European Physical Journal C: Particles and Fields (Oct 2023)

Two-pion femtoscopic correlations in Be+Be collisions at $$\sqrt{s_{\text {NN}}} = 16.84$$ s NN = 16.84 GeV measured by the NA61/SHINE at CERN

  • H. Adhikary,
  • P. Adrich,
  • K. K. Allison,
  • N. Amin,
  • E. V. Andronov,
  • T. Antićić,
  • I.-C. Arsene,
  • M. Bajda,
  • Y. Balkova,
  • M. Baszczyk,
  • D. Battaglia,
  • A. Bazgir,
  • S. Bhosale,
  • M. Bielewicz,
  • A. Blondel,
  • M. Bogomilov,
  • Y. Bondar,
  • N. Bostan,
  • A. Brandin,
  • W. Bryliński,
  • J. Brzychczyk,
  • M. Buryakov,
  • A. F. Camino,
  • M. Ćirković,
  • M. Csanád,
  • J. Cybowska,
  • T. Czopowicz,
  • C. Dalmazzone,
  • N. Davis,
  • A. Dmitriev,
  • P. von Doetinchem,
  • W. Dominik,
  • P. Dorosz,
  • J. Dumarchez,
  • R. Engel,
  • G. A. Feofilov,
  • L. Fields,
  • Z. Fodor,
  • M. Friend,
  • A. Garibov,
  • M. Gaździcki,
  • O. Golosov,
  • V. Golovatyuk,
  • M. Golubeva,
  • K. Grebieszkow,
  • F. Guber,
  • S. N. Igolkin,
  • S. Ilieva,
  • A. Ivashkin,
  • A. Izvestnyy,
  • K. Kadija,
  • N. Kargin,
  • N. Karpushkin,
  • E. Kashirin,
  • M. Kiełbowicz,
  • V. A. Kireyeu,
  • H. Kitagawa,
  • R. Kolesnikov,
  • D. Kolev,
  • Y. Koshio,
  • V. N. Kovalenko,
  • S. Kowalski,
  • B. Kozłowski,
  • A. Krasnoperov,
  • W. Kucewicz,
  • M. Kuchowicz,
  • M. Kuich,
  • A. Kurepin,
  • A. László,
  • M. Lewicki,
  • G. Lykasov,
  • V. V. Lyubushkin,
  • M. Maćkowiak-Pawłowska,
  • Z. Majka,
  • A. Makhnev,
  • B. Maksiak,
  • A. I. Malakhov,
  • A. Marcinek,
  • A. D. Marino,
  • K. Marton,
  • H.-J. Mathes,
  • T. Matulewicz,
  • V. Matveev,
  • G. L. Melkumov,
  • A. Merzlaya,
  • Ł. Mik,
  • A. Morawiec,
  • S. Morozov,
  • Y. Nagai,
  • T. Nakadaira,
  • M. Naskręt,
  • S. Nishimori,
  • V. Ozvenchuk,
  • O. Panova,
  • V. Paolone,
  • O. Petukhov,
  • I. Pidhurskyi,
  • R. Płaneta,
  • P. Podlaski,
  • B. A. Popov,
  • B. Pórfy,
  • M. Posiadała-Zezula,
  • D. S. Prokhorova,
  • D. Pszczel,
  • S. Puławski,
  • J. Puzović,
  • R. Renfordt,
  • L. Ren,
  • V. Z. Reyna Ortiz,
  • D. Röhrich,
  • E. Rondio,
  • M. Roth,
  • Ł. Rozpłochowski,
  • B. T. Rumberger,
  • M. Rumyantsev,
  • A. Rustamov,
  • M. Rybczynski,
  • A. Rybicki,
  • K. Sakashita,
  • K. Schmidt,
  • A. Yu. Seryakov,
  • P. Seyboth,
  • U. A. Shah,
  • Y. Shiraishi,
  • A. Shukla,
  • M. Słodkowski,
  • P. Staszel,
  • G. Stefanek,
  • J. Stepaniak,
  • M. Strikhanov,
  • H. Ströbele,
  • T. Šuša,
  • Ł. Świderski,
  • J. Szewiński,
  • R. Szukiewicz,
  • A. Taranenko,
  • A. Tefelska,
  • D. Tefelski,
  • V. Tereshchenko,
  • A. Toia,
  • R. Tsenov,
  • L. Turko,
  • T. S. Tveter,
  • M. Unger,
  • M. Urbaniak,
  • F. F. Valiev,
  • D. Veberič,
  • V. V. Vechernin,
  • V. Volkov,
  • A. Wickremasinghe,
  • K. Wójcik,
  • O. Wyszyński,
  • A. Zaitsev,
  • E. D. Zimmerman,
  • A. Zviagina,
  • R. Zwaska,
  • NA61/SHINE Collaboration

DOI
https://doi.org/10.1140/epjc/s10052-023-11997-8
Journal volume & issue
Vol. 83, no. 10
pp. 1 – 15

Abstract

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Abstract This paper reports measurements of two-pion femtoscopic correlations in Be+Be collisions at a beam momentum of 150 $$A\,\hbox {GeV}\!/\!c$$ A GeV / c (energy available in the center-of-mass system for nucleon pair $$\sqrt{s_{\text {NN}}} = 16.84$$ s NN = 16.84 GeV) by the NA61/SHINE experiment at the CERN SPS accelerator. The obtained momentum space correlation functions can be well described by a Lévy distributed source model. The transverse mass dependence of the Lévy source parameters is presented, and their possible theoretical interpretations are discussed. The results show that the Lévy exponent $$\alpha $$ α is approximately constant as a function of $$m_{\text {T}}$$ m T , and far from both the Gaussian case of $$\alpha = 2$$ α = 2 or the conjectured value at the critical endpoint, $$\alpha = 0.5$$ α = 0.5 . The radius scale parameter R shows a slight decrease in $$m_{\text {T}}$$ m T , which can be explained as a signature of transverse flow. Finally, an approximately constant trend of the intercept parameter $$\lambda $$ λ as a function of $$m_{\text {T}}$$ m T was observed, similar to previous NA44 S + Pb results (obtained with a Gaussian approximation, but unlike RHIC results).