Abstract
From the approximate chiral symmetry of QCD, it is known that the pion loops in chiral perturbation theory play a vital role in understanding the nucleon’s long-range structure. We demonstrate the equivalence of the light-front, equal-time and covariant formulations for the interactions of nucleons with pions in chiral perturbation theory. In particular, we discuss the self-energy Σ of a nucleon dressed by pion loops with the pseudovector πNN coupling. It is shown that the leading nonanalytic behavior of Σ is equivalent whichever formulations are used for the derivation. We also discuss the relation between the mass shift and the wavefunction renormalization as well as the difference between the pseudovector and pseudoscalar theories.
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References
Thomas A.W.: Chiral symmetry and the bag model: a new starting point for nuclear physics. Adv. Nucl. Phys. 13, 1–137 (1984)
Ji X.: Generalized parton distributions. Ann. Rev. Nucl. Part. Sci. 54, 413–450 (2004)
Belitsky A.V., Radyushkin A.V.: Unraveling hadron structure with generalized parton distributions. Phys. Rept. 418, 1–387 (2005)
Thomas A.W., Melnitchouk W., Steffens F.M.: Dynamical symmetry breaking in the sea of the nucleon. Phys. Rev. Lett. 85, 2892–2894 (2000)
Detmold W., Melnitchouk W., Negele J.W., Renner D.B., Thomas A.W.: Chiral extrapolation of lattice moments of proton quark distributions. Phys. Rev. Lett. 87, 172001 (2001)
Chen J.W., Ji X.: Is the Sullivan process compatible with QCD chiral dynamics?. Phys. Lett. B 523, 107–110 (2001)
Arndt D., Savage M.J.: Chiral corrections to matrix elements of twist-2 operators. Nucl. Phys. A 697, 429–439 (2002)
Ji C.-R., Melnitchouk W., Thomas A.W.: Equivalence of pion loops in equal-time and light-front dynamics. Phys. Rev. D 80, 054018 (2009)
Dirac P.A.M.: Forms of relativistic dynamics. Rev. Mod. Phys. 21, 392–399 (1949)
Ji, C.-R.: Zero-mode Caveats in transition form factors, pp. 86–89. IPPP/03/71, Durham (2003)
Ji C.-R.: Perspectives of light-front dynamics in few-body systems. Nucl. Phys. A 737, 255–259 (2004)
Ji C.-R., Bakker B.L.G.: Vector anomaly and practicality of light-front dynamics. Few-Body Syst. 36, 137–144 (2005)
Ji C.-R., Rey S.-J.: Light front view of the axial anomaly. Phys. Rev. D 53, 5815–5820 (1996)
Bakker B.L.G., Ji C.-R.: Manifestations of the vector anomaly in covariant and light-front calculations of the anomalous magnetic moment of W+- bosons. Phys. Rev. D 71, 053005 (2005)
Bakker B.L.G., DeWitt M.A., Ji C.-R., Mishchenko Y.: Restoring the equivalence between the light-front and manifestly covariant formalisms. Phys. Rev. D 72, 076005 (2005)
Misra A., Warawdekar S.: Equivalence of covariant and light front QED at one loop level. Phys. Rev. D 71, 125011 (2005)
Bernard V., Kaiser N., Meissner U.G.: Chiral dynamics in nucleons and nuclei. Int. J. Mod. Phys. E 4, 193–346 (1995)
Ericson T., Weise W.: Pions and Nuclei. Clarendon Press, Oxford (1988)
Leinweber D.B., Thomas A.W., Tsushima K., Wright S.V.: Baryon masses from lattice QCD: beyond the perturbative chiral regime. Phys. Rev. D 61, 074502 (2000)
Bjorken J.D., Drell S.: Relativistic quantum fields. McGraw Hill, New York (1965)
Burkardt, M., Ji, C.-R., Melnitchouk, W., Thomas, A.W. (in preparation)
Drell S.D., Levy D.J., Yan T.M.: Theory of deep-inelastic lepton–nucleon scattering and lepton pair annihilation processes. II. Deep-inelastic electron scattering. Phys. Rev. D 1, 1035 (1970)
Chen, J.W., Ji, X.: Constructing parton convolution in effective field theory. Phys. Rev. Lett. 87, 152002 (2001) [Erratum-ibid. 88, 249901 (2002)]
Chen J.W., Ji X.: Large N(c) quark distributions in the delta and chiral logarithms in quark distributions of the nucleon. Phys. Lett. B 523, 73–78 (2001)
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Ji, CR. Pion Loops in Chiral Perturbation Theory and Light-Front Dynamics. Few-Body Syst 52, 421–426 (2012). https://doi.org/10.1007/s00601-011-0270-5
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DOI: https://doi.org/10.1007/s00601-011-0270-5