Angular distributions of light projectile fragments in deep inelastic Pb + Em interactions at 160 A GeV

M.I. Adamovich - et al.

doi:doi:10.1007/s100500050365

2021 Impact factor 3.131

Hadrons and Nuclei

Eur. Phys. J. A 6, 421-425

EMU-01 Collaboration
M.I. Adamovich¹² - M.M. Agarwall¹³ - Y.A. Alexandrov¹³ - N.P. Andreeva¹ - S.K. Badyal⁷ - E.E. Basova¹⁴ - K.B. Bhalla⁶ - A. Bhasin⁷ - V.S. Bhatia³ - V. Bradnova⁵ - V.I. Bubnov¹ - X. Cai¹⁶ - I.Y. Chasnikov¹ - G.M. Chen² - L.P. Chernova¹⁵ - M.M. Chernyavsky¹² - S. Dhamija³ - K.El Chenawi¹⁰ - D. Felea³ - S.Q. Feng¹⁶ - A.S. Gaitinov¹ - E.R. Ganssauge¹¹ - S.Garpman¹⁰ - S.G. Gerasimov¹² - A. Gheata³ - M. Gheata³ - J. Grote¹³ - K.G. Gulamov¹⁵ - S.K. Gupta⁶ - V.K. Gupta⁷ - U. Henjes¹¹ - B. Jakobsson¹⁰ - E.K. Kanygina¹ - M. Karabova⁸ - S.P.Kharlamov¹² - A.D. Kovalenko⁵ - S.A. Krasnov⁵ - V.Kumar⁶ - V.G. Larionova¹² - F.G. Lepekhin¹⁷ - O.V. Levitskaya¹⁷ - Y.X. Li⁴ - L.S. Liu¹⁶ - S. Lokanathan⁶ - J.J. Lord¹³ - N.S. Lukicheva¹⁵ - Y. Lu² - S.B. Luo⁹ - L.K. Mangotra⁷ - I. Manhas⁷ - I.S. Mittra³ - A.K. Musaeva¹ - S.Z. Nasyrov¹⁴ - V.S. Navotny¹⁵ - J. Nystrand¹⁰ - I. Otterlund¹⁰ - N.G. Peresadko¹² - W.Y. Qian¹⁶ - Y.M. Qin⁹ - R. Raniwala⁶ - N.K. Rao⁷ - M.Roeper¹¹ - V.V. Rusakova⁵ - N. Saidkhanov¹⁵ - N.A. Salmanova¹² - A.M. Seitimbetov¹ - D.M. Seliverstov¹⁷ - B.B. Simonov¹⁷ - R. Sethi³ - B. Singh⁶ - D. Skelding¹³ - K. Soderstrem¹⁰ - E. Stenlund¹⁰ - L.N. Svechnikova¹⁵ - T. Svensson¹⁰ - A.M. Tawfik¹¹ - M. Tothova⁸ - M.I. Tretyakova¹² - T.P.Trofimova¹⁴ - U.I. Tuleeva¹⁴ - Vani Vashisht³ - S. Vokal⁸ - J. Vrlakova⁸ - H.Q. Wang² - X.R. Wang¹⁶ - Z.Q. Weng⁴ - R.J. Wilkes¹³ - C.B. Yang¹⁶ - Z.B. Yin¹⁶ - L.Z. Yu¹⁶ - D.H. Zhang⁹ - P.Y. Zheng² - S.I. Zhokhova¹⁵ - D.C. Zhou¹⁶

¹ High Energy Physics Institute, Almaty, Kazakstan
² Institute of High Energy Physics, Academia Sinica, Beijing, P.R. China
³ Department of Physics, Panjab University, Chandrigarh, India
⁴ Department of Physics, Hunan Education Institute, Changsha, Hunan, P.R. China
⁵ Joint Institute for Nuclear Research (JINR), Dubna, Russia
⁶ Department of Physics, University of Rajastan, Jaipur, India
⁷ Department of Physics, University of Jammu, Jammu, India
⁸ Department of Nuclear Physics and Biophysics, Safarik University, Kosice, Slovacia
⁹ Department of Physics, Shanxi Normal University, Linfen, Shanxi, P.R. China
¹⁰ Department of Physics, University of Lund, Lund, Sweden
¹¹ F.B.Physik, Philipps University, Marburg, Germany
¹² P.N.Lebedev Institute of Physics, Moscow, Russia
¹³ Department of Physics, University of Wasington, Seattle, Washington, USA
¹⁴ Institute of Nuclear Physics, Tashkent, Usbekistan
¹⁵ Physical-Technical Institute, Tashkent, Usbekistan
¹⁶ Institute of Particle Physics, Hua-Zhong Normal University, Wuhan, Hubei, P.R. China
¹⁷ St.Peterburg Nuclear Physics Institute, St.Peterburg, Russia

Received: 15 June 1999 / Revised version: 20 August 1999 Communicated by V.V. Anisovich

Abstract
The nuclear emulsion was exposed at CERN by the lead projectile at 160 A GeV. The angles between any pair of fragments with Z=2-4 have been measured in the emulsion plane for the events which did not contain heavy fragments. The constant characterizing the normal angle ( $\varphi$ ) distribution of the fragment momentum projection onto the emulsion plane with respect to initial projectile momentum ${\bf p_{0}}$ is found to be $\sigma_{\varphi}=(0.37\pm 0.02)$ mrad. Corresponding value $\sigma_{0}=(121\pm 6)$ MeV/c of nucleon momentum distribution in the lead nucleus coincides with that expected from Fermi momentum distribution for this nucleus. The peak in the pair-angle distribution of double-charged fragments, $^{8}Be\rightarrow2\alpha$ , is presented for the region of small angles ( $\,<\,0.1$ mrad). The fraction of $\alpha$ -particles coming from the decay of the ground state ⁸Be is found to be $(13\pm 2)\%$ of their whole number.