Related papers: Softer Hard Scattering and Noncommutative Gauge-St…
In this letter we discuss new soft theorems for the Goldstone boson amplitudes with non-vanishing soft limits. The standard argument is that the non-linearly realized shift symmetry leads to the vanishing of scattering amplitudes in the…
QCD is the theory of strong interactions and non-perturbative methods have been developed to address the confinement property of QCD. Many experimental measurements probe the confining dynamics, and it is well-known that hard scattering…
The weakly-coupled heterotic string is known to have problems of dilaton/moduli stabilization, supersymmetry breaking (by hidden-sector gaugino condensation), gauge coupling unification (or the Newton's constant), QCD axion, as well as…
Inclusive and semi-inclusive deep inelastic leptoproduction offers possibilities to study details of the quark and gluon structure of hadrons. In many of these experiments polarization is an essential ingredient. We also emphasize the…
In this paper we develop a QCD motivated model for both hard and soft interactions at high energies. In this model the long distance behavior of the scattering amplitude is determined by the approximate solution to the non-linear evolution…
We elaborate on the dynamics of noncommutative two-dimensional gauge field theories. We consider U(N) gauge theories with fermions in either the fundamental or the adjoint representation. Noncommutativity leads to a rather non-trivial…
In this paper, we show that multiple maximally soft (anti-)quark and gluon emissions exponentiate at the level of either the amplitude or cross-section. We first show that such emissions can be captured by introducing new soft emission…
There are various no-go theorems that tightly constrain the existence of local higher-spin theories with non-trivial S-matrix in flat space. Due to the existence of higher-spin Yang-Mills theory with non-trivial scattering amplitudes, it…
Is string theory uniquely determined by self-consistency? Causality and unitarity seemingly permit a multitude of putative deformations, at least at the level of two-to-two scattering. Motivated by this question, we initiate a systematic…
Using the Wilson formulation of lattice gauge theories, a gauge invariant grid discretization of a one-particle Hamiltonian in the presence of an external electromagnetic field is proposed. This Hamiltonian is compared both with that…
We revisit the problem of dipole-dipole scattering via exchanges of soft Pomerons in the context of holographic QCD. We show that a single closed string exchange contribution to the eikonalized dipole-dipole scattering amplitude yields a…
We investigate the strong coupling limit of lattice QCD in the Hamiltonian formulation for systems with non-zero baryon density. In leading order the Hamiltonian looks like an antiferromagnet that is invariant under global U(N_f)xU(N_f) and…
Using relationships between open and closed strings, we present a construction of tree-level scattering amplitudes for gravitons minimally coupled to matter in terms of gauge theory partial amplitudes. In particular, we present examples of…
We investigate gaugino condensation in the framework of the strongly coupled heterotic $E_8 \times E_8$ string (M--theory). Supersymmetry is broken in a hidden sector and gravitational interactions induce soft breaking parameters in the…
Starting from a standard noncommutative gauge theory and using the Seiberg-Witten map we propose a new version of a noncommutative gravity. We use consistent deformation theory starting from a free gauge action and gauging a killing…
Recent studies of the Q^2 dependence of ep scattering in the large x region and in the Q^2 range: 1 < Q^2 <leq 30 Gev^2, confirm the validity of the phenomenon of quark-hadron duality - the similarity of the deep inelastic (parton) and…
A central feature of scattering amplitudes in gravity or gauge theory is the existence of a variety of energetically soft theorems which put constraints on the amplitudes. Celestial amplitudes which are obtained from momentum-space…
In this lecture I give a short introduction to the high energy limit of hadronic interactions. The elements of the Regge theory, Pomeron in QCD and high energy scattering in AdS/CFT correspondence are presented. I discuss the resummation of…
In this letter we extend the factorization procedure of the deep-inelastic hadron tensor, proposed by Qiu, to include non-zero quark masses. The manifest gauge invariance of both soft and hard parts is preserved. Using a so-called spurion…
Quark-hadron duality is an interesting and potentially very useful phenomenon, as it relates the properly averaged hadronic data to a perturbative QCD result in some kinematic regions. While duality is well established experimentally, our…