| 1. |
- Erni, W., et al.
(author)
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Technical design report for the PANDA (AntiProton Annihilations at Darmstadt) Straw Tube Tracker
- 2013
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In: European Physical Journal A. Hadrons and Nuclei. - : Springer Science and Business Media LLC. - 1434-6001 .- 1434-601X. ; 49:2
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Journal article (peer-reviewed)abstract
- This document describes the technical layout and the expected performance of the Straw Tube Tracker (STT), the main tracking detector of the PANDA target spectrometer. The STT encloses a Micro-Vertex-Detector (MVD) for the inner tracking and is followed in beam direction by a set of GEM stations. The tasks of the STT are the measurement of the particle momentum from the reconstructed trajectory and the measurement of the specific energy loss for a particle identification. Dedicated simulations with full analysis studies of certain proton-antiproton reactions, identified as being benchmark tests for the whole PANDA scientific program, have been performed to test the STT layout and performance. The results are presented, and the time lines to construct the STT are described.
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| 2. |
- Singh, B. P., et al.
(author)
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Experimental access to Transition Distribution Amplitudes with the PANDA experiment at FAIR
- 2015
-
In: European Physical Journal A. Hadrons and Nuclei. - : Springer Science and Business Media LLC. - 1434-6001 .- 1434-601X. ; 51:8
-
Journal article (peer-reviewed)abstract
- Baryon-to-meson Transition Distribution Amplitudes (TDAs) encoding valuable new information on hadron structure appear as building blocks in the collinear factorized description for several types of hard exclusive reactions. In this paper, we address the possibility of accessing nucleon-to-pion (pi N) TDAs from (p) over barp -> e(+)e(-)pi(0) reaction with the future PANDA detector at the FAIR facility. At high center-of-mass energy and high invariant mass squared of the lepton pair q(2), the amplitude of the signal channel (p) over barp -> e(+)e(-)pi(0) admits a QCD factorized description in terms of pi N TDAs and nucleon Distribution Amplitudes (DAs) in the forward aid backward kinematic regimes. Assuming the validity of this factorized description, we perform feasibility studies for measuring (p) over barp -> e(+)e(-)pi(0) with the PANDA detector. Detailed simulations on signal reconstruction efficiency as well as on rejection of the most severe background channel, i.e. (p) over barp -> pi(+)pi(-)pi(0) were performed for the center-of-mass energy squared s = 5 GeV2 and s = 10 GeV2, in the kinematic regions 3.0 < q(2) < 4.3 GeV2 and 5 < q(2) < 9 GeV2, respectively, with a neutral pion scattered in the forward or backward cone vertical bar cos theta(pi 0)vertical bar > 0.5 in the proton-antiproton center-of-mass frame. Results of the simulation show that the particle identification capabilities of the PANDA detector will allow to achieve a background rejection factor of 5 . 10(7) (1 . 10(7)) at low (high) q(2) for s = 5 GeV2, and of 1 . 10(8) (6 . 10(6)) at low (high) q(2) for s = 10 GeV2, while keeping the signal reconstruction efficiency at around 40%. At both energies, a clean lepton signal can be reconstructed with the expected statistics corresponding to 2 of integrated luminosity. The cross sections obtained from the simulations are used to show that a test of QCD collinear factorization can be done at the lowest order by measuring scaling laws and angular distributions. The future measurement of the signal channel cross section with PANDA will provide a new test of the perturbative QCD description of a novel class of hard exclusive reactions and will open the possibility of experimentally accessing pi N TDAs.
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| 3. |
- Albrecht, Malte, et al.
(author)
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The Forward Endcap of the Electromagnetic Calorimeter for the PANDA Detector at FAIR
- 2015
-
In: Journal of Physics, Conference Series. - : IOP Publishing. - 1742-6588 .- 1742-6596. ; 587:1
-
Journal article (peer-reviewed)abstract
- The versatile 4π-detector PANDA will be built at the Facility for Antiproton and Ion Research (FAIR), an accelerator complex, currently under construction near Darmstadt, Germany. A cooled antiproton beam in a momentum range of 1.5 – 15GeV/c will be provided by the High Energy Storage Ring (HESR). All measurements at PANDA rely on an excellent performance of the detector with respect to tracking, particle identification and energy measurement. The electromagnetic calorimeter (EMC) of the PANDA detector will be equipped with 15744 PbWO(4) crystals (PWO-II), which will be operated at a temperature of – 25° C in order to increase the light output. The design of the forward endcap of the EMC has been finalized. The crystals will be read out with Large Area Avalanche Photo Diodes (LAAPDs) in the outer regions and with Vacuum Photo Tetrodes (VPTTs) in the innermost part. Production of photosensor units utilizing charge integrating preamplifiers has begun. A prototype comprised of 216 PbWO4 crystals has been built and tested at various accelerators (CERN SPS, ELSA/Bonn, MAMI/Mainz), where the crystals have been exposed to electron and photon beams of 25MeV up to 15GeV. The results of these test measurements regarding the energy and position resolution are presented.
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| 4. |
- Aloisio, A, et al.
(author)
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An FPGA Based General Purpose DAQ Module for the KLOE-2 Experiment
- 2011
-
In: Journal of Physics: Conference Series. ; 331
-
Journal article (peer-reviewed)abstract
- A general purpose FPGA based DAQ module has been developed based on a Virtex-4 FPGA. It is able to acquire up to 1024 different channels distributed over 10 slave cards. The module has an optical interface a RS-232 a USB and a Gigabit Interface. The KLOE-2 experiment is going to use it to collect data from the Inner tracker and the QCALT. An embedded processor (power pc 604) is present on the FPGA and a telnet server has been developed and installed. A new general purpose data taking system has been based on this module to acquire the Inner Tracker. The system is at the moment working at LNF (Laboratori Nazionali di Frascati).
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| 5. |
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| 6. |
- Anastasi, A., et al.
(author)
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Combination of KLOE sigma (e(+) e(-) -> pi(+)pi(-) gamma(gamma)) measurements and determination of a(mu)(pi+pi-) in the energy range 0.10 < s < 0.95 GeV2
- 2018
-
In: Journal of High Energy Physics (JHEP). - : Springer. - 1126-6708 .- 1029-8479. ; :3
-
Journal article (peer-reviewed)abstract
- The three precision measurements of the cross section sigma (e(+)e(-) -> pi(+)pi(-)gamma(gamma)) using initial state radiation by the KLOE collaboration provide an important input for the prediction of the hadronic contribution to the anomalous magnetic moment of the muon. These measurements are correlated for both statistical and systematic uncertainties and, therefore, the simultaneous use of these measurements requires covariance matrices that fully describe the correlations. We present the construction of these covariance matrices and use them to determine a combined KLOE measurement for sigma (e(+)e(-) -> pi(+)pi(-)gamma(gamma)). We find, from this combination, a two-pion contribution to the muon magnetic anomaly in the energy range 0.10 < s < 0.95 GeV2 of a(mu)(pi+pi-) (489.8 +/- 1.7(stat) +/- 4.8(sys)) x 10(-10).
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| 7. |
- Anastasi, A., et al.
(author)
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Limit on the production of a low-mass vector boson in e(+)e(-) -> U gamma, U -> e(+)e(-) with the KLOE experiment
- 2015
-
In: Physics Letters B. - : Elsevier BV. - 0370-2693 .- 1873-2445. ; 750, s. 633-637
-
Journal article (peer-reviewed)abstract
- The existence of a new force beyond the Standard Model is compelling because it could explain several striking astrophysical observations which fail standard interpretations. We searched for the light vector mediator of this dark force, the U boson, with the KLOE detector at the DA Phi NE e(+)e(-) collider. Using an integrated luminosity of 1.54 fb(-1), we studied the process e(+)e(-) -> U gamma, with U -> e(+)e(-), using radiative return to search for a resonant peak in the dielectron invariant-mass distribution. We did not find evidence for a signal, and set a 90% CL upper limit on the mixing strength between the Standard Model photon and the dark photon, epsilon(2), at 10(-6)-10(-4) in the 5-520 MeV/c(2) mass range.
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| 8. |
- Anastasi, A., et al.
(author)
-
Measurement of the running of the fine structure constant below 1 GeV with the KLOE detector
- 2017
-
In: Physics Letters B. - : ELSEVIER SCIENCE BV. - 0370-2693 .- 1873-2445. ; 767, s. 485-492
-
Journal article (peer-reviewed)abstract
- We have measured the running of the effective QED coupling constant alpha(s) in the time-like region 0.6 < root s < 0.975 GeV with the KLOE detector at DA Phi NE using the Initial-State Radiation process e(+) e(-) -> mu(+) mu(-)gamma. It represents the first measurement of the running of alpha(s) in this energy region. Our results show a more than 5 sigma significance of the hadronic contribution to the running of alpha(s), which is the strongest direct evidence both in time- and space-like regions achieved in a single measurement. By using the e(+) e(-) -> pi(+) pi(-) cross section measured by KLOE, the real and imaginary parts of the shift Delta alpha(s) have been extracted. From a fit of the real part of Delta alpha(s) and assuming the lepton universality the branching ratio BR(omega -> mu(+) mu(-)) = (6.6 +/- 1.4(stat) +/- 1.7(syst)) (.) 10 (5)has been determined.
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| 9. |
- Archilli, F., et al.
(author)
-
Search for a vector gauge boson in phi meson decays with the KLOE detector KLOE-2 Collaboration
- 2012
-
In: Physics Letters B. - : Elsevier BV. - 0370-2693 .- 1873-2445. ; 706:4-5, s. 251-255
-
Journal article (peer-reviewed)abstract
- The existence of a light dark force mediator has been tested with the KLOE detector at DA Phi NE. This particle, called U. is searched for using the decay chain phi -> eta U, eta -> pi(+)pi(-)pi(0), U -> e(+)e(-). No evidence is found in 1.5 fb(-1) of data. The resulting exclusion plot covers the mass range 5 < M-U < 470 MeV, setting an upper limit on the ratio between the U boson coupling constant and the One structure constant, alpha'/alpha, of <= 2 x 10(-5) at 90% C.L. for 50 < M-U < 420 MeV.
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| 10. |
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| 11. |
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| 12. |
- Atomassa, Ermias, et al.
(author)
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Feasibility studies for nucleon structure measurements with PANDA
- 2014
-
In: EPJ Web of Conferences. - : EDP Sciences. - 2100-014X. ; 81
-
Journal article (peer-reviewed)abstract
- The study of nucleon structure is one of the main physics goals of PANDA to be built at the FAIR accelerator complex. The excellent particle identification performance of the PANDA detector will enable measurements of exclusive channels p̄ p -> e^+e^- and p̄ p -> pi^0 J/psi -> pi^0e^+e^- to extract the electromagnetic form factors of protons and pi-nucleon Transition Distribution Amplitudes (pi-N TDAs). After a brief description of the PANDA apparatus and a method to handle momentum resolution degradation due to Bremsstrahlung, the physics of pi-N TDAs is discussed. An estimate for the expected signal to background ratio for p̄ p -> pi^0 J/psi -> pi^0e^+e^- that takes into account the main background source is given.
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| 13. |
- Babusci, D., et al.
(author)
-
Limit on the production of a light vector gauge boson in phi meson decays with the KLOE detector
- 2013
-
In: Physics Letters B. - : Elsevier BV. - 0370-2693 .- 1873-2445. ; 720:1-3, s. 111-115
-
Journal article (peer-reviewed)abstract
- We present a new limit on the production of a light dark-force mediator with the KLOE detector at DA Phi NE. This boson, called U, has been searched for in the decay phi -> eta U, U -> e(+)e(-), analyzing the. decay eta -> pi(0)pi(0)pi(0) in a data sample of 1.7 fb(-1). No structures are observed in the e(+)e(-) invariant mass distribution over the background. This search is combined with a previous result obtained from the decay eta -> pi(+)pi(-)pi(0), increasing the sensitivity. We set an upper limit at 90% C.L. on the ratio between the U boson coupling constant and the fine structure constant of alpha'/alpha < 1.7 x 10(-5) for 30 < M-U < 400 MeV and alpha'/alpha <= 8 x 10(-6) for the sub-region 50 < M-U <210 MeV. This result assumes the Vector Meson Dominance expectations for the phi eta gamma* transition form factor. The dependence of this limit on the transition form factor has also been studied.
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| 14. |
- Babusci, D., et al.
(author)
-
Measurement of Γ(η→π+π-γ)/Γ(η→π+π-π0) with the KLOE detector
- 2013
-
In: Physics Letters B. - : Elsevier BV. - 0370-2693 .- 1873-2445. ; 718:3, s. 910-914
-
Journal article (peer-reviewed)abstract
- The ratio Rη=Γ(η→π+π-γ)/Γ(η→π+π-π0) has been measured by analysing 22 million φ→ηγ decays collected by the KLOE experiment at DAΦNE, corresponding to an integrated luminosity of 558 pb-1. The η→π+π-γ proceeds both via the ρ resonant contribution, and possibly a non-resonant direct term, connected to the box anomaly. Our result, Rη=0.1856±0.0005stat±0.0028syst, points out a sizable contribution of the direct term to the total width. The di-pion invariant mass for the η→π+π-γ decay could be described in a model-independent approach in terms of a single free parameter, α. The determined value of the parameter α is α=(1.32±0.08stat-0.09syst+0.10±0.02theo) GeV-2.
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| 15. |
- Babusci, D., et al.
(author)
-
Study of the Dalitz decay phi -> eta e(+)e(-) with the KLOE detector
- 2015
-
In: Physics Letters B. - : Elsevier BV. - 0370-2693 .- 1873-2445. ; 742, s. 1-6
-
Journal article (peer-reviewed)abstract
- We have studied the vector to pseudoscalar conversion decay phi -> eta e(+)e(-), with.. eta -> pi(0)pi(0)pi(0), with the KLOE detector at DA phi NE. The data set of 1.7 fb(-1) of e(+)e(-) collisions at root s similar to M-phi contains a clear conversion decay signal of similar to 31,000 events from which we measured a value of BR(phi -> eta e(+)e-) = (1.075 +/- 0.007 +/- 0.038) x 10(-4). The same sample is used to determine the transition form factor by a fit to the e(+)e(-) invariant mass spectrum, obtaining b(phi eta)=( 1.28 +/- 0.10(-0.08)(+0.09)) GeV-2, that improves by a factor of five the precision of the previous measurement and is in good agreement with VMD expectations.
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| 16. |
- Babuscih, D., et al.
(author)
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Measurement of the absolute branching ratio of the K+ -> pi(+) pi(-) pi(+) (gamma) decay with the KLOE detector
- 2014
-
In: Physics Letters B. - : Elsevier BV. - 0370-2693 .- 1873-2445. ; 738, s. 128-133
-
Journal article (peer-reviewed)abstract
- The absolute branching ratio of the K+ -> pi(+) pi(-) pi(+) (gamma) decay, inclusive of final-state radiation, has been measured using similar to 17 million tagged K+ mesons collected with the KLOE detector at DA Phi NE, the Frascati phi-factory. The result is: BR(K+ -> pi(+) pi(-) pi(+) (gamma)) = 0.05565 +/- 0.00031(stat) +/- 0.00025(syst) a factor similar or equal to 5 more precise with respect to the previous result. This work completes the program of precision measurements of the dominant kaon branching ratios at KLOE.
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| 17. |
- Balkeståhl, Li Caldeira
(author)
-
Dalitz plot analysis for eta -> pi(+)pi(-)pi(0) at KLOE
- 2014
-
In: Menu 2013 - 13Th International Conference Meson-Nucleon Physics And The Structure Of The Nucleon. - : EDP Sciences.
-
Conference paper (peer-reviewed)abstract
- Based on 1.6 fb(-1) of data taken with the KLOE detector at the DA phi NE phi-factory, we present the status of the ongoing analysis of the eta -> pi(+)pi(-)pi(0) Dalitz plot. With 4.48 . 10(6) events in the Dalitz plot, the preliminary results for the Dalitz plot parameters are: a = 1.104(3), b = 0.144(3), d = 0.073(3) and f = 0.155(6).
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| 18. |
- Balkeståhl, Li Caldeira
(author)
-
Dalitz Plot analysis for eta -> pi(+)pi(-)pi(0) at KLOE
- 2014
-
In: INPC 2013 - International Nuclear Physics Conference, Vol. 2. - : EDP Sciences. ; , s. 06003-
-
Conference paper (peer-reviewed)abstract
- We present the status of an ongoing analysis of the eta -> pi(+)pi(-)pi(0) Dalitz plot, as well as preliminary results for the Dalitz plot parameters. The analysis is based on data taken at the DA Phi NE phi-factory with the KLOE detector.
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| 19. |
- Balkeståhl, Li Caldeira, et al.
(author)
-
Prospects for pp rarr YY studies at PANDA
- 2014
-
In: Hyperfine Interactions. - : Springer Science and Business Media LLC. - 0304-3843 .- 1572-9540. ; 229:1-3, s. 79-83
-
Journal article (peer-reviewed)abstract
- Strangeness and charm production provide an excellent probe of QCD in the confinement domain. With the PANDA detector at FAIR, this can be studied in e.g., hyperon production in the pp rarr YY reactions. In PANDA, all ground state strange hyperons and single charmed Lambda's will be accessible. Simulations show that the differential cross sections and spin observables can be well reconstructed for these reaction channels.
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| 20. |
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| 21. |
- Bersani, Andrea, et al.
(author)
-
The PANDA detector at FAIR
- 2012
-
In: Physica scripta. T. - : Institute of Physics Publishing (IOPP). - 0281-1847. ; T150, s. 014006-
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Journal article (peer-reviewed)abstract
- The PANDA detector will be installed at FAIR to enterprise a long-term, wide-spectrum physics program in the strong interaction framework. The detector will be installed at the HESR accumulation ring, which will provide an anti-proton beam of unprecedented luminosity and momentum definition. The beam will interact with an internal target. The detector has been designed to allow a 4π coverage around the interaction region. Due to the relatively high energy of the beam, up to 15 GeV, PANDA will feature two magnetic spectrometers: the target spectrometer (TS), with a superconducting solenoid and covering the interaction region, and a forward spectrometer (FS), with a normal-conducting dipole and covering the small angles region. Since the physics program is wide and the requirements on the various subsystems are different, the detector has been designed to be as flexible as possible. The complete detector will be described in detail, both from the viewpoint of the proposed techniques and from the viewpoint of the expected performances. An overview of the status of various components of the detector will be presented, too.
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| 22. |
- Biernat, Jacek, et al.
(author)
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Feasibility studies for the Forward Spectrometer
- 2015
-
In: Journal of Physics, Conference Series. - 1742-6588 .- 1742-6596. ; 599:1
-
Journal article (peer-reviewed)abstract
- The Forward Spectrometer designed for the P̄ANDA detector will consist of many different detector systems allowing for precise track reconstruction and particle identification. Feasibility studies for Forward Spectrometer done by means of specific reactions will be presented. In the first part of the paper, results of simulations focussing on rate estimates of the tracking stations based on straw tubes will be presented. Next, the importance of the Forward Tracker will be demonstrated through the reconstruction of the ψ(4040) → DD̄ decay. Finally, results from the analysis of the experimental data collected with a straw tube prototype designed and constructed at the Research Center in Juelich will be discussed.
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| 23. |
- Boca, Gianluigi, et al.
(author)
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The experiment PANDA: physics with antiprotons at FAIR
- 2015
-
In: EPJ Web of Conferences. - : EDP Sciences. - 2100-014X. ; 95
-
Journal article (peer-reviewed)abstract
- PANDA is an experiment that will run at the future facility FAIR, Darmstadt, Germany. A high intensity and cooled antiproton beam will collide on a fixed hydrogen or nuclear target covering center-of-mass energies between 2.2 and 5.5 GeV. PANDA addresses various physics aspects from the low energy non-perturbative region towards the perturbative regime of QCD. With the impressive theoretical developments in this field, e.g. lattice QCD, the predictions are becoming more accurate in the course of time. The data harvest with PANDA will, therefore, be an ideal test bench with the aim to provide a deeper understanding of hadronic phenomena such as confinement and the generation of hadron masses. A variety of physics topics will be covered with PANDA, for example: the formation or production of exotic non-qqbar charm meson states connected to the recently observed XYZ spectrum; the study of gluon-rich matter, such as glueballs and hybrids; the spectroscopy of the excited states of strange and charm baryons, their production cross section and their spin correlations; the behaviour of hadrons in nuclear matter; the hypernuclear physics; the electromagnetic proton form factors in the timelike region.
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| 24. |
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| 25. |
- Bremer, Daniel, et al.
(author)
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Performance of prototypes for the PANDA barrel EMC
- 2015
-
In: Journal of Physics, Conference Series. - : IOP Publishing. - 1742-6588 .- 1742-6596. ; 587:1
-
Journal article (peer-reviewed)abstract
- The PANDA experiment will be part of the future Facility for Antiproton and Ion Research (FAIR) and aims for the study of strong interaction within the charm sector via antiproton proton collisions up to antiproton momenta of 15 GeV/c. Reflecting the variety of the physics program the PANDA detector is designed as a multi-purpose detector able to perform tracking, calorimetry and particle identification with nearly complete coverage of the solid angle. The Electromagnetic Calorimeter (EMC) contained inside its Target Spectrometer is based on cooled PbWO(4) scintillator crystals. In order to ensure an excellent performance throughout the large dynamic range of photon/electron energies ranging from a few MeV up to 15 GeV an extensive prototyping phase is mandatory. This contribution describes the measured response of the EMC barrel part prototype PROTO60 at the largest design energy to secondary beams provided by the SPS at CERN. In addition to PROTO60 a tracking station was deployed, providing precise position information of the 15 GeV/c positrons. For calibration purposes a 150 GeV/c muon beam and cosmic radiation, in combination with estimations from GEANT4 simulations were used. The obtained performance concerning energy, position and time information is presented.
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