Longitudinal top polarization as a probe of a possible origin of forward–backward asymmetry of the top quark at the Tevatron

• Published in: Physics letters. B Vol. 701; no. 2; pp. 248 - 254
• Main Authors: Jung, Dong-Won, Ko, P., Lee, Jae Sik
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier B.V 04-07-2011; Elsevier
• Subjects: Exact sciences and technology; Hadron collider; New physics; Nuclear physics; Physics; The physics of elementary particles and fields; Top quark production; Hadron collider; New physics; Top quark production; P invariance; Operator; Top particles; Effective Lagrangian; Asymmetry; Spin polarization; Models; Quarks
• ISSN: 0370-2693; 1873-2445
• DOI: 10.1016/j.physletb.2011.05.058

If the forward–backward (FB) asymmetry of top quark (AFB) observed at the Tevatron deviates from the SM prediction, there must be P-violating interactions in qq¯→tt¯. This new interaction will necessarily affect the top spin polarization. In this Letter, we perform a model independent analysis on the longitudinal (anti)top polarization (PL and P¯L) using an effective lagrangian with dim-6 four-quark operators relevant for qq¯→tt¯, and show that the P-odd observable corresponding to the polarization difference (PL−P¯L) gives important informations on the chiral structures of new physics that might be relevant to the AFB.