PaperPanorama
FAQ

Nuclear Theory·nucl-th

Thursday·March 16, 2017

17 papers—11 primary·6 cross-listed

All17Primary11Cross-lists6
  1. 12

    [Submitted on 10 Mar 2017] (cross-list from nucl-ex)

    Two-photon exchange in elastic electron-proton scattering

    A. Afanasev🇺🇸 · P. G. Blunden🇨🇦 · D. Hasell🇺🇸 · B. A. Raue🇺🇸

    We review recent theoretical and experimental progress on the role of two-photon exchange (TPE) in electron-proton scattering at low to moderate momentum transfers. We make a detailed comparison and analysis of the results of competing experiments on the ratio of e+p to e-p elastic scattering cross sections, and of the theoretical calculations describing them. A summary of the current experimental situation is provided, along with an outlook for future experiments.

    Subjects:
    Nuclear Experiment (nucl-ex); Nuclear Theory (nucl-th)
    arXiv:
    1703.03874 [pdf]
    PPNP(2017)·113 citations
  2. 13

    [Submitted on 13 Mar 2017] (cross-list from hep-ph)

    Peripheral transverse densities of the baryon octet from chiral effective field theory and dispersion analysis

    J. M. Alarcón🇩🇪 · A. N. Hiller Blin🇪🇸 · M. J. Vicente Vacas🇪🇸 · C. Weiss🇺🇸

    The baryon electromagnetic form factors are expressed in terms of two-dimensional densities describing the distribution of charge and magnetization in transverse space at fixed light-front time. We calculate the transverse densities of the spin-1/2 flavor-octet baryons at peripheral distances b = O(M_\pi^{-1}) using methods of relativistic chiral effective field theory (\chi EFT) and dispersion analysis. The densities are represented as dispersive integrals over the imaginary parts of the form factors in the timelike region (spectral functions). The isovector spectral functions on the two-pion cut t > 4 M_\pi^2 are calculated using relativistic \chi EFT including octet and decuplet baryons. The \chi EFT calculations are extended into the \rho meson mass region using an N/D method that incorporates the pion electromagnetic form factor data. The isoscalar spectral functions are modeled by vector meson poles. We compute the peripheral charge and magnetization densities in the octet baryon states, estimate the uncertainties, and determine the quark flavor decomposition. The approach can be extended to baryon form factors of other operators and the moments of generalized parton distributions.

    Comments:
    23 pages, 12 figures, 3 tables. Typos corrected and discussion about the anomalous thresholds added. Matches the journal version
    Subjects:
    High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Lattice (hep-lat); Nuclear Theory (nucl-th)
    arXiv:
    1703.04534 [pdf]
    NPA(2017)·27 citations
  3. 14

    [Submitted on 14 Mar 2017] (cross-list from hep-ph)

    Evolution Equations for Connected and Disconnected Sea Parton Distributions

    Keh-Fei Liu🇺🇸

    It has been revealed from the path-integral formulation of the hadronic tensor that there are connected sea and disconnected sea partons. The former is responsible for the Gottfried sum rule violation primarily and evolves the same way as the valence. Therefore, the DGLAP evolution equations can be extended to accommodate them separately. We discuss its consequences and implications vis-a-vis lattice calculations.

    Comments:
    Published in PRD, references added. arXiv admin note: text overlap with arXiv:1603.07352
    Subjects:
    High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Lattice (hep-lat); Nuclear Theory (nucl-th)
    arXiv:
    1703.04690 [pdf]
    PRD(2017)·27 citations
  4. 15

    [Submitted on 15 Mar 2017] (cross-list from hep-ph)

    Light vector correlator in medium: Wilson coefficients up to dimension 6 operators

    HyungJoo Kim🇰🇷 · Philipp Gubler🇰🇷 · Su Houng Lee🇰🇷

    As an improvement of the QCD sum rule method to study modifications of light vector mesons in nuclear matter and/or at finite temperature, we calculate the Wilson coefficients of all independent gluonic non-scalar operators up to dimension 6 in the operator product expansion (OPE) of the vector channel for light quarks. To obtain the gluon part of the light quark OPE from the heavy quark one, we also compute the heavy quark expansion of the relevant quark condensates. Together with the results for the quark operators that are already available in the literature, this completes the OPE of the vector channel in a hot or dense medium for operators up to dimension 6.

    Comments:
    6 pages, no figure
    Subjects:
    High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Experiment (hep-ex); High Energy Physics — Lattice (hep-lat); Nuclear Experiment (nucl-ex); Nuclear Theory (nucl-th)
    arXiv:
    1703.04848 [pdf]
    PLB(2017)·17 citations
  5. 16

    [Submitted on 15 Mar 2017] (cross-list from hep-ph)

    Coulomb effects in high-energy electroproduction by a heavy charged particles in an atomic field

    P. A. Krachkov🇷🇺 · A. I. Milstein🇷🇺

    The cross section of high-energy pair production by a heavy charged particle in the atomic field is investigated in detail. We take into account the interaction with the atomic field of pair and a heavy particle as well. The calculation is performed exactly in the parameters of the atomic field. It is shown that, in contrast to the commonly accepted point of view, the cross section differential with respect to the final momentum of a heavy particle is strongly affected by the interaction of a heavy particle with the atomic field. However, the cross section integrated over the final momentum of a heavy particle is independent of this interaction.

    Comments:
    10 pages, 4 figures
    Subjects:
    High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th); Atomic Physics (physics.atom-ph)
    arXiv:
    1703.04898 [pdf]
    PLB(2017)·5 citations
  6. 17

    [Submitted on 15 Mar 2017] (cross-list from hep-ph)

    On the implementation of NLO high energy factorization in single inclusive forward hadron production

    B. Ducloué🇫🇮 · T. Lappi🇫🇮 · Y. Zhu🇫🇮

    Single inclusive particle production cross sections in high energy hadron collisions at forward rapidity are an important benchmark process for the CGC picture of small x QCD. Recent calculations of this process have not led to a stable perturbative expansion for this quantity at high transverse momenta. We consider the quark channel production cross section using the new rapidity factorization procedure proposed by Iancu et al. We show that for fixed coupling one does indeed obtain a physically meaningful cross section which is positive and reduces in a controlled way to previous leading order calculations. We also consider a running coupling that depends on the transverse momentum of the produced particle. This gives a stable result which, however, is not fully consistent with previous leading order calculations that use a coordinate space running coupling.

    Comments:
    REVTeX, 11 pages, 6 figures
    Subjects:
    High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
    arXiv:
    1703.04962 [pdf]
    PRD(2017)·55 citations

Affiliations

first authorsco-authorsvia INSPIRE