Abstract.
The \( \Lambda\) polarization, the analyzing power, and the \( \Lambda\) spin transfer coefficient of the reaction pp \( \rightarrow\) pK + \( \Lambda\) were measured at beam momenta of 2.70GeV/c and 2.95GeV/c corresponding to excess energies of 122MeV and 204MeV. While the analyzing power and the spin transfer coefficient do not change significantly with the excess energy, the \( \Lambda\) polarization varies strongly and changes its sign. As this is the first measurement of polarization observables below an excess energy of 200MeV, the change of the sign of the \( \Lambda\) polarization was not observed before. The high statistics of the data ( \( \approx\) 200 k events for each momentum) enables detailed studies of the dependence of the \( \Lambda\) polarization and the analyzing power on the center-of-mass momentum of the particles. The results of the spin transfer coefficient are in qualitative agreement with the DISTO experiment. The \( \Lambda\) polarization data of 2.95GeV/c are only conform with the DISTO experiment, while both the 2.70GeV/c and 2.95GeV/c data differ strongly from all previous measurements, whether exclusive or inclusive.
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References
COSY-TOF Collaboration (S. Jowzaee et al.), Eur. Phys. J. A 52, 7 (2016)
G. Bunce et al., Phys. Rev. Lett. 36, 1113 (1976)
HADES Collaboration (G. Agakishiev et al.), Eur. Phys. J. A 50, 81 (2014)
DISTO Collaboration (S. Choi), Nucl. Phys. A 639, 1 (1998)
R. Muenzer, private communication (2015)
B.E. Bonner et al., Phys. Rev. Lett. 58, 447 (1987)
B.E. Bonner et al., Phys. Rev. D 38, 729 (1988)
E704 Collaboration (A. Bravar et al.), Phys. Rev. Lett. 78, 4003 (1997)
DISTO Collaboration (F. Balestra et al.), Phys. Rev. Lett. 83, 1534 (1999)
F. Hauenstein, PhD Thesis, University Erlangen-Nuernberg (2014) http://opus4.kobv.de/opus4-fau/frontdoor/index/index/docId/5614
S. Jowzaee, PhD Thesis, Jagiellonian University Cracow (2014) http://juser.fz-juelich.de/record/185801
R. Arndt, W. Briscoe, I. Strakovsky, R. Workman, Phys. Rev. C 76, 025209 (2007)
COSY-TOF Collaboration (M. Röder et al.), Eur. Phys. J. A 49, 157 (2013)
R. Gebel, O. Felden, R. Maier, AIP Conf. Proc. 980, 231 (2008)
D. Besset et al., Nucl. Instrum. Methods 166, 515 (1979)
G.G. Ohlsen, P.W. Keaton, Nucl. Instrum. Methods 109, 41 (1973)
Particle Data Group Collaboration (K. Olive et al.), Chin. Phys. C 38, 090001 (2014)
COSY-TOF Collaboration (R. Bilger et al.), Phys. Lett. B 420, 217 (1998)
K.J. Heller et al., Phys. Rev. Lett. 41, 607 (1978)
F. Abe et al., Phys. Rev. D 34, 1950 (1986)
R608 Collaboration (A.M. Smith et al.), Phys. Lett. B 185, 209 (1987)
J. Felix et al., Phys. Rev. Lett. 76, 22 (1996)
J. Felix et al., Phys. Rev. Lett. 82, 5213 (1999)
B. Lundberg et al., Phys. Rev. D 40, 3557 (1989)
E690 Collaboration (J. Felix et al.), Phys. Rev. Lett. 88, 061801 (2002)
E. Ramberg et al., Phys. Lett. B 338, 403 (1994)
NA48 Collaboration (V. Fanti et al.), Eur. Phys. J. C 6, 265 (1999)
HERA-B Collaboration (I. Abt et al.), Phys. Lett. B 638, 415 (2006)
ATLAS Collaboration (G. Aad et al.), Phys. Rev. D 91, 032004 (2015)
H.A. Neal, E. De La Cruz Burelo, arXiv:hep-ph/0602079 (2006)
E.C. Dukes et al., Phys. Lett. B 193, 135 (1987)
R608 Collaboration (T. Henkes et al.), Phys. Lett. B 283, 155 (1992)
J. Felix, AIP Conf. Proc. B 857, 320 (2006)
J. Felix, PoS (HEP2005), 122 (2006)
DISTO Collaboration (M. Maggiora), Nucl. Phys. A 691, 329 (2001)
DISTO Collaboration (F. Balestra), Nucl. Phys. Proc. Suppl. 93, 58 (2001)
A. Saha et al., Phys. Rev. Lett. 51, 759 (1983)
J.A. Niskanen, AIP Conf. Proc. 69, 62 (1981)
A. Gasparyan, J. Haidenbauer, C. Hanhart, Phys. Rev. C 72, 034006 (2005)
COSY-TOF Collaboration (F. Hauenstein), arXiv:nucl-ex/1607.04783 (2016)
F. Hauenstein et al., Nucl. Instrum. Methods A 817, 42 (2016)
A. Lesnik et al., Phys. Rev. Lett. 35, 770 (1975)
DISTO Collaboration (F. Balestra et al.), Nucl. Instrum. Methods A 426, 385 (1999)
J. Laget, Phys. Lett. B 259, 24 (1991)
G. Fäldt, C. Wilkin, Eur. Phys. J. A 24, 431 (2005)
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The COSY-TOF Collaboration., Hauenstein, F., Borodina, E. et al. Measurement of polarization observables of the associated strangeness production in proton proton interactions. Eur. Phys. J. A 52, 337 (2016). https://doi.org/10.1140/epja/i2016-16337-1
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DOI: https://doi.org/10.1140/epja/i2016-16337-1