Related papers: Spin and hard processes
I review recent developments in theoretical spin physics. Topics include pion production in nucleon-nucleon collisions, the implications of heavy quark spin symmetry for heavy hadron molecules, the nucleon electric dipole form factors and…
Single spin asymmetries in polarized proton(antiproton) + proton -> pion + X have been measured to be large. They can be understood within perturbative QCD by introducing new k_perp and spin dependences in fragmentation and/or distribution…
Symmetry is a fundamentally important concept in many branches of physics. In this work, we discuss two types of symmetries, external symmetry and internal symmetry, which appear frequently in controlled quantum spin chains and apply them…
Gravity is specifically the attractive force between two masses separated at a distance. Is this force a derived or a fundamental interaction? We believe that all fundamental interactions are quantum in nature but a derived interaction may…
The present thesis is divided into three parts. In Part I we address a problem within Higher-Spin Gauge Theory in dimension three: namely, that of computing the asymptotic symmetry algebra of supersymmetric models, describing an infinite…
Soft interactions are not easily disentangled from hard ones. In an operational definition of soft and hard processes one finds that at presently analyzed scales there is an interplay of soft and hard processes. As the scale increases, so…
For a century, spin has been an indispensable probe of the fundamental laws of nature. A reflection on the role of spin in shaping modern physics is presented, from the early days of quantum mechanics to the latest precision tests of the…
We summarize the present status of the theories of spin fluctuations in dealing with the anomalous or non-Fermi liquid behavior and unconventional superconductivity in strongly correlated electron systems around their magnetic instabilities…
Precision gauge coupling unification is one of the primary quantitative successes of low energy or split supersymmetry. Preserving this success puts severe restrictions on possible matter and gauge sectors that might appear at…
A new handed interaction between quarks could be at the origin of some small parity violating effects in the inclusive production of one-jet in polarized $pp$ collisions. This interaction could originate from compositeness or from the…
A self-consistent theory of both spin and charge fluctuations in the Hubbard model is presented. It is in quantitative agreement with Monte Carlo data at least up to intermediate coupling $(U\sim 8t)$. It includes both short-wavelength…
Direct consequences on kaon production of the picture proposed in a recent Letter and subsequent publications are discussed. Further evidence supporting the proposed picture is obtained. Comparison with the data for the inclusive cross…
In the leading log approximation and at large $N_C$ the interaction of two fermionic and one gluonic reggeons is described by an integrable system corresponding to an open spin chain.
The physics of hadron single transverse spin asymmetries is discussed. Possible measurements of both the quark and gluon Sivers functions are proposed.
This is a late answer to question #79 by R.I. Khrapko, "Does plane wave not carry a spin?," Am. J. Phys. /69/, 405 (2001), and a complement (on gauge invariance, massive spin 1 and 1/2, and massless spin 2 fields) to the paper by H.C.…
We derive the explicit expressions of the canonical and helicity wave functions for massive particles with arbitrary spins. Properties of these wave functions are discussed.
New possibilities arising from the availability at GSI of antiproton beams, possibly polarised, are discussed. The investigation of the nucleon structure can be boosted by accessing in Drell-Yan processes experimental asymmetries related to…
We present a coherent scenario for the physics of cuprate superconductors, which is based on a charge-driven inhomogeneity, i.e. the ``stripe phase''. We show that spin and charge critical fluctuations near the stripe instability of…
The study of critical properties of systems with long-range interactions has attracted in the last decades a continuing interest and motivated the development of several analytical and numerical techniques, in particular in connection with…
Further properties of a recently proposed higher order infinite spin particle model are derived. Infinitely many classically equivalent but different Hamiltonian formulations are shown to exist. This leads to a condition of uniqueness in…