Related papers: Probing Positron Gravitation at HERA
The COMPASS collaboration at CERN has investigated pion Compton scattering, $\pi^-\gamma\rightarrow \pi^-\gamma$, at centre-of-mass energy below 3.5 pion masses. The process is embedded in the reaction…
The cross section of the $ep \to e' p' \gamma$ reaction has been measured at $Q^2 = 0.33$ (GeV/c)$^2$. The experiment was performed using the electron beam of the MAMI accelerator and the standard detector setup of the A1 Collaboration. The…
We extend de concept of Compton scattering to the case of plasmons. This concept was originally applied to electrons in vacuum. Here, we consider electrons in a plasma, and study the scattering properties of photon-plasmon interactions. We…
A review on recent investigations of local fluctuations and genuine correlations in electron-positron annihilations at LEP and in positron-proton collisions at HERA is given.
The rejection of the contamination, or background, from low-energy strong interactions at hadron collider experiments is a topic that has received significant attention in the field of particle physics. This article builds on a…
High energy scattering processes of charged particles are accompanied by radiation of hard photons. Emission collinear to the incident particles, which leads to a reduction of the effective beam energy, and the possibility to directly…
We report a variational approach to the nonlinearly screened interaction of charged particles with a many-electron system. This approach has been developed by introducing a modification of the Schwinger variational principle of scattering…
Data on the hadronic final state of deep-inelastic events at the ep collider HERA are reviewed. Fragmentation properties in the current region extracted from charged particle spectra are compared to e+e- and fixed target experiments at…
HERA measurements of diffractive ep scattering - the quasi-elastic scattering of the photon in the proton colour field - are summarised. Emphasis is placed on the most recent data.
A search for excited neutrinos produced in electron--proton collisions is performed using a data sample corresponding to an integrated luminosity of 114 pb$^{-1}$ recently collected by the H1 detector at HERA. In absence of a signal, the…
The early observation at HERA of an excess of events compared to the expectation from the Standard Model in very short distance $e^+p$ deep-inelastic scattering processes has renewed the interest in the search for new physics which could…
Some strong field effects on test particle motion associated with the propagation of a plane electromagnetic wave in the exact theory of general relativity are investigated. Two different profiles of the associated radiation flux are…
The noncommutative spectral action extends our familiar notion of commutative spaces, using the data encoded in a spectral triple on an almost commutative space. Varying a rather simple action, one can derive all of the standard model of…
Compton scattering on light nuclei ($A=2,3$) has emerged as an effective avenue to search for signatures of neutron polarizabilities, both spin--independent and spin--dependent ones. In this discussion I will focus on the theoretical aspect…
We describe a method by which gravitational wave observations of eccentric binary systems could be used to test General Relativity's prediction that gravitational waves are dispersionless. We present our results in terms of the graviton…
Recent experimental results on the partonic structure of the photon and on the color singlet exchange in strong interaction processes are reviewed. At the LEP electron-positron and HERA lepton-proton colliders, complementary and consistent…
Data taken with positrons of different longitudinal polarisation states in collision with unpolarised protons at HERA are used to measure the total cross sections of the charged current process, e^+ p \to \bar{\nu}X, for negative…
A model-independent search for deviations from the Standard Model prediction has been performed in e+p and e-p collisions at HERA using H1 data. All experimentally measurable event topologies involving isolated electrons, photons, muons,…
The paper deals with the Compton disintegration of positronium and a comparison of the differential cross sections of this process with the similar cross sections in the case of the Compton ionization of the hydrogen atom. Special attention…
An experimental search for non-newtonian, gravity-like force in a precision measurement of the scattering of slow neutrons in Xenon gas is proposed. A preliminary experiment with small statistics of 25 hours irradiation time was performed…