Measurement of the Inclusive 3-jet Production Differential Cross Section in Proton-proton Collisions at 7 TeV and Determination of the Strong Coupling Constant in the TeV Range

Measurement of the Inclusive 3-jet Production Differential Cross Section in Proton-proton Collisions at 7 TeV and Determination of the Strong Coupling Constant in the TeV Range

Author:

Publisher:

Published: 2015

Total Pages: 223

ISBN-13:

DOWNLOAD EBOOK

This paper presents a measurement of the inclusive 3-jet production differential cross section at a proton-proton centre-of-mass energy of 7 TeV using data corresponding to an integrated luminosity of 5 fb$^{-1}$ collected with the CMS detector. The analysis is based on the three jets with the highest transverse momenta. The cross section is measured as a function of the invariant mass of the three jets in a range of 445-3270 GeV and in two bins of the maximum rapidity of the jets up to a value of 2. A comparison between the measurement and the prediction from perturbative QCD at next-to-leading order is performed. Within uncertainties, data and theory are in agreement. The sensitivity of the observable to parameters of the theory such as the parton distribution functions of the proton and the strong coupling constant $\alpha_S$ is studied. A fit to all data points with 3-jet masses larger than 664 GeV gives a value of the strong coupling constant of $\alpha_S(M_\mathrm{Z})$ = 0.1171 $\pm$ 0.0013 (exp) $^{+0.0073}_{-0.0047}$ (theo).


The Black Book of Quantum Chromodynamics

The Black Book of Quantum Chromodynamics

Author: John Campbell

Publisher: Oxford University Press

Published: 2018

Total Pages: 760

ISBN-13: 0199652740

DOWNLOAD EBOOK

This title provides an in-depth introduction to the particle physics of current and future experiments at particle accelerators. The text provides the reader with an overview of practically all aspects of the strong interaction necessary to understand and appreciate modern particle phenomenology at the energy frontier.


Measurements of the Differential Cross Sections for the Inclusive Production of a Photon and Heavy Flavor Jet

Measurements of the Differential Cross Sections for the Inclusive Production of a Photon and Heavy Flavor Jet

Author: Daniel J. Duggan

Publisher:

Published: 2009

Total Pages:

ISBN-13:

DOWNLOAD EBOOK

ABSTRACT: This thesis presents the first measurement of the differential production cross section of a heavy flavor (bottom or charm) jet and direct photon at the Fermilab Tevatron. These measurements were performed using data recorded with the D0 detector from proton-antiproton collisions at a center of mass energy of sqrt(s) = 1.96 TeV. These results probe a kinematic range for the photon transverse momentum of 30 to 150 GeV and photon rapidity y


Differential Cross Section Measurements for the Production of a W Boson in Association with Jets in Proton-proton Collisions at $\sqrt S

Differential Cross Section Measurements for the Production of a W Boson in Association with Jets in Proton-proton Collisions at $\sqrt S

Author:

Publisher:

Published: 2014

Total Pages: 26

ISBN-13:

DOWNLOAD EBOOK

Our measurements are reported of differential cross sections for the production of a W boson, which decays into a muon and a neutrino, in association with jets, as a function of several variables, including the transverse momenta (pT) and pseudorapidities of the four leading jets, the scalar sum of jet transverse momenta (HT), and the difference in azimuthal angle between the directions of each jet and the muon. Furthermore, the data sample of pp collisions at a centre-of-mass energy of 7 TeV was collected with the CMS detector at the LHC and corresponds to an integrated luminosity of 5.0 fb-1. The measured cross sections are compared to predictions from Monte Carlo generators, MADGRAPH + PYTHIAand SHERPA, and to next-to-leading-order calculations from BLACKHAT + SHERPA. The differential cross sections are found to be in agreement with the predictions, apart from the pT distributions of the leading jets at high pT values, the distributions of the HT at high-HT and low jet multiplicity, and the distribution of the difference in azimuthal angle between the leading jet and the muon at low values.


Study of Double Parton Scattering in Photon + 3 Jets Final State

Study of Double Parton Scattering in Photon + 3 Jets Final State

Author: You-Hao Chang

Publisher: Springer

Published: 2017-01-20

Total Pages: 107

ISBN-13: 9811038244

DOWNLOAD EBOOK

This book mainly focuses on the study of photon + 3 jets final state in Proton-Proton Collisions at √s = 7TeV, searching for patterns of two (or more) distinct hard scatterings in the same collision, i.e the so-called Double Parton Scattering (DPS). A new method by using Monte Carlo generators was performed and provides higher order corrections to the description of the Single Parton Scattering (SPS) background. Further it is investigated whether additional contributions from DPS can improve the agreement between the measured data and the Monte Carlo predictions. The current theoretical uncertainties related to the SPS background are found to be larger than expectation. At the same time a rich set of DPS-sensitive measurements is reported for possible further interpretation.