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Nuclear Theory·nucl-th

Monday·February 27, 2017

8 papers—4 primary·4 cross-listed

All8Primary4Cross-lists4
  1. 05

    [Submitted on 21 Feb 2017] (cross-list from hep-ph)

    A toy model of elastic scattering of high energy protons

    I.M. Dremin🇷🇺

    The ratio of elastic to total proton cross sections is related to the darkness of the spatial profile of inelastic interactions by a single parameter in the framework of a simple analytical model. Their critical values at LHC energies are discussed. Two possible variants of their asymptotical behavior are described.

    Comments:
    11 p
    Subjects:
    High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Experiment (hep-ex); Nuclear Experiment (nucl-ex); Nuclear Theory (nucl-th)
    arXiv:
    1702.06304 [pdf]
    5 citations
  2. 06

    [Submitted on 23 Feb 2017] (cross-list from hep-ph)

    Dispersion relation for hadronic light-by-light scattering: two-pion contributions

    Gilberto Colangelo🇨🇭 · Martin Hoferichter🇺🇸 · Massimiliano Procura🇨🇭 · Peter Stoffer🇩🇪

    In this third paper of a series dedicated to a dispersive treatment of the hadronic light-by-light (HLbL) tensor, we derive a partial-wave formulation for two-pion intermediate states in the HLbL contribution to the anomalous magnetic moment of the muon , including a detailed discussion of the unitarity relation for arbitrary partial waves. We show that obtaining a final expression free from unphysical helicity partial waves is a subtle issue, which we thoroughly clarify. As a by-product, we obtain a set of sum rules that could be used to constrain future calculations of . We validate the formalism extensively using the pion-box contribution, defined by two-pion intermediate states with a pion-pole left-hand cut, and demonstrate how the full known result is reproduced when resumming the partial waves. Using dispersive fits to high-statistics data for the pion vector form factor, we provide an evaluation of the full pion box, . As an application of the partial-wave formalism, we present a first calculation of -rescattering effects in HLbL scattering, with helicity partial waves constructed dispersively using phase shifts derived from the inverse-amplitude method. In this way, the isospin- part of our calculation can be interpreted as the contribution of the to HLbL scattering in . We argue that the contribution due to charged-pion rescattering implements corrections related to the corresponding pion polarizability and show that these are moderate. Our final result for the sum of pion-box contribution and its -wave rescattering corrections reads .

    Comments:
    70 pages, 14 figures, Mathematica notebook with full expressions for the basis change included as supplementary material. Version accepted for publication in JHEP
    Subjects:
    High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Experiment (hep-ex); High Energy Physics — Lattice (hep-lat); Nuclear Theory (nucl-th)
    arXiv:
    1702.07347 [pdf]
    JHEP(2017)·555 citations
  3. 07

    [Submitted on 24 Feb 2017] (cross-list from cond-mat.quant-gas)

    Semisuper Efimov effect of two-dimensional bosons at a three-body resonance

    Yusuke Nishida

    Wave-particle duality in quantum mechanics allows for a halo bound state whose spatial extension far exceeds a range of the interaction potential. What is even more striking is that such quantum halos can be arbitrarily large on special occasions. The two examples known so far are the Efimov effect and the super Efimov effect, which predict that spatial extensions of higher excited states grow exponentially and double exponentially, respectively. Here, we establish yet another new class of arbitrarily large quantum halos formed by spinless bosons with short-range interactions in two dimensions. When the two-body interaction is absent but the three-body interaction is resonant, four bosons exhibit an infinite tower of bound states whose spatial extensions scale as for a large . The emergent scaling law is universal and is termed a semisuper Efimov effect, which together with the Efimov and super Efimov effects constitutes a trio of few-body universality classes allowing for arbitrarily large quantum halos.

    Comments:
    5 pages; published version
    Subjects:
    Quantum Gases (cond-mat.quant-gas); Nuclear Theory (nucl-th)
    arXiv:
    1702.07532 [pdf]
    PRL(2017)·20 citations
  4. 08

    [Submitted on 24 Feb 2017] (cross-list from hep-ph)

    Tensor-polarized structure function by convolution picture for deuteron

    W. Cosyn🇧🇪 · Yu-Bing Dong🇨🇳 · S. Kumano🇯🇵 · M. Sargsian🇺🇸

    There are polarized structure functions for the spin-1 deuteron. We calculated the leading-twist tensor structure function by using convolution description for the deuteron. We found large differences between our theoretical functions and HERMES experimental data on . Although higher-twist effects should be considered in obtaining experimental , it suggests a possible existence of new hadron physics mechanism for spin-1 hadrons. Furthermore, we found that there are significant distributions at large Bjorken . In future, an experimental measurement is planned at JLab for and there is a possibility of a proton-deuteron Drell-Yan experiment at Fermilab with the tensor-polarized deuteron, so that further theoretical studies are needed for clarifying the physics origin of tensor structure in terms of quark and gluon degrees of freedom.

    Comments:
    4 pages, 2 eps figures, 22nd International Spin Symposium (Spin-2016), University of Illinois, Champaign, Illinois, USA, September 25-30, 2016
    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:
    1702.07594 [pdf]
    1 citation

Affiliations

first authorsco-authorsvia INSPIRE