Zoltan Ligeti

Email: ligeti[at]berkeley.edu

Tel:      510-486-4361

Fax:     510-486-6808

Office: 50A-5115, OLC 423

Personal web page


Zoltan Ligeti received his undergraduate education at the Eotvos University in Hungary, and his Ph.D. at the Weizmann Institute of Science in Israel.  He was the McCone Postdoctoral Fellow at Caltech from 1994-97, then a postdoc at UC San Diego, before joining Fermilab in 1998, and moving to Berkeley in 2000.  He has worked on flavor physics, beyond standard model scenarios, neutrinos, and dark matter.  He received the DOE Outstanding Junior Investigator Award, and is a Fellow of the American Physical Society.

Research interests

I have broad interests in particle physics, including the physics of the LHC, dark matter detection, flavor physics, CP violation, and neutrinos.  Most of my recent research focuses on theoretical questions about “indirect” searches for new physics.  Yet undiscovered particles can influence measurements via virtual effects due to the uncertainty principle.  Such searches for new physics were very successful in the past; for example, effects of the top quark were measured much before it was directly discovered.  Quark and lepton decays (especially flavor-changing neutral currents and CP violation) already probe mass scales comparable and possibly well above LHC energies, depending on the details of the underlying physics.  A clear empirical evidence for new physics comes from the observed baryon asymmetry of the Universe, which requires CP violation beyond the standard model.  In the next decade the sensitivity of many measurements that can reveal new sources of CP violation and virtual effects of new heavy particles will increase 100-fold or more, enhancing the sensitivity to new phenomena to several times shorter distance scales (higher energy scales) than we can access today.  I pursue several research directions toward better understanding the predictions of the standard model relevant for upcoming experiments, devising new observables sensitive to new physics, and studying the influence of beyond standard model scenarios on upcoming measurements and their synergies and complementarity with the LHC new particle searches.

Selected publications

(Full list of publications can be found here.)

Precision Global Determination of the B→Xs γ Decay Rate,
with F. Bernlochner, H. Lacker, I. Stewart, F. Tackmannn, K. Tackmann, arXiv:2007.04320

Das ist der HAMMER: Consistent new physics interpretations of semileptonic decays,
with F. Bernlochner, S. Duell, M. Papucci, D. Robinson, arXiv:2002.00020

Combined analysis of semileptonic B decays to D and D*: R(D(*)), |Vcb|, and new physics,
with F. Bernlochner, M. Papucci, D. Robinson, PRD 95 (2017) 115008 [arXiv:1703.05330]

Flavor models for B → D(*)τν,
with M. Freytsis and J. Ruderman, PRD 92 (2015) 054018 [arXiv:1506.08896]

TASI Lectures on Flavor Physics, arXiv:1502.01372

On dark matter models with uniquely spin-dependent detection possibilities,
with M. Freytsis, PRD 83 (2011) 115009 [arXiv:1012.5317].

Disentangling neutrino oscillations,
with A. Cohen and S. Glashow, PLB 678 (2009) 191 [arXiv:0810.4602].