Theoretical particle physics in Bulgaria

1. Theoretical particle physics in Bulgaria Serious development after 1950 First generation: Professors Assen Datsev and Christo Christov Second generation: Professors Ivan Zlatev and Ivan Todorov – founders of modern particle physics Present senior theorists are third generation Matey Mateev, University of Sofia

2. Theoretical particle physics in Bulgaria Laboratory of Theoretical Physics, JINR, Dubna– Zlatev, Todorov, D. Stoyanov, Mateev, Ch. Stoyanov, Chizhov and many other. ICTP (Trieste) Ch Palev CERN THZlatev, S Petkov, E Sokachev PhD students mainly in Moscow and Sankt Petersburg Nisimov, Gerdgikov, D. Kirilova Important role of CERN-JINR Summer Schools in Bulgaria • Varna 1971 Jentchke and Bogoliubov • Varna 1987 Schopper and Bogoliubov Matey Mateev, University of Sofia

3. Shumen Sofia Plovdiv Matey Mateev, University of Sofia

4. Theoretical particle physics in Bulgaria Two big centers in Sofia Institute of Nuclear Research and Nuclear Energy at Bulgarian Academy of Sciences University of Sofia Matey Mateev, University of Sofia

5. Theoretical particle physics in Bulgaria Institute of nuclear research and nuclear energy • Laboratory “Theory of Elementary Particles” • Laboratory of Mathematical Modeling • Laboratory of Solitons, Coherence and Geometry • Laboratory of Nuclear Theory Matey Mateev, University of Sofia

6. University of Sofia Department of Theoretical Physics • Joint Group on Gravity and Astrophysics • Quantum Optics and Quantum Information • Theory of Superconductivity Department of Atomic Physics Computer simulations of complex biological systems Computational Theoretical PhysicsMonte Carlo Group http://cluster.phys.uni-sofia.bg Matey Mateev, University of Sofia

7. Laboratory “Theory of Elementary Particles” • centered around various major trends in modern theoretical and mathematical physics; • executed within the framework of a broad international collaboration with leading international centers such as CERN (Geneva), ICTP and SISSA (Trieste), JINR (Dubna), as well as with numerous leading universities and academic research institutions in Austria, Belgium, Finland, France, Germany, Greece, Hungary, Israel, Italy, Romania, Russia, Serbia, Spain, Switzerland, United Kingdom, United States of America. • Participation in four large EC networks: FP5 “EUCLID” (2002-2006) HPRN-CT-2002-00325, FP6 “Forces-Universe” (2004-2008) MRTN-CT-2004-005104, FP6 “HEP-Tools” (2006-2010) MRTN-CT-2006-03550, FP7 TMD network“Mapping out the Transverse Structure of the Nucleon” • Organizer of 5 representative international conferences, including 2 annual workshops of the FP5 (2006) and FP6 (2008) EC networks Matey Mateev, University of Sofia

8. Laboratory “Theory of Elementary Particles” • Scientific staff – 29 + 1 secretary Full professors - 6, assoc. professors – 16, assist. prof. – 5, researchers - 2 • Total number of publications (2005-2009): 213 105 in international journals with impact factor By years: 2005 - 15, 2006 - 19, 2007 - 21, 2008 - 26, 2009 - 24 108 in international conference proceedings By years: 2005 - 34, 2006 - 20, 2007 - 23, 2008 - 12, 2009 - 19 • Total number of citations appeared in 2005-2009: 1721 Total number of independent citations by years: 2005 - 330, 2006 - 316, 2007 - 342, 2008 - 356, 2009 - 367 • Defended thesis in the period 2005-2009: Ph.D. thesis – 1, “Doctor of Sciences” thesis- 4 • Doctoral students in the period 2005-2009: 4 Matey Mateev, University of Sofia

9. Studies of the quantum structure and geometric nature of the fundamental forces between elementary particles at (ultra-)high energies • Motivated by the advent of string theory as a central and most promising model of a unified theory of all fundamental forces in Nature • Dualities between strings versus gravity and gauge theories of elementary particles interactions • Cosmological aspects – black holes in higher-dimensional general relativity, wormholes and “brane worlds” (parallel universes) • Get deeper insights into the structure and behaviour of matter at very short distances • Main impact - address some of the core questions on the structure, origin and future of our Universe

10. A loop configuration on a triangulation with boundaries A loop configuration on a triangulation with boundaries A loop configuration on a triangulation with boundaries A loop configuration on a triangulation with boundaries String theory encompasses the achievements of many branches of theoretical physics, at the same time applying the tools of modern pure and applied mathematics and inspiring new progress in these most advanced fields.

11. Contribute to confirmation of the famous Maldacena duality - fundamental milestone of modern non-perturbative string theory . • It will lead to a revolutionary breakthrough in understanding : • (a) how string theory as the fundamental theory of all forces in Nature selects its various ground states; • (b) symmetries of the latter and the patterns of subsequent dynamical symmetry breakings: • (c) pertinent spectra of fundamental particles; • (d) how all this will ultimately explains the presently observed world of elementary particles and their fundamental interactions at the presently available collision energies in modern particle accelerators. • New types of brane-world scenarios, where “our Universe” is a lightlike brane from the point of view of the embedding higher-dimensional space, are expected to shed new light on the intrinsic dynamics of the brane-world itself with respect to the extra space dimensions. • Expect to achieve via lightlike brane-world scenarios a natural explanation for the practical unobservability of the extra space dimensions from the point of view of standard observers confined on “our Universe”.

12. Studies of the structure of nucleon and lepton-nucleon processes • understanding of the internal spin structure of the nucleon • knowledge of the polarized quark and gluon densities is essential for interpreting the results of modern high-energy physics experiments testing crucial aspects of the Standard Model of fundamental particle interaction and beyond it (Jefferson Lab, CERN, DESY and Brookhaven). • polarized structure functions of the proton used to refine earlier estimates of the proton polarizability correction to the hyperfine splitting in muonic hydrogen and to extract from experimental data an improved value of proton radius. The process of muon capture in muonic hydrogen is analyzed in a search for new data on the weak lepton-nucleon interactions

13. The method, suggested by E. Christova and E. Leader (IC of UK), for determining the valence quarks in a model independent way without any assumptions about fragmentation functions in any QCD order was accepted by Jefferson Lab (Newport News, USA) for the planned experiment Å04-113 (http://adsabs.harvard.edu/abs/2004hep.ex...12010J)

14. Polarized parton densities (PDFs) The LSS [Leader(London), Sidorov(Dubna), Stamenov(Sofia)] Collaboration is one of the three groups in the world who have carried out a detailed analysisof the world polarized Deep Inelastic Scattering data in the framework of Quantum Chromodynamics (QCD) The LSS results on PDFs are presented on the Durham HEPDATA website (http://durpdg.dur.ac.uk/HEPDATA/PDF)and have been used extensively by experimentalists and theorists Errors → Dχ2=1 in calculations for future high energy experiments using polarized particles A good knowledge of the combination of polarized densities (Δu(x) + Δū(x)) and (Δd(x) + Δd(x)) for the “up” and “down” quarks  A well determination of the sea quarks Δū, Δd and Δs, as well as the polarized gluonsΔG(x), is a challenge to the future investigations  Positivity is broken 

15. The expected uncertainties for the polarized PDFs have been calculated by the LSS group including the data set will be collected by the CLAS12 experiment planned to be performed using a 12 GeV electron beam at Jefferson Laboratory, USA.These results became an important part of the Research Proposal for this experiment (http://www.jlab.org/exp_prog/proposals/06/PR12-06-109.pdf) approved with highest priority, and the LSS team was invited to be a member of CLAS12 Collaboration.

16. Theoretical particle physics in Bulgaria Laboratory of Mathematical Modeling • Scientific staff – 7 Full prof. - 1, assoc. prof. – 4, assist. prof. – 2, • Total number of publications (2005-2009): 24 • Total number of citations appeared in 2005-2009: 370 • Defended thesis in the period 2005-2009: Ph.D. thesis – 1, “Doctor of Sciences” thesis- 1 Main achievements (2004-9): • High precision spectroscopy of the helium antiprotonic atom and the ion HD+, for the ASACUSA experiment at CERN. • Theoretical study of the muon transfer and proposal for the measurement of proton radius from the HFS of muonic hydrogen. • Two-dimensional super-Liouville theory. Matey Mateev, University of Sofia

17. Laboratory of solitons, coherence and geometry Staff: 2 professors, 3 assoc. professors, 2 PhD students, 3 researchers TOPICS: • Soliton theory and its applications to several areas of nonlinear optics, including fiber optics communications, Bose-Einstein condensate etc. • Coherent states, dynamical invariants and uncertainty relations for (pseudo) Hermitian systems • Geometric Structures and Physical Nonlinearities • Nonlinear phenomena in physics and biophysics Contracts with the National Science fund of Bulgaria. “Soliton models and applications to nonlinear optics» (F-1410, 2004 – 2008) “Geometrical structures and nonlinear dynamics” (F-1515,2005 – 2008) Collaborations: University of Salerno, Salerno, Italy University of Cergy Pontoise, Paris, France Univesity of Central Florida, Florida, USA Institute of physics, Minsk, Belorussia University of Leeds, Leeds, UK University of Bab Ezzouar, Algiers, Algeria Dublin Institute of Technology, Dublin, Ireland

18. Publications for the last 5 years:47 articles in international journals39 reports in proceedings of international conferences3 monographs and 2 proceedings volumes Two PhD theses defended successfully • Year Mono- Articles Reports • graphs in proceedings • 2004 1 10 4 • 1 11 15 • 0 6 8 • 0 8 8 • 1 5 8 • 1 11 12 • MORE than 350 citations.

19. Laboratory of Theoretical Nuclear Physics The laboratory consists of 15 members, 4 Professors, 4 Ass. Prof. and 6 PhD. 4 PhD students The results obtained in 2009 by the researchers from the laboratory are published in 12 papers in refereed scienfic journal and 6 are accepted for publications, 10 talks on international conferences in 2009are already published in their respective proceedings and 6 more will be published in the near future.

20. Laboratory of Theoretical Nuclear Physics nucleon-nucleon correlation effects on nuclear structure and reactions symmetries in nuclear physics exotic nuclei and few-body systems advanced studies of many-fermion systems

21. Theoretical particle physics in Bulgaria Department of Theoretical Physics Staff: 20, prof – 2 (+4), assoc. prof – 9(-4) ass. prof – 7, phys – 2, PhD Students – 11 Research Topics: Particle Physics and QFT, Super Strings, Mathematical Physics, Gravity and Astrophysics, Condensed Matter Physics, Superconductivity, Quantum Optics, Quantum Information Active participation in particle physics experiments: NA49, CMS, ATLAS, HERA Matey Mateev, University of Sofia

22. Department of Theoretical Physics Scientific Groups: Joint Group on Gravity and Astrophysics Quantum Optics and Quantum Information Theory of Superconductivity Matey Mateev, University of Sofia

23. Excited particles (compositeness)M. Chizhov Searches for excited fermions y *have been fulfilled at all powerful colliders, such as LEP, HERA and Tevatron. They are also included in experimental program at the LHC. y* why not Z* ? Z* has differentinteractions than Z’ !

24. Invariant dilepton mass distributions Several models predict high mass resonances that could decay into dileptons (Z’, G, TC, KK, …) Z Z’ Z* MZ

25. Angular distribution of Z* Z* p p

26. Comparison between Z’ andZ*for 3sdifference 7sdifference

27. There are intense searches for excited fermions, but not for excitedbosons at electroweak scale. • In contrast to the gauge bosons the excited bosons have anomalous chiral couplings to matter. This leads to a distinctive signature of their production at the hadron colliders. • The clearest channel for their discovery by the early LHC data should be the dilepton one. • The discovery of new type of the distributions could be pointed out to existence of new kind of the symmetry or extra spatial dimensions.

28. The Sofia University group led by Prof. S.Yazadjiev study gravitation in four and higher dimensions and its application to relativistic astrophysics and cosmology. The group consists entirely of young people: 1 professor, 2 scientists defended their PhD thesis very recently, 3 PhD students and 2 graduate students. Matey Mateev, University of Sofia

29. Matey Mateev, University of Sofia

30. Department of Atomic Physics Matey Mateev, University of Sofia

31. Molecular Mechanical Quantum Mechanical Computer simulations of complex biological systems • Time evolution of quantum systems of (tens of) thousands of atoms  large systems of ODE/PDE • Approximations: Hartree – Fock, DFT etc. • Hybrid quantum-classical description  high-performance computing • ab-initio quantumcomputations • Simulation: exploring the energy landscape • Computation of measurable macroparameters • QM/MM potential (packages AMBER, CHARMM, GROMACS, NAMD etc.)

32. Computer simulations of complex biological systems • Long-term perspective: computer-aided (in-silico) drug design • Two types of computations  many jobs over distributed clusters – Grid •  a single job on many (parallel) processors – supercomputer BlueGene/P • Research topics  human interferon-gamma binding to its extracellular receptors  inhibition of hIFN –g activity -hIFN –g artifically mutated forms - interaction with a third party – heparin & HS  virtual screening/docking  Interdisciplinary interinstitutional team: Center of Excellence “Supercomputer applications” • Lecture courses: L. Litov, P. Petkov, V. Kozhuharov /Atomic Physics Dept., University of Sofia (CERN - CMS Team) - Modeling of biological molecules - Programing in UNIX environment - 3 MSc students, 8 Bchl. students

33. Theoretical particle physics in Bulgaria Conclusions: 1. TH groups with good qualification and sound international collaboration. 2. Few PhD students and young scientists, specially in INRNE, better in the Sofia University. Matey Mateev, University of Sofia