자료유형  

 학위논문

Control Number  

0017164476

International Standard Book Number  

9798384044291

Dewey Decimal Classification Number  

539.7

Main Entry-Personal Name  

Nunez, Cynthia.

Publication, Distribution, etc. (Imprint  

[S.l.] : University of Michigan., 2024

Publication, Distribution, etc. (Imprint  

Ann Arbor : ProQuest Dissertations & Theses, 2024

Physical Description  

160 p.

General Note  

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

General Note  

Advisor: Aidala, Christine.

Dissertation Note  

Thesis (Ph.D.)--University of Michigan, 2024.

Summary, Etc.  

요약Λ hyperons are baryons consisting of up, down, and strange (uds) valence quarks. Spontaneous transverse polarization of Λ hyperons produced in unpolarized hadronic collisions was first observed over four decades ago and contradicted expectations from early leading-order perturbative calculations in quantum chromodynamics (QCD). Recent studies have linked the polarization to spin-momentum correlations in the process of hadronization. In theoretical calculations, hyperon polarization from unpolarized proton-proton and proton-nucleus collisions comes from including spin-momentum correlations either as higher-order twist-3 collinear multi-parton correlation matrix elements or as a convolution of a twist-2 transverse-momentum-dependent parton distribution function with a transverse-momentum-dependent fragmentation function. Complementary measurements of hyperon polarization from unpolarized hadronic collisions, electron-positron annihilation, and semi-inclusive deep-inelastic lepton-nucleon scattering measurements can advance our understanding of this effect in QCD. The Large Hadron Collider beauty (LHCb) experiment at the Large Hadron Collider studies proton-proton, proton-nucleus, and nucleus-nucleus collisions at TeV energy scales. It is unique among hadronic collider experiments in its forward detector geometry, providing complementary kinematic coverage. The Λ and Λ polarization transverse to the production plane is measured in proton-lead collisions at a center-of-mass energy of √sNN = 5.02 TeV, using minimum bias data collected by the LHCb detector in the year 2013. The measured transverse polarization averaged over transverse momentum, pT , from 0 to 6 GeV/c and Feynman-x, xF , from 0.005 to 0.04 is 0.005 ± 0.005(stat) ± 0.007(sys) for Λ and 0.007±0.005(stat)±0.006(sys) for Λ. The measured transverse polarization averaged over pT from 0 to 6 GeV/c and xF from -0.10 to -0.01 is 0.004 ± 0.004(stat) ± 0.010(sys) for Λ and −0.005 ± 0.005(stat) ± 0.006(sys) for Λ. The polarization is additionally measured as a function of xF and pT and is consistent with zero. The results are compared to prior measurements, including a concurrent measurement using LHCb fixed-target proton-neon data. The LHCb results are compatible with the trends of previous measurements, adding additional data at different energies and collision configurations in a kinematic region that was previously poorly explored.

Subject Added Entry-Topical Term  

Nuclear physics.

Subject Added Entry-Topical Term  

Physics.

Subject Added Entry-Topical Term  

Particle physics.

Subject Added Entry-Topical Term  

Quantum physics.

Index Term-Uncontrolled  

Hyperon polarization

Index Term-Uncontrolled  

Quantum chromodynamics

Index Term-Uncontrolled  

High-energy nuclear physics

Index Term-Uncontrolled  

High-energy particle physics

Index Term-Uncontrolled  

Large hadron collider

Added Entry-Corporate Name  

University of Michigan Physics

Host Item Entry  

Dissertations Abstracts International. 86-03B.

Electronic Location and Access  

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Control Number  

joongbu:656950