2 research outputs found
Wigner's Friend paradoxes: consistency with weak-contextual and weak-macroscopic realism models
Wigner's friend paradoxes highlight contradictions between measurements made
by Friends inside a laboratory and superobservers outside a laboratory, who
have access to an entangled state of the measurement apparatus. The
contradictions lead to no-go theorems for observer-independent facts, thus
challenging concepts of objectivity. Here, we examine the paradoxes from the
perspective of establishing consistency with macroscopic realism. We present
versions of the Brukner-Wigner-friend and Frauchiger-Renner paradoxes in which
the spin- system measured by the Friends corresponds to two
macroscopically distinct states. The local unitary operations that
determine the measurement setting are carried out using nonlinear
interactions, thereby ensuring measurements need only distinguish between the
macroscopically distinct states. The macroscopic paradoxes are perplexing,
seemingly suggesting there is no objectivity in a macroscopic limit. However,
we demonstrate consistency with a contextual weak form of macroscopic realism
(wMR): The premise wMR asserts that the system can be considered to have a
definite spin outcome , at the time after the system has
undergone the unitary rotation to prepare it in a suitable pointer
basis. We further show that the paradoxical outcomes imply failure of
deterministic macroscopic local realism, and arise when there are unitary
interactions occurring due to a change of measurement setting at
both sites, with respect to the state prepared by each Friend. In models which
validate wMR, there is a breakdown of a subset of the assumptions that
constitute the Bell-Locality premise. A similar interpretation involving a weak
contextual form of realism exists for the original paradoxes
The Higgs Boson Reconstruction Technique in tt̄H(H →bb̄) Based On Boosted Decision Tree (BDT)
According to the Standard model, all quarks, charged leptons and W and Z bosons obtain their respective masses through their interaction with the Higgs field which gives rise to the Higgs boson. One of the important tests of the Standard Model is the measurement of the Yukawa coupling of the Higgs boson with the top quark. This coupling can be directly measured via the associated production process of pp→tt̄H