Probing the Higgs Self Coupling Via Single Higgs Production at the LHC.

Probing the Higgs Self Coupling Via Single Higgs Production at the LHC. PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 31

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Book Description
Here, we propose a method to determine the trilinear Higgs self coupling that is alternative to the direct measurement of Higgs pair production total cross sections and differential distributions. Furthermore, the method relies on the effects that electroweak loops featuring an anomalous trilinear coupling would imprint on single Higgs production at the LHC. We first calculate these contributions to all the phenomenologically relevant Higgs production (ggF, VBF, WH, ZH, t$\bar{t}$) and decay ([gamma][gamma], WW*/ZZ*2!4f, b$\bar{b}$, [tau][tau]) modes at the LHC and then estimate the sensitivity to the trilinear coupling via a one-parameter fit to the single Higgs measurements at the LHC 8 TeV. We also found that the bounds on the self coupling are already competitive with those from Higgs pair production and will be further improved in the current and next LHC runs.

Probing the Higgs Self Coupling Via Single Higgs Production at the LHC.

Probing the Higgs Self Coupling Via Single Higgs Production at the LHC. PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 31

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Book Description
Here, we propose a method to determine the trilinear Higgs self coupling that is alternative to the direct measurement of Higgs pair production total cross sections and differential distributions. Furthermore, the method relies on the effects that electroweak loops featuring an anomalous trilinear coupling would imprint on single Higgs production at the LHC. We first calculate these contributions to all the phenomenologically relevant Higgs production (ggF, VBF, WH, ZH, t$\bar{t}$) and decay ([gamma][gamma], WW*/ZZ*2!4f, b$\bar{b}$, [tau][tau]) modes at the LHC and then estimate the sensitivity to the trilinear coupling via a one-parameter fit to the single Higgs measurements at the LHC 8 TeV. We also found that the bounds on the self coupling are already competitive with those from Higgs pair production and will be further improved in the current and next LHC runs.

Probing Triple-Higgs Productions Via [math Display

Probing Triple-Higgs Productions Via [math Display PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages :

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Book Description
We report that the quartic self-coupling of the Standard Model Higgs boson can only be measured by observing the triple-Higgs production process, but it is challenging for the LHC Run 2 or International Linear Collider (ILC) at a few TeV because of its extremely small production rate. In this paper, we present a detailed Monte Carlo simulation study of the triple-Higgs production through gluon fusion at a 100 TeV hadron collider and explore the feasibility of observing this production mode. We focus on the decay channel HHH 2!b\bar{b}$$b\bar{b}$[gamma][gamma], investigating detector effects and optimizing the kinematic cuts to discriminate the signal from the backgrounds. Our study shows that, in order to observe the Standard Model triple-Higgs signal, the integrated luminosity of a 100 TeV hadron collider should be greater than 1.8×104 ab1. We also explore the dependence of the cross section upon the trilinear ([lambda]3) and quartic ([lambda]4) self-couplings of the Higgs. Ultimately, we find that, through a search in the triple-Higgs production, the parameters [lambda]3 and [lambda]4 can be restricted to the ranges [−1,5] and [−20,30], respectively. We also examine how new physics can change the production rate of triple-Higgs events. For example, in the singlet extension of the Standard Model, we find that the triple-Higgs production rate can be increased by a factor of O(10).

Higgs boson potential at colliders: status and perspectives

Higgs boson potential at colliders: status and perspectives PDF Author: Biagio Di Micco
Publisher: Roma TrE-Press
ISBN:
Category : Science
Languages : en
Pages : 281

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Book Description
Questo documento riassume lo stato attuale degli ricerche studi, teorici e sperimentali, sulla produzione di coppie di bosoni di Higgs, e sui vincoli, sia diretti che indiretti, al valore del termine di auto-interazione del bosone di Higgs, con l’intento di servire da referenza per i prossimi anni. Il documento discute lo stato degli studi teorici, includendo le più recenti stime della sezione di produzione di coppie di bosoni di Higgs, sviluppi sulle teorie di campo efficaci, e studi su specifici scenari di nuova fisica che possono contribuire alla produzione di due bosoni di Higgs. Sono presentati i più recenti risultati sperimentali sulle ricerche di coppie di bosoni di Higgs e sui limiti diretti e indiretti al termine di auto-interazione, ottenuti al Large Hadron Collider di Ginevra, con una panoramica delle tecniche sperimentali. Infine, sono discusse le capacità dei collisionatori futuri di determinare il termine di auto-interazione del bosone di Higgs. Questo lavoro è iniziato come raccolta di contributi della conferenza “Di-Higgs ai Colliders”, che ha avuto luogo a Fermilab dal 4 al 9 settembre 2018, ma gli argomenti discussi vanno al di là di quelli presentati alla conferenza, includendo ulteriori sviluppi.

Response of the High Granularity Calorimeter HGCAL and Characterisation of the Higgs Boson

Response of the High Granularity Calorimeter HGCAL and Characterisation of the Higgs Boson PDF Author: Matteo Bonanomi
Publisher: Springer Nature
ISBN: 3031268334
Category : Science
Languages : en
Pages : 281

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Book Description
This book highlights the most complete characterization of the Higgs boson properties performed to date in the "golden channel," i.e., decay into a pair of Z bosons which subsequently decay into four leptons. The data collected by the CMS experiment in the so-called Run-II data-taking period of the LHC are used to produce an extensive set of results that test in detail the predictions of the Standard Model. Given the remarkable predictive power of the SM when including the Higgs boson, possible new physics will require even more extensive studies at higher statistics. A massive upgrade of the detectors is necessary to maintain the current physics performance in the harsh environment of the High-Luminosity LHC (HL-LHC) project, expected to start by the end of 2027. The CMS Collaboration will replace the current endcap calorimeters with a High Granularity Calorimeter (HGCAL). The HGCAL will be the very first large-scale silicon-based imaging calorimeter ever employed in a high-energy physics experiment. This book presents the results of the analysis of the test beam data collected with the first large-scale prototype of the HGCAL. The results of this analysis are used to corroborate the final design of the HGCAL and its nominal physics performance expected for the HL-LHC operations.

Higgs Pair Production Searches with the ATLAS Experiment at the LHC and the HL-LHC

Higgs Pair Production Searches with the ATLAS Experiment at the LHC and the HL-LHC PDF Author: Jannicke Andree Pearkes
Publisher:
ISBN:
Category :
Languages : en
Pages : 0

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Book Description
Exploring the Higgs potential and electroweak symmetry breaking is one of the main goals at the Large Hadron Collider (LHC). Higgs pair production (HH) provides experimental access to the shape of Higgs potential and is the only direct probe of the Higgs self-coupling in proton-proton collisions. This thesis presents a search for HH production in the bbyy channel with the ATLAS experiment at the LHC with 139/fb of data at 13 TeV. The results from this search are combined with results from the bbtautau and bbbb channels to produce the most stringent limits on Standard Model HH production and the Higgs self-coupling to date. In addition to the present results, this thesis discuss ways to improve sensitivity to HH production during Run 3 and our projected sensitivity to HH production at the High Luminosity-LHC with 4000/fb at 14 TeV. The ATLAS Inner Tracker detector upgrade which is required to enable these searches is also presented.

Search for Higgs Boson Pair Production in the bb̅ τ+ τ- Decay Channel

Search for Higgs Boson Pair Production in the bb̅ τ+ τ- Decay Channel PDF Author: Luca Cadamuro
Publisher: Springer
ISBN: 3030040550
Category : Science
Languages : en
Pages : 273

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Book Description
This thesis presents innovative contributions to the CMS experiment in the new trigger system for the restart of the LHC collisions in Run II, as well as original analysis methods and important results that led to official publications of the Collaboration. The author's novel reconstruction algorithms, deployed on the Field-Programmable Gate Arrays of the new CMS trigger architecture, have brought a gain of over a factor 2 in efficiency for the identification of tau leptons, with a very significant impact on important H boson measurements, such as its decays to tau lepton pairs and the search for H boson pair production. He also describes a novel analysis of HH → bb tautau, a high priority physics topic in a difficult channel. The original strategy, optimisation of event categories, and the control of the background have made the result one of the most sensitive concerning the self-coupling of the Higgs boson among all possible channels at the LHC.

Lectures on LHC Physics

Lectures on LHC Physics PDF Author: Tilman Plehn
Publisher: Springer
ISBN: 3319059424
Category : Science
Languages : en
Pages : 340

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Book Description
With the discovery of the Higgs boson, the LHC experiments have closed the most important gap in our understanding of fundamental interactions, confirming that such interactions between elementary particles can be described by quantum field theory, more specifically by a renormalizable gauge theory. This theory is a priori valid for arbitrarily high energy scales and does not require an ultraviolet completion. Yet, when trying to apply the concrete knowledge of quantum field theory to actual LHC physics - in particular to the Higgs sector and certain regimes of QCD - one inevitably encounters an intricate maze of phenomenological know-how, common lore and other, often historically developed intuitions about what works and what doesn’t. These lectures cover three aspects to help understand LHC results in the Higgs sector and in searches for physics beyond the Standard Model: they discuss the many facets of Higgs physics, which is at the core of this significantly expanded second edition; then QCD, to the degree relevant for LHC measurements; as well as further standard phenomenological background knowledge. They are intended to serve as a brief but sufficiently detailed primer on LHC physics to enable graduate students and all newcomers to the field to find their way through the more advanced literature, and to help those starting to work in this very timely and exciting field of research. Advanced readers will benefit from this course-based text for their own lectures and seminars. .

Looking Inside Jets

Looking Inside Jets PDF Author: Simone Marzani
Publisher: Springer
ISBN: 3030157091
Category : Science
Languages : en
Pages : 205

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Book Description
This concise primer reviews the latest developments in the field of jets. Jets are collinear sprays of hadrons produced in very high-energy collisions, e.g. at the LHC or at a future hadron collider. They are essential to and ubiquitous in experimental analyses, making their study crucial. At present LHC energies and beyond, massive particles around the electroweak scale are frequently produced with transverse momenta that are much larger than their mass, i.e., boosted. The decay products of such boosted massive objects tend to occupy only a relatively small and confined area of the detector and are observed as a single jet. Jets hence arise from many different sources and it is important to be able to distinguish the rare events with boosted resonances from the large backgrounds originating from Quantum Chromodynamics (QCD). This requires familiarity with the internal properties of jets, such as their different radiation patterns, a field broadly known as jet substructure. This set of notes begins by providing a phenomenological motivation, explaining why the study of jets and their substructure is of particular importance for the current and future program of the LHC, followed by a brief but insightful introduction to QCD and to hadron-collider phenomenology. The next section introduces jets as complex objects constructed from a sequential recombination algorithm. In this context some experimental aspects are also reviewed. Since jet substructure calculations are multi-scale problems that call for all-order treatments (resummations), the bases of such calculations are discussed for simple jet quantities. With these QCD and jet physics ingredients in hand, readers can then dig into jet substructure itself. Accordingly, these notes first highlight the main concepts behind substructure techniques and introduce a list of the main jet substructure tools that have been used over the past decade. Analytic calculations are then provided for several families of tools, the goal being to identify their key characteristics. In closing, the book provides an overview of LHC searches and measurements where jet substructure techniques are used, reviews the main take-home messages, and outlines future perspectives.

Anticipating The Next Discoveries In Particle Physics (Tasi 2016) - Proceedings Of The 2016 Theoretical Advanced Study Institute In Elementary Particle Physics

Anticipating The Next Discoveries In Particle Physics (Tasi 2016) - Proceedings Of The 2016 Theoretical Advanced Study Institute In Elementary Particle Physics PDF Author: Rouven Essig
Publisher: World Scientific
ISBN: 9813233354
Category : Science
Languages : en
Pages : 634

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Book Description
This volume is a compilation of lectures delivered at the TASI 2016 summer school, 'Anticipating the Next Discoveries in Particle Physics', held at the University of Colorado at Boulder in June 2016. The school focused on topics in theoretical particle physics, phenomenology, dark matter, and cosmology of interest to contemporary researchers in these fields. The lectures are accessible to graduate students in the initial stages of their research careers.

Probing the Higgs Self-coupling at Hadron Colliders Using Rare Decays

Probing the Higgs Self-coupling at Hadron Colliders Using Rare Decays PDF Author: Ulrich Baur
Publisher:
ISBN:
Category :
Languages : en
Pages :

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Book Description