Heavy baryons as polarimeters at colliders

Mario Galanti, Andrea Giammanco, Yuval Grossman, Yevgeny Kats, Emmanuel Stamou, Jure Zupan

Research output: Contribution to journalArticlepeer-review

19 Scopus citations


Abstract: In new-physics processes that produce b or c jets, a measurement of the initial b or c-quark polarization could provide crucial information about the structure of the new physics. In the heavy-quark limit, the b and c-quark polarizations are preserved in the lightest baryons they hadronize into, Λb and Λc, respectively. We revisit the prediction for the polarization retention after the hadronization process and extend it to the case of transverse polarization. We show how ATLAS and CMS can measure the b-quark polarization using semileptonic Λbdecays, and the c-quark polarization using Λc+ → pKπ+ decays. For calibrating both measurements we suggest to use tt¯samples in which these polarizations can be measured with precision of order 10% using 100 fb−1 of data in Run 2 of the LHC. Measurements of the transverse polarization in QCD events at ATLAS, CMS and LHCb are motivated as well. The proposed measurements give access to nonperturbative QCD parameters relevant to the dynamics of the hadronization process.

Original languageEnglish
Article number67
Pages (from-to)1-49
Number of pages49
JournalJournal of High Energy Physics
Issue number11
StatePublished - 1 Nov 2015
Externally publishedYes

Bibliographical note

Publisher Copyright:
© 2015, The Author(s).


  • Hadronic Colliders
  • QCD Phenomenology


Dive into the research topics of 'Heavy baryons as polarimeters at colliders'. Together they form a unique fingerprint.

Cite this