Future prospects of di-jet production constraining Dg(x) at low x at STAR at RHIC

Abstract

© Copyright owned by the author(s) under the terms of the Creative Commons Attribution-NonCommercial Share like Licence. One of the main objectives of the high-energy spin physics program at RHIC at BNL is the precis determination of the polarized gluon distribution function, δg(x). Polarized p+p collision at ps = 200GeV and at √ = 500GeV at RHIC provide an unique way to probe the proton spi structure. Inclusive measurements, such as inclusive jet and hadron production, have so far bee the prime focus of various results at radic; = 200GeV constraining δg(x) for 0:05 < x < 0:2. A recen global analysis provides for the first time evidence of a non-zero value of the gluon polarizatio 10:05 δg(x)dx (Q2 =10GeV2)=0:20+0:006+0.07 First results of di-jet production at ps=200Ge by the STAR collaboration will allow a better constraint of the underlying event kinematics. Extendin the current program to smaller values of x is a key goal for the future high-energy spi physics program at RHIC. Forward di-jet production measurements at STAR beyond the curren acceptance from 1< <+2 to +2:5< <+4, in particular those carried out atps=500GeV provides access to low x values at the level of 103 where current uncertainties of Dg(x) remai very large. Those measurements will eventually be complemented by a future Electron-Ion Collide facility probing δg(x) in polarized e+p collisions.