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Full-Text Articles in Physics
Correlations Between The Strange Quark Condensate, Strange Quark Mass, And Kaon Pcac Relation, Derek Harnett, Jason N.E. Ho, Tom G. Steele
Correlations Between The Strange Quark Condensate, Strange Quark Mass, And Kaon Pcac Relation, Derek Harnett, Jason N.E. Ho, Tom G. Steele
Faculty Work Comprehensive List
Correlations between the strange quark mass, strange quark condensate ⟨¯ss⟩, and the kaon partially conserved axial current (PCAC) relation are developed. The key dimensionless and renormalization-group invariant quantities in these correlations are the ratio of the strange to nonstrange quark mass rm=ms/mq, the condensate ratio rc=⟨¯ss⟩/⟨¯qq⟩, and the kaon PCAC deviation parameter rp=−ms⟨¯ss+¯qq⟩/2f2Km2K. The correlations define a self-consistent trajectory in the {rm,rc,rp} parameter space constraining strange quark parameters that can be used to assess the compatibility of different predictions of these parameters. Combining the constraint with Particle Data Group (PDG) values of rm results in {rc,rp} constraint trajectories that are …
On-Shell Representations Of Two-Body Transition Amplitudes: Single External Current, Raúl A. Briceño, Andrew W. Jackura, Felipe G. Ortega-Gama, Keegan H. Sherman
On-Shell Representations Of Two-Body Transition Amplitudes: Single External Current, Raúl A. Briceño, Andrew W. Jackura, Felipe G. Ortega-Gama, Keegan H. Sherman
Physics Faculty Publications
This work explores scattering amplitudes that couple two-particle systems via a single external current insertion, 2 + J → 2. Such amplitudes can provide structural information about the excited QCD spectrum. We derive an exact analytic representation for these reactions. From these amplitudes, we show how to rigorously define resonance and bound-state form factors. Furthermore, we explore the consequences of the narrow-width limit of the amplitudes as well as the role of the Ward-Takahashi identity for conserved vector currents. These results hold for any number of two-body channels with no intrinsic spin, and a current with arbitrary Lorentz structure and …
Simultaneous Monte Carlo Analysis Of Parton Densities And Fragmentation Functions, Eric Moffat, W. Melnitchouk, Ted C. Rogers, N. Sato, Jefferson Lab Angular Momentum Collaboration
Simultaneous Monte Carlo Analysis Of Parton Densities And Fragmentation Functions, Eric Moffat, W. Melnitchouk, Ted C. Rogers, N. Sato, Jefferson Lab Angular Momentum Collaboration
Physics Faculty Publications
We perform a comprehensive new Monte Carlo analysis of high-energy lepton-lepton, lepton-hadron and hadron-hadron scattering data to simultaneously determine parton distribution functions (PDFs) in the proton and parton to hadron fragmentation functions (FFs). The analysis includes all available semi-inclusive deep-inelastic scattering and single-inclusive e+e− annihilation data for pions, kaons and unidentified charged hadrons, which allows the flavor dependence of the fragmentation functions to be constrained. Employing a new multistep fitting strategy and more flexible parametrizations for both PDFs and FFs, we assess the impact of different datasets on sea quark densities and confirm the previously observed suppression …
Drell-Yan Angular Lepton Distributions At Small X From Tmd Factorization, Ian Balitsky
Drell-Yan Angular Lepton Distributions At Small X From Tmd Factorization, Ian Balitsky
Physics Faculty Publications
The Drell-Yan process is studied in the framework of TMD factorization in the Sudakov region s » Q2 » q2⊥ corresponding to recent LHC experiments with Q2 of order of mass of Z-boson and transverse momentum of DY pair ∼ few tens GeV. The DY hadronic tensors are expressed in terms of quark and quark-gluon TMDs with 1Q2 and 1Nc2 accuracy. It is demonstrated that in the leading order in Nc the higher-twist quark-quark-gluon TMDs reduce to leading-twist TMDs due to QCD equation of motion. The resulting hadronic tensors depend on …
Unpolarized Gluon Distribution In The Nucleon From Lattice Quantum Chromodynamics, Tanjib Khan, Raza Sabbir Sufian, Joseph Karpie, Christopher J. Monahan, Colin Egerer, Bálint Joó, Wayne Morris, Kostas Orginos, Anatoly Radyushkin, David G. Richards, Eloy Romero, Savvas Zafeiropoulos, On Behalf Of The Hadstruc Collaboration
Unpolarized Gluon Distribution In The Nucleon From Lattice Quantum Chromodynamics, Tanjib Khan, Raza Sabbir Sufian, Joseph Karpie, Christopher J. Monahan, Colin Egerer, Bálint Joó, Wayne Morris, Kostas Orginos, Anatoly Radyushkin, David G. Richards, Eloy Romero, Savvas Zafeiropoulos, On Behalf Of The Hadstruc Collaboration
Physics Faculty Publications
In this study, we present a determination of the unpolarized gluon Ioffe-time distribution in the nucleon from a first principles lattice quantum chromodynamics calculation. We carry out the lattice calculation on a 323 × 64 ensemble with a pion mass of 358 MeV and lattice spacing of 0.094 fm. We construct the nucleon interpolating fields using the distillation technique, flow the gauge fields using the gradient flow, and solve the summed generalized eigenvalue problem to determine the gluonic matrix elements. Combining these techniques allows us to provide a statistically well-controlled Ioffe-time distribution and unpolarized gluon parton distribution function. We …
Energy-Dependent Π⁺Π⁺Π⁺ Scattering Amplitude From Qcd, Maxwell T. Hansen, Raúl A. Briceño, Robert G. Edwards, Christopher E. Thomas, David J. Wilson
Energy-Dependent Π⁺Π⁺Π⁺ Scattering Amplitude From Qcd, Maxwell T. Hansen, Raúl A. Briceño, Robert G. Edwards, Christopher E. Thomas, David J. Wilson
Physics Faculty Publications
Focusing on three-pion states with maximal isospin π⁺π⁺π⁺, we present the first nonperturbative determination of an energy-dependent three-hadron scattering amplitude from first-principles QCD. The calculation combines finite-volume three-hadron energies, extracted using numerical lattice QCD, with a relativistic finite-volume formalism, required to interpret the results. To fully implement the latter, we also solve integral equations that relate an intermediate three-body K matrix to the physical three-hadron scattering amplitude. The resulting amplitude shows rich analytic structure and a complicated dependence on the two-pion invariant masses, represented here via Dalitz-like plots of the scattering rate.
First Measurement Of Timeline Compton Scattering, P. Chatagnon, S. Niccolai, S. Stepanyan, M. J. Amaryan, C. E. Hyde, S. E. Kuhn, P. Pandey, Jiwan Poudel, Y. Prok, N. Zachariou, J. Zhang, Z. W. Zhao, Et Al., Clas Collaboration
First Measurement Of Timeline Compton Scattering, P. Chatagnon, S. Niccolai, S. Stepanyan, M. J. Amaryan, C. E. Hyde, S. E. Kuhn, P. Pandey, Jiwan Poudel, Y. Prok, N. Zachariou, J. Zhang, Z. W. Zhao, Et Al., Clas Collaboration
Physics Faculty Publications
We present the first measurement of the timelike Compton scattering process, 𝛾p →p′𝛾∗(𝛾∗→e+e−), obtained with the CLAS12 detector at Jefferson Lab. The photon beam polarization and the decay lepton angular asymmetries are reported in the range of timelike photon virtualities 2.25 < Q2 < 9 GeV2, squared momentum transferred 0.1 < −t < 0.8 GeV2, and average total center-of-mass energy squared s = 14.5 GeV2 . The photon beam polarization asymmetry, similar to the beam-spin asymmetry in deep virtual Compton scattering, is sensitive to the imaginary part of the Compton form factors and provides a …
P-Wave Nucleon-Pion Scattering Amplitude In The Δ(1232) Channel From Lattice Qcd, Giorgio Silvi, Srijit Paul, Constantia Alexandrou, Stefan Krieg, Luka Leskovec, Stefan Meinel, John Negele, Marcus Petschlies, Andrew Pochinsky, Gumaro Rendon, Sergey Syritsyn, Antonio Todaro
P-Wave Nucleon-Pion Scattering Amplitude In The Δ(1232) Channel From Lattice Qcd, Giorgio Silvi, Srijit Paul, Constantia Alexandrou, Stefan Krieg, Luka Leskovec, Stefan Meinel, John Negele, Marcus Petschlies, Andrew Pochinsky, Gumaro Rendon, Sergey Syritsyn, Antonio Todaro
Physics Faculty Publications
We determine the Δ(1232) resonance parameters using lattice QCD and the Lüscher method. The resonance occurs in elastic pion-nucleon scattering with JP = 3/2+ in the isospin I=3/2, P-wave channel. Our calculation is performed with Nf = 2+1 flavors of clover fermions on a lattice with L ≈ 2.8 fm. The pion and nucleon masses are mπ = 255.4 (1.6) MeV and mN = 1073(5) MeV, respectively, and the strong decay channel Δ → πN is found to be above the threshold. To thoroughly map out the energy dependence of the nucleon-pion …