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Title: PROCEEDINGS FROM RIKEN-BNL RESEARCH CENTER WORKSHOP: PARITY-VIOLATING SPIN ASYMMETRIES AT RHIC.

Abstract

The RHIC spin program is now fully underway. Several runs have been successfully completed and are producing exciting first results. Luminosity and polarization have improved remarkably and promising advances toward the higher RHIC energy of {radical}s = 500 GeV have been made. At this energy in particular, it will become possible to perform measurements of parity-violating spin asymmetries. Parity violation occurs in weak interactions, and in combination with the unique polarization capabilities at RHIC fascinating new opportunities arise. In particular, parity-violating single- and double-spin asymmetries give new insights into nucleon structure by allowing probes of up and down sea and anti-quark polarizations. Such measurements at RHIC are a DOE performance milestone for the year 2013 and are also supported by a very large effort from RIKEN. With transverse polarization, charged-current interactions may be sensitive to the Sivers effect. Parity-violating effects at RHIC have been proposed even as probes of physics beyond the Standard Model. With the era of measurements of parity-violating spin asymmetries at RHIC now rapidly approaching, we had proposed a small workshop that would bring together the main experts in both theory and experiment. We are very happy that this worked out. The whole workshop contained 17 formalmore » talks, both experiment (10) and theory (7), and many fruitful discussions. The physics motivations for, the planned measurements were reviewed first. The RHIC machine prospects regarding polarized 500 GeV running were discussed, as well as the plans by the RHIC experiments for the vital upgrades of their detectors needed for the W physics program. We also had several talks on the topic of ''semi-inclusive deep-inelastic scattering'', which provides different access to related physics observables. On the theory side, new calculations were presented, for example in terms of QCD all-order resummations of perturbation theory. Also, new observables, such as jet and W+charrn final states and spin asymmetries in Z production, were proposed and discussed. All of the talks attracted much interest and initiated active discussions. This was a very successful workshop. It stimulated many discussions and new collaborations. We are grateful to all participants and speakers for coming to the Center, and for their excellent work. The support provided for this workshop by Dr. N. Samios and his RIKEN-BNL Research Center has been magnificent, and we are very grateful for it. We thank Brookhaven National Laboratory and the U.S. Department of Energy for providing the facilities to hold the workshop. Finally, sincere thanks go to Jane Lysik for her efficient work on organizing and running the workshop.« less

Authors:
; ;
Publication Date:
Research Org.:
Brookhaven National Lab. (BNL), Upton, NY (United States)
Sponsoring Org.:
Doe - Office Of Science
OSTI Identifier:
913072
Report Number(s):
BNL-79146-2007
R&D Project: 81133; KB0201; TRN: US0800634
DOE Contract Number:
DE-AC02-98CH10886
Resource Type:
Technical Report
Country of Publication:
United States
Language:
English
Subject:
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS; 71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; CHARGED-CURRENT INTERACTIONS; LUMINOSITY; NUCLEONS; ORGANIZING; PARITY; PERTURBATION THEORY; PHYSICS; POLARIZATION; PROBES; QUANTUM CHROMODYNAMICS; SCATTERING; SEAS; SPIN; STANDARD MODEL; WEAK INTERACTIONS

Citation Formats

VOGELSANG,W., PERDEKAMP, M., and SURROW, B. PROCEEDINGS FROM RIKEN-BNL RESEARCH CENTER WORKSHOP: PARITY-VIOLATING SPIN ASYMMETRIES AT RHIC.. United States: N. p., 2007. Web. doi:10.2172/913072.
VOGELSANG,W., PERDEKAMP, M., & SURROW, B. PROCEEDINGS FROM RIKEN-BNL RESEARCH CENTER WORKSHOP: PARITY-VIOLATING SPIN ASYMMETRIES AT RHIC.. United States. doi:10.2172/913072.
VOGELSANG,W., PERDEKAMP, M., and SURROW, B. Thu . "PROCEEDINGS FROM RIKEN-BNL RESEARCH CENTER WORKSHOP: PARITY-VIOLATING SPIN ASYMMETRIES AT RHIC.". United States. doi:10.2172/913072. https://www.osti.gov/servlets/purl/913072.
@article{osti_913072,
title = {PROCEEDINGS FROM RIKEN-BNL RESEARCH CENTER WORKSHOP: PARITY-VIOLATING SPIN ASYMMETRIES AT RHIC.},
author = {VOGELSANG,W. and PERDEKAMP, M. and SURROW, B.},
abstractNote = {The RHIC spin program is now fully underway. Several runs have been successfully completed and are producing exciting first results. Luminosity and polarization have improved remarkably and promising advances toward the higher RHIC energy of {radical}s = 500 GeV have been made. At this energy in particular, it will become possible to perform measurements of parity-violating spin asymmetries. Parity violation occurs in weak interactions, and in combination with the unique polarization capabilities at RHIC fascinating new opportunities arise. In particular, parity-violating single- and double-spin asymmetries give new insights into nucleon structure by allowing probes of up and down sea and anti-quark polarizations. Such measurements at RHIC are a DOE performance milestone for the year 2013 and are also supported by a very large effort from RIKEN. With transverse polarization, charged-current interactions may be sensitive to the Sivers effect. Parity-violating effects at RHIC have been proposed even as probes of physics beyond the Standard Model. With the era of measurements of parity-violating spin asymmetries at RHIC now rapidly approaching, we had proposed a small workshop that would bring together the main experts in both theory and experiment. We are very happy that this worked out. The whole workshop contained 17 formal talks, both experiment (10) and theory (7), and many fruitful discussions. The physics motivations for, the planned measurements were reviewed first. The RHIC machine prospects regarding polarized 500 GeV running were discussed, as well as the plans by the RHIC experiments for the vital upgrades of their detectors needed for the W physics program. We also had several talks on the topic of ''semi-inclusive deep-inelastic scattering'', which provides different access to related physics observables. On the theory side, new calculations were presented, for example in terms of QCD all-order resummations of perturbation theory. Also, new observables, such as jet and W+charrn final states and spin asymmetries in Z production, were proposed and discussed. All of the talks attracted much interest and initiated active discussions. This was a very successful workshop. It stimulated many discussions and new collaborations. We are grateful to all participants and speakers for coming to the Center, and for their excellent work. The support provided for this workshop by Dr. N. Samios and his RIKEN-BNL Research Center has been magnificent, and we are very grateful for it. We thank Brookhaven National Laboratory and the U.S. Department of Energy for providing the facilities to hold the workshop. Finally, sincere thanks go to Jane Lysik for her efficient work on organizing and running the workshop.},
doi = {10.2172/913072},
journal = {},
number = ,
volume = ,
place = {United States},
year = {Thu Apr 26 00:00:00 EDT 2007},
month = {Thu Apr 26 00:00:00 EDT 2007}
}

Technical Report:

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  • International workshop on II Polarized Partons at High Q2 region 11 was held at the Yukawa Institute for Theoretical Physics, Kyoto University, Kyoto, Japan on October 13-14, 2000, as a satellite of the international conference ''SPIN 2000'' (Osaka, Japan, October 16-21,2000). This workshop was supported by RIKEN (The Institute of Physical and Chemical Research) and by Yukawa Institute. The scientific program was focused on the upcoming polarized collider RHIC. The workshop was also an annual meeting of RHIC Spin Collaboration (RSC). The number of participants was 55, including 28 foreign visitors and 8 foreign-resident Japanese participants, reflecting the international naturemore » of the RHIC spin program. At the workshop there were 25 oral presentations in four sessions, (1) RHIC Spin Commissioning, (2) Polarized Partons, Present and Future, (3) New Ideas on Polarization Phenomena, (4) Strategy for the Coming Spin Running. In (1) the successful polarized proton commissioning and the readiness of the accelerator for the physics program impressed us. In (2) and (3) active discussions were made on the new structure function to be firstly measured at RHIC, and several new theoretical ideas were presented. In session (4) we have established a plan for the beam time requirement toward the first collision of polarized protons. These proceedings include the transparencies presented at the workshop. The discussion on ''Strategy for the Coming Spin Running'' was summarized by the chairman of the session, S. Vigdor and G. Bunce.« less
  • A major objective of the workshop was to establish a firm collaboration to develop suitable event generators for the spin physics program at RHIC. With the completion of the Relativistic Heavy Ion Collider (RHIC) as a polarized collider a completely new domain of high-energy spin physics will be opened. The planned studies address the spin structure of the nucleon, tests of the standard model, and transverse spin effects in initial and final states. RHIC offers the unique opportunity to pursue these studies because of its high and variable energy, 50 {le} {radical}s {le} 500 GeV, high polarization, 70%, and highmore » luminosity, 2 {times} 10{sup 32} cm{sup {minus}2} sec{sup {minus}1} or more at 500 GeV. To maximize the output from the spin program at RHIC, the understanding of both experimental and theoretical systematic errors is crucial. It will require full-fledged event generators, to simulate the processes of interest in great detail. The history of event generators shows that their development and improvement are ongoing processes taking place in parallel to the physics analysis by various experimental groups. The number of processes included in the generators has been increasing and the precision of their predictions is being improved continuously. This workshop aims at getting this process well under way for the spin physics program at RHIC, based on the first development in this direction, SPHINX.« less
  • The much anticipated RHIC spin physics program will commence this fall when the first physics run with colliding beams of polarized protons is expected. More specifically, the planned year-1 RHIC-Spin measurements are (1) the double-spin asymmetry A{sub LL}{sup {pi}} in production of pions by collisions of longitudinally polarized protons (in order to obtain first information on the proton's spin-dependent gluon density, {Delta}g); (2) the transverse single-spin asymmetry A{sub N}{sup {pi}} for pion production. These two reactions provided part of the motivation for our workshop. On the first day there were informative talks on the specific plans of STAR (by Rakness)more » and PHENIX (by Goto) for the polarized run of Year-1. Some of the theoretical questions related to the double-spin asymmetry A{sub LL}{sup {pi}} were discussed on the first day by Vogelsang and Kretzer, which centered mostly around the questions of how well the unpolarized fragmentation functions are known, the need for next-to-leading order calculations, and on how sensitive the asymmetry is to the possible {Delta}g distributions. Vetterli presented HERMES measurements of fragmentation functions, which overlap in Q{sup 2} with the future lower-p{sub T} measurements at RHIC.« less
  • Since its inception, the RHIC Spin Collaboration (RSC) has held semi-regular meetings each year to discuss the physics possibilities and the operational details of the program. Having collected our first data sample of polarized proton-proton collisions in Run02 of RHIC, we are now in the process of examining the performance of both the accelerator and the experiments. During the PAC meeting on August 29, 2002, the beam use proposal with a four week, polarized proton physics run was approved as part of the plan for Run-03. So, we meet at BNL on September 16, 2002 to discuss the concrete plansmore » for this proton-proton run.« less