Discrimination of Ohmic thermal baths by quantum dephasing probes

We address the discrimination of structured baths at different temperatures by dephasing quantum probes. derive exact reduced dynamics and evaluate minimum error probability achievable three kinds probes, namely, a qubit, qutrit, register made two qubits. Our results indicate that probes are useful in discriminating low values temperature lower probabilities achieved for intermediate interaction time, where scales as $1/2N$, with $N$ number energy levels probe. A qutrit probe outperforms qubit one task, whereas entangled show smaller optimal times.