A new spin on top-quark physics: using angular distributions to probe top-quark properties, and make the first observation of entanglement between quarks

Simpson, Ethan Lewis

doi:10.5525/gla.thesis.84277

A new spin on top-quark physics: using angular distributions to probe top-quark properties, and make the first observation of entanglement between quarks

Ethan Lewis Simpson
(
- Glasgow U.
)

2024

232 pages

Supervisor:

James Howarth

Thesis: PhD

Glasgow U.

(2024)

Published: 2024

DOI:

10.5525/gla.thesis.84277

reference search1 citation

Citations per year

Abstract: (Glasgow U.)

Measurements of angular properties of top-quarks constitute stringent tests of the Standard Model, probe physics beyond it, and even reveal underlying quantum information phenomena. This thesis discusses angular top-quark properties in two new contexts. A study of tt¯ spin correlations and top-quark polarisations in associated tt¯Z production presents theoretical predictions for these parameters at √s = 13TeV. A measurement strategy for observation of spin correlations in tt¯Z production at the Large Hadron Collider is proposed, and the constraint on effective field theory models provided by angular observables investigated. Related angular observables are used to make the first ever observation of quantum entanglement between quarks, in the di-leptonic tt¯ -production channel. An entanglement marker D is extracted from an angular differential cross-section measured in ATLAS √s = 13TeV proton-proton collision data, and corrected to a fiducial particle-level phase-space. This observed entanglement marker is found to be −0.547 ±0.022, corresponding to an exclusion of the no-entanglement hypothesis well in excess of five standard deviations. Short studies on novel methods to emulate the ATLAS detector response are also presented.

QB Astronomy
QC Physics

References(469)

Figures(0)

[1]

LHC Machine

Lyndon Evans
(
- CERN
)
(ed.)
,
Philip Bryant
(
- CERN
)
(ed.)

- JINST 3 (2008) S08001
•
DOI:
- 10.1088/1748-0221/3/08/S08001

[2]

Implications of Dynamical Symmetry Breaking

Steven Weinberg
(
- Harvard U.
)

- Phys.Rev.D 13 (1976) 974-996,
- Phys.Rev.D 19 (1979) 1277-1280 (addendum),
- Also in *Farhi, E. (ed.), Jackiw, R. (ed.): Dynamical Gauge Symmetry Breaking*, 127-149
•
DOI:
- 10.1103/PhysRevD.19.1277

[3]

Supersymmetric dark matter

Gerard Jungman
(
- Syracuse U.
)
,
Marc Kamionkowski
(
- Columbia U. and
- Princeton, Inst. Advanced Study
)
,
Kim Griest
(
- UC, San Diego
)

- Phys.Rept. 267 (1996) 195-373
•
e-Print:
- hep-ph/9506380
•
DOI:
- 10.1016/0370-1573(95)00058-5

[4]

Approaches to fundamental physics: An assessment of current theoretical ideas

C. Kiefer

[5]

B anomalies: Hopes, disillusions, and future prospects, Mar.. [Online]. Available:

G. Isidori

[6]

Measurement of the Positive Muon Anomalous Magnetic Moment to 0.20 ppm

Muon g-2

Collaboration

•

D.P. Aguillard
(
- Michigan U.
)

et al.

- Phys.Rev.Lett. 131 (2023) 16, 161802
•
e-Print:
- 2308.06230
•
DOI:
- 10.1103/PhysRevLett.131.161802

[7]

Precise measurement of the $W$ -boson mass with the CDF II detector

CDF

Collaboration

•

T. Aaltonen
(
- Helsinki Inst. of Phys.
)

et al.

- Phys.Rev.Lett. 108 (2012) 151803
•
e-Print:
- 1203.0275
•
DOI:
- 10.1103/PhysRevLett.108.151803

[8]

Review of semileptonic B anomalies

Bernat Capdevila
(
- Cambridge U., DAMTP and
- Barcelona, IFAE
)
,
Andreas Crivellin
(
- Zurich U. and
- PSI, SLS
)
,
Joaquim Matias
(
- Barcelona, IFAE
)

- Eur.Phys.J.ST 233 (2024) 2, 409-428,
- Eur.Phys.J.ST 1 (2023) 20
•
e-Print:
- 2309.01311
•
DOI:
- 10.1140/epjs/s11734-023-01012-2

[9]

On the Einstein-Podolsky-Rosen paradox

J.S. Bell
(
- Wisconsin U., Madison
)

- Physics Physique Fizika 1 (1964) 195-200
•
DOI:
- 10.1103/PhysicsPhysiqueFizika.1.195

[10]

Nobel Prize in Physics Summary

[11]

Observation of quantum entanglement with top quarks at the ATLAS detector

ATLAS

Collaboration

•

Georges Aad
(
- Marseille, CPPM
)

et al.

- Nature 633 (2024) 8030, 542-547
•
e-Print:
- 2311.07288
•
DOI:
- 10.1038/s41586-024-07824-z

[12]

Richard feynman on the scientific method

R. Feynman

[13]

Quantum field theory and the standard model. Cambridge University Press,(cit. on pp. 5, 10). 179 Bibliography 180

M.D. Schwartz

[14]

Field Theory and Standard Model

W. Buchmuller
(
- DESY
)
,
C. Ludeling
(
- DESY
)

e-Print:
- hep-ph/0609174

[15]

Quantum field theory

M. Srednicki

[16]

The quantum theory of fields. Cambridge university press,, vol. 2 (cit. on p. 5)

S. Weinberg

[17]

Light-Cone current Algebra, 𝜋0 Decay and 𝑒+ 𝑒- Annihilation

W.A. Bardeen
,
H. Fritzsch
,
M. Gell-Mann

[18]

Nonabelian Gauge Theories of the Strong Interactions

Steven Weinberg
(
- Harvard U.
)

- Phys.Rev.Lett. 31 (1973) 494-497,
- Also in *Mohapatra, R. N. (ed.), Lai, C. H. (ed.): Gauge Theories Of Fundamental Interactions*, 357-360, and in *Froggatt, C.D., Nielsen, H.B.: Origin of symmetries* 256-259
•
DOI:
- 10.1103/PhysRevLett.31.494

[19]

Advantages of the Color Octet Gluon Picture

- Phys.Lett.B 47 (1973) 365-368,
- Also in *Lichtenberg, D. B. (Ed.), Rosen, S. P. (Ed.): Developments In The Quark Theory Of Hadrons, Vol. 1*, 151-154
•
DOI:
- 10.1016/0370-2693(73)90625-4

[20]

Partial Symmetries of Weak Interactions

S.L. Glashow
(
- Copenhagen U.
)

- Nucl.Phys. 22 (1961) 579-588,
- Also in *Lai, C. H. (Ed.): Gauge Theory Of Weak and Electromagnetic Interactions*, 171-180
•
DOI:
- 10.1016/0029-5582(61)90469-2

[21]

A Model of Leptons

Steven Weinberg
(
- MIT, LNS
)

- Phys.Rev.Lett. 19 (1967) 1264-1266,
- Also in *Lichtenberg, D. B. (ed.), Rosen, S. P. (ed.): Developments In The Quark Theory Of Hadrons, Vol. 1*, 157-159,
- In *Lai, C. H. (ed.): Gauge Theory Of Weak and Electromagnetic Interactions*, 185-187,
- In *Rosner, J. L. (ed.): New Particles*, 26-28
•
DOI:
- 10.1103/PhysRevLett.19.1264

[22]

Weak and electromagnetic interactions

A. Salam
,
J.C. Ward

•
DOI:
- 10.1142/9789812795915_

[23]

All Possible Symmetries of the S Matrix

Sidney R. Coleman
(
- Harvard U.
)
,
J. Mandula
(
- Harvard U.
)

- Phys.Rev. 159 (1967) 1251-1256,
- Also in *Bohm, A. et al.: Dynamical groups and spectrum generating algebras, vol. 1* 469-474 and *Erice 1967, School *Ettore Majorana**, New York 1968, 393-402
•
DOI:
- 10.1103/PhysRev.159.1251

[24]

Introduction to Supersymmetry

Edward Witten
(
- Princeton U.
)

- The Unity of the Fundamental Interactions 1983, pp 305-371
•
DOI:
- 10.1007/978-1-4613-3655-6_7

[25]

Dirac operators in Riemannian geometry. American Mathematical Soc.,, vol. 25 (cit. on p. 6)

T. Friedrich

1-25 of 469
1
2
3
4
5
•••
19
25 / page