Vakhtang Kartvelishvili

On the fragmentation functions of heavy quarks into hadrons

An explicit form for the charmed quark fragmentation function DCc(z) into hadrons has been obtained with the help of the “reciprocity relation” and the c-quark distribution function in charmed mesons (the function calculated in terms of the Kuti-Weisskopf model). DCc(z) turns out to peak mainly at z close to 1. The analysis of new data on muon pair production in neutrino reactions points to such a behaviour of the DCc(z) function. The obtained fragmentation function, contrary to those, used earlier, leads to a charmed particle (average) multiplicity in e+e−-annihilation independent of energy.

Investigation of CP violation in B-0 -> J/psi K-s(0) decays at LEP

An investigation of CP violation was performed using a total of 24 candidates for B^0 ->J/psi K^0_S decay, with a purity of about 60%. These events were selected from 4.4 million hadronic Z^0 decays recorded by the OPAL detector at LEP. An analysis procedure, involving techniques to reconstruct the proper decay times and tag the produced b-flavours, B^0 or B^0(bar), has been developed to allow a first direct study of the time dependent CP asymmetry that, in the Standard Model, is sin(2beta). The result is sin(2beta) = 3.2_{-2.0}^{+1.8} +/- 0.5, where the first error is statistical and the second systematic. This result is used to determine probabilities for different values of sin(2beta) in the physical region from -1 to +1.

Study of the B+c→J/ψD+sBc+→J/ψDs+ and B+c→J/ψD∗+sBc+→J/ψDs∗+ decays with the ATLAS detector

The decays

Double production of vector quarkonia in exclusive Higgs boson decays

B_c^+ \rightarrow J/\psi D_s^+

Decay ηb→J/ψJ/ψ in light cone formalism

Bc+→J/ψDs+ and

Prompt and non-prompt J/ψ elliptic flow in Pb+Pb collisions at √sNN=5.02 Tev with the ATLAS detector

B_c^+ \rightarrow J/\psi D_s^{*+}