Nuclear Effects in High-energy Proton-nucleus Collisions

Nuclear Effects in High-energy Proton-nucleus Collisions PDF Author: Florian Cougoulic
Publisher:
ISBN:
Category :
Languages : en
Pages : 0

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Book Description
In the Standard Model of particle physics,the theory of the strong interaction, Quantum Chromodynamics (QCD), is a gauge theory of symmetry group SU (Nc) with respect to the color quantum number. QCD obeys the property of asymptotic freedom, allowing the computation of high-energy physical observables using perturbative QCD (pQCD). This thesis deals with the pQCD description of hadron production rates in high-energy hadronic collisions, in view of applications to the phenomenology of proton-nucleus and nucleus-nucleus collisions at hadron colliders (RHIC,LHC), where so-called nuclear effects (shadowing, parton energy loss, transverse momentum broadening) come into play. In a first part, I study the transverse broadening of an energetic parton system crossing a nucleus, putting emphasis on the color structure of the process. A theoretical setup based on the dipole formalism is used,and a kinetic equation is derived for the parton pair transverse momentum distribution, requiring the parton pair to be in a given color state (SU (Nc) irreducible representation) both in the initial and final state. The color structure is encoded in a color evolution operator, which is obtained for any type of parton pair. For a small-size compact pair, the derivation yields a transparent physical interpretation of the pair transverse broadening process. In a second part, I discuss the soft anomalous dimension matrix Q, which is formally analogous to the previous evolution operator, and which appears when studying soft gluon radiation associated to 2 -> 2 hard parton scattering. It has been noticed that the Q-matrix associated to gg -> gg has a surprising symmetry (relating external and internal degrees of freedom). I developed tools to derive the Q-matrices associated to2 -> 2 scatterings involving generalized partons, in order to explore if the symmetry observed for gg -> gg is fortuitous or not.

Nuclear Effects in High-energy Proton-nucleus Collisions

Nuclear Effects in High-energy Proton-nucleus Collisions PDF Author: Florian Cougoulic
Publisher:
ISBN:
Category :
Languages : en
Pages : 0

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Book Description
In the Standard Model of particle physics,the theory of the strong interaction, Quantum Chromodynamics (QCD), is a gauge theory of symmetry group SU (Nc) with respect to the color quantum number. QCD obeys the property of asymptotic freedom, allowing the computation of high-energy physical observables using perturbative QCD (pQCD). This thesis deals with the pQCD description of hadron production rates in high-energy hadronic collisions, in view of applications to the phenomenology of proton-nucleus and nucleus-nucleus collisions at hadron colliders (RHIC,LHC), where so-called nuclear effects (shadowing, parton energy loss, transverse momentum broadening) come into play. In a first part, I study the transverse broadening of an energetic parton system crossing a nucleus, putting emphasis on the color structure of the process. A theoretical setup based on the dipole formalism is used,and a kinetic equation is derived for the parton pair transverse momentum distribution, requiring the parton pair to be in a given color state (SU (Nc) irreducible representation) both in the initial and final state. The color structure is encoded in a color evolution operator, which is obtained for any type of parton pair. For a small-size compact pair, the derivation yields a transparent physical interpretation of the pair transverse broadening process. In a second part, I discuss the soft anomalous dimension matrix Q, which is formally analogous to the previous evolution operator, and which appears when studying soft gluon radiation associated to 2 -> 2 hard parton scattering. It has been noticed that the Q-matrix associated to gg -> gg has a surprising symmetry (relating external and internal degrees of freedom). I developed tools to derive the Q-matrices associated to2 -> 2 scatterings involving generalized partons, in order to explore if the symmetry observed for gg -> gg is fortuitous or not.

New Aspects of High-Energy Proton-Proton Collisions

New Aspects of High-Energy Proton-Proton Collisions PDF Author: A. Ali
Publisher: Springer Science & Business Media
ISBN: 1461595401
Category : Science
Languages : en
Pages : 437

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Book Description
Articles focus on the planned European proton-proton collider, and concentrate on physics issues, rather than the more technical concerns addressed in the three previous workshops. The use of energies much higher than those of the American Superconducting Super Collider is featured. Topics include reviews of current projects, hadron collisions, lep

The Effect of Free-particle Collisions in High Energy Proton and Pion-induced Nuclear Reactions

The Effect of Free-particle Collisions in High Energy Proton and Pion-induced Nuclear Reactions PDF Author: Norman Peara Jacob
Publisher:
ISBN:
Category :
Languages : en
Pages : 380

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Book Description


Introduction to High-energy Heavy-ion Collisions

Introduction to High-energy Heavy-ion Collisions PDF Author: Cheuk-Yin Wong
Publisher: World Scientific
ISBN: 9789810202637
Category : Science
Languages : en
Pages : 542

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Book Description
Written primarily for researchers and graduate students who are new in this emerging field, this book develops the necessary tools so that readers can follow the latest advances in this subject. Readers are first guided to examine the basic informations on nucleon-nucleon collisions and the use of the nucleus as an arena to study the interaction of one nucleon with another. A good survey of the relation between nucleon-nucleon and nucleus-nucleus collisions provides the proper comparison to study phenomena involving the more exotic quark-gluon plasma. Properties of the quark-gluon plasma and signatures for its detection are discussed to aid future searches and exploration for this exotic matter. Recent experimental findings are summarised.

Strangeness Production in High Energy Proton-nucleus Collision

Strangeness Production in High Energy Proton-nucleus Collision PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages :

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Book Description
Results on strange particles produced by high energy protons on nuclear targets are reviewed. Topics included are inclusive cross- sections, A-dependence, particle ratios and production polarization of hyperons. 49 refs., 41 figs., 1 tab.

Probing Nucleons And Nuclei In High Energy Collisions - Proceedings Of The Int Program Int-18-3

Probing Nucleons And Nuclei In High Energy Collisions - Proceedings Of The Int Program Int-18-3 PDF Author: Alexei Prokudin
Publisher: World Scientific
ISBN: 9811214964
Category : Science
Languages : en
Pages : 344

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Book Description
This book contains proceedings of the 7-week INT program dedicated to the physics of the Electron-Ion Collider (EIC), the world's first polarized electron-nucleon (ep) and electron-nucleus (eA) collider to be constructed in the United States. The 2015 NSAC Long Range Plan recommended EIC as the 'highest priority for new facility construction following the completion of FRIB'. The primary goal of the EIC is to establish precise multi-dimensional imaging of quarks and gluons inside nucleons and nuclei. This includes (i) understanding the spatial and momentum space structure of the nucleon through the studies of TMDs (transverse-momentum-dependent parton distributions), GPD (generalized parton distributions) and the Wigner distribution; (ii) determining the partonic origin of the nucleon spin; (iii) exploring the new quantum chromodynamics (QCD) frontier of ultra-strong gluon fields, with the potential to seal the discovery of a new form of dense gluon matter predicted to exist in all nuclei and nucleons at small Bjorken x — the parton saturation.The program brought together both theorists and experimentalists from Jefferson Lab (JLab), Brookhaven National Laboratory (BNL) along with the national and international nuclear physics communities to assess and advance the EIC physics.

Collisions of High-energy Nuclear Particles with Nuclei

Collisions of High-energy Nuclear Particles with Nuclei PDF Author: B. J. Moyer
Publisher:
ISBN:
Category : Particles (Nuclear physics)
Languages : en
Pages : 30

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Book Description


Production of High $P(t$) Jets in Hadron - Nucleus Collisions

Production of High $P(t$) Jets in Hadron - Nucleus Collisions PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 30

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Book Description
We present results on the production of jets and "jetlike" clusters in 800-GeV/c proton-nucleus (pA) collisions. Events with high values of transverse energy in the central kinematic region were selected for nuclear targets of H, Be, C, Cu, and Pb. A jet-finding algorithm was used in analyzing the data. The A dependence of the jet and dijet cross sections was parametrized as A?. The values of? for events with "jetlike" cluster pairs found by the algorithm without any additional kinematic cuts reach a plateau of approximately 1.5 at dijet transverse energies> GeV. The collimation of observed "jetlike" clusters decreases with A, and the fragmentation is softer for heavier target nuclei. However, nuclear effects become less pronounced with the increasing cluster or cluster-pair transverse energy. We argue that the observed nuclear enhancement for the production of "jetlike" clusters is due to underlying event or/and soft-scattering contributions to the heavy-nuclei data. We show that the nuclear enhancement becomes consistent with a value of? within 0.10 from unity once the data are corrected for the underlying event or kinematic cuts enhancing clear jet structure are applied.

The Production of High Energy Neutrons by Stripping

The Production of High Energy Neutrons by Stripping PDF Author: R. Serber
Publisher:
ISBN:
Category : Deuterons
Languages : en
Pages : 26

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Book Description


Nuclear Physics

Nuclear Physics PDF Author: National Research Council
Publisher: National Academies Press
ISBN: 0309173663
Category : Science
Languages : en
Pages : 222

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Book Description
Dramatic progress has been made in all branches of physics since the National Research Council's 1986 decadal survey of the field. The Physics in a New Era series explores these advances and looks ahead to future goals. The series includes assessments of the major subfields and reports on several smaller subfields, and preparation has begun on an overview volume on the unity of physics, its relationships to other fields, and its contributions to national needs. Nuclear Physics is the latest volume of the series. The book describes current activity in understanding nuclear structure and symmetries, the behavior of matter at extreme densities, the role of nuclear physics in astrophysics and cosmology, and the instrumentation and facilities used by the field. It makes recommendations on the resources needed for experimental and theoretical advances in the coming decade.