Coherent Bremsstrahlung, Coherent Pair Production, Birefringence and Polarimetry in the 20-170 GeV energy range using aligned crystals

@misc{citeulike:908525, abstract = {The processes of coherent bremsstrahlung (CB) and coherent pair production (CPP) based on aligned crystal targets have been studied in the energy range 20-170 GeV. The experimental arrangement allowed these phenomena as well as their polarization dependence to be evaluated under conditions where single-photon cross-sections could be measured. This proved very important as the theoretical description of CB and CPP is an area of active theoretical debate and development. The theoretical approach used in this paper predicts both the cross sections and polarization observables very well for the experimental conditions investigated, indicating that the understanding of CB and CPP is reliable up to energies of 170 GeV. A birefringence effect in CPP was studied and it was demonstrated this enabled new technologies for high energy photon beam optics, such as polarimeters (for both linear and circular polarization) and phase plates. We also present new results regarding the features of coherent high energy photon emission for the Strings-Of-Strings (SOS) orientation, where the coherent enhancement of hard photon radiation is larger than for the CB case. The photon polarization in this case has been controversial. Our measurements commented on this situation as well.}, author = {Collaboration, Na59 and Apyan, A. and Avakian, R. O. and Badelek, B. and Ballestrero, S. and Biino, C. and Birol, I. and Cenci, P. and Connell, S. H. and Eichblatt, S. and Fonseca, T. and Freund, A. and Gorini, B. and Groess, R. and Ispirian, K. and Ketel, T. J. and Kononets, Yu V. and Lopez, A. and Mangiarotti, A. and van Rens, B. and Sellschop, J. P. F. and Shieh, M. and Sona, P. and Strakhovenko, V. and Uggerhoj, E. and Uggerhoj, U. I. and Unel, G. and Velasco, M. and Vilakazi, Z. Z. and Wessely, O. }, citeulike-article-id = {908525}, eprint = {hep-ex/0512017}, keywords = {channeling, crystals, hep, na59, photons, physics, polarization}, month = {Dec}, posted-at = {2006-10-20 23:14:23}, priority = {0}, title = {Coherent Bremsstrahlung, Coherent Pair Production, Birefringence and Polarimetry in the 20-170 GeV energy range using aligned crystals}, url = {http://arxiv.org/abs/hep-ex/0512017}, year = {2005} }

TY - ELEC ID - citeulike:908525 L3 - citeulike-article-id:908525 TI - Coherent Bremsstrahlung, Coherent Pair Production, Birefringence and Polarimetry in the 20-170 GeV energy range using aligned crystals N2 - The processes of coherent bremsstrahlung (CB) and coherent pair production (CPP) based on aligned crystal targets have been studied in the energy range 20-170 GeV. The experimental arrangement allowed these phenomena as well as their polarization dependence to be evaluated under conditions where single-photon cross-sections could be measured. This proved very important as the theoretical description of CB and CPP is an area of active theoretical debate and development. The theoretical approach used in this paper predicts both the cross sections and polarization observables very well for the experimental conditions investigated, indicating that the understanding of CB and CPP is reliable up to energies of 170 GeV. A birefringence effect in CPP was studied and it was demonstrated this enabled new technologies for high energy photon beam optics, such as polarimeters (for both linear and circular polarization) and phase plates. We also present new results regarding the features of coherent high energy photon emission for the Strings-Of-Strings (SOS) orientation, where the coherent enhancement of hard photon radiation is larger than for the CB case. The photon polarization in this case has been controversial. Our measurements commented on this situation as well. KW - channeling KW - crystals KW - hep KW - na59 KW - photons KW - physics KW - polarization AU - Collaboration, Na59 AU - Apyan, A AU - Avakian, RO AU - Badelek, B AU - Ballestrero, S AU - Biino, C AU - Birol, I AU - Cenci, P AU - Connell, SH AU - Eichblatt, S AU - Fonseca, T AU - Freund, A AU - Gorini, B AU - Groess, R AU - Ispirian, K AU - Ketel, TJ AU - Kononets, Yu AU - Lopez, A AU - Mangiarotti, A AU - van Rens, B AU - Sellschop, JPF AU - Shieh, M AU - Sona, P AU - Strakhovenko, V AU - Uggerhoj, E AU - Uggerhoj, UI AU - Unel, G AU - Velasco, M AU - Vilakazi, ZZ AU - Wessely, O PY - 2005/Dec/07/ UR - http://arxiv.org/abs/hep-ex/0512017 ER -