Measurement of high-mass dimuon production for p+p and p+d collisions with 120 GeV proton beam at Fermilab

SeaQuest is a fixed-target experiment at Fermilab using 120 GeV proton beam from the Main Injector. High-mass muon pairs from the interaction of proton beam with various liquid and solid targets were detected in a newly constructed spectrometer. The primary goal of the experiment is to study the sea quark contents in nucleons and nuclei. In particular, the Drell-Yan cross-section ratios for liquid deuterium over hydrogen will allow the measurement of sea quark asymmetry, $\bar{d}/\bar{u}$, for Bjorken-{\it x} ranging from 0.1 to 0.45, extending the measurements of the previous experiment NuSea/E866. Improved statistics expected at SeaQuest for ${\it x}>0.25$ will allow us to check the surprising behaviour of $\bar{d}/\bar{u}$ at large {\it x} observed in NuSea. Additionally, SeaQuest data also provides the opportunity to study other very interesting physics. One such physics is the absolute p+d and p+p Drell-Yan differential cross-section (M³d²σ/dMdx_F). The measurement of the Drell-Yan cross-section allows improved constraints on the magnitude and shape of sea and valence parton distribution functions (PDFs). In particular, the p+d measurement is sensitive to the $\bar{d}(x)+\bar{u}(x)$ distribution. This quantity is required for extracting $\bar{d}(x)-\bar{u}(x)$ from $\bar{d}(x)/\bar{u}(x)$. The current global PDFs for light sea quarks are very poorly constrained beyond Bjorken-{\it x} $>$ 0.3. SeaQuest coverage in dimuon mass (M_μ^-μ⁺) ranging from 4.2 GeV to 8.8 GeV (equivalently $\sqrt{\tau}$ in range 0.3 to 0.9 ) and Feynman-{\it x} (x_F) ranging from 0 to 0.8 will extend the measurement from NuSea. Current results are presented in chapter 5. A comparison of E866 p+d and E772 p+d measurement is presented in chapter 8. The transverse momentum dependence of the Drell-Yan cross-sections has also been presented. Results on double differential cross sections (d²σ/dMdp_T and d²σ/dx_Fdp_T) from p+d and p+p Drell-Yan data from SeaQuest are presented in chapter 7. The analysis of p_T distribution from SeaQuest data will provide the value of <p_T> for the lowest value of $\sqrt{s}$ in the study of dependence of <p_T> on $\sqrt{s}$. Additionally, p_T data from existing Drell-Yan experiments have been analyzed and compiled systematically to study possible dependence such as <p_T> on x_F and M_μ^-μ⁺ of dimuon. The only published result on the dependence of <p_T> on x_F has been reported by pion induced Drell-Yan experiment, E615. This thesis presents the dependence of <p_T> on x_F for proton-induced Drell-Yan data from E866 and E906.

Name thesis:degree_name

Ph.D.

Level thesis:degree_level

Dissertation

Discipline thesis:degree_discipline

Physics

Grantor

University of Illinois at Urbana-Champaign

Year dc:date

2021

Author dc:creator

• Prasad, Shivangi

Contributors dc:contributor

• Peng, Jen-Chieh
• Beck, Douglas H
• Willenbrock, Scott S
• Fields, Brian D

• proton
• Drell-Yan
• SeaQuest
• Absolute cross section
• deuterium

Statement dc:rights

• Copyright 2020 Shivangi Prasad

Language dc:language

en

Handle dc:identifier

http://hdl.handle.net/2142/109365

OAI identifier oai:identifier

oai:www.ideals.illinois.edu:2142/109365