Schopper was born inLanškroun, Czechoslovakia, on 28 February 1924,[2] to a family ofAustrian descent; his father was a teacher.[3] He grew up in a German-speaking town in the newly foundedCzechoslovakia. A few years after Schopper's birth, his parents amicably divorced, and he lived with his mother during the week and with his father on weekends. His parents and relatives encouraged his scientific and musical interests.[4]: 1–11
Schopper was advanced one year early into secondary school and took his final exams in 1942, after being taught alone in his last year because his classmates had left school early with anemergency diploma [de]. In 1938, following the annexation of theSudetenland as a result of theMunich Agreement, Schopper had become a German citizen. After completing school, he was conscripted into theReich Labour Service and then drafted into theWehrmacht, where he was assigned to theLuftwaffe's intelligence service. He chose a career as anofficer, which meant alternating between training and combat service (twice on theEastern Front, then in the West during theArdennes Offensive). At the end of the war, Schopper was taken prisoner by the British inSchleswig-Holstein.[4]: 15–29
During these fellowships, Schopper worked onnuclear physics and contributed substantially to the evidence ofparity violation inweak interactions. He measured the circular polarization ofgamma rays following abeta decay, thought unfeasible byLee andYang,[8] and showed in the same experiment that thehelicities of neutrino and antineutrino are opposite. Later, he was involved in an experiment to testtime reversal symmetry. In 1956, he followed Fleischmann to theUniversity of Erlangen where he continued to do research inoptics andsolid-state physics, with emphasis on thin metal layers, which he had started at Hamburg. Also he developed, along with Clausnitzer, the first source of polarised protons.[9] In 1957 he becamePrivatdozent at the University of Erlangen.[7]
From 1958 to 1961, Schopper was an associate professor at theUniversity of Mainz where he established the Institute for Experimental Nuclear Physics. In 1960 and 1961 he worked underRobert R. Wilson atCornell University to be introduced toelementary particle physics, namely the use of electron scattering to study the structure of the proton and neutron.[10]
Schopper was appointed professor at theUniversity of Karlsruhe in 1961 and director of the newly established Institutes for Experimental Nuclear Physics of TH Karlsruhe and the Karlsruhe Nuclear Research Centre.[11] In order to continue his research on electron scattering he set up a group to carry out one of the first experiments atDESY. He also created a group atCERN to investigate neutron scattering at high energies at theProton Synchrotron (PS) andIntersecting Storage Rings (ISR). These experiments where then continued at theInstitute for High Energy Physics (IHEP) inSerpukhov, Russia. The group made important contributions to the study of neutron-proton and neutron-nuclei scattering cross sections.[12] For this purpose, the first hadron calorimeter was developed and optimised by Monte Carlo simulations.[13] Another group at Karlsruhe developed the first superconducting high frequency cavities in Europe, a technology which was transferred to CERN for particle separators and later for particle acceleration atLEP.[2]
At CERN, he was a research associate in 1966–67, became division leader of the Nuclear Physics Division in 1970, member of the directorate responsible for the co-ordination of the experimental programme until 1973 and chairman of the ISR Committee from 1973 to 1976.[14]
In 1973 Schopper became professor at the University of Hamburg and the chairman of the directorate of DESY, serving until end of 1980.[15] He was responsible for the installation of theARGUS detector at DORIS which later resulted in the first evidence of B – B bar mixing.[16] Also, by establishing HASYLAB at DORIS synchrotron light science became an important branch of research at DESY. He proposed and completed the construction of the electron-positron collider PETRA which led to the discovery and study of the gluon.[17] During his mandate, DESY, a national laboratory became as far as science was concerned an international particle physics laboratory. This included the start of the first collaboration with China.[2]
After being member of the Scientific Policy Committee at CERN, Schopper was elected director general and served from 1981 to 1988.[18][15][19][7] His first task was to unite the two CERN laboratories existing at that time under two Directors General. TheLarge Electron–Positron Collider (LEP) was also proposed and constructed under his leadership. This facility allowed the verification of the standard model of particle physics, namely that it is a renormalizable field theory, leading to the award of the Nobel Prize to the theoreticiansVeltman andt'Hooft. Furthermore, it enabled the precise determination of fundamental parameters of the electroweak force, such as the W± and Z masses, and proved the existence of three neutrino families.[20] Thus, this particle accelerator transformed high energy physics into a field of precision measurements and provided estimates to the mass of thetop quark,Higgs boson and other supersymmetric and hypothetical particles. LEP was approved under the condition of a reduced and constant budget with the consequence that some unique activities at CERN (e.g. ISR) had to be abandoned. Schopper was obliged to introduce a new way of international collaboration for the four LEP experiments since CERN could not provide funds for them. The experiments became rather independent activities organised in a rather democratic way bringing together hundreds of scientists from many universities and national organisations.[21] The LEP experiments became a model for the laterLHC experiments, shaping the way this organization works today. He contributed to the globalisation of research at CERN and was also responsible for the return of Spain and Portugal in the CERN's member states.[22][23]
Schopper at the Second International Conference on Research and Communications in Physics
Schopper was professor at the University of Hamburg from 1973 and professor emeritus from 1989.[15][5] From 1992 to 1994, he was president of theGerman Physical Society and president of theEuropean Physical Society in 1995–97.[24] For many years he was member of the scientific council of theJoint Institute for Nuclear Research inDubna and of the board of trustees of the Max Planck Institute for Plasma Physics in Garching.[2]
AtUNESCO, he served as member of the Physics Action Council and chairman of the Working Group on Large Facilities, president of the scientific council of the Regional Office for Science and Technology ROSTE of UNESCO in Venice (2001–2002) and in 2003–2009 he was the chairman of the international advisory committee for the International Basic Science Programs.[25]
Schopper's vision of science without borders resulted in him becoming a founding father ofSESAME, the laboratory for Synchrotron-Light for Experimental Science and Applications in the Middle East, which provides an extremely bright light source to investigate a broad range of domains from condensed matter to biology and archeology.[22] In 1999–2008 he became president of the Preliminary International Council and later, after the formal foundation of SESAME, of the International Council. Without his dedication this international research facility would probably not have been built. SESAME was founded analogous to CERN, under the umbrella of UNESCO, with presently nine member states: Bahrain, Cyprus, Egypt, Iran, Israel, Jordan, Pakistan, the Palestinian Authority and Turkey. It provides an environment where countries with different political systems, traditions, religions and mentalities are able to work together peacefully.[26]
Schopper was a founding member ofThe Cyprus Institute at Nicosia, Cyprus, and from 2000, a Member of the board of trustees. He was also chairman of the Scientific Council, and member of the executive committee of the board of trustees of the Cyprus Institute.[27] He later worked as an advisor and goodwill ambassador on science for peace. He wrote articles about research policy, science and religion, and also science and society.[2]
Schopper died in Hamburg on 19 August 2025, at the age of 101.[2][3]
Schopper wrote more than 200 original publications in optics, nuclear physics, elementary particle physics and accelerator technology, including:[5]
Fleischmann R. and H. Schopper, The determination of the optical constants and thickness of the layer of absorbent layers by means of the measurement of the absolute phase changeZ.Physik 129.285 (1951) (first method for the measurement of the absolute phase upon reflection of light on the thin metal layers)
H. Schopper, The interpretation of the optical constants of alkali metals,Z.Physik 135, 163 (1953) (the abnormal optical behaviour of thin alkali metal layers does not require a special physical state of the metal)
H. Schopper, Circular polarization of gamma rays: Further proof for parity failure in beta-decay,Phil.Mag.' 2, 710 (1957) (One of the experiments proposed by Lee and Yang, but considered impossible. In this experiment it was shown for the first time that the helicity of the neutrino and antineutrino are opposite.)
G. Clausnitzer, R. Fleischmann and H. Schopper, Production of a hydrogen atom beam with parallel nuclear spins,Z.Physik 144, 336 (1956)
H. Schopper and S. Galster, The circular polarization of internal and external bremsstrahlung,Nucl.Phys. 6, 125 (1958) (first measurement of the circular polarization of the internal bremsstrahlung of beta decay)
J. Halbritter, R. Hietschold, P. Kneisel, and H. Schopper, Coupling losses and the measurement of Q-values of superconducting cavities, KFK-report Karlsruhe 3 / 86-6 (1968) (early publication of the study of superconducting cavities to accelerate particles)
R. M. Littauer, H. Schopper, R. R. Wilson, Electromagnetic properties of the proton and neutron,Phys. Rev. Lett. 6, 286 (1961), Phys. Rev. Lett. 7, 141 (1961) and 7, 144 (1961) (measurement of nuclear form factors, improvement of the first measurements by R. Hofstadter)
Behrend et al., Elastic electron-proton scattering at momentum transfers up to 110 fermi-2,Nuov.Cim. 48.140 (1967)
J. Engler, W. Flauger, AS. Gibbard, F. Mönnig, K. Runge and H. Schopper, A total absorption spectrometer for energy measurements of high-energy particles,Nucl.Instr.Meth. 106, 189 (1973) (first usage and optimization of a 'hadron calorimeter')
V. Boehmer et al., Neutron-proton elastic scattering from 10 to 70 GeV / c, Nucl.Phys. B91, 266 (1975) and other publications (neutron-proton scattering at high energies, the ISR at CERN and at the Institute for High Energy Physics in Protvino, Russia)
L3 Collaboration, Upsilon production in Z decays,Phys.Lett. B 413, 167 (1997) and Heavy Quarkonium Production in Z decays, CERN-PPE/92-99 andPhys.Lett.B (Schopper was principal author of these publications)
H.Schopper, The light of SESAME: A dream becomes reality,La Rivista del Nuovo Cimento, 40, 199 (2017)
^Engler, J.; Horn, K.; Mönnig, F.; Schludecker, P.; Schmidt-Parzefall, W.; Schopper, H.; Sievers, P.; Ullrich, H.; Hartung, R.; Runge, K.; Galaktionov, Yu (11 May 1970). "Neutron-proton total cross-sections between 8 GeVc and 21 GeVc".Physics Letters B.31 (10):669–672.Bibcode:1970PhLB...31..669E.doi:10.1016/0370-2693(70)90031-6.
^Engler, J.; Flauger, W.; Gibbard, B.; Mönnig, F.; Runge, K.; Schopper, H. (1 January 1973). "A total absorption spectrometer for energy measurements of high-energy particles".Nuclear Instruments and Methods.106 (1):189–200.Bibcode:1973NucIM.106..189E.doi:10.1016/0029-554x(73)90063-3.
^Schopper, Herwig (2009). "What Have We Learned from LEP? – Physics Results".LEP The Lord of the Collider Rings at CERN 1980-2000: What Have We Learned from LEP? - Physics Results. Geneva, Switzerland: Springer. pp. 113–142.doi:10.1007/978-3-540-89301-1_8.ISBN978-3-540-89300-4.
^Schopper, Herwig (2009). "The Approval, or How to Persuade Governments".LEP The Lord of the Collider Rings at CERN 1980-2000: The Approval, or How to Persuade Governments. Geneva, Switzerland: Springer. pp. 19–30.doi:10.1007/978-3-540-89301-1_3.ISBN978-3-540-89300-4.
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