摘要:

The RHIC (Relativistic Heavy Ion colliders) project is reviewed. The design, the status, and the detectors are discussed briefly. (AIP)

ISSN:0094-243X    

DOI:10.1063/1.40472

出版商:AIP    

年代:1991

数据来源: AIP

摘要:

A polarized proton program at RHIC, with the same luminosity as for unpolarized protons of L=2×1032 cm−2 sec−1, is a very attractive possibility. Solutions for technical difficulties seem to be mostly in hand. As a benchmark, the error on a 2‐spin asymmetry measurement for jets at p⊥=50 GeV/c, for one &Dgr;p⊥=1 GeV/c bin, &Dgr;y=1, &Dgr;&fgr;=2&pgr; is &Dgr;ALL=.005 for one month of running. This level of sensitivity offers a remarkable discovery potential.In these remarks I will discuss the steps necessary to arrive at polarized protons in RHIC, and develop benchmarks for sensitivity for measuring spin asymmetries for direct photons, jets, W±, and Drell‐Yan production. Closing remarks include possibilities for detectors, a discussion of the focus of the spin program, how a RHIC spin program fits in with other plans, and suggestions on our next step.

ISSN:0094-243X    

DOI:10.1063/1.40474

出版商:AIP    

年代:1991

数据来源: AIP

摘要:

We give some results on jet production of future polarized hadronic collider.

ISSN:0094-243X    

DOI:10.1063/1.40475

出版商:AIP    

年代:1991

数据来源: AIP

摘要:

We argue that inclusive direct photon production at large transverse momentum in proton‐proton interaction with longitudinally polarized beam and target is an incisive probe of the polarized gluon distribution in a proton. We provide predictions of cross sections for a range of reasonable choices of the polarized gluon distribution. At current fixed target energies, the cross sections are small but measurable. At collider energies, such as the SSC energy, isolated direct photon production should be considered in order to minimize the nonperturbative contribution due to fragmentation.

ISSN:0094-243X    

DOI:10.1063/1.40468

出版商:AIP    

年代:1991

数据来源: AIP

摘要:

The availability of high‐intensity polarized beams at the future hadronic colliders would allow to reveal interesting spin effects as possible manifestations of the presence of New Physics beyond the Standard Model. Illustrative examples are given, which concern supersymmetry, compositeness and new gauge bosons.

ISSN:0094-243X    

DOI:10.1063/1.40476

出版商:AIP    

年代:1991

数据来源: AIP

摘要:

An introduction to transverse polarization phenomena in deep inelastic processes is given. A transversely polarized state of a massive or massless particle is defined as a coherent superposition of different helicity states; for a quark, it corresponds to transverse spin; for a gluon, to linear polarization. A simple toy model shows that quarks could have a sizeable transverse polarization in a transversely polarized baryon. A transverse polarization asymmetry corresponds to the exchange of a parton‐antiparton pair of nonzero total helicity in thet‐channel of the unitarity diagram. Conservation ofg‐channel helicity is used to select experiments which are sensitive to transverse polarization to leading order in &agr;sand 1/Q. The transversely polarized quark and gluon densities have independent evolutions withQ2.

ISSN:0094-243X    

DOI:10.1063/1.40477

出版商:AIP    

年代:1991

数据来源: AIP

摘要:

The transverse spin distribution of quarks in protons contributes at leading twist to the angular distribution of lepton pairs produced in doubly polarized proton‐proton collisions. It is the last classic parton model distribution left to be measured and it is not as subtle as often assumed.

ISSN:0094-243X    

DOI:10.1063/1.40512

出版商:AIP    

年代:1991

数据来源: AIP

摘要:

Theoretical analyses of polarized leptoproduction data suggest that the polarized gluon structure function might be large, but there has been no independent measurement of this quantity. Measurements of single spin asymmetries in the production of muon pairs from the scattering of two protons, one of which is longitudinally polarized, can be interpreted in terms of polarized gluon and polarized quark structure functions. Here we compute the asymmetries for the parton subprocesses that contribute to the measured muon pair production.

ISSN:0094-243X    

DOI:10.1063/1.40478

出版商:AIP    

年代:1991

数据来源: AIP

摘要:

By using a model for polarized parton densities that fits EMC data on polarized deep inelastic scattering, we make prediction for double helicity asymmetries in 1 and 2 jet inclusive production from polarized proton proton scattering at RHIC energies.

ISSN:0094-243X    

DOI:10.1063/1.40479

出版商:AIP    

年代:1991

数据来源: AIP

摘要:

The Physics case is presented for the use of polarized protons at RHIC for one or two months each year. This would provide a facility with polarizations of ≳50%, high luminosity∼2.0×1032cm−2s−1, the possibility of both longitudinal and transverse polarization at the interaction regions, and frequent polarization reversal for control of systematic errors. The annual integrated luminosity for such running (∼106sec per year) would be ∫Ldt=2×1038cm−2— roughly 20 times the total luminosity integrated in ∼10 years of operation of the CERN Collider (∼10 inverse picobarns, 1037cm−2). This facility would be unique in the ability to perform parity‐violating measurements and polarization tests of QCD. Also, the existence ofp‐pcollisions in a new energy range would permit the study of ‘‘classical’’ reactions like the total cross section and elastic scattering, etc., and serve as a complement to measurements fromp‐p¯ colliders.

ISSN:0094-243X    

DOI:10.1063/1.40481

出版商:AIP    

年代:1991

数据来源: AIP