Download or read book Dilepton Production from Collisions of Polarized Spin 1 2 Hadrons 2 Parton model Predictions written by and published by . This book was released on 1980 with total page 57 pages. Available in PDF, EPUB and Kindle. Book excerpt: Parton-model predictions for lepton-pair production from polarized spin-1/2 particles are considered within the context of a formalism explained in a companion paper. The polarization effects in the quantum-chromodynamic 2 → 2 subprocesses which contribute to lepton-pair production are found to be quite simple. Following the work of Ralston and Soper, polarized distribution functions are defined for gluons as well as quarks. Finally, a detailed discussion of polarization and the hard-scattering formalism is presented for the two cases of intrinsic parton transverse momentum allowed or forbidden.
Download or read book Dilepton Production from Polarized Hadron Hadron Collisions written by and published by . This book was released on 2009 with total page 34005 pages. Available in PDF, EPUB and Kindle. Book excerpt: In this paper we present a comprehensive formalism for dilepton production from the collision of two polarized spin-1/2 hadrons by identifying the general angular distribution of the cross section in combination with a complete set of structure functions. The various structure functions are computed in the parton model approximation where we mainly consider the case when the transverse momentum of the dilepton pair is much smaller than its invariant mass. In this kinematical region dilepton production can be described in terms of transverse momentum dependent parton distributions.
Download or read book Energy Research Abstracts written by and published by . This book was released on 1993 with total page 600 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Physics Briefs written by and published by . This book was released on 1993 with total page 640 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book INIS Atomindex written by and published by . This book was released on 1983 with total page 958 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book PROMPT PHOTON PRODUCTION IN POLARIZED HADRON COLLISIONS written by and published by . This book was released on 2000 with total page 3 pages. Available in PDF, EPUB and Kindle. Book excerpt: We consider spin asymmetries for prompt photon production in collisions of longitudinally polarized hadrons. This reaction will be a key tool at the BNL-RHIC {rvec p}{rvec p} collider for determining the gluon spin density in a polarized proton. We study the effects of QCD corrections, such as all-order soft-gluon ''threshold'' resummations.
Download or read book Particle Polarization in High Energy Physics written by Pietro Faccioli and published by Springer Nature. This book was released on 2023-01-17 with total page 313 pages. Available in PDF, EPUB and Kindle. Book excerpt: This open-access book addresses the following questions: how does the polarization of a particle, i.e., the angular momentum state in which it is produced, manifest itself in nature? What are the concepts and tools needed to perform rigorous measurements providing complete and unambiguous physical information? Polarization measurements are important because they reflect the nature and coupling properties of a particle and provide unique insights into the underlying fundamental interactions, playing a central role in the study and understanding of the mechanisms of particle production. Besides gradually reviewing many fundamental notions, the book presents several case studies relevant to physics analyses underway at the LHC, including the lepton-antilepton decays of vector states (Drell–Yan, Z and W bosons, quarkonia, etc.). The book also offers a detailed discussion of cascade decays, where the vector particle is a daughter of another particle, as well as a survey of typical angular distributions of particles of any integer or half-integer spin. With a visual approach to the presentation of the concepts and frequent use of pedagogical examples, taken from real measurements, gedankenexperiments, or detailed simulations, the book focuses on aspects of polarization measurements that are sometimes underestimated or left unexplored in experimental analyses, such as the importance of the choice of the reference frame, the existence of frame-independent relations, and the shapes of the physically allowed parameter domains. Several examples are provided of pitfalls introduced when the intrinsic multidimensionality of the problem is neglected in exchange for a simplified analysis. Targeting an audience of graduate students, post-docs, and other researchers involved in analyses of LHC data, this book helps to establish a solid bridge between high precision data, existing or soon to be collected, and accurate measurements, including high-sensitivity tests of the Standard Model.
Download or read book Dilepton Production by Hadrons written by Fazal-e-Aleem and published by . This book was released on 1996-02 with total page 184 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Cumulative Author Index of Physical Review volumes 23 32 and Physical Review Letters volumes 46 55 1981 1985 written by and published by . This book was released on 1986 with total page 602 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Longitudinal Double spin Asymmetry and Cross Section for Inclusive Neutral Pion Production in Polarized Proton Collisions at the Square Root of Sigma written by Alan Michael Hoffman and published by . This book was released on 2009 with total page 126 pages. Available in PDF, EPUB and Kindle. Book excerpt: Twenty years of polarized lepton-nucleon scattering experiments have found that the contribution from quark spins (1/2[delta] [sigma]) to the spin of the proton is only ~ 35%. This has lead researchers to look elsewhere, specifically to gluon spin ([delta sigma]) for a large contribution to proton spin. [delta sigma] has been only loosely constrained in polarized DIS and SIDIS experiments. Polarized proton-proton collisions at RHIC provide sensitivity to [delta sigma] through measurements of the longitudinal double-spin asymmetry, ALL. This work presents a measurement of ALL for inclusive 7ro production in polarized proton-proton collisions using the STAR detector and data from RHIC Run 6. 7r0s are abundantly produced at mid-rapidity in proton-proton collisions, making them natural candidates for studies of [delta] [sigma]. Novel techniques for reconstructing 7ros at STAR are discussed, and a measurement of the unpolarized cross section presented. Finally, the measured ALL is compared to perturbative QCD predictions and from this comparison constraints are placed on [delta] [sigma].
Download or read book Forward Di hadron Asymmetries from P P at 8 s written by James Lucas Drachenberg and published by . This book was released on 2012 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: One unresolved question in hadronic physics is the origin of large transverse single-spin asymmetries, AN, observed in hadron production from high-energy polarized-proton collisions. Collinear perturbative Quantum Chromodynamics (pQCD) predicts that AN should scale with the quark mass, however, experiments have since reported large AN for inclusive hadron production. Recent measurements from RHIC experiments show examples of these asymmetries at forward angles in a kinematic region where pQCD cross-section calculations reasonably agree with measured cross-sections. Disentangling dynamical contributions to AN from hadro-production requires moving beyond inclusive measurements. One possibility is to investigate asymmetries in two-particle correlations due to Interference Fragmentation Functions (IFF) and the Sivers effect. In 2008, RHIC dedicated a portion of the run to transversely polarized proton collisions at sqrt(s) = 200 GeV. STAR was equipped with a Foward Meson Spectrometer (FMS) and a Forward Time Projection Chamber (FTPC), overlapping in the pseudorapidity range of 2.5 eta & lt; 4. By analyzing neutral pions with the FMS correlated with charged particles from the FTPC, correlation asymmetries can be measured at kinematics where large inclusive asymmetries have been measured. Correlations are measured for pi^0's with 2 & lt; pT, pi^0 & lt; 5 GeV/c and associated charged particles in two ranges of transverse momentum: 1 & lt; pT, ch & lt; 2 GeV/c and 0.5 & lt; pT, ch & lt; 1 GeV/c. IFF and Sivers asymmetries manifest themselves through the correlation of two particles from the same jet. These events are selected through a cut on the pair radius, delta R. Gain non-uniformities and electronics failures have resulted in large holes in trigger acceptance and associated particle acceptance, respectively. This non-uniform acceptance allows the Sivers and IFF effects to mix and distort the raw asymmetries. Techniques are developed to measure this leak-through by means of unpolarized yields and event weighting. They result in small corrections to the asymmetries. IFF and Sivers asymmetries both for xF 0 and for xF & lt; 0 are reported for forward-angle pi^0-charged particle correlations from polarized-proton collisions at sqrt(s) = 200 GeV. Asymmetries are shown corrected for full underlying-event and pileup backgrounds, as well as corrected only for pile-up contributions. It appears the asymmetries are less sensitive to delta R when corrected for the full underlying-event background. Unfortunately, statistics limitations preclude a firm conclusion.
Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1994 with total page 312 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Spin Physics written by Donald G. Crabb and published by American Inst. of Physics. This book was released on 2009-08-25 with total page 1236 pages. Available in PDF, EPUB and Kindle. Book excerpt: The topics covered in the conference ranged from the physics that can be done with polarized beams of particles (protons, electrons, gamma-rays, etc.) to the techniques and instrumentation necessary to achieve this. Topics included: nucleon structure measurements (from where does the spin of the proton and neutron come), the acceleration, storage and polarization of particle beams and the polarized targets and sources necessary for mounting the experiments.
Download or read book High Energy Physics Index written by and published by . This book was released on 1993 with total page 640 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Dissertation Abstracts International written by and published by . This book was released on 1995 with total page 776 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book An Assessment of U S Based Electron Ion Collider Science written by National Academies of Sciences, Engineering, and Medicine and published by National Academies Press. This book was released on 2018-10-13 with total page 153 pages. Available in PDF, EPUB and Kindle. Book excerpt: Understanding of protons and neutrons, or "nucleons"â€"the building blocks of atomic nucleiâ€"has advanced dramatically, both theoretically and experimentally, in the past half century. A central goal of modern nuclear physics is to understand the structure of the proton and neutron directly from the dynamics of their quarks and gluons governed by the theory of their interactions, quantum chromodynamics (QCD), and how nuclear interactions between protons and neutrons emerge from these dynamics. With deeper understanding of the quark-gluon structure of matter, scientists are poised to reach a deeper picture of these building blocks, and atomic nuclei themselves, as collective many-body systems with new emergent behavior. The development of a U.S. domestic electron-ion collider (EIC) facility has the potential to answer questions that are central to completing an understanding of atoms and integral to the agenda of nuclear physics today. This study assesses the merits and significance of the science that could be addressed by an EIC, and its importance to nuclear physics in particular and to the physical sciences in general. It evaluates the significance of the science that would be enabled by the construction of an EIC, its benefits to U.S. leadership in nuclear physics, and the benefits to other fields of science of a U.S.-based EIC.
Download or read book Introduction to Relativistic Heavy Ion Physics written by Jerzy Bartke and published by World Scientific. This book was released on 2009 with total page 239 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book attempts to cover the fascinating field of physics of relativistic heavy ions, mainly from the experimentalist's point of view. After the introductory chapter on quantum chromodynamics, basic properties of atomic nuclei, sources of relativistic nuclei, and typical detector set-ups are described in three subsequent chapters. Experimental facts on collisions of relativistic heavy ions are systematically presented in 15 consecutive chapters, starting from the simplest features like cross sections, multiplicities, and spectra of secondary particles and going to more involved characteristics like correlations, various relatively rare processes, and newly discovered features: collective flow, high pT suppression and jet quenching. Some entirely new topics are included, such as the difference between neutron and proton radii in nuclei, heavy hypernuclei, and electromagnetic effects on secondary particle spectra.Phenomenological approaches and related simple models are discussed in parallel with the presentation of experimental data. Near the end of the book, recent ideas about the new state of matter created in collisions of ultrarelativistic nuclei are discussed. In the final chapter, some predictions are given for nuclear collisions in the Large Hadron Collider (LHC), now in construction at the site of the European Organization for Nuclear Research (CERN), Geneva. Finally, the appendix gives us basic notions of relativistic kinematics, and lists the main international conferences related to this field. A concise reference book on physics of relativistic heavy ions, it shows the present status of this field.
