Eur. Phys. J. C (2015) 75: 361
https://doi.org/10.1140/epjc/s10052-015-3566-7

Regular Article - Experimental Physics

Bose–Einstein correlations in hadron-pairs from lepto-production on nuclei ranging from hydrogen to xenon

HERMES Collaboration

¹ Physics Division, Argonne National Laboratory, Argonne, IL, 60439-4843, USA
² Sezione di Bari, Istituto Nazionale di Fisica Nucleare, 70124, Bari, Italy
³ School of Physics, Peking University, Beijing, 100871, China
⁴ Department of Theoretical Physics, University of the Basque Country UPV/EHU, 48080, Bilbao, Spain
⁵ IKERBASQUE, Basque Foundation for Science, 48013, Bilbao, Spain
⁶ Nuclear Physics Laboratory, University of Colorado, Boulder, CO, 80309-0390, USA
⁷ DESY, 22603, Hamburg, Germany
⁸ DESY, 15738, Zeuthen, Germany
⁹ Joint Institute for Nuclear Research, Dubna, 141980, Russia
¹⁰ Physikalisches Institut, Universität Erlangen-Nürnberg, 91058, Erlangen, Germany
¹¹ Sezione di Ferrara, Istituto Nazionale di Fisica Nucleare, 44122, Ferrara, Italy
¹² Dipartimento di Fisica e Scienze della Terra, Università di Ferrara, 44122, Ferrara, Italy
¹³ Istituto Nazionale di Fisica Nucleare, Laboratori Nazionali di Frascati, 00044, Frascati, Italy
¹⁴ Department of Physics and Astronomy, Ghent University, 9000, Ghent, Belgium
¹⁵ II. Physikalisches Institut, Justus-Liebig Universität Gießen, 35392, Gießen, Germany
¹⁶ SUPA, School of Physics and Astronomy, University of Glasgow, Glasgow, G12 8QQ, UK
¹⁷ Department of Physics, University of Illinois, Urbana, IL, 61801-3080, USA
¹⁸ Randall Laboratory of Physics, University of Michigan, Ann Arbor, MI, 48109-1040, USA
¹⁹ Lebedev Physical Institute, Moscow, 117924, Russia
²⁰ National Institute for Subatomic Physics (Nikhef), 1009 DB, Amsterdam, The Netherlands
²¹ B.P. Konstantinov Petersburg Nuclear Physics Institute, Gatchina, Leningrad Region, 188300, Russia
²² Institute for High Energy Physics, Protvino, Moscow Region, 142281, Russia
²³ Institut für Theoretische Physik, Universität Regensburg, 93040, Regensburg, Germany
²⁴ Sezione di Roma, Gruppo Collegato Sanità, Istituto Nazionale di Fisica Nucleare, 00161, Rome, Italy
²⁵ Istituto Superiore di Sanità, 00161, Rome, Italy
²⁶ TRIUMF, Vancouver, BC, V6T 2A3, Canada
²⁷ Department of Physics, Tokyo Institute of Technology, Tokyo, 152, Japan
²⁸ Department of Physics and Astronomy, VU University, 1081 HV, Amsterdam, The Netherlands
²⁹ National Centre for Nuclear Research, 00-689, Warsaw, Poland
³⁰ Yerevan Physics Institute, 375036, Yerevan, Armenia

^* e-mail: gunar.schnell@desy.de

Received: 13 May 2015
Accepted: 10 July 2015
Published online: 8 August 2015

Abstract

Bose–Einstein correlations of like-sign charged hadrons produced in deep-inelastic electron and positron scattering are studied in the HERMES experiment using nuclear targets of H, H, He, He, N, Ne, Kr, and Xe. A Gaussian approach is used to parametrize a two-particle correlation function determined from events with at least two charged hadrons of the same sign charge. This correlation function is compared to two different empirical distributions that do not include the Bose–Einstein correlations. One distribution is derived from unlike-sign hadron pairs, and the second is derived from mixing like-sign pairs from different events. The extraction procedure used simulations incorporating the experimental setup in order to correct the results for spectrometer acceptance effects, and was tested using the distribution of unlike-sign hadron pairs. Clear signals of Bose–Einstein correlations for all target nuclei without a significant variation with the nuclear target mass are found. Also, no evidence for a dependence on the invariant mass W of the photon-nucleon system is found when the results are compared to those of previous experiments.