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Key research themes
1. How can collider experiments and theoretical models probe flavor-changing neutral currents and rare heavy flavor decays as indicators of new physics beyond the Standard Model?
This theme focuses on studying rare heavy flavor processes, such as flavor-changing neutral-current (FCNC) decays of the top quark and other heavy flavors, to search for signatures of physics beyond the Standard Model (SM). Collider experiments like the LHC and Tevatron provide high statistics samples to investigate these rare decays whose SM rates are extremely suppressed, making them sensitive probes of new physics. Theoretical frameworks employing effective field theories and supersymmetry models provide predictions for branching ratios and production cross sections, guiding experimental searches. The interplay of data and theory helps place limits on anomalous couplings and guide future studies.
Key finding: Develops a theoretical framework for top quark FCNC decays within new physics models, illustrating that rare decay modes like t → c + Z0 can have enhanced branching ratios in supersymmetric models with and without R-parity... Read more
Key finding: Performs an experimental search at the LHC (ATLAS) for single top-quark production via FCNC interactions with up or charm quarks and a gluon. Utilizes neural network-based discriminants to separate signal from background,... Read more
Key finding: Summarizes extensive measurements from the Tevatron on heavy flavor hadrons including lifetimes, branching fractions, CP violation, and mixing, demonstrating the experimental precision achievable in charm and bottom quark... Read more
Key finding: Outlines the overall experimental and theoretical status of quark flavor physics, emphasizing the importance of precision flavor measurements (strange, charm, bottom sector) as indirect probes of new physics at high scales.... Read more
2. How do flavor symmetries and extended seesaw mechanisms illuminate neutrino mass generation, mixing parameters, and charged lepton flavor violation?
This theme concerns theoretical constructions of neutrino mass models that invoke discrete flavor symmetries such as A4 and mechanisms like inverse and linear seesaw to explain observed neutrino oscillation data including mixing angles, CP phases, and absolute mass scale. These frameworks not only provide predictive patterns for neutrino properties but also induce charged lepton flavor violation (cLFV) processes like µ → e + γ, whose rates can be enhanced by new particles and mixing. Combined global fits and model-specific assumptions shed light on parameter regions accessible to forthcoming experiments.
Key finding: Computes the branching ratio for the cLFV decay µ → e + γ within inverse and linear seesaw models supplemented by A4 flavor symmetry for various flavon vacuum alignments. Demonstrates that the µ → e + γ branching ratio can... Read more
Key finding: Proposes a predictive extension of the scotogenic model by promoting the stabilizing Z2 symmetry to a non-Abelian discrete flavor symmetry Σ(81), underpinning dark matter stability. This setup strongly constrains the lepton... Read more
3. What role do quantum field theory treatments and conformal coupling models play in understanding neutrino flavor oscillations and mixing phenomena?
This theme covers rigorous QFT-based approaches to neutrino mixing and oscillations going beyond quantum mechanical approximations, considering issues such as unitary inequivalence of flavor and mass vacua, condensate structures, and charge conservation. It also studies environmental effects on neutrinos, including propagation in curved spacetime and matter in conformally coupled scalar-tensor gravity models (e.g., chameleon, symmetron), which induce modifications to oscillation probabilities through altered resonance conditions (MSW effect). These insights refine theoretical predictions essential for interpreting neutrino experiments and searching for new physics linked to gravity and cosmology.
Key finding: By calculating the neutron β-decay amplitude using three different neutrino state representations (Pontecorvo, mass, exact QFT flavor states), the study shows that only QFT flavor states—eigenstates of flavor charge—yield... Read more
Key finding: Derives the general formula for neutrino flavor transition probabilities in matter within static, spherically symmetric spacetimes including effects from conformally coupled scalar fields like chameleons and symmetrons.... Read more
Key finding: Reviews QFT formulations of neutrino mixing emphasizing the nonperturbative flavor vacuum as a coherent condensate, unitarily inequivalent to the mass vacuum. Discusses the gauge-theoretic interpretation where neutrino mixing... Read more