Deciphering the <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mi>X</mml:mi><mml:mo stretchy="false">(</mml:mo><mml:mn>3872</mml:mn><mml:mo stretchy="false">)</mml:mo></mml:math> via its Polarization in Prompt Production at the CERN LHC

Abstract

Based on the hypothesis that the X(3872) exotic hadron is a mixture of χ_{c1}(2P) and other states and that its prompt hadroproduction predominately proceeds via its χ_{c1}(2P) component, we calculate the prompt-X(3872) polarization at the CERN LHC through next-to-leading order in α_{s} within the factorization formalism of nonrelativistic QCD, including both the color-singlet ^{3}P_{1}^{[1]} and color-octet ^{3}S_{1}^{[8]} cc[over ¯] Fock states. We also consider the polarization of the J/ψ produced by the subsequent X(3872) decay. We predict that, under ATLAS, CMS, and LHCb experimental conditions, the X(3872) is largely longitudinally polarized, while the J/ψ is largely transversely polarized. We propose that the LHC experiments perform such polarization measurements to pin down the nature of the X(3872) and other X, Y, Z exotic states with nonzero spin.