The discovery of neutrino oscillations and masses provides strong motivation to extend the Standard Model by including right-handed neutrinos, which lead to heavy neutrino states that could exist at the electroweak scale. These states may also be influenced by new high-scale, weakly interacting physics. Incorporating right-handed neutrinos into an effective field theory framework -- the $ν$SMEFT -- offers a systematic approach to study the phenomenology of heavy neutrinos in current and upcoming experiments. In this work, we present the first prospective 95\% exclusion plots achievable at a future lepton collider operating at a center-of-mass energy of $\sqrt{s}=0.5 ~\rm{TeV}$ for what we term the agnostic $ν$SMEFT scenario. This study focuses on the high-mass regime where the heavy neutrino $N$ decays promptly into leptons and jets. Specifically, we analyze the processes $e^+e^- \to νN \to νμ^{-} μ^{+} ν$ and $e^+e^- \to νN \to νμ^{-} \mathrm{j} \mathrm{j}$, deriving the exclusion regions in the $\fracα{Λ^2}$ vs. $m_N$ parameter space. When compared to prospective limits for the LHeC, we find that the semi-leptonic process with final jets in a lepton collider offers the greatest sensitivity, even with a straightforward cut-based analysis. The expected bounds are as stringent as those considered in recent studies for the low-mass regime where the $N$ may be long-lived and detectable via displaced decay searches, both at the LHC and future colliders.
The effect of the two-loop SMEFT RGEs at future colliders
Instituto de Física Corpuscular (IFIC), Universidad de Valencia-CSIC（瓦伦西亚大学-西班牙国家研究委员会粒子物理研究所）；Dipartimento di Fisica e Astronomia “G. Galilei”, Università di Padova, and Istituto Nazionale di Fisica Nucleare, Sezione di Padova（帕多瓦大学伽利略物理与天文学系，意大利国家核物理研究所帕多瓦分部）
Electroweak phase transition in SMEFT: Gravitational wave and collider complementarity
State Key Laboratory of Nuclear Physics and Technology, Institute of Quantum Matter, South China Normal University（华南师范大学量子物质研究所核物理与技术国家重点实验室）；Guangdong Basic Research Center of Excellence for Structure and Fundamental Interactions of Matter, Guangdong Provincial Key Laboratory of Nuclear Science（广东省基础与应用基础研究基金委物质结构与基本相互作用卓越中心广东省核科学重点实验室）；Department of Physics, Indian Institute of Technology Guwahati（印度理工学院古瓦哈提分校物理系）
Differentiating Dimension-6 and Dimension-8 Effects in $ν$SMEFT at the HL-LHC
Institute of Physics（印度物理研究所）；Homi Bhabha National Institute（霍米·巴巴国立研究所）；Institute for Particle Physics Phenomenology, Department of Physics, Durham University（达勒姆大学粒子物理现象学研究所）
Constraining the SMEFT Extended with Sterile Neutrinos at FCC-ee
SISSA, International School for Advanced Studies（国际高等研究学校）；INFN, Sezione di Trieste（意大利国家核物理研究所的里雅斯特分部）；Jožef Stefan Institute（约热·斯特凡研究所）；University College London（伦敦大学学院）；Institute of Physics, NAWI Graz, University of Graz（格拉茨大学NAWI物理研究所）；Institute of Physics, ELTE Eötvös Loránd University（厄特沃什·罗兰大学物理研究所）
Measuring Higgs Boson Self-couplings with $2\rightarrow 3$ VBS Processes
在标准模型有效场理论（SMEFT）框架下，研究了在质子和轻子对撞机上通过$2\rightarrow 3$矢量玻色子散射（VBS）过程测量希格斯玻色子自耦合.以$W_L W_L\rightarrow W_L W_L h$和$W_L W_L\rightarrow h h h$为例，SMEFT对$2\to3$ VBS过程振幅的贡献随能量$\frac{\mathcal{A}^{\text{BSM}}}{\mathcal{A}^{\text{SM}}} \sim \frac{E^2}{Λ^2}$的增加而增强，表明这些过程对SMEFT中相关的六维算子的敏感性.在不同的碰撞能量下，对强子和轻子对撞机上的全过程进行了模拟，以估计$c_6$和$c_{Φ_1}$上的允许区域。特别是我们发现，在Higgs自耦合的测量中，$WWh$过程与三重Higgs产生过程（$hhh$）一样重要，它只需要在末态中选择合适的纵极化和适当的$p_T$切割。我们的分析表明，这些过程可以发挥重要作用，在未来的100 TeV pp对撞机和μ子对撞机的希格斯自耦合测量。然而，它们的横截面在低能机器上通常很小，这使得它们的探索更具挑战性。
Sensitivity prospects for lepton-trijet signals in the $ν$SMEFT at the LHeC
Instituto de Física de Mar del Plata (IFIMAR) CONICET, UNMDP（马德普拉塔物理研究所 (IFIMAR) 阿根廷国家科学研究委员会，马德普拉塔国立大学）；Instituto de Física La Plata (IFLP) CONICET, UNLP（拉普拉塔物理研究所 (IFLP) 阿根廷国家科学研究委员会，拉普拉塔国立大学）；Instituto de Física, Facultad Ingeniería, Universidad de la República（共和国大学工程学院物理研究所）；Departamento de Física, Universidad Nacional de Mar del Plata（马德普拉塔国立大学物理系）；Instituto de Física, Facultad de Ciencias, Universidad de la República（共和国大学理学院物理研究所）
New Physics Reach through Precision at Future Colliders: a Multi-Pronged Approach
Université catholique de Louvain（天主教鲁汶大学）；University of Milano and INFN, Sezione di Milano（米兰大学及意大利国家核物理研究所米兰分部）；University of Manchester（曼彻斯特大学）；University of Cyprus（塞浦路斯大学）；University of Edinburgh（爱丁堡大学）；CERN（欧洲核子研究中心）；Instituto de Física Corpuscular (IFIC), Universidad de Valencia-CSIC（瓦伦西亚大学-西班牙国家研究委员会粒子物理研究所）；Nikhef Theory Group（尼赫夫理论组）；Vrije Universiteit Amsterdam（阿姆斯特丹自由大学）；Max-Planck-Institut für Physik（马克斯·普朗克物理学研究所）
