Magnetic moment measurement of baryons with heavy-flavored quarks by planar channeling through a bent crystal

The precession angle of a polarization vector is calculated for a positively charged short-lived baryon channeling between single-crystal planes. When very energetic polarized baryons are produced such that the production plane of the baryon is almost parallel to the crystal plane, it is shown that the interaction of the polarization with inhomogeneous electric fields inside the crystal can be neglected from the equation of motion of the particle. In this case, the equation of motion of the polarization vector becomes the same as when the electric field is homogeneous. It is also shown that when the crystal is bent perpendicular to the planar direction, the precession angle of the polarization vector of short-lived baryons can be expressed ass Δθ R τ = 1 2 γ 2 [(2 − g + g/γ 2 )]ντ/R under the same condition as above, where γ is the Lorentz factor, g the g factor of the magnetic moment, R the bending radius of the crystal and τ the lifetime of the particle. It is also shown that in some cases this precession should be large enough to determine the magnetic moment of short-lived particles, such as the charmed baryon Λ c + .