Laboratory-frame tests of quantum entanglement in $H \to WW$

We present the first analysis of top spin polarizations, $$ t\overline{t} $$ t t ¯ spin correlations, and $$ t\overline{t} $$ t t ¯ spin entanglement at the LHC in the context of the Standard Model Effective Field Theory, that goes beyond Leading Order QCD accuracy. The complete set of independent dimension-6 operators entering $$ t\overline{t} $$ t t ¯ production is identified, and their effects on all top spin observables are extracted at linear and quadratic order in c/Λ2. By comparing results at LO and NLO, we note that the inclusion of higher orders, while not dramatically changing the picture, often amounts to notable numerical differences, that are not fully captured by LO scale variation. We also find that the expected deviations from the SM have an intricate phase space structure, and show up predominantly at large top pT. For this reason, we advocate for the measurement of spin observables differentially or doubly-differentially in the $$ t\overline{t} $$ t t ¯ phase-space. We show how the inclusion of present and future top spin measurements will improve global fits to top LHC data, by also addressing the issue of flat directions.

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“…with progress having been reported recently [17]. Other collider processes have also been investigated [21][22][23][24][25][26].…”

Section: Jhep01(2023)148mentioning

confidence: 99%

Quantum entanglement and top spin correlations in SMEFT at higher orders

Severi

Vryonidou

2023

J. High Energ. Phys.

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“…Numerous studies based on simulations [2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17] have elaborated further on these ideas, providing evidence that several more quantum effects may be visible in data collected (and to be collected) at the LHC, as well as at future colliders. Apart from establishing entanglement, these measurements could also potentially detect a violation of Bell inequalities.…”

Section: Introductionmentioning

confidence: 99%

Quantum detection of new physics in top-quark pair production at the LHC

Maltoni,

Severi,

Tentori

et al. 2024

J. High Energ. Phys.

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The recent observation of entanglement between top and anti-top quarks at the LHC opens the way to interpreting collider data with quantum information tools. In this work we investigate the relevance of quantum observables in searches of new physics. To this aim, we study spin correlations of $$t\overline{t }$$ pairs originating from various intermediate resonances, and compare the discovery reach of quantum observables compared to classical ones. We find that they provide complementary information and, in several notable cases, also the additional leverage necessary to detect new effects.

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Laboratory-frame tests of quantum entanglement in $H \to WW$

Cited by 2 publications

References 22 publications

Quantum entanglement and top spin correlations in SMEFT at higher orders

Quantum entanglement and top spin correlations in SMEFT at higher orders

Quantum detection of new physics in top-quark pair production at the LHC

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