Virtual Photon Structure from Jet Production at HERA

The feasibility of measuring parton distribution functions of of virtual photons via the jet production at HERA is investigated.Comment: Contribution to the Workshop on "Future Physics at HERA", eds. G. Ingelman, A. De Roeck, R. Klanner,4 pages, 3 figures, epsfi

Real and virtual photon structure from dijet events

Jet production in $ep$ collisions is sensitive to the partonic structure of photon. The latest measurements of dijet production from the H1 experiment provide new results of the gluon density of real photons at low $x$ and, for the first time, on the partonic density of virtual photons. Properties of the photon remnant were measured as a function of the hard scale defined by the $p_T$ of the jets. The comparison of dijet cross sections with the NLO QCD calculation shows the non-triviality of the concept of virtual photon structure.Comment: 4 pages, Latex with 4 ps figures, references for section 5 updated, Talk presented at DIS99 Workshop at Zeuthen, April 199

QCD Analysis of Dijet Production at Low {\boldmath Q2Q^2} at HERA

Recent H1 data on triple differential dijet cross sections in $e^\pm p$ interactions in the region of low photon virtualities are shown to be in reasonable agreement with the predictions of the NLO QCD calculations obtained using the program NLOJET++. The implications of this observation for the phenomenological relevance of the concept of resolved virtual photon are discussed.Comment: 5 pages, 3 figure

Parton content of the real photon: astrophysical implications

We possess convincing experimental evidence for the fact that the real photon has non-trivial parton structure. On the other hand, interactions of the cosmic microwave background photons with high energy particles propagating through the Universe play an important role in astrophysics. In this context, to invoke the parton content could be convenient for calculations of the probabilities of different processes involving these photons. As an example, the cross section of inclusive resonant $W^+$ boson production in the reaction $\nu \gamma\to W^+X$ is calculated by using the parton language. Neutrino--photon deep inelastic scattering is considered.Comment: 4 pages, 2 figures. The spin states of the initial particles in the reaction $\nu\gamma\to W^+X$ are correctly treated. As a result, the corresponding cross section becomes two times greater than the one from the previous version. Some changes in the tex

Exploration of key stakeholders' preferences for pre-hospital physiologic monitoring by emergency rescue services

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