1,720,961 research outputs found
Study of the Bc → J/ψ + D(*)q decays in covariant confined quark model
No full textIn this work we study the Bc → J/ψ + D(*)q decays. It was defined ratios (RD*s/Ds, RD*/D, RD*/D*s and RD/Ds) of nonleptonic branching ratios of Bc meson, which will be hopefully tested on LHC experiments. We compare the obtained results with available experimental data and with the results from other theoretical approaches
Bs → K*0 decay form factors from covariant confined quark model
Get PDFWe evaluate Bs → K*0 transition form factors in the full kinematical region within the covariant confined quark model. The calculated form factors can be used to calculate the Bs → K*0 μ+μ– rare decay branching ratio, which was recently measured by LHCb collaboration
The study of b-s anomaly decays in covariant quark model
No full textThe work is devoted to the study of b-s anomaly decays. We compute the relevant form factors in the framework of the covariant quark model with infrared confinement in the full kinematical momentum transfer region. The calculated form factors are used to evaluate branching fractions and polarization observables in the decay caused by the presence of the intermediate scalar and in the cascade decay . We compare the obtained results with available experimental data and the results from other theoretical approaches
Proceedings of the Helmholtz International Summer School 2016 (HQ 2016) : Quantum Field Theory at the Limits : from Strong Fields to Heavy Quarks
No full textThe Helmholtz International Summer School (HISS) entitled “Quantum Field Theory at the Limits:from Strong Fields to Heavy Quarks (SF→ HQ)”, was held in the period July 18-30, 2016 at the Bogoliubov Laboratory of Theoretical Physics (BLTP) of the Joint Institute for Nuclear Research (JINR)in Dubna, Russia, as part of the activities of the Dubna International Advanced School of Theoretical Physics (DIAS-TH). The HISS series of schools has played an important role in bringing together an international faculty and young physicists (Ph.D. and postdocs), mostly from Russia and Germany, but increasingly also from other countries, including those affiliated to JINR Dubna. They participate in two-week long intense scientific discourse, mainly dedicated lectures on selected topics covering the foundation and the frontiers of high energy physics and cosmology. The novelty of this year’s school was its bifocal interest, which brought together two different physical science communities - particle and laser physicists. There were two broad areas of research covered at this school: heavy quark physics and physics of high field intensities. The focus of the former was on the latest results on heavy quark physics from all four large experimental collaborations at the LHC (ALICE, ATLAS, CMS, LHCb), at the B-factory experiments(BaBar and Belle), and from BESIII. This was accompanied with lectures on the theoretical aspectsof heavy quark physics, Quarkonia and Quarkonia-like multiquarks states (tetra- and pentaquarks), including various state-of-the-art calculational techniques, such as perturbative QCD, lattice-QCD, and effective field theories. The focus on the later topic was on the high intensity frontier and extreme statesof matter as probed by current and upcoming high power laser and high-Z ion facilities all around theworld. An afternoon tour at the heavy ion collider facility NICA, the superconducting accelerator complex under construction at the Veksler-Baldin Laboratory for High-Energy Physics, was also organized
Anomalies in Weak Decays of Hadrons Containing a b Quark
No full textA brief review of the current state of observed deviations of theoretical
predictions from experimental data in semileptonic decays of and
mesons is given. A theoretical analysis of these decays is carried out, taking
into account the effects of new physics, which appear due to the introduction
of new four-fermion operators, which are absent in the basis of the Standard
Model (SM) operators. The necessary form factors are calculated within the
framework of the covariant quark model developed in our papers.Comment: Contribution to: International Conference on Quantum Field Theory,
High-Energy Physics, and Cosmolog
meson parameters and radiative decay width within the covariant confined quark model
Get PDFIn this work we tried to predict the parameters of meson. Simple
assumptions gave us following parametres MeV and
MeV (for GeV
in covariant confined quark model). We calculated widths of radiative decays of
mesons, where and compared them with other theoretical
works. It was shown that the width of the meson very sensitive to
the mass as expected and less to the size parameter
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Semileptonic decays of Bc mesons into charmonium states
No full textIn this work we study the semileptonic decays of Bc meson. We evaluated
Bc→ D
D
*
,
B
c
→
D
s
D
s
*
and
Bc→ηc→
J
/
ψ
transitions form factors in the full kinematical region within the covariant quark model. The calculated form factors are used to evaluate the semileptonic decays of Bc meson and it was defined ratios (Rηc , RJ/ψ, RD ,RD*) of the branching ratios, which will be hopefully tested on LHC experiments.We compare the obtained results with the results from other theoretical approaches
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