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

Prasad, Shivangi

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https://hdl.handle.net/2142/109365 Copy

Description

Title

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

Author(s)

Prasad, Shivangi

Issue Date

2020-11-19

Director of Research (if dissertation) or Advisor (if thesis)

Peng, Jen-Chieh

Doctoral Committee Chair(s)

Beck, Douglas H

Committee Member(s)

• Willenbrock, Scott S
• Fields, Brian D

Department of Study

Physics

Discipline

Physics

Degree Granting Institution

University of Illinois at Urbana-Champaign

Degree Name

Ph.D.

Degree Level

Dissertation

Keyword(s)

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

Abstract

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 ($M^3d^2\sigma/dMdx_F$). 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 ($M_{\mu^-\mu^+}$) 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 ($d^2\sigma/dMdp_T$ and $d^2\sigma/dx_Fdp_T$) 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 $$ for the lowest value of $\sqrt{s}$ in the study of dependence of $$ on $\sqrt{s}$. Additionally, $p_T$ data from existing Drell-Yan experiments have been analyzed and compiled systematically to study possible dependence such as $$ on $x_F$ and $M_{\mu^{-}\mu^{+}}$ of dimuon. The only published result on the dependence of $$ on $x_F$ has been reported by pion induced Drell-Yan experiment, E615. This thesis presents the dependence of $$ on $x_F$ for proton-induced Drell-Yan data from E866 and E906.

Graduation Semester

2020-12

Type of Resource

Thesis

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Copyright 2020 Shivangi Prasad

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