자료유형  

 학위논문

Control Number  

0017163303

International Standard Book Number  

9798384423935

Dewey Decimal Classification Number  

593.7

Main Entry-Personal Name  

Sathyan, Deepak.

Publication, Distribution, etc. (Imprint  

[S.l.] : University of Maryland, College Park., 2024

Publication, Distribution, etc. (Imprint  

Ann Arbor : ProQuest Dissertations & Theses, 2024

Physical Description  

94 p.

General Note  

Source: Dissertations Abstracts International, Volume: 86-03, Section: B.

General Note  

Advisor: Agashe, Kaustubh.

Dissertation Note  

Thesis (Ph.D.)--University of Maryland, College Park, 2024.

Summary, Etc.  

요약The Standard Model (SM) of particle physics has been extremely successful in describing the interactions of electromagnetic, weak nuclear, and strong nuclear forces. Yet, there are both unexplained phenomena and experimentally observed tensions with the SM, motivating searches for new physics (NP).Collider experiments typically perform two kinds of analyses: direct searches for new physics and precision measurements of SM observables. For example, experimental collaborations use collider data to search for NP particles like the heavy superpartners of the SM particles, whose observation would be clear evidence of supersymmetry (SUSY). These direct searches often consider kinematic regions where the SM background is small. This strategy is unable to probe regions of the NP parameter space where the SM background is dominant.The same collaborations also measure the masses of SM particles, which not only serve as consistency tests of the SM, but can also probe effects of NP. In 2022, the Collider Detector at Fermilab (CDF) collaboration published the most precise measurement of the W boson mass: mW = 80433.5 ± 9.4 MeV. This measurement is in 7σ significance tension with the SM prediction via the electroweak (EW) fit, mWpred. = 80354 ± 7 MeV. Many extensions to the SM can affect the prediction of mW with indirect effects of heavy NP. However, in 2023, the ATLAS re-measurement of the W boson mass, mW = 80360 ± 16 MeV, was found to be consistent with the SM prediction. Both collaborations found a high-precision agreement between the measured kinematic distributions and the SM prediction of the kinematic distributions for their corresponding extracted mW.We propose using the precision measurements of mW to directly probe NP contributing to the same final state used to measure mW : a single charged lepton ℓ and missing transverse energy ET . This strategy is independent of modifying the EW fit, which tests indirect effects of NP on the predicted value of mW . Any NP producing ℓ+ ET which modifies the kinematic distributions used to extract mW can be probed with this method. With this strategy, since these distributions are used to search for NP while measuring mW , a simultaneous fit of NP and SM parameters is required, thus unifying searches and measurements. This simultaneous fitting can induce a bias in the measured mW , but only to a limited extent for our considered models.We consider three categories of NP which can be probed: (i) modified decay of W bosons; (ii) modified production of W bosons; and (iii) ℓ + ET scenarios without an on-shell W boson. We also show that models whose signals extend beyond the kinematic region used to measure mW can be probed in an intermediate kinematic region. Our results highlight that new physics can still be discovered at the LHC, including light new physics, via SM precision measurements. Additionally, anticipated improvements in precision SM measurements at the High Luminosity LHC further enables new searches for physics Beyond the Standard Model (BSM).

Subject Added Entry-Topical Term  

Particle physics.

Subject Added Entry-Topical Term  

Theoretical physics.

Subject Added Entry-Topical Term  

Physics.

Subject Added Entry-Topical Term  

Nuclear physics.

Subject Added Entry-Topical Term  

Computational physics.

Index Term-Uncontrolled  

Invisible new physics

Index Term-Uncontrolled  

Precision measurements

Index Term-Uncontrolled  

Searches and measurements

Index Term-Uncontrolled  

Supersymmetry

Index Term-Uncontrolled  

W boson mass

Added Entry-Corporate Name  

University of Maryland, College Park Physics

Host Item Entry  

Dissertations Abstracts International. 86-03B.

Electronic Location and Access  

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Control Number  

joongbu:656070