Towards Global Interpretation Of Lhc Data

This book presents the first global interpretation of measurements of jet and top quark production at the Large Hadron Collider, including a simultaneous extraction of the standard model parameters together with constraints on new physics, unbiased from the assumptions on the standard model parameters. As a long-standing problem, any hadron collider search for new physics depends on parton distribution functions, which cannot be predicted but are extracted experimentally. However, performing the extraction in the same kinematic region where physics beyond the standard model is expected to manifest causes the risk of absorbing the new physics effects into the parton distributions. In this book, the issue is addressed by extending the standard model by effective contributions from quark contact interactions describing new physics and extracting the parton distributions and standard model parameters simultaneously with setting limits on the contact interactions. In the process, the most precise single measurement of the strong coupling constant at the LHC is performed, to date. Furthermore, the book details the first investigation of the mass renormalization scale dependence of the top quark mass, highlighting the importance of a proper scale choice for obtaining robust predictions and improving the precision of experimental analyses. The initial chapters provide the reader with a succinct yet accessible introduction to the relevant theoretical and experimental topics. The presented investigations are at the edge of precision in the phenomenology of high-energy physics and serve to pave the road toward a global interpretation of LHC data.

The Large Hadron Collider (LHC) is the highest energy collider ever built. It resides near Geneva in a tunnel 3.8m wide, with a circumference of 26.7km, which was excavated in 1983-1988 to initially house the electron-positron collider LEP. The LHC was approved in 1995, and it took until 2010 for reliable operation. By now, a larger set of larger integrated luminosities have been accumulated for physics analyses in the four collider experiments: ATLAS, CMS, LHCb and ALICE.The LHC operates with an extended cryogenic plant, using a multi-stage injection system comprising the PS and SPS accelerators (still in use for particle physics experiments at lower energies). The beams are guided by 1232 superconducting high field dipole magnets.Intense works are underway in preparation of the High Luminosity LHC, aimed at upgrading the LHC and detectors for collecting ten times more luminosity, and extending the collider life to the early 2040's. So far, the (HL-)LHC project represents a cumulation of around one hundred thousand person-years of innovative work by technicians, engineers, and physicists from all over the world; probably the largest scientific effort ever in the history of humanity. The book is driven by the realisation of the unique value of this accelerator complex and by the recognition of the status of high energy physics, described by a Standard Model — which still leaves too many questions unanswered to be the appropriate theory of elementary particles and their interactions.Following the Introduction are: three chapters which focus on the initial decade of operation, leading to the celebrated discovery of the Higgs Boson, on the techniques and physics of the luminosity upgrade, and finally on major options - of using the LHC in a concurrent, power economic, electron-hadron scattering mode, when upgraded to higher energies or eventually as an injector for the next big machine. The various technical and physics chapters, provided by 61 authors, characterise the fascinating opportunities the LHC offers for the next two decades ahead (possibly longer), with the goal to substantially advance our understanding of nature.

This thesis discusses in detail the measurement of the polarizations of all S-wave vector quarkonium states in LHC proton-proton collisions with the CMS detector. Heavy quarkonium states constitute an ideal laboratory to study non-perturbative effects of quantum chromodynamics and to understand how quarks bind into hadrons. The experimental results are interpreted through an original phenomenological approach, which leads to a coherent picture of quarkonium production cross sections and polarizations within a simple model, dominated by one single color-octet production mechanism. These findings provide new insights into the dynamics of heavy quarkonium production at the LHC, an important step towards a satisfactory understanding of hadron formation within the standard model of particle physics.

This comprehensive volume summarizes and structures the multitude of results obtained at the LHC in its first running period and draws the grand picture of today’s physics at a hadron collider. Topics covered are Standard Model measurements, Higgs and top-quark physics, flavour physics, heavy-ion physics, and searches for supersymmetry and other extensions of the Standard Model. Emphasis is placed on overview and presentation of the lessons learned. Chapters on detectors and the LHC machine and a thorough outlook into the future complement the book. The individual chapters are written by teams of expert authors working at the forefront of LHC research.

Proceedings of the International School of Subnuclear Physics, ISSP 2014, 52nd Course, ERICE, Erice, 24 June – 3 July 2014.

This thesis provides a detailed and comprehensive description of the search for New Physics at the Large Hadron Collider (LHC) in the mono-jet final state, using the first 3.2 fb-1 of data collected at the centre of mass energy of colliding protons of 13~TeV recorded in the ATLAS experiment at LHC. The results are interpreted as limits in different theoretical contexts such as compressed supersymmetric models, theories that foresee extra-spatial dimensions and in the dark matter scenario. In the latter the limits are then compared with those obtained by other ATLAS analyses and by experiments based on completely different experimental techniques, highlighting the role of the mono-jet results in the context of dark matter searches.Lastly, a set of possible analysis improvements are proposed to reduce the main uncertainties that affect the signal region and to increase the discovery potential by further exploiting the information on the final state.

This book is the proceedings of the International School of Subnuclear Physics, ISSP 2012, 50th Course — ERICE, 23 June 2013 – 2 July 2012. This course was devoted to the celebrations of the 50th Anniversary of the Subnuclear Physics School which was started in 1961 by Antonino Zichichi with John Bell at CERN and formally established in 1962 by Bell, Blackett, Weisskopf, Rabi and Zichichi in Geneva (CERN). The lectures covered the latest and most significant achievements in theoretical and in experimental subnuclear physics. Contents:QCD Celebrations and Gold-Medal to Murray Gell-Mann:Opening Remarks (A Zichichi)Some Reminiscences of Research Leading to QCD and Beyond (M Gell-Mann)The Erice Centre, Gell-Mann, QCD, the Effective Energy and Complexity (A Zichichi)History of QCD (H Fritzsch)On the History of the Strong Interaction (H Leutwyler)Colour Transparency and Saturation in QCD (D Schildknecht)Glue-mesons: Their Conception Needs All of QCD in the Infrared (P Minkowski)Quark Masses in QCD (C A Dominguez)The Quark Model and QCD (F Close)Key Steps Toward the Creation of QCD — Notes on the Logic and History of the Genesis of QCD (T Y Cao)Hot Theoretical Topics:Perturbative Gravity from Gauge Theory (Z Bern)Black Holes and Supersymmetry (L Andrianopoli, R D'Auria and S Ferrara)Composite Weak Bosons at the LHC (H Fritzsch)High Energy Scattering in QCD and in Quantum Gravity (L N Lipatov)One-Parameter Model for the Superworld (D V Nanopoulos et al.)Beyond Relativistic Quantum String Theory (G 't Hooft)Hot Experimental Topics:Borexino Latest Results (G Bellini)Highlights from LHC (P Bloch)Highlights from ATLAS (P Jenni)Origin and Status of Luna at Gran Sasso (C Broggini)Highlights from ALICE (P Giubellino)Highlights from BNL-RHIC (M J Tannenbaum)Origin and Status of the Gran Sasso INFN Laboratory (L Votano)Seminars on Specialized Topics:Status of Opera (D Autiero)The Origin and Status of the Third Neutrino (A Bettini)High Energy Physics and Gravitational Waves (E Coccia)Four Decades of Computing in Subnuclear Physics — from Bubble Chamber to LHC (J Knobloch)The LAA Project and the Consequences on LHC (H Wenninger)Complexity and the QGCW Project (A Zichichi)Special Sessions for New Talents:Patterns of Flavour Violation at the Dawn of the LHC Era (M V Carlucci)Precise Measurement of the W Boson Mass with the DØ Detector (R Lopes de Sá)QFT and Unification of Knot Theories (A Sleptsov)Hunting in Daya Bay Neutrino Experiment (F Zhang)Vacuum Stability in the SM and the Three-loop β-function for the Higgs Self-interaction (M F Zoller)Closing Ceremony:DiplomasAwardsParticipantsGroup Photo Readership: Directed to experts and advanced-level students in the field of Theoretical and Experimental Subnuclear Physics. Keywords:Quantum Chromodynamics;Complexity;Fundamental Level;LHC Results;Higgs-SUSY;Particle Physics;Quantum Gravity;Black Holes