We investigate how possible new CP-violating top-quark interactions are encoded in the quantum state of a produced $t\bar t$ pair. We derive analytic expressions for the production density matrix in several benchmark channels relevant to hadron, lepton and photon colliders. In a common spin basis, we identify two characteristic CP-odd structures in the Fano--Bloch decomposition: a difference between the top and antitop polarisation vectors and an antisymmetric component of the spin-correlation matrix. We construct observables that directly probe these structures and study how quantum information measures, including discord, concurrence, magic and trace distance, respond to CP-even and CP-odd SMEFT contributions. Finally, using current measurements and future collider projections, we assess the sensitivity of these observables to possible new sources of CP violation in top-quark production. This establishes the production-level framework whose experimental reconstruction is developed in a companion paper.
We develop a quantum-tomographic framework for determining whether possible CP-odd effects in $t\bar t$ events originate in production, in decay, or in both. In the narrow-width approximation, the process $I\to t\bar t\to b\ell^+\nu\,\bar b\ell^-\bar\nu$ factorises into a production density matrix and top and antitop d...
P. Lamba, F. Maltoni, Olimpia Miniati et al.· 0 citations
The naive-$T$-odd angular coefficients $A_5$--$A_7$ in Drell--Yan production are highly suppressed in the Standard Model (SM), making them sensitive probes of CP-violating interactions beyond the SM. We study these observables within the Standard Model Effective Field Theory (SMEFT), focusing on dimension-six electrowe...
LHC measurements now reconstruct all fifteen parameters of the $t\bar t$ two-qubit spin density matrix, which amounts to a full quantum tomography of the pair. We show that this data constrains CP violation in the top-Yukawa coupling. The coupling enters the density matrix at one loop and produces spin correlations tha...
Quantum tomography program reconstructs the full spin density matrix of top-quark pairs from dilepton angular correlations at both electron-positron and hadron colliders. We use symmetry arguments to identify tomographic observables sensitive to CP violation in top quark couplings. As a concrete example, we study the s...
M. Perelstein, Minal Shaik, Taewook Youn· 0 citations
We study quantum spin correlations in top-quark pair production at future lepton colliders in the presence of a neutral gauge boson from anomaly-free general $U(1)$ extensions of the Standard Model. The process $\ell^+\ell^-\to t\bar t$, with $\ell=e,\mu$, is analyzed through the spin-density matrix including $\gamma$,...
ShivaSankar K. A., Arindam Das, Sanjoy Mandal· 0 citations
Bottomonium production in Pb-Pb collisions at $\sqrt{s_{NN}}=5.02$ TeV is studied using a Lindblad master equation derived from potential non-relativistic quantum chromodynamics (QCD), where quantum regeneration of color-singlet states is matched to the lattice QCD imaginary potential via collapse operators. Two parame...
Shuhan Zheng, Shu-Zhe Shi· 0 citations
We use cookies to run the site and, with your consent, for analytics and to show ads.
See our Cookie Policy.
