Scientific Research
Research Field
Research
My recent research focuses on highenergy theory, in particular, the nonperturbative QCD, hadron structure and computational physics. You can check out my published work, recent talks and developements.
Here are some information for beginners.
Physical background
The quantum chromodynamics (QCD) describes the interactions between quarks and gluons. It is strong coupling at lowenegy scale, which leads to remarkable nonperturbative physics, e.g. confinement and chiral symmetry breaking.
The nonperturbative calculation of QCD is one of the most formidable challenges in physics. It is also the key to answer some of the fundamental questions in Nuclear Physics, such as how the quarks and gluons are binding together, and how the nuclear forces are formed to bind the nucleons. The nonperturbative properties of hadrons is also the focii of some present and forthcoming highenergy experiments, such as the 12 GeV upgrade of CEBAF at Jefferson Lab, the electronion collider (eRHIC) at Brookheaven National Lab, both in United States, the LHCb & ALICE experiments at CERN in Europe, the electron ion collider of China (EicC) at HIAF in Huizhou, the BESIII experiment at BEPC in Beijing, as well as the Belle II experiment at KEK in Japan.
The Hamiltonian formalism is one of the fundamental theoretical frameworks of quantum theory and is widely used in physics. This formulation is nonperturbative and provides access to information at the amplitude level as well as the realtime evolution information, through the Schrödinger equation. The Hamiltonian formalism has been a standard tool in addressing strong coupling quantum manybody systems, such as the nuclei, atoms as well as the molecules. The lightfront dynamics, proposed by Paul Dirac, exploits dynamical evolution in the lightfront time. It brings several dramatic simplification to the relativistic dynamics. Thus the lightfront Hamiltonian formalism is a natural framework for describing hadrons as relativistic bound states. It is nonperturbative and provides direct access to the hadronic observables in Richard Feynman's parton picture, one of the modern pillars in highenergy scattering experiments.
Recent advances in computational sciences (including quantum computing) provide opportunities to compute the nonperturbative solutions of QCD from first principles. Of course, the unique challenges posed by QCD require significant efforts in both the computational front and the physical front, separately and joinly, which are what I try to address in my research.
Basis lightfront quantization
Basis lightfront quantization (BLFQ) is a numerical framework to solve lightfront QCD as quantum manybody problems. It is inspired by the recent development in ab initio nuclear structure calculations. BLFQ is designed to preserve all kinematically symmetries of the Hamiltonian and exploits the sparse matrix technologies to accelerate the quantum manybody calculations.
The starting point of BLFQ is an effective Hamiltonian defined in a designated model space. To obtain the effective Hamiltonian, one can start from the canonical QCD Hamiltonian at highenergy scales and obtain the boundstate effective Hamiltonian from the Hamiltonian renormalization group method, as is demonstrated in quantum electrodynamics (QED).
Alternatively, one can employ phenomenological effective interactions at lowenergy scale. We proposed a model based on confining interactions from lightfront holography and a onegluon exchange interaction. We use the model to investigate the meson spectroscopy. The obtained lightfront wave functions can be used to access hadronic observables and parton distributions.
Fock sector dependent renormalization
Nonperturbative renormalization is one of the fundamental challenges in quantum field theory (QFT) at strong coupling. The challenge is amplified in the Hamiltonian formulation of QFT, as explicit covariance is lost there. Remarkably, cluster decomposition still holds in lightfront dynamics, even though all diagrams are strictly lightfront time ordered. This fact is exploited in the Fock sector dependent renormalization (FSDR) to enable nonperturbative renormalization in lightfront field theories with systematic Fock sector truncations. FSDR has been successfully applied to (3+1)d QFTs, including scalar Yukawa theory, Yukawa theory and QED, with exact cancellations of ultraviolet divergences. The scalar Yukawa theory in particular is computed up to a Fock sector of 3 dressing particles and a good Fock sector convergence is achieved for form factors.
Other interests
QCD at finite temperature
Quantum manybody theory & quantum computing
Lowenergy nuclear physics
Advanced algorithms in computational physics
Foundations of quantum mechanics
Paper Publications
+more

Yang Li, James Vary, Stress inside the pion in holographic lightfront QCD, arXiv:2312.02543 [hepth].

Yang Li, and J.P. Vary, Lightfront holography with chiral symmetry breaking, Phys. Lett. B 825 (2022) 136860; [arXiv:2103.09993 [hepph]].

S. Leitão, Yang Li, P. Maris, M.T. Peña, A. Stadler, J.P. Vary, E.P. Biernat, Comparison of two Minkowskispace approaches to heavy quarkonia, Eur. J. Phys. C, 66, 696 (2017); [arXiv:1705.06178 [hepph]].

M. Li, X. Zhao, P. Maris, G. Chen, Yang Li, K. Tuchin and J.P. Vary, Ultrarelativistic quarknucleus scattering in a lightfront Hamiltonian approach, Phys. Rev. D 101, no.7, 076016 (2020); [arXiv:2002.09757 [nuclth]]..

Yang Li, Kirill Tuchin, Electrodynamics of dual superconducting chiral medium, Phys. Lett. B 776, 270 (2018); [arXiv:1708.08536 [hepph]].

Yang Li, V.A. Karmanov, P. Maris and J.P. Vary, Ab Initio Approach to the NonPerturbative Scalar Yukawa Model, Phys. Lett. B 748, 278 (2015); [arXiv:1504.05233 [nuclth]].
Patents
Published Books
Research Projects
Talks
Conferences
Light front holography with chiral symmetry breaking: a quest for a semiclassical approximation to QCD. 轻味矢量介子理论与实验联合研讨会. July 1923, 2021, Xining, Qinghai. Invited Talk.
Basis LightFront Quantization Approach to meson spectrum and structures. ILCAC Wednesday Seminars. March 3, 2021 (online). Invited Talk.
Quarkonium as a relativistic bound state on the light cone. 2017 Fall Meeting of the American Physical Society, Dvision of Nuclear Physics (DNP 2017), Oct. 2528, 2017, Pittsburgh, Pennsylvannia, U.S. Invited Talk.
Basis LightFront Quantization Approach to Heavy Quarkonium. Baryons 2016, May 1620, 2016, Tallahassee, Florida, U.S.
Heavy Quarkonia on the Light Front. APS April Meeting 2016, April 1619, 2016, Salt Lake City, Utah, U.S.
Heavy quarkonium in a lightfront holographic basis. Light Cone 2016 (LC2016), Sep. 58, 2016, Lisbon, Portugal. Invited Talk.
Quarkonium in a Holographic Basis. 2015 Fall Meeting of the APS Division of Nuclear Physics (DNP2015), Oct. 2831, 2015, Santa Fe, New Mexico, U.S.
Quarkonium in a holographic basis. XXVIII Midwest Theory GetTogether (MWTGT), Sep. 1112, 2015, Argonne National Lab, Illinois, U.S.
Scalar Yukawa Model on the Light Front: ab initio approach to quantum field theory. APS April meeting 2015, Apr. 1114, Baltimore, Maryland, U.S.
NonPerturbative Calculation of Scalar Yukawa Theory in LightFront Dynamics. Light Cone 2014 (LC2014), May 2630, 2014, Raleigh, North Carolina, U.S. Invited Talk.
Convergence of the Fock Sector Expansion in LightFront Hamiltonian Field Theory. XXVII Midwest Theory GetTogether (MWTGT), Sep. 56, 2014, Argonne National Lab, Illinois, U.S.
Introduction to basis lightfront quantization approach to QCD bound state problem. International Conference on Nuclear Theory in the Supercomputing Era (NTSE 2013), May 1317, 2013, Ames, Iowa, U.S. Invited Talk.
A Novel Basis for LightFront Quantum Field Theory. XXV Midwest Theory GetTogether (MWTGT), Sep. 78, 2012, Argonne National Lab, Illinois, U.S.
Calculation of BLFQ Hamiltonian Matrix Elements. XXIV Midwest Theory GetTogether (MWTGT), Sep. 2324, 2011, Argonne National Lab, Illinois, U.S.
Seminars
Light front holography with chiral symmetry breaking: from semiclassical approximation to ab initio QCD. Particle and Nuclear Physics Seminar, June 4, 2021, University of Science and Technology of China, Hefei.
物质基本结构与超级计算机. Guest Lecture on the Undergraduate Research Program, Nov. 20, 2020, University of Chinese Academy of Sciences, Beijing.
Electrodynamics of dual superconducting medium. Institute of Modern Physics, Chinese Academy of Sciences, January 4, 2018, Lanzhou, China.
Quarkonium on the light front. Theory Center Cake Seminar, November 8, 2017, Jefferson Lab, Virginia, U.S.
NonPerturbative Quantum Field Theories on the Light Front. Guest Lectures given at PHYS 625: Physics of Strong Interactions, Iowa State University, August 22 & 24, 2017, Ames, Iowa, U.S.


Yang Li
ZipCode:52c9ab2533ce514a1a885e74a1342fc6b73de36e785baa3e07cdd5a7b1234d742197243126974fa2d7f664ed7d2e5a67cbd4c522a53cdf7d80ceb39928c7039b528bb15c9ba80a39ab0e149f9b2e9c09f59aa8081c897dd70ff6d191397c82f7cd3a3befe211634c0cd859c7c66d7460ad307de7bcbf3431ed677f37d4784f77
PostalAddress:8177bcbe02cd9866ef724065c5674779d9ed4ec553663f979ff046b821be30665d755d070cf596325287bcd4d9a674e0a96ddb8e91137d60fc46690653f24d615d0d1ccec341f198f1b0e29de7ef856ff5066272b5eba84d9e72b029edd10ea36622a2aad4ebb10c89e6595e19ba0692a131fa14b28233ae2c4a714308600178
Email:79d2c1f28b9643ea8533eb0af0dca5f170e6d7883dbea4bbcd603def76d83d0e593eaffd7b4c88ec73a4e126f511a505c2ff088827bc91450aede9192d15708036389a507496d6becad67291427ee9de056baa585f534116216096724bd219df5bbd398d7c36a1732f9f97914732d3a29462dc15212599d0ac8ad5b482ee1f35
