Inclusive ALL Measurements at STAR
نویسنده
چکیده
One of the primary goals of the RHIC Spin program is to determine the gluon polarization distribution within the proton. At leading order, pp collisions involve a mixture of quark-quark, quark-gluon, and gluon-gluon scattering. In RHIC, the gluon-gluon and quark-gluon contributions dominate, making the accelerator an ideal tool to explore gluon polarization. The STAR experiment has measured the longitudinal double-spin asymmetry ALL for inclusive production of jets and pions, and for charged pion production opposite a jet, at √ s = 200GeV . The results provide valuable new constraints on the gluon polarization in the proton when included in a next-to-leading-order global analysis. The current status of the STAR measurements and the plans for future measurements will be discussed.
منابع مشابه
Inclusive Hadron Production in p+p Collisions at STAR
The STAR experiment at RHIC has measured a variety of inclusive hadron cross sections in p + p collisions at √ s = 200 GeV. Measurements of the differential cross section for inclusive charged pion production at mid rapidity and for inclusive neutral pion production at forward rapidity (3.0 < η < 4.2) as well as the first preliminary result from STAR for the differential cross section for inclu...
متن کاملRecent Longitudinal Spin Asymmetry Measurements for Inclusive Jet Production at STAR
We present measurements of the longitudinal spin asymmetry, ALL, for the inclusive jet signal at STAR. The data presented here are mid-rapidity jets in the transverse momentum range of 5 < pT < 35 GeV/c and come from polarized proton-proton collisions at center of mass energies of √ s = 200 GeV. We compare our measured ALL values to predictions derived from various parameterizations of the pola...
متن کاملRecent results and prospects on exploring the helicity structure of the proton at RHIC in high-energy polarized proton-proton collisions
The STAR Collaboration is pursuing measurements to help understand the origin of the proton spin. The gluon polarization is accesible via measurements of the longitudinal double-spin asymmetry, ALL , for inclusive charged and neutral pions and inclusive jet production. A recent global analysis of polarized DIS data and RHIC spin data disfavors extreme gluon polarization scenarios. The measureme...
متن کاملJet Production in Polarized pp Collisions at RHIC
One of the primary goals of the RHIC spin program is to determine the gluon polarization distribution within the proton. At leading order, pp collisions at RHIC involve a mixture of quark-quark (qq), quark-gluon (qg), and gluon-gluon (gg) scattering processes, with qg and gg contributions dominating. This makes RHIC an ideal place to study gluon polarization. For the past several years, the STA...
متن کاملRecent results from the STAR spin program at RHIC
The STAR experiment uses polarized p+p collisions at RHIC to determine the contributions to the spin of the proton from gluon spin and from orbital angular momentum of the quarks and gluons. Selective STAR measurements of the longitudinal double spin asymmetry for inclusive jet and inclusive hadron production are presented here. In addition, we report measurements of the transverse spin asymmet...
متن کامل