Author: Shreyasi AcharyaPublisher:
ISBN:
Category :
Languages : en
Pages : 0
Book Description
Multiplicity Dependence of Charged-particle Jet Production in Pp Collisions at √s
Author: Shreyasi AcharyaJet and Underlying Event Properties as a Function of Charged-particle Multiplicity in Proton-proton Collisions at Sqrt(s)
Author: Publisher:
ISBN:
Category :
Languages : en
Pages : 41
Book Description
Characteristics of multi-particle production in proton-proton collisions at sqrt(s) = 7 TeV are studied as a function of the charged-particle multiplicity, N[ch]. The produced particles are separated into two classes: those belonging to jets and those belonging to the underlying event. Charged particles are measured with pseudorapidity abs(eta) 2.4 and transverse momentum pt 0.25 GeV. Jets are reconstructed from charged-particles only and required to have pt> 5 GeV. The distributions of jet pt, average pt of charged particles belonging to the underlying event or to jets, jet rates, and jet shapes are presented as functions of N[ch] and compared to the predictions of the PYTHIA and HERWIG event generators. Predictions without multi-parton interactions fail completely to describe the N[ch]-dependence observed in the data. For increasing N[ch], PYTHIA systematically predicts higher jet rates and harder pt spectra than seen in the data, whereas HERWIG shows the opposite trends. At the highest multiplicity, the data-model agreement is worse for most observables, indicating the need for further tuning and/or new model ingredients.
Production of Leading Charged Particles and Leading Charged-particle Jets at Small Transverse Momenta in Pp Collisions at $\sqrt{s}$
Author: Publisher:
ISBN:
Category :
Languages : en
Pages :
Book Description
The per-event yield of the highest transverse momentum charged particle and charged-particle jet, integrated above a given pminT threshold starting at pminT=0.8 and 1 GeV, respectively, is studied in pp collisions at s√=8 TeV. Furthermore, the particles and the jets are measured in the pseudorapidity ranges.
Looking Inside Jets
Author: Simone MarzaniPublisher: Springer
ISBN: 3030157091
Category : Science
Languages : en
Pages : 205
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.
J/ψ Production as a Function of Charged Particle Multiplicity in Pp Collisions at √s
Author: Betty AbelevCharged-particle Production as a Function of Multiplicity and Transverse Spherocity in Pp Collisions at S√
Author: Shreyasi AcharyaCorrelations Between Jets and Charged Particles in PbPb and Pp Collisions at $ \sqrt{s_{\mathrm{NN}}}
Author: Publisher:
ISBN:
Category :
Languages : en
Pages : 39
Book Description
In this study, the quark-gluon plasma is studied via medium-induced changes to correlations between jets and charged particles in PbPb collisions compared to pp reference data. This analysis uses data sets from PbPb and pp collisions with integrated luminosities of 166 inverse microbarns and 5.3 inverse picobarns, respectively, collected at $ \sqrt{s_{\mathrm{NN}}}=2.76 $ TeV. The angular distributions of charged particles are studied as a function of relative pseudorapidity ([Delta][eta]) and relative azimuthal angle ([Delta][Phi]) with respect to reconstructed jet directions. Charged particles are correlated with all jets with transverse momentum (pT) above 120 GeV, and with the leading and subleading jets (the highest and second-highest in pT, respectively) in a selection of back-to-back dijet events. Modifications in PbPb data relative to pp reference data are characterized as a function of PbPb collision centrality and charged particle pT. A centrality-dependent excess of low-pT particles is present for all jets studied, and is most pronounced in the most central events. This excess of low-pT particles follows a Gaussian-like distribution around the jet axis, and extends to large relative angles of [Delta][eta] ≈ 1 and [Delta][Phi] ≈ 1.
Shape, Transverse Size, and Charged Hadron Multiplicity of Jets in Pp Collisions at 7 TeV.
Author: Publisher:
ISBN:
Category :
Languages : en
Pages : 37
Book Description
Measurements of jet characteristics from inclusive jet production in proton-proton collisions at a centre-of-mass energy of 7 TeV are presented. The data sample was collected with the CMS detector at the LHC during 2010 and corresponds to an integrated luminosity of 36 inverse picobarns. The mean charged hadron multiplicity, the differential and integral jet shape distributions, and two independent moments of the shape distributions are measured as functions of the jet transverse momentum for jets reconstructed with the anti-kT algorithm. The measured observables are corrected to the particle level and compared with predictions from various QCD Monte Carlo generators.
Multiplicity Dependence of Jet-like Two-particle Correlation Structures in P-Pb Collisions at [arrow]"NN
![Multiplicity Dependence of Jet-like Two-particle Correlation Structures in P-Pb Collisions at [arrow]](https://books.google.com/books/content/images/frontcover/O_B4nQAACAAJ?fife=w80-h100)
Author: Publisher:
ISBN:
Category :
Languages : en
Pages : 13
Book Description
Two-particle angular correlations between unidentified charged trigger and associated particles are measured by the ALICE detector in p-Pb collisions at a nucleon-nucleon centre-of-mass energy of 5.02 TeV. The transverse-momentum range 0.7
Author: Shreyasi Acharya