The Black Book of Quantum Chromodynamics

Author(s):  
John Campbell ◽  
Joey Huston ◽  
Frank Krauss

The LHC (Large Hadron Collider) will serve as the energy frontier for high-energy physics for the next 20 years. The highlight of the LHC running so far has been the discovery of the Higgs boson, but the LHC programme has also consisted of the measurement of a myriad of other Standard Model processes, as well as searches for Beyond-the-Standard-Model physics, and the discrimination between possible new physics signatures and their Standard Model backgrounds. Essentially all of the physics processes at the LHC depend on quantum chromodynamics, or QCD, in the production, or in the decay stages, or in both. This book has been written as an advanced primer for physics at the LHC, providing a pedagogical guide for the calculation of QCD and Standard Model predictions, using state-of-the-art theoretical frameworks. The predictions are compared to both the legacy data from the Tevatron, as well as the data obtained thus far from the LHC, with intuitive connections between data and theory supplied where possible. The book is written at a level suitable for advanced graduate students, and thus could be used in a graduate course, but is also intended for every physicist interested in physics at the LHC.

Author(s):  
Peter Jenni

For the past year, experiments at the Large Hadron Collider (LHC) have started exploring physics at the high-energy frontier. Thanks to the superb turn-on of the LHC, a rich harvest of initial physics results have already been obtained by the two general-purpose experiments A Toroidal LHC Apparatus (ATLAS) and the Compact Muon Solenoid (CMS), which are the subject of this report. The initial data have allowed a test, at the highest collision energies ever reached in a laboratory, of the Standard Model (SM) of elementary particles, and to make early searches Beyond the Standard Model (BSM). Significant results have already been obtained in the search for the Higgs boson, which would establish the postulated electro-weak symmetry breaking mechanism in the SM, as well as for BSM physics such as Supersymmetry (SUSY), heavy new particles, quark compositeness and others. The important, and successful, SM physics measurements are giving confidence that the experiments are in good shape for their journey into the uncharted territory of new physics anticipated at the LHC.


2021 ◽  
Vol 81 (7) ◽  
Author(s):  
Xi-Yan Tian ◽  
Liu-Feng Du ◽  
Yao-Bei Liu

AbstractThe vectorlike top partners are potential signature of some new physics beyond the Standard Model at the TeV scale. In this paper, we propose to search for the vectorlike T quark with charge 2/3 in the framework of a simplified model where the top partners only couples with the third generation of Standard Model quarks. We investigate the observability for electroweak production of a vectorlike T quark in association with a standard model bottom quark through the process $$pp \rightarrow T\bar{b}j$$ p p → T b ¯ j with the subsequent decay mode of $$T\rightarrow t(\rightarrow b W^+\rightarrow b \ell ^{+} \nu _{\ell })h( \rightarrow \gamma \gamma )$$ T → t ( → b W + → b ℓ + ν ℓ ) h ( → γ γ ) , at the proposed High Energy Large Hadron Collider (HE-LHC) and Future Circular Collider in hadron-hadron mode (FCC-hh) including the realistic detector effects. The 95% confidence level excluded regions and the $$5\sigma $$ 5 σ discovery reach in the parameter plane of $$\kappa _{T}-m_T$$ κ T - m T , are respectively obtained at the HE-LHC with the integrated luminosity of 15 ab$$^{-1}$$ - 1 and the FCC-hh with the integrated luminosity of 30 ab$$^{-1}$$ - 1 . We also analyze the projected sensitivity in terms of the production cross section times branching fraction at the HE-LHC and FCC-hh.


2021 ◽  
Vol 4 (2) ◽  
Author(s):  
Andy Buckley ◽  
Jonathan Butterworth ◽  
Louie Corpe ◽  
Martin Habedank ◽  
Danping Huang ◽  
...  

Measurements at particle collider experiments, even if primarily aimed at understanding Standard Model processes, can have a high degree of model independence, and implicitly contain information about potential contributions from physics beyond the Standard Model. The CONTUR package allows users to benefit from the hundreds of measurements preserved in the RIVET library to test new models against the bank of LHC measurements to date. This method has proven to be very effective in several recent publications from the CONTUR team, but ultimately, for this approach to be successful, the authors believe that the CONTUR tool needs to be accessible to the wider high energy physics community. As such, this manual accompanies the first user-facing version: CONTUR v2. It describes the design choices that have been made, as well as detailing pitfalls and common issues to avoid. The authors hope that with the help of this documentation, external groups will be able to run their own CONTUR studies, for example when proposing a new model, or pitching a new search.


2005 ◽  
Vol 20 (22) ◽  
pp. 5164-5173 ◽  
Author(s):  
BEATE HEINEMANN

Recent searches for physics beyond the Standard Model at high energy colliders are presented. The main focus is on searches for supersymmetry, extra dimensions and new gauge bosons. In all search analyses the data are found to agree well with the Standard Model background expectation and no evidence for contributions from physics beyond the Standard Model is found. The data are thus used to place limits on new physics scenarios.


2005 ◽  
Vol 20 (22) ◽  
pp. 5234-5243
Author(s):  
W. J. STIRLING

Quantum Chromodynamics is an established part of the Standard Model and an essential part of the toolkit for searching for new physics at high-energy colliders. I present a status report on the theory of QCD and review some of the important developments in the past year.


2008 ◽  
Vol 23 (33) ◽  
pp. 2799-2809 ◽  
Author(s):  
ROUZBEH ALLAHVERDI

There is strong evidence from cosmological data that the universe underwent an epoch of superluminal expansion called inflation. A satisfactory embedding of inflation in fundamental physics has been an outstanding problem at the interface of cosmology and high energy physics. We show how inflation can be realized within the Minimal Supersymmetric Standard Model (MSSM). The inflaton candidates are two specific combinations of supersymmetric partners of quarks and leptons. MSSM inflation occurs at a low scale and generates perturbations in the range experimentally allowed by the latest data from Wilkinson Microwave Anisotropy Probe (WMAP). The parameter space for inflation is compatible with supersymmetric dark matter, and the Large Hadron Collider (LHC) is capable of discovering the inflaton candidates in the allowed regions of parameter space.


2021 ◽  
Vol 2021 (12) ◽  
Author(s):  
Tao Han ◽  
Wolfgang Kilian ◽  
Nils Kreher ◽  
Yang Ma ◽  
Jürgen Reuter ◽  
...  

Abstract We explore the sensitivity of directly testing the muon-Higgs coupling at a high-energy muon collider. This is strongly motivated if there exists new physics that is not aligned with the Standard Model Yukawa interactions which are responsible for the fermion mass generation. We illustrate a few such examples for physics beyond the Standard Model. With the accidentally small value of the muon Yukawa coupling and its subtle role in the high-energy production of multiple (vector and Higgs) bosons, we show that it is possible to measure the muon-Higgs coupling to an accuracy of ten percent for a 10 TeV muon collider and a few percent for a 30 TeV machine by utilizing the three boson production, potentially sensitive to a new physics scale about Λ ∼ 30 − 100 TeV.


Author(s):  
Martino Borsato ◽  
Xabier Cid-Vidal ◽  
Yuhsin Tsai ◽  
Carlos Vázquez Sierra ◽  
Jose Francisco Zurita ◽  
...  

Abstract In this paper, we describe the potential of the LHCb experiment to detect Stealth physics. This refers to dynamics beyond the Standard Model that would elude searches that focus on energetic objects or precision measurements of known processes. Stealth signatures include long-lived particles and light resonances that are produced very rarely or together with overwhelming backgrounds. We will discuss why LHCb is equipped to discover this kind of physics at the Large Hadron Collider and provide examples of well-motivated theoretical models that can be probed with great detail at the experiment.


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