A5056236658- Particle physics theoretical and experimental studies
- Quantum Chromodynamics and Particle Interactions
- High-Energy Particle Collisions Research
- Black Holes and Theoretical Physics
- Cosmology and Gravitation Theories
- Cold Atom Physics and Bose-Einstein Condensates
- Atomic and Subatomic Physics Research
- Dark Matter and Cosmic Phenomena
- Particle Detector Development and Performance
- Computational Physics and Python Applications
- Atomic and Molecular Physics
- Quantum, superfluid, helium dynamics
- Quantum Mechanics and Applications
- Particle Accelerators and Free-Electron Lasers
- Quantum and Classical Electrodynamics
- Nuclear physics research studies
- Superconducting Materials and Applications
- Particle accelerators and beam dynamics
- Quantum Information and Cryptography
- Reservoir Engineering and Simulation Methods
- Muon and positron interactions and applications
- Relativity and Gravitational Theory
- Neutrino Physics Research
- Advanced X-ray Imaging Techniques
- Noncommutative and Quantum Gravity Theories
Stanford University
2016-2025
SLAC National Accelerator Laboratory
2016-2025
Thomas Jefferson National Accelerator Facility
2003-2023
Nanjing University
2023
Stanford Synchrotron Radiation Lightsource
2002-2020
Joint Institute for Nuclear Research
2020
Lomonosov Moscow State University
2009-2020
Comenius University Bratislava
2020
University of Washington
1995-2020
Universidade de São Paulo
2018-2019
We present a systematic analysis in perturbative quantum chromodynamics (QCD) of large-momentum-transfer exclusive processes. Predictions are given for the scaling behavior, angular dependence, helicity structure, and normalization elastic inelastic form factors large-angle scattering amplitudes hadrons photons. prove that these reactions dominated by quark gluon subprocesses at short distances, thus dimensional-counting rules power-law falloff with momentum transfer rigorous predictions...
We discuss the light-cone quantization of gauge theories as a calculational tool for representing hadrons QCD bound-states relativistic quarks and gluons, also novel method simulating quantum field theory on computer. The Fock state expansion wavefunctions provides precise definition parton model general calculus hadronic matrix elements. present several new applications methods, including calculations exclusive weak decays heavy hadrons, intrinsic heavy-quark contributions to structure...
The application of simple dimensional counting to bound states pointlike particles enables us derive scaling laws for the asymptotic energy dependence electromagnetic and hadronic scattering at fixed c.m. angle which only depend on number constituent fields hadrons. Assuming quark constituents, some $s\ensuremath{\rightarrow}\ensuremath{\infty}$, fixed-$\frac{t}{s}$ predictions are...
We present a new method for resolving the scheme-scale ambiguity that has plagued perturbative analyses in quantum chromodynamics (QCD) and other gauge theories. For Abelian theories reduces to standard criterion only vacuum-polarization insertions contribute effective coupling constant. Given scheme, our procedure automatically determines coupling-constant scale appropriate particular process. This leads convergence of expansions QCD. examine number well known reactions QCD, find...
The physics programme and the design are described of a new collider for particle nuclear physics, Large Hadron Electron Collider (LHeC), in which newly built electron beam 60 GeV, up to possibly 140 energy collides with intense hadron beams LHC. Compared HERA, kinematic range covered is extended by factor twenty negative four-momentum squared, $Q^2$, inverse Bjorken $x$, while luminosity $10^{33}$ cm$^{-2}$s$^{-1}$ LHeC projected exceed integrated HERA two orders magnitude. devoted an...
Experimental constraints on possible lepton and quark substructure are analyzed expressed in terms of a general formalism for describing composite particles their constituents. In particular, the measured gyromagnetic ratios may very severely restrict internal structure light leptons (electrons muons) some models. Simple expressions hadronic $g$ values electromagnetic radii given quarkgluon infinite-momentum-frame wave function. The contribution to anomalous moment fermion due is shown...
Dimensional scaling laws are developed as an approach to understanding the energy dependence of high-energy scattering processes at fixed center-of-mass angle. Given a reasonable assumption on short-distance behavior bound states, and absence internal mass scale, we show that large $s$ $t$, $\frac{d\ensuremath{\sigma}}{\mathrm{dt}}(AB\ensuremath{\rightarrow}CD)\ensuremath{\sim}{s}^{\ensuremath{-}n+2}f(\frac{t}{s})$; $n$ is total number fields in $A$, $B$, $C$, $D$ which carry finite fraction...
We show how the string amplitude $\Phi(z)$ defined on fifth dimension in AdS$_5$ space can be precisely mapped to light-front wavefunctions of hadrons physical spacetime. find an exact correspondence between holographic variable $z$ and impact $\zeta$, which represents measure transverse separation constituents within hadrons. In addition, we derive effective four dimensional Schr\"odinger equations for bound states massless quarks gluons exactly reproduce AdS/CFT results give a realistic...
The AdS/CFT correspondence between string theory in AdS space and conformal field theories physical space-time leads to an analytic, semiclassical model for strongly-coupled QCD which has scale invariance dimensional counting at short distances color confinement large distances. also provides insights into the inherently nonperturbative aspects of such as orbital radial spectra hadrons form hadronic wavefunctions. In particular, we show that there is exact fifth-dimensional coordinate...
We demonstrate that the distinctive features of forward differential cross section diffractive leptoproduction a vector meson can be legitimately calculated in perturbative QCD terms light-cone qq\ifmmode\bar\else\textasciimacron\fi{} wave function and gluon distribution target. In particular, we calculate ${\mathit{Q}}^{2}$ nuclear dependence mesons estimate section. The production longitudinally polarized by virtual photons is predicted to dominant component, yielding behaving as...
We compute the spectrum of light hadrons in a holographic dual QCD defined on ${\mathrm{AdS}}_{5}\ifmmode\times\else\texttimes\fi{}{S}^{5}$ which has conformal behavior at short distances and confinement large interquark separation. Specific are identified by correspondence string modes with dimension interpolating operator hadron's valence Fock state. Higher orbital excitations matched quanta to fluctuations about AdS background. Since only one parameter, scale...
The form factors of baryons at large momentum transfer are computed in quantum chromodynamics (QCD) to leading order ${\ensuremath{\alpha}}_{s}({Q}^{2})$ and $\frac{{m}^{2}}{{Q}^{2}}$. Asymptotically, we predict ${Q}^{4}{{G}_{M}}^{p}({Q}^{2})\ensuremath{\rightarrow}C{[{\ensuremath{\alpha}}_{s}({Q}^{2})]}^{2+\frac{4}{3\ensuremath{\beta}}}$ $\frac{{{G}_{M}}^{n}}{{{G}_{M}}^{p}}\ensuremath{\rightarrow}\ensuremath{-}\frac{2}{3}$, where...
Detailed leading-order quantum-chromodynamics (QCD) predictions are given for the scaling, angular, and helicity dependence of reactions $\ensuremath{\gamma}\ensuremath{\gamma}\ensuremath{\rightarrow}M\overline{M}$ ($M=\ensuremath{\pi},K,\ensuremath{\rho}$, etc.) at large momentum transfer. In addition to providing a basic test QCD short distances, measurements can be used determine process-independent meson distribution amplitudes ${\ensuremath{\varphi}}_{M}(x,Q)$. Other related two-photon...
By quantizing a realistic field theory in one space and time dimension at equal light-cone \ensuremath{\tau}=t+x/c rather than t, can find exact solutions to the bound-state problem. The method is nonperturbative amounts diagonalization of finite matrices Fock space. It applies also for non-Abelian gauge 1+1 dimensions, but demonstrated here simple case fermions interacting with scalar fields. success quantization rests on existence new dynamical quantum number, harmonic resolution K, which...
We show how the helicity and angular dependence of large-momentum-transfer exclusive processes can be used to test gluon spin other basic elements perturbative quantum chromodynamics (QCD). Unlike inclusive reactions, these isolate QCD hard-scattering subprocesses in situations where helicities all interacting quarks are controlled. The predictions summarized terms a general selection rule which states that total hadron is conserved...
Starting from the Hamiltonian equation of motion in QCD, we identify an invariant light-front coordinate zeta which allows separation dynamics quark and gluon binding kinematics constituent spin internal orbital angular momentum. The result is a single-variable Schrödinger for QCD determines eigenspectrum wave functions hadrons general This equivalent to equations describe propagation spin-J modes on anti-de Sitter (AdS) space.
We report on the calculation of cross sections for production positive-charge-conjugation states such as ${\ensuremath{\pi}}^{0}$, $\ensuremath{\eta}$, ${e}^{+}{e}^{\ensuremath{-}}$, ${\ensuremath{\mu}}^{+}{\ensuremath{\mu}}^{\ensuremath{-}}$, and ${\ensuremath{\pi}}^{+}{\ensuremath{\pi}}^{\ensuremath{-}}$ by a two-photon mechanism in ${e}^{\ensuremath{-}}{e}^{+}$ ${e}^{\ensuremath{-}}{e}^{\ensuremath{-}}$ collisions. give precise relationship process $e+e\ensuremath{\rightarrow}e+e+X (X...