Lai, Wai Kin
(2017)
Applications of Effective Theories of QCD in Collider Physics.
Doctoral Dissertation, University of Pittsburgh.
(Unpublished)
This is the latest version of this item.
Abstract
In this thesis, we apply effective theories of Quantum Chromodynamics (QCD) in collider
physics.
First, we apply heavy quark effective theory (HQET) on the production asymmetries of
heavy hadrons in collider experiments. Asymmetries of the partial widths of a heavy hadron
and its antiparticle contain information about CP -violation. In collider experiments, Partial
widths are inevitably entangled with production rates. Therefore, understanding production
asymmetries is essential in extracting information about CP violation from collider experiments. At leading twist in perturbative QCD, such production asymmetries are absent. Using heavy quark effective theory (HQET), we examine the subleading-twist processes which
can produce the productions asymmetries. By fitting several non-perturbative parameters
to data, the production asymmetries of D+/D− measured at LHCb can be explained reasonably well. We also make predictions on production asymmetries of ΛQ/\bar ΛQ at the LHC. The asymmetries are found to be significant in the forward region and should be measurable
by LHCb. In addition, for further investigation in the future, we compute the partonic cross
sections for P waves.
Second, we apply soft-collinear effective theory (SCET) to resum large logarithms ln(1 −m^2_VH/\hat s ) in the threshold region m^2_VH → \hat s for the associated production of the Higgs boson with a vector boson at the LHC. The effect of NNNLL resummation on the total cross
section at NNLO is found to be negligible. For the distribution in τ = M^2_VH /s, the NNLL
resummation increases the fixed-order NLO result by ∼ 10% at τ ∼ 0.1, suggesting the
the importance of threshold resummation at τ of moderate size.
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Details
| Item Type: |
University of Pittsburgh ETD
|
| Status: |
Unpublished |
| Creators/Authors: |
|
| ETD Committee: |
|
| Date: |
26 January 2017 |
| Date Type: |
Publication |
| Defense Date: |
21 September 2016 |
| Approval Date: |
26 January 2017 |
| Submission Date: |
7 October 2016 |
| Access Restriction: |
No restriction; Release the ETD for access worldwide immediately. |
| Number of Pages: |
181 |
| Institution: |
University of Pittsburgh |
| Schools and Programs: |
Dietrich School of Arts and Sciences > Physics |
| Degree: |
PhD - Doctor of Philosophy |
| Thesis Type: |
Doctoral Dissertation |
| Refereed: |
Yes |
| Uncontrolled Keywords: |
Particle Physics, QCD, Effective Field Theory, Higgs Production, Resummation, Heavy Quark Recombination |
| Date Deposited: |
26 Jan 2017 15:47 |
| Last Modified: |
27 Jan 2017 06:15 |
| URI: |
http://d-scholarship.pitt.edu/id/eprint/30622 |
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Applications of Effective Theories of QCD in Collider Physics. (deposited 26 Jan 2017 15:47)
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