Download or read book Double spin Asymmetries in the Cross Section of R0 rho and F phi Production at Intermediate Energies written by HERMES Collaboration and published by . This book was released on 2003 with total page 8 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Double spin Asymmetries in the Cross Section of 0 rho and phi Production at Intermediate Energies written by and published by . This book was released on 2003 with total page 8 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Double spin Asymmetries in the Cross Section of r63 1hn0 rho and f63 phi Production at Intermediate Energies written by and published by . This book was released on 2003 with total page 8 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Double Spin Asymmetry in the Cross Section for Exclusive R0 rho 0 Production in Lepton Proton Scattering written by HERMES Collaboration and published by . This book was released on 2001 with total page 11 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Double Spin Asymmetry in the Cross Section for Exclusive 0 rho 0 Production in Lepton Proton Scattering written by and published by . This book was released on 2001 with total page 11 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Double Spin Asymmetry in the Cross Section for Exclusive r63 1hn0 rho 0 Production in Lepton Proton Scattering written by and published by . This book was released on 2001 with total page 11 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Double spin Asymmetrics in the Cross Section of P superscript 0 and Production at Intermediate Energies written by and published by . This book was released on 2003 with total page 8 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book DOUBLE TRANSVERSE SPIN ASYMMETRIES AT NLO written by A.STRATMANN MUKHERJEE (M.VOGELSANG, W.) and published by . This book was released on 2003 with total page 3 pages. Available in PDF, EPUB and Kindle. Book excerpt: We report on a next-to-leading order QCD calculation of the cross section and the spin asymmetry for isolated large-p{sub T} prompt photon production in collisions of transversely polarized protons. Corresponding measurements may be used at RHIC to determine the transversity parton distributions of the proton.

Download or read book Nuclear Science Abstracts written by and published by . This book was released on 1976 with total page 612 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Measurement of Longitudinal Double Spin Asymmetries of pi Production in P over arrow P over arrow Collisions at sqrt s written by Adam Philip Kocoloski and published by . This book was released on 2010 with total page 105 pages. Available in PDF, EPUB and Kindle. Book excerpt: Spin dependent measurements provide incisive tests for modern theories of particle physics. The discovery that the integral of the quark helicity distribution is much too small to account for the spin of the proton is an excellent case in point. It inspired an intense period of theoretical scrutiny and a new generation of experiments to study [Delta]g, the helicity distribution of gluons in the nucleon. In particular, the unique polarized proton collider at RHIC enables a class of asymmetry measurements that are directly sensitive to gluon polarization. The STAR experiment at RHIC measures the double spin asymmetry A[subscript LL] for a variety of final states in collisions of longitudinally polarized protons in order to constrain [Delta]g. Asymmetries for mid-rapidity charged pion production benefit from large cross sections and the excellent tracking and particle identification capabilities of the STAR Time Projection Chamber. This thesis presents the first measurements of charged pion A[subscript LL] at STAR. The measurements are compared to predictions based on perturbative QCD calculations and from this comparison model-dependent constraints are placed on the integral gluon polarization [Delta]G.

Download or read book Transverse Spin Physics written by Dr. Vincenzo Barone and published by World Scientific. This book was released on 2003 with total page 308 pages. Available in PDF, EPUB and Kindle. Book excerpt: This study deals with the theory and phenomenology of transverse spin effects in high-energy hadronic physics. Contrary to common past belief, it is now rather clear that these effects are far from irrelevant. A decade or so of intense theoretical work has shed much light on the subject and brought to the surface an entire class of new phenomena, which now await thorough experimental investigation. Over the next few years a number of experiments worldwide (at DESY, CERN and Brookhaven) will run with transversely polarised particles, providing data that will enrich our knowledge of the transverse spin structure of hadrons. The principle aim of this work is to assess the state of the art as it stands in 2002. After a few introductory remarks (Chapter 1), in the first part (Chapters 2-4) attention is directed to polarised deep inelastic scattering (DIS), particularly DIS on transversely polarised targets, which probes the transverse spin structure function g2. This structure function is examined within the framework of the quark-parton model and its improvement via perturbative QCD. The existing data are reviewed and commented on (for completeness and comparison, a brief presentation of longitudinally polarised DIS and of the helicity structure of the proton is provided). The second part of the book (Chapters 5-8) focuses on the transverse polarisation of quarks, the so-called "transversity". The partonic content and the QCD evolution of the transversity distributions are presented in detail. The phenomenology of transversity is then studied in the context of Drell-Yan processes and of semi-inclusive lepto- and hadroproduction. The interpretation of data on single-spin asymmetries is discussed and, finally, the prospects for future measurements are reviewed.

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 Longitudinal Double spin Asymmetry and Cross Section for Inclusivejet Production in Polarized Proton Collisions at Sqrt s written by and published by . This book was released on 2006 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: We report a measurement of the longitudinal double-spinasymmetry A_LL and the differential cross section for inclusivemidrapidity jet production in polarized proton collisions at sqrt(s)=200GeV. The cross section data cover transverse momenta 5

Download or read book Longitudinal Double spin Asymmetries for Intermediate Rapidity Inclusive 0 from Polarized s written by William Grey Solyst and published by . This book was released on 2021 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book The Double Spin Asymmetry in Exclusive Pi Electro production with CLAS written by and published by . This book was released on 2007 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The eg1b run was conducted using CLAS at Jefferson Lab in 2000 by the CLAS collab- oration. A 1.6 GeV - 5.6 GeV polarized electron beam and polarized nuclear targets (composed of NH3 and ND3) were used, allowing single and double spin asymmetries to be measured. This analysis deals with the double spin asymmetry A.

Download or read book Inclusive Cross Section and Double helicity Asymmetry for math Display written by and published by . This book was released on 2016 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: We present PHENIX measurements for the cross section and double-helicity asymmetry (ALL) in inclusive [pi]0 production at midrapidity from p + p collisions at √s = 510 GeV from data taken in 2012 and 2013 at the Relativistic Heavy Ion Collider. The next-to-leading-order perturbative-quantum-chromodynamics theory calculation is in excellent agreement with the presented cross section results. The calculation utilized parton-to-pion fragmentation functions from the recent DSS14 global analysis, which prefer a smaller gluon-to-pion fragmentation function. Our [pi]0ALL results follow an increasingly positive asymmetry trend with pT and √s with respect to the predictions and are in excellent agreement with the latest global analysis results. This analysis incorporated earlier results on [pi]0 and jet ALL and suggested a positive contribution of gluon polarization to the spin of the proton [Delta]G for the gluon momentum fraction range x > 0.05. Finally, the data presented here extend to a currently unexplored region, down to x similar to 0.01, and thus provide additional constraints on the value of [Delta]G.

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.