Related papers: Real photon structure at an e^+e^- linear collider
The first part of the physics programme of the integrated FCC (Future Circular Colliders) proposal includes measurements of Standard Model processes in $e^+e^-$ collisions (FCC-ee) with an unprecedented precision. In particular, the…
We perform joint fits using measurements of the proton structure functions $F_2(x,Q^2)$ and $F_L(x,Q^2)$, of the photon structure function $F_2^\gamma(x,Q^2)$ and of the total cross-sections $\sigma\left( \gamma p \rightarrow X\right)$ and…
The possibility of a photon collider extension to the beam dump of the $17.5$ GeV European XFEL has already been discussed before as the first high energy collider of its sort. It would not only be the first proof of concept and test of a…
We review the different approaches used to treat the photon structure function. We suggest that despite some uncertainties it should remain sensitive to $\Lambda .$
We present the second in a series of studies into the forward tracking system for a future linear $ e^+ e^- $ collider with a center-of-mass energy in the range from 250 GeV to 3 TeV. In this note a number of specific challenges are…
At the high luminosity electron-positron circular colliders like FCC-ee in CERN and CEPC in China it will possible to measure very precisely $e^+e^-\to Z\gamma$ process with subsequent Z decay into particles invisible in the detector, that…
It has already been shown that the energy flow distributions in tagged events disagree with those predicted by QCD models, generating serious systematic errors in the unfolding of the photon structure function $F_{2}^{\gamma}$. This new…
Fully differential heavy quark contributions to the photon structure functions in deeply inelastic scattering are computed in next-to-leading order QCD, including both the direct and resolved contributions. A variety of distributions are…
We investigate the sensitivity to the effective operators describing interactions between dark matter particles and photons at future high energy $e^+e^-$ colliders via the $\gamma+ \slashed{E}$ channel. Such operators could be useful to…
A future Electron Ion Collider (EIC) will be able to provide collisions of polarized electrons with protons and heavy ions over a wide range of center-of-mass energies (20 $\mathrm{GeV}$ to 140 $\mathrm{GeV}$) at an instanteous luminosity…
Two photon collisions offer a variety of physics studies that can be performed at the future electron-positron colliders. Using the planned CEPC parameters as a benchmark we consider several topics to be studied in the two-photon…
The process e+e- -> gamma gamma (gamma) is studied using data collected by the OPAL detector at LEP between the years 1997 and 2000. The data set corresponds to an integrated luminosity of 672.3pb-1 at centre-of-mass energies lying between…
High precision measurements of electroweak observables at $e^\pm$ colliders indicate the existence of a light Higgs boson below the $W^\pm$ threshold. If such a fundamental scalar should be found in the near future it is important to fully…
We investigate the effects of gluon number fluctuations on the total $\gamma\gamma$, $\gamma^*\gamma^*$ cross sections and the photon structure function $F_2^\gamma(x,Q^2)$. Considering a model which relates the dipole-dipole and…
The $e^{+}\,e^{-}\,\rightarrow\,l^{+}\, \l^{-}\,\gamma\,\gamma$ anomalous events, detected by $L3$ de\-tec\-tor at $e^+ e^-$ $CERN-LEP$ collider have been analysed. It has been shown that the interpretation of such events as a manifestation…
A high energy linear e^+e^- collider (LC) can also be used as a Photon Collider (PC), using Compton scattering of laser photons on the e^+/e^- beams. The leading order cross-section for the production of heavy quarks, e^+e^- -> e^+e^-…
Monte Carlo models of DIS e-gamma scattering must describe hard emissions as well as the soft and collinear limits. Comparison with the observed experimental hadronic energy flow has shown that various models underestimate the high-p_T…
We investigate the Lepton Flavor Violating (LFV) process $e^{+}e^{-}\to e^{+}e^{-}e\mu$ ($e=e^-,\,e^+,\,\mu=\mu^-,\,\mu^+ $) at future circular colliders, probing the effective $\gamma\gamma e\mu$ interaction through photon fusion. Within…
We will gain unprecedented, high-accuracy insights into the internal structure of the atomic nucleus thanks to lepton-hadron collision studies in the coming years at the Electron-Ion-Collider (EIC) in the United States. A good control of…
A first measurement is reported of the longitudinal proton structure function F_L(x,Q^2) at the ep collider HERA. It is based on inclusive deep inelastic e^+p scattering cross section measurements with a positron beam energy of 27.5 GeV and…