Double Copy in Higher Derivative Operators of Nambu-Goldstone Bosons
Résumé
We investigate the existence of double copy structure, or the lack thereof, in higher derivative operators for Nambu-Goldstone bosons. At the leading O(p2), tree amplitudes of Nambu-Goldstone bosons in the adjoint representation can be (trivially) expressed as the double copy of itself and the cubic biadjoint scalar theory, through the Kawai-Lewellen-Tye bilinear kernel. At the next-to-leading O(p4) there exist four operators in general, among which we identify one operator whose amplitudes exhibit the flavor-kinematics duality and can be written as the double copy of O(p2) Nambu-Goldstone amplitudes and the Yang-Mills+ϕ3 theory, involving both gluons and gauged cubic biadjoint scalars. The specific operator turns out to coincide with the scalar O(p4) operator in the so-called extended Dirac-Born-Infeld theory, for which the aforementioned double copy relation holds more generally.