CKM matrix elements from tree-level decays and b-hadron lifetimes

We give an updated summary of the topics covered in Working Group I of the 2nd Workshop on the CKM Unitarity Triangle, with emphasis on the results obtained since the 1st CKM Workshop. The topics covered include the measurement of |V_{ub}|, of |V_{cb}| and of non-perturbative Heavy Quark Expansion parameters, and the determination of b-hadron lifetimes and lifetime differences.Comment: 12 pages, 8 figures. Based on Working Group I's summary talk given by L.L. for the group's convenors (Elisabetta Barberio (SMU), Lawrence Gibbons (Cornell), Toru Iijima (Nagoya), L.L.) at the 2nd Workshop on the CKM Unitarity Triangle, IPPP Durham, 5-9 April, 200

Delta m_d, Delta m_s/Delta m_d and epsilon_K in Quenched QCD

I present quenched, lattice QCD calculations of the hadronic matrix elements relevant for B^0_{d(s)}-\bar B^0_{d(s)} and K^0-\bar K^0 mixing and briefly review the status of lattice predictions.Comment: 7 pages, 1 figure, epsfig, mymoriond (included). Invited talk given at the XXXIVth Rencontres de Moriond: Electroweak Interactions and Unified Theories, Les Arcs, France, 13-20 March 1999. v2: Typos in eqs. 1 and 2 corrected; more appropriate figure 1; other minor cosmetic changes; all results untouched. v3: small changes in wordin

Parametric Instabilities in Resonantly-Driven Bose-Einstein Condensates

Shaking optical lattices in a resonant manner offers an efficient and versatile method to devise artificial gauge fields and topological band structures for ultracold atomic gases. This was recently demonstrated through the experimental realization of the Harper-Hofstadter model, which combined optical superlattices and resonant time-modulations. Adding inter-particle interactions to these engineered band systems is expected to lead to strongly-correlated states with topological features, such as fractional Chern insulators. However, the interplay between interactions and external time-periodic drives typically triggers violent instabilities and uncontrollable heating, hence potentially ruling out the possibility of accessing such intriguing states of matter in experiments. In this work, we study the early-stage parametric instabilities that occur in systems of resonantly-driven Bose-Einstein condensates in optical lattices. We apply and extend an approach based on Bogoliubov theory [PRX 7, 021015 (2017)] to a variety of resonantly-driven band models, from a simple shaken Wannier-Stark ladder to the more intriguing driven-induced Harper-Hofstadter model. In particular, we provide ab initio numerical and analytical predictions for the stability properties of these topical models. This work sheds light on general features that could guide current experiments to stable regimes of operation.Comment: 15 pages, 6 figures, one appendi

Vapor pressure isotope fractionation effects in planetary atmospheres: application to deuterium

The impact of the vapor pressure difference between deuterated and nondeuterated condensing molecules in planetary atmospheres is quantitatively assessed. This difference results in a loss of deuterium in the vapor phase above the condensation level. In Titan, Uranus and Neptune, the effect on CH3D is too subtle to alter current D/H ratio determinations. In Mars, the effect can induce a large depletion of HDO, starting about one scale height above the condensation level. Although the current infrared measurements of the D/H ratio appear to be almost unaffected, the intensity of disk-averaged millimetric HDO lines can be modified by about 10%. The effect is much stronger in limb sounding, and can be easily detected from orbiter observations.Comment: 24 pages, 1 table, 6 figures. Paper accepted for publication in ICARU