Search for a heavy composite Majorana neutrino in events with dilepton signatures from proton-proton collisions at √&lt;em&gt;s&lt;/em&gt; = 13 TeV

Tumasyan, A.; Adam, W.; Andrejkovic, J.W.; Bergauer, T.; Chatterjee, S.; Damanakis, K.; Dragicevic, M.; Escalante Del Valle, A.; Hussain, P.S.; Jeitler, M.; Caminada, L.; Ebrahimi, A.; Erdmann, W.; Horisberger, R.; Ingram, Q.; Kaestli, H.C.; Kotlinski, D.; Lange, C.; Missiroli, M.; Noehte, L.; Rohe, T.; Zhokin, A.

doi:10.1016/j.physletb.2023.137803

Search for a heavy composite Majorana neutrino in events with dilepton signatures from proton-proton collisions at √s = 13 TeV

Tumasyan A, Adam W, Andrejkovic JW, Bergauer T, Chatterjee S, Damanakis K, Dragicevic M, Escalante Del Valle A, Hussain PS, Jeitler M, Caminada L, Ebrahimi A, Erdmann W, Horisberger R, Ingram Q, Kaestli HC, Kotlinski D, Lange C, Missiroli M, Noehte L, Rohe T, Zhokin A, et al.

Citation

Tumasyan, A., Adam, W., Andrejkovic, J. W., Bergauer, T., Chatterjee, S., Damanakis, K., … Zhokin, A. (2023). Search for a heavy composite Majorana neutrino in events with dilepton signatures from proton-proton collisions at √s = 13 TeV. Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics, 843, 137803 (25 pp.). https://doi.org/10.1016/j.physletb.2023.137803

Persistent URL https://www.dora.lib4ri.ch/psi/islandora/object/psi:54150

Results are presented of a search for a heavy Majorana neutrino N_ℓ decaying into two same-flavor leptons ℓ (electrons or muons) and a quark-pair jet. A model is considered in which the N_ℓ is an excited neutrino in a compositeness scenario. The analysis is performed using a sample of proton-proton collisions at √s =13 TeV recorded by the CMS experiment at the CERN LHC, corresponding to an integrated luminosity of 138fb^-1. The data are found to be in agreement with the standard model prediction. For the process in which the N_ℓ is produced in association with a lepton, followed by the decay of the N_ℓ to a same-flavor lepton and a quark pair, an upper limit at 95% confidence level on the product of the cross section and branching fraction is obtained as a function of the N_ℓ mass m_Nℓ and the compositeness scale Λ. For this model the data exclude the existence of N_ℓ (N_μ) for m_Nℓ below 6.0 (6.1) TeV, at the limit where m_Nℓ is equal to Λ. For m_Nℓ ≈1 TeV, values of Λ less 20 (23) TeV are excluded. These results represent a considerable improvement in sensitivity, covering a larger parameter space than previous searches in pp collisions at 13 TeV.