Julia Velkovska

Last updated
Julia Apostolova Velkovska
Alma mater Sofia University
Stony Brook University
Scientific career
Institutions Brookhaven National Laboratory
Vanderbilt University
Thesis Quasi-fission reaction dynamics  (1997)

Julia Apostolova Velkovska is a Bulgarian-American high energy particle physicist who is the Cornelius Vanderbilt Professor of Physics at Vanderbilt University. Her research considers nuclear matter in the extreme conditions generated at the Relativistic Heavy Ion Collider. She hopes that this work will help to explain the mechanisms that underpin the strong force.

Contents

Early life and education

Velkovska was born in Bulgaria. She attended Sofia University, where she majored in physics. [1] After earning her bachelor's degree in 1988, Velkovska joined Stony Brook University for her doctoral research. [1] [2] She remained at Stony Brook for a short postdoctoral position, before moving to Brookhaven National Laboratory as an assistant scientist. [1]

Research

Velkovska's research considers high-energy physics and nuclear matter. Velkovska uses the extreme conditions of the Relativistic Heavy Ion Collider to study the mechanisms that underpin the strong force. The strong force is responsible for confining the quarks and gluons in hadrons (e.g. protons and neutrons). At the RHIC, nuclei collide at speeds approaching the speed of light, which forces protons and neutrons to melt into a soup of gluons and quarks. [3] She showed that in these extreme environments, matter exists in a novel phase, with an unexpected increase in the number of protons and anti-protons. The phase, the quark–gluon plasma, [4] [5] is expected to be the most hot and dense, and believed to have existed in the first microseconds of the universe. She has investigated how particles interact with the quark–gluon plasma as part of the Pioneering High Energy Nuclear Interaction eXperiment (PHENIX). [3] She investigated the collisions of protons, deuterons and Helium-3 nuclei travelling at nearly the speed of light with gold nuclei. [6] [7] After the identification of the quark–gluon plasma, [8] Velkovska worked on improving the detectors of the Relativistic Heavy Ion Collider. [9] The most surprising result was that this quark-gluon plasma behaved like a highly coordinated liquid, not a gas. [7] To see what happened at even higher energies, Velkovska studied the quark–gluon plasma at the Large Hadron Collider. [7] Velkovska was at CERN, participating in the CMS experiment, when the discovery of the Higgs boson was announced. [10] [11]

In 2018, Velkovska showed that these collisions result in small droplets of almost perfect fluid, i.e. a cohesive liquid that flows at zero viscosity, [12] that emerge in distinctive patterns, including ellipses and triangles. [6] Specifically, she found a correlation between the geometry of the collision and the patterns created, providing evidence for the formation of the quark–gluon plasma irrespective of the environmental conditions. [6] She has studied how these hydrodynamic flow patterns are impacted by the volume and time duration of the collision. [4]

Awards and honors

Selected publications

Related Research Articles

<span class="mw-page-title-main">Relativistic Heavy Ion Collider</span> Particle accelerator at Brookhaven National Laboratory in Upton, New York, USA

The Relativistic Heavy Ion Collider is the first and one of only two operating heavy-ion colliders, and the only spin-polarized proton collider ever built. Located at Brookhaven National Laboratory (BNL) in Upton, New York, and used by an international team of researchers, it is the only operating particle collider in the US. By using RHIC to collide ions traveling at relativistic speeds, physicists study the primordial form of matter that existed in the universe shortly after the Big Bang. By colliding spin-polarized protons, the spin structure of the proton is explored.

<span class="mw-page-title-main">High-energy nuclear physics</span> Intersection of nuclear physics and high-energy physics

High-energy nuclear physics studies the behavior of nuclear matter in energy regimes typical of high-energy physics. The primary focus of this field is the study of heavy-ion collisions, as compared to lighter atoms in other particle accelerators. At sufficient collision energies, these types of collisions are theorized to produce the quark–gluon plasma. In peripheral nuclear collisions at high energies one expects to obtain information on the electromagnetic production of leptons and mesons that are not accessible in electron–positron colliders due to their much smaller luminosities.

<span class="mw-page-title-main">STAR detector</span>

The STAR detector is one of the four experiments at the Relativistic Heavy Ion Collider (RHIC) in Brookhaven National Laboratory, United States.

Quark matter or QCD matter refers to any of a number of hypothetical phases of matter whose degrees of freedom include quarks and gluons, of which the prominent example is quark-gluon plasma. Several series of conferences in 2019, 2020, and 2021 were devoted to this topic.

<span class="mw-page-title-main">ALICE experiment</span>

ALICE is one of nine detector experiments at the Large Hadron Collider at CERN. The experiment is designed to study the conditions that are thought to have existed immediately after the Big Bang by measuring the properties of quark-gluon plasma.

In theoretical physics, the anti-de Sitter/quantum chromodynamics correspondence is a goal to describe quantum chromodynamics (QCD) in terms of a dual gravitational theory, following the principles of the AdS/CFT correspondence in a setup where the quantum field theory is not a conformal field theory.

Color-glass condensate (CGC) is a type of matter theorized to exist in atomic nuclei when they collide at near the speed of light. During such collision, one is sensitive to the gluons that have very small momenta, or more precisely a very small Bjorken scaling variable. The small momenta gluons dominate the description of the collision because their density is very large. This is because a high-momentum gluon is likely to split into smaller momentum gluons. When the gluon density becomes large enough, gluon-gluon recombination puts a limit on how large the gluon density can be. When gluon recombination balances gluon splitting, the density of gluons saturate, producing new and universal properties of hadronic matter. This state of saturated gluon matter is called the color-glass condensate.

<span class="mw-page-title-main">Quark–gluon plasma</span> Phase of quantum chromodynamics (QCD)

Quark–gluon plasma is an interacting localized assembly of quarks and gluons at thermal and chemical (abundance) equilibrium. The word plasma signals that free color charges are allowed. In a 1987 summary, Léon Van Hove pointed out the equivalence of the three terms: quark gluon plasma, quark matter and a new state of matter. Since the temperature is above the Hagedorn temperature—and thus above the scale of light u,d-quark mass—the pressure exhibits the relativistic Stefan-Boltzmann format governed by temperature to the fourth power and many practically massless quark and gluon constituents. It can be said that QGP emerges to be the new phase of strongly interacting matter which manifests its physical properties in terms of nearly free dynamics of practically massless gluons and quarks. Both quarks and gluons must be present in conditions near chemical (yield) equilibrium with their colour charge open for a new state of matter to be referred to as QGP.

In high-energy nuclear physics, strangeness production in relativistic heavy-ion collisions is a signature and diagnostic tool of quark–gluon plasma (QGP) formation and properties. Unlike up and down quarks, from which everyday matter is made, heavier quark flavors such as strange and charm typically approach chemical equilibrium in a dynamic evolution process. QGP is an interacting localized assembly of quarks and gluons at thermal (kinetic) and not necessarily chemical (abundance) equilibrium. The word plasma signals that color charged particles are able to move in the volume occupied by the plasma. The abundance of strange quarks is formed in pair-production processes in collisions between constituents of the plasma, creating the chemical abundance equilibrium. The dominant mechanism of production involves gluons only present when matter has become a quark–gluon plasma. When quark–gluon plasma disassembles into hadrons in a breakup process, the high availability of strange antiquarks helps to produce antimatter containing multiple strange quarks, which is otherwise rarely made. Similar considerations are at present made for the heavier charm flavor, which is made at the beginning of the collision process in the first interactions and is only abundant in the high-energy environments of CERN's Large Hadron Collider.

<span class="mw-page-title-main">John Harris (physicist)</span> American experimental physicist

John William Harris is an American experimental high energy nuclear physicist and D. Allan Bromley Professor of Physics at Yale University. His research interests are focused on understanding high energy density QCD and the quark–gluon plasma created in relativistic collisions of heavy ions. Dr. Harris collaborated on the original proposal to initiate a high energy heavy ion program at CERN in Geneva, Switzerland, has been actively involved in the CERN heavy ion program and was the founding spokesperson for the STAR collaboration at RHIC at Brookhaven National Laboratory in the U.S.

The PHENIX detector is the largest of the four experiments that have taken data at the Relativistic Heavy Ion Collider (RHIC) in Brookhaven National Laboratory, United States.

Sergei Voloshin is a Russian-American experimental high-energy nuclear physicist and Professor of Physics at Wayne State University. He is best known for his work on event-by-event physics in heavy ion collisions.

An electron–ion collider (EIC) is a type of particle accelerator collider designed to collide spin-polarized beams of electrons and ions, in order to study the properties of nuclear matter in detail via deep inelastic scattering. In 2012, a whitepaper was published, proposing the developing and building of an EIC accelerator, and in 2015, the Department of Energy Nuclear Science Advisory Committee (NSAC) named the construction of an electron–ion collider one of the top priorities for the near future in nuclear physics in the United States.

Helen Louise Caines is a Professor of Physics at Yale University. She studies the quark–gluon plasma and is the co-spokesperson for the STAR experiment.

Olga Evdokimov is a Russian born professor of physics at the University of Illinois, Chicago (UIC). She is a High Energy Nuclear Physicist, who currently collaborates on two international experiments; the Solenoidal Tracker At RHIC (STAR) experiment at the Relativistic Heavy Ion Collider (RHIC), Brookhaven National Laboratory, Upton, New York and the Compact Muon Solenoid (CMS) experiment at the LHC, CERN, Geneva, Switzerland.

Claude Pruneau is a Canadian-American experimental high-energy nuclear physicist. He is a professor of physics at Wayne State University and the author of several books. He is best known for his work on particle correlation measurements in heavy ion collisions at the Relativistic Heavy Ion Collider and the Large Hadron Collider.

Saskia Mioduszewski is a nuclear physicist and professor at Texas A&M University.

Reinhard Stock is a German experimental physicist, specializing in heavy-ion physics.

Larry D. McLerran is an American physicist and an academic. He is a professor of physics at the University of Washington.

Dipanwita Dutta is an Indian physicist and professor known for her contributions to the field of High Energy Nuclear Physics, particularly in the study of Quark-Gluon Plasma (QGP). She currently serves as the Associate Dean at the Homi Bhabha National Institute (HBNI) and as a Scientific Officer at the Bhabha Atomic Research Centre (BARC). As of September 2024, she holds the record of being highly cited researcher in India with an h-index of 244 and more than 286,000 citations.

References

  1. 1 2 3 "People". Department of Physics and Astronomy. Retrieved 2022-01-03.
  2. ↑ Velkovska, Julia Apostolova (1997). Quasi-fission reaction dynamics (Thesis). OCLC   40391842.
  3. 1 2 "Vanderbilt students selected by the Department of Energy's Office of Science Graduate Student Research Program". Vanderbilt University. June 1, 2021. Retrieved 2022-01-03.
  4. 1 2 "Primordial cosmic soup easier to create than previously thought". Vanderbilt University. October 3, 2017. Retrieved 2022-01-03.
  5. ↑ "Scientists discover early universe behaved like a liquid after Big Bang". Vanderbilt University. April 21, 2005. Retrieved 2022-01-03.
  6. 1 2 3 "Vanderbilt physicists help find compelling evidence for small drops of perfect fluid". Vanderbilt University. December 10, 2018. Retrieved 2022-01-03.
  7. 1 2 3 "World's largest atom smashers create world's smallest droplets". Vanderbilt University. October 2, 2015. Retrieved 2022-01-03.
  8. ↑ "Physicists Measure Material Hotter Than the Sun". Vanderbilt University. April 7, 2010. Retrieved 2022-01-03.
  9. 1 2 3 "Sloan Foundation awards Vanderbilt physicist for 'exceptional promise'". Vanderbilt University. March 12, 2007. Retrieved 2022-01-03.
  10. ↑ "Discovery of new sub-atomic particle a major leap forward". Vanderbilt University. July 6, 2012. Retrieved 2022-01-03.
  11. ↑ Chatrchyan, S.; Khachatryan, V.; Sirunyan, A.M.; Tumasyan, A.; Adam, W.; Aguilo, E.; Bergauer, T.; Dragicevic, M.; Erö, J.; Fabjan, C.; Friedl, M.; Frühwirth, R.; Ghete, V.M.; Hammer, J.; Hoch, M. (2012). "Observation of a new boson at a mass of 125 GeV with the CMS experiment at the LHC". Physics Letters B. 716 (1): 30–61. arXiv: 1207.7235 . Bibcode:2012PhLB..716...30C. doi:10.1016/j.physletb.2012.08.021.
  12. ↑ "Fermilab Today: The consistency of quark soup". Vanderbilt University. May 16, 2012. Retrieved 2022-01-03.
  13. ↑ "Three junior Vanderbilt faculty win competitive federal grants to support new talent". Vanderbilt University. September 21, 2004. Retrieved 2022-01-03.
  14. ↑ "Julia Velkovska". www.nasonline.org. Retrieved 2022-01-03.
  15. ↑ "APS Fellow Archive". www.aps.org. Retrieved 2022-01-03.
  16. ↑ "Greene and Velkovska named fellows of American Physical Society". Vanderbilt University. January 14, 2015. Retrieved 2022-01-03.
  17. ↑ "Chancellor presents top prizes, including new award for excellence in equity, diversity and inclusion research, at fall assembly". Vanderbilt University. August 25, 2016. Retrieved 2022-01-03.
  18. ↑ "Vanderbilt honors 29 distinguished faculty with endowed chairs". Vanderbilt University. November 11, 2020. Retrieved 2022-01-03.
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