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The Hadron Electron Ring Anlage (HERA) at DESY provides collisions between a 920 GeV proton beam and a 27.5 GeV electron beam in two interaction regions. The strong beam-beam force, which mainly affects the electrons, induces a tune shift together with a dynamical beta beat. The latter leads to a modification of the transverse beam profile, which can be observed in different profile monitors in HERA. The time-like evolution of the electron beam shape during luminosity tuning and before and after dump of the proton beam, averaged over all bunches, could be studied by means of a synchrotron radiation profile monitor. Measurements with a wire scanner allowed to see the beam-beam force's influence on each individual bunch at the expense of resolution. The observations could be explained qualitatively in the frame of linear incoherent beam-beam interaction.
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