A Study of the Contribution from Non-Perturbative Effects to Di-jet Yields at Forward Rapidity

POSTER

Abstract

It is well known that the proton's spin is equal to $\hbar$/2, but its internal structure and the spin contributions made by its parton constituents, especially gluons, remain enigmatic. By studying asymmetric di-jets produced in polarized proton-proton collisions at forward rapidity, more information about the spin contribution of the gluon can be attained. Next-to-leading order perturbative QCD calculations indicate that measurements of di-jets at forward rapidity with transverse momenta of 5 and 8 GeV/c can provide valuable information regarding the gluon polarization. However these calculations do not include background contributions from initial state-radiation, underlying events and beam remnants that can create additional particles which appear in the detector as jets. In this study, PYTHIA simulations were used to analyze jets of stable final state hadrons. A simple procedure is found to reject the background. Most of the di-jets that remain can be matched to initial hard scattered partons with momentum fractions x$_{2}$ of the order 10$^{-3}$ and x$_{1}$ of 0.4 or greater. These kinematics indicate that the remaining di-jets will provide relevant information about the gluon's polarization and lead to a better understanding of the proton's structure at the partonic level.

Authors

  • Anna Poulsen

    University of Dallas

  • Dennis McNabb

    University of Washington, Argonne National Laboratory, NSCL, CAEN, Michigan State University, Laboratoire de physique corpusculaire de Caen, Argonne National Lab, Los Alamos National Laboratory, North Carolina State University, Indiana University, Los Alamos National Lab, Yerevan, Catholic University of America, Jefferson Laboratory, Drake University, Benha University, LBNL, Rutgers Univ., Univ. Nacional de Colombia, UCB Nuclear Engineering, Millsaps College, ORNL, Univ. Bonn, LLNL,UCB Nuclear Engineering, LBNL, Rutgers Univ, Lund University, LNL-INFN, GSI, University of Warsaw, University of York, CSNSM, Slovak Academy of Science, JAEA, UTK, Soltan Inst. for Nuclear Studies, Univ. Complutense Madrid, Univ. of Warsaw, Univ. of Jyvaskyla, LPSC, Grenoble, Univ. of Notre Dame, Uppsala Univ., Univ. of Notre Dame, JINR, Tsinghua Univ., Vanderbilt Univ., Variable Energy Cyclotron Centre, GANIL, University of California, Davis, Iwate University, Japan, University of Illinois at Urbana-Champaign, University of Tokyo, Japan, Neils Bohr Institute, University of Copenhagen, Denmark, Theoretical Research Division, Nishina Center, RIKEN, Japan, University of Notre Dame, Institute for Nuclear Research, Kiev, Ukraine, University of Tennessee / Oak Ridge National Laboratory, National Institute of Standards and Technology, TUNL and Duke University, Triangle University Nuclear Lab, Lawrence Livermore National Laboratory, UC Berkeley, Univ of Michigan, Univ of Notre Dame, Oak Ridge National Laboratory, Univ of Tennessee, Knoxville, None, The Ohio State University, University Of Illinois, University Of Kentucky, Brown University, California Institute Of Technology, Los Alamos Natl Lab, Sandia National Laboratory, Univ. of Tenn., Col. Sch. of Mines, Univ. of Wisc. LaCrosse, Notre Dame, Rutgers, INL, US Air Force, Rutgers University, University of Tennessee - Knoxville, U Notre Dame, U Manitoba, ANL, LLNL, McGill U, U Chicago, LSU, UW, UW/ORNL, UTK/ORNL, Physics Division, Oak Ridge National Laboratory, Physics Division, Argonne National Laboratory, ISOLDE, CERN, Switzerland, National Superconducting Cyclotron Laboratory, Michigan State University, University of Tennessee-Knoxville, Oak Ridge Associated Universities, University of Tennessee at Knoxville / Oak Ridge National Laboratory, University of Tennessee at Knoxville, TRIUMF, Lawrence Livermore Natl Lab, Hope College, NSCL, Michigan State University, IFIC (CSIC-Univ. of Valencia), XIA LLC, Duke University, University of Kentucky, Charles University, Prague, KVI-CART, University of Groningen, 9747 AA Groningen, The Netherlands, Department of Physics, Kyoto University, Kyoto 606-8502, Japan, Department of Physics, Konan University, Hyogo 658-8501, Japan, Research Center for Nuclear Physics, Osaka University, Osaka 567-0047, Japan, Cyclotron and Radioisotope Center, Tohoku University, Sendai 980-8578, Japan, Physics Department, University of Notre Dame, Notre Dame, IN 46556, USA, Khalifa University, Department of Physics, University of Oslo, IFIC, CSIC-Universidad de Valencia, Central Michigan University, Fakult\"at f\"ur Physik, Technische Universit\"at M\"unchen, CMU, LBL, FSU, Dept. of Physics, Univ. of Hong Kong, Dept. of Physics, WMU, Dept. of Chemistry and Physics, WashU - Saint Louis, The Australian National University, Hebrew University of Jerusalem, Vienna Environmental Research Laboratory, University of Dallas, Irving, TX USA, United States Naval Academy, Annapolis, MD USA, University of Kentucky, Lexington, KY USA, University of the Witwatersrand, iThemba LABS, Universiteit Stellenbosch University, Colorado School of Mines, NSCL \& Michigan State University, Pacific Northwest National Laboratory, Texas A\&M University, McMaster University, Clemson University, LPC-Caen, Wittenberg University, Facility for Rare Isotope Beams, National Superconducting Cyclotron Laboratory, BHSU, LANL, Passport Systems, Inc., UMass Lowell, Institute for Nuclear Research of the Russian Academy of Sciences, NIST - Natl Inst of Stds \& Tech, Yale University, University of Maryland, Duke University/TUNL, University of Houston, Dept. of Physics, Univ. of Kentucky, U. Manitoba, Tel Aviv U., NSCL/Dept. of Chemistry, MSU, NSCL/Dept. of Physics and Astronomy, MSU, NSCL, MSU, NSCL/Dep. Chemistry, MSU, NSCL/Dep. Physics and Astronomy, MSU, McMaster Univ., Michigan State Univ., NSCL, JINA, NSCL, Univ. Notre Dame, Michigan State Univ., NSCL, NSCL, JINA, Michigan State Univ., NSCL, Univ. Washington, Yale Univ., Colorado Sch. Mines, ORNL, Univ. Tennessee, Knoxville, Michigan State Univ., NSCL, Kalamazoo Coll., Florida State University, Colorado State University, Universiy of Notre Dame, South Dakota School of Mines and Technology, JINA and UND, OU, INFN, TAMU, TUNL at Duke, Paul Scherrer Inst., Weizmann Inst., Soreq NRC, Hebrew University, Cyclotron Laboratory, Texas A\&M University, Louisiana State University, LLE, Ohio University, MIT, University of Mantitoba, Texas A\&M University Cyclotron Institute, Tel Aviv University, National Nuclear Data Center, Brookhaven National Laboratory, Upton, NY 11973-5000, Suleyman Demirel University, Department of Physics, Isparta, Turkey, Henan Normal University, CIAE, IU, WU-STL, MSU/NSCL, WMU, NSCL/MSU, Cyclotron Institute Texas A\&M University, Texas A\&M Univ, Division of Science Education, Chonbuk National University, Jeonju 561-756, Korea, Institute of Physics, Silesia University, Katowice, Poland, University of Michigan, College of Wooster, BNL, UML, San Diego State University, Grand Valley State Univ, Washington Univ - St. Louis, Western Michigan Univ, Univ of Connecticut, Argonne Nat. Lab., Australian National University, University of the Western Cape, Ludwig-Maximilians-Universit\"{a}t M\"{u}nchen, Technische Universit\"{a}t M\"{u}nchen, University of Guelph, University of Wisconsin La-Crosse, Ludwig Maximilian Universit\"{a}t M\"{u}nchen, Triumf, University of Richmond, University of Surrey, University of Richmond, University of Oslo, Lawrence Livermore National Laboratory, Rutgers University, University of Richmond, University of Notre Dame, Univ of Illinois - Urbana, Tsinghua University, Vanderbilt University, Texas A\&M University - Cyclotron Institute, Tennessee Technological University, North Carolina A\&T, Augustana College, NSCL/MSU, Dep. Chemistry, NSCL/MSU, Dep. Physics and Astronomy, University of Tennessee, Department of Physics, University of Notre Dame, Juelich Center for Neutron Science, Physikalisch-Technische Bundesanstalt, Technische Universitaet Muenchen, University of Connecticut, Thomas Jefferson National Accelerator Facility, Duquesne University, Jefferson Lab, TUNL, Houghton College, Bundesamt f\"{u}r Strahlenschutz, Ohio Wesleyan University, University of Massachusetts Lowell, Brookhaven National Laboratory, Oregon State University, U.S. Naval Academy, UM-DAE Centre for Excellence in Basic Sciences, Universidad de Buenos Aires and IFIBA, Rajamangala University of Technology Isan and Thailand Center of Excellence in Physics, University of Chicago, Argonne National Laboratory, University of Chicago, Northwestern University, UMASS, Lowell, Hofstra University, Oak Ridge National Lab, Oak Ridge TN, University of Virginia, Charlottesville VA, General Atomics, San Diego CA, Jefferson Lab, Newport News VA, University of Surrey, NSCL and Michigan State Univ, Michigan State Univ, Shanghai Institute of Applied Physics, China, Indiana University, Bloomington, Cyclotron Institute, Texas A\&M University, Indiana Univ - Bloomington, Westmont College, Wabash College, Duke University and Triangle Universities Nuclear Lab, Iowa State University, Universidad de Concepcion, Chile, Departments of Chemistry and Physics \& Astronomy, University of Kentucky, T-2, Los Alamos National Laboratory, P-27, Los Alamos National Laboratory, C-NR, Los Alamos National Laboratory, McGill University, U. Chicago, Univ of Manitoba, McGill Univ, Univ of Chicago, University of Kentucky, Lexington, KY, USA, Georgia Institute of Technology, Atlanta, GA, USA, TRIUMF, Vancouver, BC, Canada, Simon Fraser University, Burnaby, BC, Canada, University of Guelph, Guelph, ON, Canada, Shanghai Jiao Tong University, Huzhou University, IN2P3- CNRS, Rudjer Boskovich Institute, Croatia, University of Tennessee, Knoxville, Lawrence Livermore Lab

  • Dennis McNabb

    University of Washington, Argonne National Laboratory, NSCL, CAEN, Michigan State University, Laboratoire de physique corpusculaire de Caen, Argonne National Lab, Los Alamos National Laboratory, North Carolina State University, Indiana University, Los Alamos National Lab, Yerevan, Catholic University of America, Jefferson Laboratory, Drake University, Benha University, LBNL, Rutgers Univ., Univ. Nacional de Colombia, UCB Nuclear Engineering, Millsaps College, ORNL, Univ. Bonn, LLNL,UCB Nuclear Engineering, LBNL, Rutgers Univ, Lund University, LNL-INFN, GSI, University of Warsaw, University of York, CSNSM, Slovak Academy of Science, JAEA, UTK, Soltan Inst. for Nuclear Studies, Univ. Complutense Madrid, Univ. of Warsaw, Univ. of Jyvaskyla, LPSC, Grenoble, Univ. of Notre Dame, Uppsala Univ., Univ. of Notre Dame, JINR, Tsinghua Univ., Vanderbilt Univ., Variable Energy Cyclotron Centre, GANIL, University of California, Davis, Iwate University, Japan, University of Illinois at Urbana-Champaign, University of Tokyo, Japan, Neils Bohr Institute, University of Copenhagen, Denmark, Theoretical Research Division, Nishina Center, RIKEN, Japan, University of Notre Dame, Institute for Nuclear Research, Kiev, Ukraine, University of Tennessee / Oak Ridge National Laboratory, National Institute of Standards and Technology, TUNL and Duke University, Triangle University Nuclear Lab, Lawrence Livermore National Laboratory, UC Berkeley, Univ of Michigan, Univ of Notre Dame, Oak Ridge National Laboratory, Univ of Tennessee, Knoxville, None, The Ohio State University, University Of Illinois, University Of Kentucky, Brown University, California Institute Of Technology, Los Alamos Natl Lab, Sandia National Laboratory, Univ. of Tenn., Col. Sch. of Mines, Univ. of Wisc. LaCrosse, Notre Dame, Rutgers, INL, US Air Force, Rutgers University, University of Tennessee - Knoxville, U Notre Dame, U Manitoba, ANL, LLNL, McGill U, U Chicago, LSU, UW, UW/ORNL, UTK/ORNL, Physics Division, Oak Ridge National Laboratory, Physics Division, Argonne National Laboratory, ISOLDE, CERN, Switzerland, National Superconducting Cyclotron Laboratory, Michigan State University, University of Tennessee-Knoxville, Oak Ridge Associated Universities, University of Tennessee at Knoxville / Oak Ridge National Laboratory, University of Tennessee at Knoxville, TRIUMF, Lawrence Livermore Natl Lab, Hope College, NSCL, Michigan State University, IFIC (CSIC-Univ. of Valencia), XIA LLC, Duke University, University of Kentucky, Charles University, Prague, KVI-CART, University of Groningen, 9747 AA Groningen, The Netherlands, Department of Physics, Kyoto University, Kyoto 606-8502, Japan, Department of Physics, Konan University, Hyogo 658-8501, Japan, Research Center for Nuclear Physics, Osaka University, Osaka 567-0047, Japan, Cyclotron and Radioisotope Center, Tohoku University, Sendai 980-8578, Japan, Physics Department, University of Notre Dame, Notre Dame, IN 46556, USA, Khalifa University, Department of Physics, University of Oslo, IFIC, CSIC-Universidad de Valencia, Central Michigan University, Fakult\"at f\"ur Physik, Technische Universit\"at M\"unchen, CMU, LBL, FSU, Dept. of Physics, Univ. of Hong Kong, Dept. of Physics, WMU, Dept. of Chemistry and Physics, WashU - Saint Louis, The Australian National University, Hebrew University of Jerusalem, Vienna Environmental Research Laboratory, University of Dallas, Irving, TX USA, United States Naval Academy, Annapolis, MD USA, University of Kentucky, Lexington, KY USA, University of the Witwatersrand, iThemba LABS, Universiteit Stellenbosch University, Colorado School of Mines, NSCL \& Michigan State University, Pacific Northwest National Laboratory, Texas A\&M University, McMaster University, Clemson University, LPC-Caen, Wittenberg University, Facility for Rare Isotope Beams, National Superconducting Cyclotron Laboratory, BHSU, LANL, Passport Systems, Inc., UMass Lowell, Institute for Nuclear Research of the Russian Academy of Sciences, NIST - Natl Inst of Stds \& Tech, Yale University, University of Maryland, Duke University/TUNL, University of Houston, Dept. of Physics, Univ. of Kentucky, U. Manitoba, Tel Aviv U., NSCL/Dept. of Chemistry, MSU, NSCL/Dept. of Physics and Astronomy, MSU, NSCL, MSU, NSCL/Dep. Chemistry, MSU, NSCL/Dep. Physics and Astronomy, MSU, McMaster Univ., Michigan State Univ., NSCL, JINA, NSCL, Univ. Notre Dame, Michigan State Univ., NSCL, NSCL, JINA, Michigan State Univ., NSCL, Univ. Washington, Yale Univ., Colorado Sch. Mines, ORNL, Univ. Tennessee, Knoxville, Michigan State Univ., NSCL, Kalamazoo Coll., Florida State University, Colorado State University, Universiy of Notre Dame, South Dakota School of Mines and Technology, JINA and UND, OU, INFN, TAMU, TUNL at Duke, Paul Scherrer Inst., Weizmann Inst., Soreq NRC, Hebrew University, Cyclotron Laboratory, Texas A\&M University, Louisiana State University, LLE, Ohio University, MIT, University of Mantitoba, Texas A\&M University Cyclotron Institute, Tel Aviv University, National Nuclear Data Center, Brookhaven National Laboratory, Upton, NY 11973-5000, Suleyman Demirel University, Department of Physics, Isparta, Turkey, Henan Normal University, CIAE, IU, WU-STL, MSU/NSCL, WMU, NSCL/MSU, Cyclotron Institute Texas A\&M University, Texas A\&M Univ, Division of Science Education, Chonbuk National University, Jeonju 561-756, Korea, Institute of Physics, Silesia University, Katowice, Poland, University of Michigan, College of Wooster, BNL, UML, San Diego State University, Grand Valley State Univ, Washington Univ - St. Louis, Western Michigan Univ, Univ of Connecticut, Argonne Nat. Lab., Australian National University, University of the Western Cape, Ludwig-Maximilians-Universit\"{a}t M\"{u}nchen, Technische Universit\"{a}t M\"{u}nchen, University of Guelph, University of Wisconsin La-Crosse, Ludwig Maximilian Universit\"{a}t M\"{u}nchen, Triumf, University of Richmond, University of Surrey, University of Richmond, University of Oslo, Lawrence Livermore National Laboratory, Rutgers University, University of Richmond, University of Notre Dame, Univ of Illinois - Urbana, Tsinghua University, Vanderbilt University, Texas A\&M University - Cyclotron Institute, Tennessee Technological University, North Carolina A\&T, Augustana College, NSCL/MSU, Dep. Chemistry, NSCL/MSU, Dep. Physics and Astronomy, University of Tennessee, Department of Physics, University of Notre Dame, Juelich Center for Neutron Science, Physikalisch-Technische Bundesanstalt, Technische Universitaet Muenchen, University of Connecticut, Thomas Jefferson National Accelerator Facility, Duquesne University, Jefferson Lab, TUNL, Houghton College, Bundesamt f\"{u}r Strahlenschutz, Ohio Wesleyan University, University of Massachusetts Lowell, Brookhaven National Laboratory, Oregon State University, U.S. Naval Academy, UM-DAE Centre for Excellence in Basic Sciences, Universidad de Buenos Aires and IFIBA, Rajamangala University of Technology Isan and Thailand Center of Excellence in Physics, University of Chicago, Argonne National Laboratory, University of Chicago, Northwestern University, UMASS, Lowell, Hofstra University, Oak Ridge National Lab, Oak Ridge TN, University of Virginia, Charlottesville VA, General Atomics, San Diego CA, Jefferson Lab, Newport News VA, University of Surrey, NSCL and Michigan State Univ, Michigan State Univ, Shanghai Institute of Applied Physics, China, Indiana University, Bloomington, Cyclotron Institute, Texas A\&M University, Indiana Univ - Bloomington, Westmont College, Wabash College, Duke University and Triangle Universities Nuclear Lab, Iowa State University, Universidad de Concepcion, Chile, Departments of Chemistry and Physics \& Astronomy, University of Kentucky, T-2, Los Alamos National Laboratory, P-27, Los Alamos National Laboratory, C-NR, Los Alamos National Laboratory, McGill University, U. Chicago, Univ of Manitoba, McGill Univ, Univ of Chicago, University of Kentucky, Lexington, KY, USA, Georgia Institute of Technology, Atlanta, GA, USA, TRIUMF, Vancouver, BC, Canada, Simon Fraser University, Burnaby, BC, Canada, University of Guelph, Guelph, ON, Canada, Shanghai Jiao Tong University, Huzhou University, IN2P3- CNRS, Rudjer Boskovich Institute, Croatia, University of Tennessee, Knoxville, Lawrence Livermore Lab