Measurement of transverse polarization of Λ and Λ ̅ hyperons inside jets in unpolarized proton-proton collisions at √s=200 GeV

@article{aboona2026measurement,
  title = {{Measurement of transverse polarization of Λ and $$\overline\Lambda $$ hyperons inside jets in unpolarized proton-proton collisions at $$\sqrts=200$$ GeV}},
  author = {B. E. Aboona and Jaroslav Adam and G. Agakishiev and I. Aggarwal and Madan Mohan Aggarwal and Z. Ahammed and A. Aitbayev and Igor Genadievich Alekseev and E. Alpatov and A. K. Alshammri and A. Aparin and S. Aslam and Joseph E. Atchison and G. S. Averichev and V. Bairathi and Xianwen Bao and P. Barik and Kenneth N. Barish and S. Behera and Pratibha Bhagat and A. Bhasin and S. Bhatta and Igor G. Bordyuzhin and J. D. Brandenburg and A. V. Brandin and C. Broodo and X. Z. Cai and H. Caines and M. Calderon De La Barca Sanchez and D. Cebra and Jakub Ceska and I. Chakaberia and Y. S. Chang and Z. Chang and Arghya Chatterjee and D. Chen and Jinhui Chen and L. Chen and Q. Chen and W. Chen and Zhenyu Chen and J. Cheng and Yunshan Cheng and W. Christie and X. Chu and S. Corey and H. J. Crawford and Gabriel Dale-Gau and Ayanabha Das and D. S. Lemos and T. G. Dedovich and Ingo Deppner and A. A. Derevschikov and Abhay Deshpande and A. Dhamija and Aman Dimri and Prabhupada Dixit and X. Dong and J. L. Drachenberg and E. Duckworth},
  journal = {Journal of High Energy Physics},
  year = {2026},
  month = jun,
  doi = {10.1007/jhep06(2026)050},
  url = {https://doi.org/10.1007/jhep06(2026)050},
  note = {CC BY},
}

TY  - JOUR
TI  - Measurement of transverse polarization of Λ and Λ ̅ hyperons inside jets in unpolarized proton-proton collisions at √s=200 GeV
AU  - B. E. Aboona
AU  - Jaroslav Adam
AU  - G. Agakishiev
AU  - I. Aggarwal
AU  - Madan Mohan Aggarwal
AU  - Z. Ahammed
AU  - A. Aitbayev
AU  - Igor Genadievich Alekseev
AU  - E. Alpatov
AU  - A. K. Alshammri
AU  - A. Aparin
AU  - S. Aslam
AU  - Joseph E. Atchison
AU  - G. S. Averichev
AU  - V. Bairathi
AU  - Xianwen Bao
AU  - P. Barik
AU  - Kenneth N. Barish
AU  - S. Behera
AU  - Pratibha Bhagat
AU  - A. Bhasin
AU  - S. Bhatta
AU  - Igor G. Bordyuzhin
AU  - J. D. Brandenburg
AU  - A. V. Brandin
AU  - C. Broodo
AU  - X. Z. Cai
AU  - H. Caines
AU  - M. Calderon De La Barca Sanchez
AU  - D. Cebra
AU  - Jakub Ceska
AU  - I. Chakaberia
AU  - Y. S. Chang
AU  - Z. Chang
AU  - Arghya Chatterjee
AU  - D. Chen
AU  - Jinhui Chen
AU  - L. Chen
AU  - Q. Chen
AU  - W. Chen
AU  - Zhenyu Chen
AU  - J. Cheng
AU  - Yunshan Cheng
AU  - W. Christie
AU  - X. Chu
AU  - S. Corey
AU  - H. J. Crawford
AU  - Gabriel Dale-Gau
AU  - Ayanabha Das
AU  - D. S. Lemos
AU  - T. G. Dedovich
AU  - Ingo Deppner
AU  - A. A. Derevschikov
AU  - Abhay Deshpande
AU  - A. Dhamija
AU  - Aman Dimri
AU  - Prabhupada Dixit
AU  - X. Dong
AU  - J. L. Drachenberg
AU  - E. Duckworth
PY  - 2026
DA  - 2026/06/04
JO  - Journal of High Energy Physics
DO  - 10.1007/jhep06(2026)050
UR  - https://doi.org/10.1007/jhep06(2026)050
AB  - A bstract A surprisingly large transverse polarization of Λ hyperons in unpolarized hadron-nucleon/nucleus collisions has been observed for 50 years, and the origin of this polarization remains an important open question. Recently, theoretical frameworks have advanced in describing this puzzle with the polarizing fragmentation function (PFF). We report the first measurement of Λ and Λ ̅ transverse polarization inside jets in unpolarized proton-proton collisions, which is directly attributed to the PFF. The polarization is measured as a function of the jet transverse momentum, the fraction of the jet momentum carried by Λ (Λ ̅) hyperons, and the transverse momentum of Λ (Λ ̅) hyperons relative to the jet axis. Covering a wide jet-energy range, these data provide the first constraints on the gluon PFF and allow tests of TMD evolution and its universality.
SN  - 1029-8479
SN  - 1126-6708
SN  - 1127-2236
ER  -