A Beauty-ful Boson

A Beauty-ful Boson
Author: Giulia Di Gregorio
Publisher: Springer Nature
Total Pages: 229
Release: 2023-01-01
Genre: Science
ISBN: 3031200136

The analysis described in this thesis is the search for the Higgs boson, decaying into bb pair, in the associated production with a vector boson, in the extreme Higgs boson transverse momentum region where the Higgs boson is reconstructed using the large-R jet technique. The use of the large-R jets allows to add a part of the phase space unexplored so far, which is particularly sensitive to possible new physics. The analysed data have been collected at LHC by the ATLAS detector between 2015 and 2018 at a centre-of-mass energy of √s = 13 TeV. The same dataset has been used to perform the differential pp → ZH and pp → WH cross-section measurements used to extract the information on the Higgs couplings and to put limits on Beyond the Standard Model effects. Furthermore the analysis has been re-used to perform a cross-section measurement of the diboson ZZ and WZ processes because the diboson and the Higgs processes have a similar topology. For the first time the ZZ(bb) and WZ(bb) cross-sections are measured at √s = 13 TeV and the observed cross-section measurements are consistent with the Standard Model predictions.

Measurement of the Associated Production of a Higgs Boson Decaying Into B-quarks with a Vector Boson at High Transverse Momentum in Pp Collisions at [square Root]s

Measurement of the Associated Production of a Higgs Boson Decaying Into B-quarks with a Vector Boson at High Transverse Momentum in Pp Collisions at [square Root]s
Author: ATLAS Collaboration CERN
Publisher:
Total Pages: 0
Release: 2021
Genre:
ISBN:

Abstract: The associated production of a Higgs boson with a W or Z boson decaying into leptons and where the Higgs boson decays to a pair is measured in the high vector-boson transverse momentum regime, above 250 GeV, with the ATLAS detector. The analysed data, corresponding to an integrated luminosity of , were collected in proton-proton collisions at the Large Hadron Collider between 2015 and 2018 at a centre-of-mass energy of . The measured signal strength, defined as the ratio of the measured signal yield to that predicted by the Standard Model, is corresponding to an observed (expected) significance of 2.1 (2.7) standard deviations. Cross-sections of associated production of a Higgs boson decaying into b quark pairs with a W or Z gauge boson, decaying into leptons, are measured in two exclusive vector boson transverse momentum regions, 250-400 GeV and above 400 GeV, and interpreted as constraints on anomalous couplings in the framework of a Standard Model effective field theory

The Beauty and the Boost: A Higgs Boson Tale

The Beauty and the Boost: A Higgs Boson Tale
Author: Brian Moser
Publisher: Springer Nature
Total Pages: 250
Release: 2023-09-19
Genre: Science
ISBN: 3031394429

Precision measurements of the Higgs boson’s properties are a powerful tool to look for deviations from the predictions of the Standard Model (SM) of particle physics. The 139/fb of proton-proton collision data which have been collected by the ATLAS experiment during Run 2 of the LHC, offer an opportunity to investigate rare Higgs-boson topologies, which are particularly sensitive to new physics scenarios but experimentally difficult to access. Several such measurements, which target Higgs-boson decays to heavy-flavour quarks, as well as their combinations are presented in this thesis. A novel analysis that measures Higgs-boson production in association with a heavy vector boson V (VH, with V=W,Z) at high energies is presented. Dedicated Higgs-boson reconstruction techniques are applied to reconstruct the highly Lorentz-boosted Higgs-boson decays into pairs of bottom quarks. The measurement is subsequently combined with a VH cross-section measurement at low and intermediate pT(V) to provide a differential cross-section measurement in kinematic fiducial volumes over the largest possible pT(V) range. All cross-section measurements agree with the SM predictions within relative uncertainties that range from 30% to 300%. The results are furthermore interpreted as limits on the parameters of a SM effective field theory. Finally, a combination of measurements of Higgs decays to heavy-flavour quarks is used to experimentally determine that the Higgs-boson coupling to charm quarks is weaker than to bottom quarks, as predicted by the SM. The target audience for the thesis are physicists and physics students, in particular those with a background in high energy physics.

Particle Physics At The Silver Jubilee Of Lomonosov Conferences - Proceedings Of The Eighteenth Lomonosov Conference On Elementary Particle Physics

Particle Physics At The Silver Jubilee Of Lomonosov Conferences - Proceedings Of The Eighteenth Lomonosov Conference On Elementary Particle Physics
Author: Studenikin Alexander I
Publisher: World Scientific
Total Pages: 612
Release: 2019-05-28
Genre: Science
ISBN: 9811202346

The volume of these proceedings is devoted to a wide variety of items, both in theory and experiment, of particle physics such as neutrino and astroparticle physics, tests of standard model and beyond, hadron physics, gravitation and cosmology, physics at the present and future accelerators.

The God Particle

The God Particle
Author: Leon M. Lederman
Publisher: Houghton Mifflin Harcourt
Total Pages: 452
Release: 2006
Genre: Science
ISBN: 9780618711680

A fascinating tour of particle physics from Nobel Prize winner Leon Lederman. At the root of particle physics is an invincible sense of curiosity. Leon Lederman embraces this spirit of inquiry as he moves from the Greeks' earliest scientific observations to Einstein and beyond to chart this unique arm of scientific study. His survey concludes with the Higgs boson, nicknamed the God Particle, which scientists hypothesize will help unlock the last secrets of the subatomic universe, quarks and all--it's the dogged pursuit of this almost mystical entity that inspires Lederman's witty and accessible history.

Measurement of Higgs Boson Decay Into B-quarks in Associated Production with a Top-quark Pair in Pp Collisions at [square Root]s

Measurement of Higgs Boson Decay Into B-quarks in Associated Production with a Top-quark Pair in Pp Collisions at [square Root]s
Author: [Study Group] ATLAS Collaboration CERN
Publisher:
Total Pages: 0
Release: 2022
Genre:
ISBN:

Abstract: The associated production of a Higgs boson and a top-quark pair is measured in events characterised by the presence of one or two electrons or muons. The Higgs boson decay into a b-quark pair is used. The analysed data, corresponding to an integrated luminosity of 139 fb−1, were collected in proton-proton collisions at the Large Hadron Collider between 2015 and 2018 at a centre-of-mass energy of s√ = 13 TeV. The measured signal strength, defined as the ratio of the measured signal yield to that predicted by the Standard Model, is 0.35+0.36−0.34. This result is compatible with the Standard Model prediction and corresponds to an observed (expected) significance of 1.0 (2.7) standard deviations. The signal strength is also measured differentially in bins of the Higgs boson transverse momentum in the simplified template cross-section framework, including a bin for specially selected boosted Higgs bosons with transverse momentum above 300 GeV

Particle Physics Reference Library

Particle Physics Reference Library
Author: Herwig Schopper
Publisher: Springer Nature
Total Pages: 632
Release: 2020
Genre: Heavy ions
ISBN: 3030382079

This first open access volume of the handbook series contains articles on the standard model of particle physics, both from the theoretical and experimental perspective. It also covers related topics, such as heavy-ion physics, neutrino physics and searches for new physics beyond the standard model. A joint CERN-Springer initiative, the "Particle Physics Reference Library" provides revised and updated contributions based on previously published material in the well-known Landolt-Boernstein series on particle physics, accelerators and detectors (volumes 21A, B1,B2,C), which took stock of the field approximately one decade ago. Central to this new initiative is publication under full open access

Grace in All Simplicity

Grace in All Simplicity
Author: Robert N. Cahn
Publisher: Simon and Schuster
Total Pages: 275
Release: 2023-11-07
Genre: Science
ISBN: 163936482X

An enthralling and accessible account of humanity’s quest to make sense of our physical world, told through interwoven tales of inspiration, tragedy, and triumph. How do the remarkable recent discoveries of the Higgs boson, dark matter, and dark energy connect with the equally revolutionary discoveries in centuries past? In Grace in All Simplicity, readers will delight in Cahn and Quigg's engaging prose and see how the infinite and the infinitesimal are joined. Today, physicists and astronomers are exploring distances from a billionth of a billionth of the human scale to the entire cosmos, and contemplating time intervals that range from less than a trillionth of a trillionth of a second out to far longer than the age of the universe. Leaving home in this metaphorical way requires devising new instruments that spectacularly expand our senses and conceiving original ways of thinking that expand our minds. This is at once an act of audacity and an exercise in humility. Grace in All Simplicity narrates the saga of how we have prospected for some of Nature’s most tightly held secrets, the basic constituents of matter and the fundamental forces that rule them. Our current understanding of the world (and universe) we inhabit is the result of curiosity, diligence, and daring, of abstraction and synthesis, and of an abiding faith in the value of exploration. In these pages we will meet scientists of both past and present. These men and women are professional scientists and amateurs, the eccentric and the conventional, performers and introverts. Scientists themselves, Cahn and Quigg convey their infectious joy as they search for new laws of nature. Join the adventure as scientists ascend mountain tops and descend into caverns deep underground, travel to the coldest places on Earth, and voyage back in time to near the birth of the Universe. Visit today’s great laboratories and the astounding instruments they house. Grace in All Simplicity is a thrilling voyage filled with improbable discoveries and the extraordinary community of people who make them. Together, we will travel the path to the Higgs boson, weigh the evidence for subliminal dark matter, and learn what makes scientists invoke a mysterious agent named "dark energy." We will behold the emergence of a compelling picture of matter and forces, simple in its structure, graceful in the interplay of its parts, but still tantalizingly incomplete.