Bounds on new Polarization parameters of an entangled channel spin-1 system Veena Adiga 1, 2* and Swarnamala Sirsi 1 1 Department of Physics, Yuvaraja’s College, University of Mysore, Mysore-05, INDIA and 2 St.Joseph’s College (autonomous), Bengaluru-27, INDIA Introduction Entanglement, which is considered to be the most nonclassical manifestation of quantum formalism is a valuable resource for quantum computation and quantum information. Here we study entanglement of a channel spin-1 system which can be realised using polarised spin 1/2 beam and polarised spin 1/2 target which naturally arise in nuclear physics ex- periments like hadron scattering and reaction processes. This discussion is best done by em- ploying a new representation for the density matrix which provides physical interpretation for the polarization parameters. These param- eters are real and shown to be related to the expectation values, variances and co-variances of spin operators J x , J y and J z . Bounds on these parameters for entangled regions of channel spin-1 system are discussed. A new representation of spin-1 density matrix The standard expression for the density ma- trix ‘ρ’ for a spin j system in terms of irre- ducible tensor operators τ k q is given by ρ = Tr(ρ) (2j + 1) 2j  k=0 +k  q=−k t k q τ k † q , (1) where t k q = Tr(ρτ k q ) Trρ . Since ρ is Hermitian and τ k † q =(−1) q τ k −q , * Electronic address: vadiga11@gmail.com t k q satisfy the condition t k ∗ q =(−1) q t k −q . Following the well known Weyl construction [1], τ k q (  J )= N kj (  J ·  ▽) k r k Y k q (ˆ r) , (2) where N kj is the normalization factor and Y k q (ˆ r) are the spherical harmonics. Considering the particular case of spin-1 density matrix, we now define a complete set of Hermitian, linearly independent operators M 0 , M 1 , ......., M 8 as follows. M 0 =  2 3 τ 0 0 , M 1 = τ 1 1 + τ 1† 1 √ 3 , M 2 = i(τ 1 1 − τ 1† 1 ) √ 3 , M 3 =  2 3 τ 1 0 , M 4 = i(τ 2 2 − τ 2† 2 ) √ 3 , M 5 = i(τ 2 1 − τ 2† 1 ) √ 3 , M 6 = τ 2 1 + τ 2† 1 √ 3 ,M 7 = τ 2 2 + τ 2† 2 √ 3 ,M 8 =  2 3 τ 2 0 . and the corresponding matrices in angular mo- mentum basis are M 0 =  2 3   100 010 001   ,M 1 = 1 √ 2   0 −1 0 −1 0 −1 0 −1 0   , M 2 = i √ 2   0 −1 0 1 0 −1 0 1 0   ,M 3 =   10 0 00 0 00 −1   , Proceedings of the DAE Symp.on Nucl. Phys. 55 (2010) 272 Avilable online at www.sympnp.org/proceedings