous limits, averaged over the mass range 0.04≤mφL≤6.5 GeV. We exclude the parameter space below 4 GeV favored by measurement of the anomalous magnetic moment of the muon.

Search for a dark leptophilic scalar produced in association with τ+τ- pair in e+e- annihilation at center-of-mass energies near 10.58 GeV / Biswas, D., Banerjee, S., Adachi, I., Aihara, H., Asner, D.M., Aushev, T., Ayad, R., Babu, V., Behera, P., Bennett, J., Bessner, M., Bhardwaj, V., Bhuyan, B., Bilka, T., Bodrov, D., Borah, J., Bozek, A., Bracko, M., Branchini, P., Browder, T.E., et al.. - In: PHYSICAL REVIEW D. - ISSN 2470-0010. - 109:3(2024). [10.1103/PhysRevD.109.032002]

Search for a dark leptophilic scalar produced in association with τ+τ- pair in e+e- annihilation at center-of-mass energies near 10.58 GeV

Campajola M.;De Nardo G.;Di Capua F.;Merola M.;Pardi S.;Russo Guido;
2024

Abstract

A dark leptophilic scalar (φL) is a hypothetical particle that couples only to leptons rather than quarks. We report on a search for φL in the e+e-→τ+τ-φL, φL→ℓ+ℓ-(ℓ=e,μ) process using 626 fb-1 of data collected by the Belle experiment near the ϒ(4S) resonance. We validate the backgrounds with multiple control regions in data, using a novel multiclass multivariate event classifier. In absence of a signal, we quote upper limits at the 90% confidence level on the coupling between φL and leptons. Our bounds, obtained in a blinded approach, are 19% more constraining than the previous limits, averaged over the mass range 0.04≤mφL≤6.5 GeV. We exclude the parameter space below 4 GeV favored by measurement of the anomalous magnetic moment of the muon.
2024
Search for a dark leptophilic scalar produced in association with τ+τ- pair in e+e- annihilation at center-of-mass energies near 10.58 GeV / Biswas, D., Banerjee, S., Adachi, I., Aihara, H., Asner, D.M., Aushev, T., Ayad, R., Babu, V., Behera, P., Bennett, J., Bessner, M., Bhardwaj, V., Bhuyan, B., Bilka, T., Bodrov, D., Borah, J., Bozek, A., Bracko, M., Branchini, P., Browder, T.E., et al.. - In: PHYSICAL REVIEW D. - ISSN 2470-0010. - 109:3(2024). [10.1103/PhysRevD.109.032002]
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11588/968824
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