Rigorous constraints on the matrix elements of the energy–momentum tensor

Journal Article · Wed Nov 01 00:00:00 EDT 2017 · Physics Letters B

DOI:https://doi.org/10.1016/j.physletb.2017.09.050· OSTI ID:1393987

Lowdon, Peter ; Chiu, Kelly Yu-Ju; Brodsky, Stanley J.

The structure of the matrix elements of the energy–momentum tensor play an important role in determining the properties of the form factors A(q²), B(q²) and C(q²) which appear in the Lorentz covariant decomposition of the matrix elements. In this paper we apply a rigorous frame-independent distributional-matching approach to the matrix elements of the Poincaré generators in order to derive constraints on these form factors as q → 0. In contrast to the literature, we explicitly demonstrate that the vanishing of the anomalous gravitomagnetic moment B(0) and the condition A(0) = 1 are independent of one another, and that these constraints are not related to the specific properties or conservation of the individual Poincaré generators themselves, but are in fact a consequence of the physical on-shell requirement of the states in the matrix elements and the manner in which these states transform under Poincaré transformations.

• Research Organization: SLAC National Accelerator Laboratory (SLAC), Menlo Park, CA (United States)
• Sponsoring Organization: USDOE Office of Science (SC)
• Grant/Contract Number: AC02-76SF00515
• OSTI ID: 1393987
• Alternate ID(s): OSTI ID: 1443873
• Report Number(s): SLAC-PUB-17111; S0370269317307621; PII: S0370269317307621
• Journal Information: Physics Letters B, Journal Name: Physics Letters B Vol. 774 Journal Issue: C; ISSN 0370-2693
• Publisher: Elsevier
• Country of Publication: Netherlands
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
Energy–momentum tensor
Form factor
Anomalous gravitomagnetic moment