Ground state of Li and Be+^+ using explicitly correlated functions

We compare the explicitly correlated Hylleraas and exponential basis sets in the evaluations of ground state of Li and Be$^+$. Calculations with Hylleraas functions are numerically stable and can be performed with the large number of basis functions. Our results for ground state energies $-7.478 060 323 910 10(32)$, $-14.324 763 176 790 43(22)$ of Li and Be$^+$ correspondingly, are the most accurate to date. When small basis set is considered, explicitly correlated exponential functions are much more effective. With only 128 functions we obtained about $10^{-9}$ relative accuracy, but the severe numerical instabilities make this basis costly in the evaluation.Comment: 15 page

Comment on "New Methods for Old Coulomb Few-Body Problems"

In this Comment on the above mentioned paper by F. E. Harris, A. M. Frolov, and V. H. Smith, we briefly review our contributions to development of new methods for solution of the Coulomb four-body problem. We show that our research group, headed by Prof. T. K. Rebane, had a priority in using the fully correlated exponential basis for variational calculations of four-body systems. We also draw attention to the fact that our group subsequently implemented a more advanced method, which uses highly efficient exponential-trigonometric basis functions for solution of the same problem.Comment: Accepted by the International Journal of Quantum Chemistr

Analytic Evaluation of Four-Particle Integrals with Complex Parameters

The method for analytic evaluation of four-particle integrals, proposed by Fromm and Hill, is generalized to include complex exponential parameters. An original procedure of numerical branch tracking for multiple valued functions is developed. It allows high precision variational solution of the Coulomb four-body problem in a basis of exponential-trigonometric functions of interparticle separations. Numerical results demonstrate high efficiency and versatility of the new method.Comment: 13 pages, 4 figure

Searches for the associated ttˉHt\bar{t}H production at CMS

After the recent discovery of the Higgs boson, the next important goal is to measure its properties. Probing the Yukawa coupling of the Higgs boson to top quarks is a particularly important test of physics beyond the standard model. This coupling can be experimentally accessed by measuring the cross section of the Higgs boson production in association with a top quark pair ($t\bar{t}H$). The talk gives an overview of CMS results on $t\bar{t}H$ searches, using the full dataset of pp-collision data collected at the centre of mass energies of 7 and 8 TeV. All relevant Higgs boson decay modes have been studied, including Higgs decays to b-quarks, photons, $\tau$-leptons and multi-lepton final states. Additionally, the first Matrix Element Method based analysis has been carried out, that aims to further increase the sensitivity to the signal.Comment: Proceedings of the 8th International Workshop on the CKM Unitarity Triangle (CKM 2014), Vienna, Austria, September 8-12, 201

Vibrational spectroscopy of H2+: precise evaluation of the Zeeman effect

We present an accurate computation of the g-factors of the hyperfine states of the hydrogen molecular ion H2+. The results are in good agreement with previous experiments, and can be tested further by rf spectroscopy. Their implication for high-precision two-photon vibrational spectroscopy of H2+ is also discussed. It is found that the most intense hyperfine components of two-photon lines benefit from a very small Zeeman splitting

Antikoagulantravi kasutamine insuldi ja kodade virvendusarütmiaga patsientidel

Vaatamata tõhusatele tõenduspõhistele ennetusvõimalustele suureneb maailmas insulti haigestumine. Insuldi oluliseks riskiteguriks on lisaks kõrgvererõhktõvele ja ateroskleroosile ka kodade virvendusarütmia (KVA). Selle uuringu eesmärgiks oli retrospektiivselt välja selgitada suukaudse antikoagulantravi (SAKR) kasutamine insuldi eel ja järel 2004. ja 2005. aastal TÜ Kliinikumi (TÜK) neuroloogia osakonda hospitaliseeritud isheemilise insuldi ja KVAga patsientidel ning analüüsida SAKRi mittekasutamise põhjusi. Tulemusi võrreldi ravijuhendites avaldatud soovitustega. Selgus, et enne hospitaliseerimist tarvitas varfariini 9% patsientidest. Haiglas olid sagedasemad SAKRi mittemääramise põhjused raske insult ning patsiendi kõrge vanus, kuid 45%-l jäi põhjus ebaselgeks. Patsientidel, kellel haiglas antikoagulantravi jätkati või alustati, oli insult statistiliselt oluliselt kergem. SAKRi vähene kasutamine KVAga patsientidel nii insuldi primaarseks kui ka sekundaarseks preventsiooniks on probleemiks paljudes riikides. Eesti Arst 2009; 88(9):545−55