Heavy mesons in a hadronic medium: interaction and transport coefficients

We review the recent results of heavy meson diffusion in thermal hadronic matter. The interactions of D and B-bar mesons with other hadrons (light mesons and baryons) are extracted from effective field theories based on chiral and heavy-quark symmetries. When these guiding principles are combined with exact unitarity, physical values of the cross sections are obtained. These cross sections (which contain resonant contributions) are used to calculate the drag and diffusion coefficients of heavy mesons immersed in a thermal and dense medium. The transport coefficients are computed using a Fokker-Planck reduction of the Boltzmann equation.Comment: 4 pages, 3 figures. Contribution to the proceedings of the 15th International Conference on Strangeness in Quark Matter (SQM 2015), 06-11 Jul 2015. Dubna, Moscow region, Russi

Open bottom states and the anti-B meson propagation in hadronic matter

The interaction and propagation of anti-B mesons with light mesons, N and Delta baryons is studied within a unitarized approach based on effective models that are compatible with chiral and heavy-quark symmetries. We find several heavy-quark spin doublets in the open-bottom sectors, where anti-B and anti-B* mesons are present. In the meson sector we find several resonant states, among them, a B0 and a B1 with masses 5530 MeV and 5579 MeV as well as Bs0* and Bs1* narrow states at 5748 MeV and 5799 MeV, respectively. They form two doublets with no experimental identification yet, the first one being the bottom counterpart of the D0(2400) and D1(2430) states, and the second bottom doublet associated to the ubiquitous Ds0* (2317) and the Ds1 (2460). In the baryon sector, several Lambda_b and Sigma_b doublets are identified, among them the one given by the experimental Lambda_b(5910) and Lambda*_b(5921). Moreover, one of our states, the Sigma_b*(5904), turns out to be the bottom counterpart of the Sigma*(1670) and Sigma_c*(2549), which is a case for discovery. We finally analyze different transport coefficients for the anti-B meson in hot matter, such as formed in heavy-ion collisions at RHIC and LHC. For RHIC/LHC energies, the main contribution to the coefficients comes from the interaction of anti-B mesons with pions. However, we also include the effects of baryonic density which might be sizable at temperatures T < 100 MeV, as the chemical potential is expected to increase in the last stages of the expansion. We conclude that although the relaxation time decreases with larger baryonic densities, the anti-B meson does not thermalize at RHIC/LHC energies, representing an ideal probe for the initial bottom distribution.Comment: 13 pages, 5 figure

Heavy Hadrons in Dense Matter

We study the behavior of dynamically-generated baryon resonances with heavy-quark content within a unitarized coupled-channel theory in matter that fulfills heavy-quark spin symmetry constraints. We analyze the implications for the formation of charmed mesic nuclei and the propagation of heavy mesons in heavy-ion collisions from RHIC to FAIR.Comment: 4 pages, 1 table, 2 figures, contribution to the proceedings of Strangeness in Quark Matter (SQM2015), Dubna, 6-11 July 201

Dynamically-generated baryon resonances with heavy flavor

De studie van zware hadronen is een belangrijk onderwerp in de deeltjesfysica. In tegenstelling tot deeltjes die opgebouwd zijn uit lichte quarks,zijn toestanden met zware quarks (bijvoorbeeld charm of bottom quarks) moeilijk te beschrijven, omdat er geen goed model is. De ontwikkeling van nieuwe experimentele technieken maakt het echter mogelijk om nieuwe toestanden met zware quarks te observeren. Tegenwoordig is het een uitdaging om de aard van deze nieuwe deeltjes te interpreteren. Hadronresonanties, deeltjes die kunnen vervallen, kunnen worden beschreven als toestanden bestaand uit quarks en/of als toestanden bestaand uit hadronen, de zogenaamde moleculaire toestanden. Olena Romanets bestudeert in haar proefschrift baryonresonanties met zware quarks, moleculaire toestanden die dynamisch worden gegenereerd uit mesonen en baryonen. Hiervoor gebruikt ze een model dat twee belangrijke symmetrieën van de sterke interactie behoudt, de chirale symmetrie en de zware-quark spinsymmetrie. Ze vond een aantal charm en strange baryonresonanties die vergeleken kunnen worden met experimentele toestanden en deed voorspellingen voor andere toestanden met totale charm nummer 1, 2 en 3. Bovendien verkreeg ze met het model twee bottomtoestanden met massa’s 5912 en 5920 MeV. Deze toestanden zijn vorig jaar gevonden door de LHCb collaboratie. ‘We hebben ook baryonresonanties met verborgen charm geanalyseerd en we voorspellen een aantal toestanden met massa’s rond de 4 GeV, de meesten als een gebonden toestand. Al onze resultaten zullen binnenkort worden getest in het PANDA experiment bij de FAIR faciliteit in Duitsland.’ The study of heavy hadrons is a central topic in particle physics. In contrast to the particles built of light quarks, states that contain heavy quarks (charm or bottom) are difficult to treat, because there is no rigorous model to describe these states. On the other hand, the development of new techniques in experimental physics makes possible the observation of new states with heavy flavor. It is nowadays a challenge to interpret the nature of these new detected particles. Hadron resonances (particles that can decay in other ones) can be interpreted as states made of quarks or/and states built of hadrons, called molecular states. In this thesis we study baryon resonances with heavy flavor, molecular states generated dynamically from the scattering of mesons with baryons. For this purpose we use a model which respects two important symmetries Quantum Chromodynamics, chiral symmetry and heavy-quark spin symmetry. We find charm and strange baryon resonances that can be compared to experimental states, and also make predictions for other states, with total number of charm 1, 2, and 3. Moreover, two bottom-flavored states with masses 5912 and 5920 MeV have been obtained in our model. These states were found by the LHCb collaboration last year. We have also analyzed hidden-charm baryon resonances, and predict states with masses around 4 GeV, most of them as bound states. All these results will be tested in the near future by the PANDA experiment at the FAIR facility in Germany.

The Theory of Relativity Questions in Textbooks for Higher Education Institutions in Ukraine: to the Formation of Teaching Methodology

Досліджено процес проникнення спеціальної теорії відносності (СТВ) у підручники, що використовувалися у закладах вищої освіти України від моменту виникнення теорії до середини ХХ ст. Вивчені оригінальні праці вчених, що працювали в Україні, відповідні підручники та методичні підходи в роботах. Проаналізований підхід Л. Кордиша до виведень перетворень Лоренца, що й донині використовується у сучасних підручниках з фізики. Матеріали і методи. Метод дослідження: системний аналіз методичних підходів до викладення понять теорії відносності. Аналізу підлягали підручники, поширені в Україні у досліджуваний період. Формулювання проблеми. Становленню методики викладення СТВ та загальної теорії відносності (ЗТВ) у підручниках присвячено незначну кількість наукових праць; методи, що використовуються для пояснення класичних питань теорії відносності «відкривалися» без урахування досвіду їх становлення і розвитку; низка праць є невідомою. Результати. Доведено, що О.П. Грузинцев першим в Україні у 1911 р. увів теоретичні основи СТВ у підручники. Показано, що до 1930-х рр у підручниках, питання СТВ або відсутні, або висвітлювалися обмежено. Наприкінці 1930-х рр. Формується новий погляд на викладення теоретичної фізики з урахуванням новітніх досягнень. Ці принципи були втілені Л.Д. Ландау та його співробітниками у серії підручників. Висновки. Саме в представленні теорії відносності у підручниках того часу і були закладені методичні відмінності її викладання. Методика викладання теорії відносності формувалась у підручниках. Їх автори доносили до студентства СТВ та ЗТВ, спираючись на досвід їх осмислення залежно від своїх поглядів на їх важливість. Чіткі методичні підходи ще не були вироблені і знаходилися у пошуковому стані. Але, напрацювання Л. Й. Кордиша та інших стали підґрунтям розвитку методики викладання СТВ та ЗТВ застосовуються й у сучасних підручниках..The process of special theory of relativity (STR) penetration into the textbooks used in higher education institutions of Ukraine since the theory origin to the middle of the XX century is investigated. The original works of scientists who worked in Ukraine, relevant textbooks and works methodological approaches are studied. L. Kordysh's approach to derivations of the Lorentz’ transformations is analyzed, which it is still used in modern physics textbooks. Materials and methods. The research method: is system analysis of methodological approaches to teaching the theory of relativity concepts. Textbooks distributed in Ukraine during the study period were subject to analysis. Problem formulation. A small number of scientific papers are devoted to the formation of STR and general theory of relativity (GTR) teaching methodology in textbooks; the methods used to explain the classical theory of relativity questions were "discovered" without taking into account the experience of their formation and development; several scientific papers are unknown. Results. It is proved that O.P. Gruzintsev was the first to introduce the theoretical foundations of STR in textbooks in 1911 in Ukraine. It has been shown that until the 1930s, questions of STR were absent in textbooks. At the end of the 1930s, a new view of the theoretical physics teaching was formed. These principles were embodied by L.D. Landau and others in a series of textbooks. Conclusions. The methodical features of STR teaching were laid in the textbooks of that time presentation. Their authors teach students about STR and GTR, based on their experience understanding these theories. Clear methodical approaches were not found at that time yet. However, L.Y. Kordysh and others’ developments became the basic methodology of STR and GTR teaching which are used in modern textbooks

Educational and film discourse of COVID-19 pandemic period: An influential aspect

The study aimed to examine the educational and cinematic discourse in the context of the worldwide pandemic. Methodology reflected two sets of participants with given quantitative primary research and qualitative secondary research. Research expressed surveys results to acquire a clear understanding of the impact of the pandemic on the education and film industries. The surveys clearly showed that the pandemic did have an impact on the researched industries. Around 56% of participants feel that the pandemic's long-term impact was significant, just 2% said that the impact was not obvious, and 4% were unsure of this particular circumstance. 24% of the participants feel that online education cannot adequately satisfy the needs of pupils, while 20% are uncertain. Around 40% of the participants supported the offline style of education, whereas 6% felt that the offline mode of education is becoming obsolete by the day and that one must develop to keep up. A detailed survey has also occurred based on the effect of COVID-19 on the film industry. According to this survey, it has been revealed that a huge negative condition has been generated in the film industry as well as in film discourse