We present detailed chemical analyses for a sample of twelve stars selected from the CH star catalogue of Bartkevicius ( 1996 ) .
The sample includes two confirmed binaries , four objects that are known to show radial velocity variations and the rest with no information on the binary status .
A primary objective is to examine if all these objects exhibit chemical abundances characteristics of CH stars , based on detailed chemical composition study using high resolution spectra .
We have used high resolution ( R { \sim } 42000 ) spectra from the ELODIE archive .
These spectra cover 3900 { \AA } to 6800 { \AA } in the wavelength range .
We have estimated the stellar atmospheric parameters , the effective temperature T _ { eff } , the surface gravity log g , and metallicity [ Fe/H ] from LTE analysis using model atmospheres .
Estimated temperatures of these objects cover a wide range from 4200 K to 6640 K , the surface gravity from 0.6 to 4.3 and metallicity from - 0.13 to - 1.5 .
We report updates on elemental abundances for several heavy elements , Sr , Y , Zr , Ba , La , Ce , Pr , Nd , Sm , Eu and Dy .
For the object HDÂ 89668 we present the first abundance analyses results .
Enhancement of heavy elements relative to Fe , a characteristic property of CH stars is evident from our analyses in case of four objects , HDÂ 92545 , HDÂ 104979 , HDÂ 107574 and HDÂ 204613 .
A parametric model based study is performed to understand the relative contributions from the s- and r-process to the abundances of the heavy elements .