Matrix elements from moments of correlation functions

Conference · Sat Oct 01 00:00:00 EDT 2016 · Proceedings of Science

OSTI ID:1331996

Chang, Chia Cheng ^[1]; Bouchard, Chris ^[2]; Orginos, Konstantinos ^[3]; Richards, David G. ^[4]

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1. SLAC National Accelerator Lab., Menlo Park, CA (United States)
2. College of William and Mary, Williamsburg, VA (United States)
3. Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); College of William and Mary, Williamsburg, VA (United States)
4. Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States)

Momentum-space derivatives of matrix elements can be related to their coordinate-space moments through the Fourier transform. We derive these expressions as a function of momentum transfer Q2 for asymptotic in/out states consisting of a single hadron. We calculate corrections to the finite volume moments by studying the spatial dependence of the lattice correlation functions. This method permits the computation of not only the values of matrix elements at momenta accessible on the lattice, but also the momentum-space derivatives, providing {\it a priori} information about the Q2 dependence of form factors. As a specific application we use the method, at a single lattice spacing and with unphysically heavy quarks, to directly obtain the slope of the isovector form factor at various Q2, whence the isovector charge radius. The method has potential application in the calculation of any hadronic matrix element with momentum transfer, including those relevant to hadronic weak decays.

• Research Organization: Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); SLAC National Accelerator Lab., Menlo Park, CA (United States)
• Sponsoring Organization: USDOE Office of Science (SC), Nuclear Physics (NP)
• DOE Contract Number: AC05-06OR23177; AC02-05CH11231
• OSTI ID: 1331996
• Report Number(s): JLAB-THY-16-2369; DOE/OR/23177-3967; arXiv:1610.02354
• Journal Information: Proceedings of Science, Vol. LATTICE2016; Conference: 34th annual International Symposium on Lattice Field Theory, July 24-30, 2016, Southampton UK
• Country of Publication: United States
• Language: English