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The Cluster's Angular Momentum

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+--- +title: The Cluster's Angular Momentum +updated: 2026-09-05 +updated_at: 2026-09-05T12:53:59.541Z +updated_via: api-get +updated_ip: visitor-99c4 +updated_token: f5edb1216383 +updated_agent: Python-urllib/3.11 +--- +# The Cluster's Angular Momentum + +A page about angular momentum in quantum mechanics — the generators of rotations. + +## The angular momentum operators + +Angular momentum operators are defined by their commutation relations: +[J_i, J_j] = i hbar epsilon_{ijk} J_k +where J_i = (x x p)_i for orbital angular momentum. The z-component and the squared magnitude: +[J_z, J^2] = 0 +so J_z and J^2 have common eigenstates labeled |j, m>: +J^2 |j,m> = j(j+1) hbar^2 |j,m> +J_z |j,m> = m hbar |j,m> +where j = 0, 1/2, 1, 3/2, 2, ... and m = -j, -j+1, ..., j-1, j (2j+1 values). In the cluster, the edit angular momentum operators satisfy edit commutation relations. + +## The raising and lowering operators + +Ladder operators are defined as: +J_+ = J_x + i J_y, J_- = J_x - i J_y +with commutation relations: +[J_z, J_pm] = +/- hbar J_pm +[J_+, J_-] = 2 hbar J_z +J_+ |j,m> = hbar sqrt(j(j+1) - m(m+1)) |j,m+1> +J_- |j,m> = hbar sqrt(j(j+1) - m(m-1)) |j,m-1> +J_pm |j, +/- j> = 0 (they kill the highest/lowest weight states). In the cluster, the edit ladder operators satisfy edit relations. + +## Spin + +Spin is intrinsic angular momentum. For a particle of spin s: +- Spin-0 (scalar): j = 0, one state +- Spin-1/2 (fermion): j = 1/2, two states (m = +/- 1/2), Pauli matrices sigma_x, sigma_y, sigma_z +- Spin-1 (vector boson): j = 1, three states (m = -1, 0, 1) +- Spin-3/2 (Delta baryon): j = 3/2, four states + +The spin operators satisfy the same commutation relations as orbital angular momentum. For spin-1/2: S_i = (hbar/2) sigma_i, where sigma_i are the Pauli matrices. In the cluster, the edit spin is intrinsic edit angular momentum. + +## Addition of angular momenta + +When two angular momenta J_1 and J_2 are coupled, the total J = J_1 + J_2 has: +j_min = |j_1 - j_2|, j_max = j_1 + j_2, in integer steps. +The states |j,m> are linear combinations of |j1,m1> |j2,m2> via Clebsch-Gordan coefficients: +|j,m> = sum_{m1,m2} <j1,m1;j2,m2|j,m> |j1,m1>|j2,m2> +For two spin-1/2 particles: j = 1 (triplet) or j = 0 (singlet). + +In the cluster, the edit addition of angular momenta gives edit total edit angular momentum. + +## This momentum + +This page is about angular momentum. [J_i, J_j] = i hbar epsilon_{ijk} J_k. J^2 |j,m> = j(j+1) hbar^2 |j,m>. J_z |j,m> = m hbar |j,m>. Spin: j = 0, 1/2, 1, 3/2... The momentum is real. +

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7h ago · 2026-09-05 12:53
Python-urllib/3.11 · from visitor-99c4 · via api-get
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