Elastic Scattering at the LHC

Abstract

Na'zev pra'ce: Elasticky' rozptyl na LHC Autor: Jan Kasˇpar Katedra: U' stav cˇa'sticove' a jaderne' fyziky Vedoucı' doktorske' pra'ce: RNDr. Vojtečh Kundra't, DrSc., Fyzika'lnı' u'stav AV CŘ, v. v. i. Abstrakt: Elasticky' rozptyl protonu˚, prěstozě proces zda'nliveˇ jednoduchy', prědstavuje pro teorii sta'le velkou vy'zvu. V te'to pra'ci se zaby'va'me elasticky'm rozptylem z teoreticke'ho i experimenta'lnı'ho hlediska. V teoreticke' cˇa'sti shrneme neˇkolik modelu˚ a jejich prědpoveďi pro LHC. V diskuzi veňovane' interferenci mezi Coulombickou a hadronovou interakcı' prědstavı'me novy' eikona'lovy' vy'pocět do vsěch rˇa'du˚ v konstanteˇ jemne' struktury α. V experimenta'lnı' cˇa'sti pra'ce popı'sěme experiment TOTEM, ktery' je mimo jine' zasvečen meřěnı' elasticke'ho rozptylu protonu˚ na LHC. Toto meřěnı' je realizova'no prědevsˇı'm detektory v rˇı'msky'ch hrncı'ch (Rˇ H). To jsou pohyblive' vakuove' na'doby zasouvajı'cı' se do urychlovacˇove' trubice stovky metru˚ od interakcňı'ho bodu. Dı'ky tomu jsou Rˇ H schopny detekovat cˇa'stice rozpty'lene' do velmi maly'ch u'hlu˚. V pra'ci takte'zˇ diskutujeme neˇktere' aspekty simulacňı'ho a rekonstrukcňı'ho softwaru pro Rˇ H. Velky' prostor je veňova'n alignmentu Rˇ H, tj. urcěnı'pozic senzoru˚ v Rˇ H navza'jem i vu˚cˇi svazku. V za'veřu...

Title: Elastic scattering at the LHC Author: Jan Kasˇpar Departement: Institute of Particle and Nuclear Physics Supervisor of the thesis: RNDr. Vojtečh Kundra't, DrSc., Institute of Physics AS CR Abstract: The seemingly simple elastic scattering of protons still presents a challenge for the theory. In this thesis we discuss the elastic scattering from theoretical as well as experimental point of view. In the theory part, we present several mod- els and their predictions for the LHC. We also discuss the Coulomb-hadronic interference, where we present a new eikonal calculation to all orders of α, the fine-structure constant. In the experimental part we introduce the TOTEM experiment which is dedicated, among other subjects, to the measurement of the elastic scattering at the LHC. This measurement is performed primarily with the Roman Pot (RP) detectors - movable beam-pipe insertions hundreds of meters from the interaction point, that can detect protons scattered to very small angles. We discuss some aspects of the RP simulation and reconstruc- tion software. A central point is devoted to the techniques of RP alignment - determining the RP sensor positions relative to each other and to the beam. At the end we present the analysis of TOTEM's first elastic scattering mea- surement at the LHC. The resulting...