We study the spectral form factor (SFF) of general topological gravity in limit large time and fixed temperature. It has been observed recently that this limit, called tau-scaling genus expansion SFF can be summed up late-time behavior such as ramp-plateau transition studied analytically. In paper we develop a technique for systematic computation higher order corrections to strict limit. obtain...

This talk presents an introduction to the use of dispersion relations to constrain the shapes of hadronic form factors consistent with QCD. The applications described include methods for studying |Vcb| and |Vub|, the strange quark mass, and the pion charge radius.

Relativistic integral representation in terms of experimental neutron– proton scattering phase shifts alone is used to compute the charge form factor of the deuteron GCd(Q ). The results of numerical calculations of |GCd(Q)| are presented in the interval of the four–momentum transfers squared 0 ≤ Q ≤ 35 fm−2. Zero and the prominent secondary maximum in |GCd(Q)| are the direct consequences of th...

We recalculate the proton Dirac form factor based on the perturbative QCD factorization theorem which includes Sudakov suppression. The evolution scale of the proton wave functions and the infrared cutoffs for the Sudakov resummation are carefully chosen, such that the soft divergences from large coupling constants are diminished and perturbative QCD predictions are stablized. We find that the ...

The electromagnetic form factor of the pion in the space-like region, and at finite temperature, Fπ(Q 2, T ), is obtained from a QCD Finite Energy Sum Rule. The form factor decreases with increasing T, and vanishes at some critical temperature, where the pion radius diverges. This divergence may be interpreted as a signal for quark deconfinement. John Simon Guggenheim Fellow 1994-1995 The possi...

There is an extensive history of form factor calculations on the lattice, primarily with ground states for both initial and final states. However, there have never been any radially excited transition form factor calculations. Furthermore, the lattice faces difficulty in extracting signal from noise at large transfer momenta (Q2). These measurements could give important theoretical input to exp...

The parity violation programs at MIT-Bates, Jefferson Lab and Mainz are presently focused on developing a better understanding of the sea-quark contributions to the vector matrix elements of nucleon structure. The success of these programs will allow precise semi-leptonic tests of the Standard Model such as that planned by the QWeak collaboration. In order to determine the vector matrix element...

Temperature effects on the electromagnetic couplings of pions in hot hadronic matter are studied with an effective chiral Lagrangian. We show that the Ward-Takahashi identity is satisfied at non-zero temperature in the soft pion limit. The in-medium electromagnetic form factor of the pion is obtained in the time-like region and shown to be reduced in magnitude, especially near the vector-meson ...

Results for the isovector axial form factors of the proton from a lattice QCD calculation are presented for both point-split and local currents. They are obtained on a quenched 163 × 24 lattice at β = 6.0 with Wilson fermions for a range of quark masses from strange to charm. For each quark mass, we find that the axial form factor falls off slower than the corresponding proton electric form fac...