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Measurement of parity-violating spin asymmetries in W$^{pm}$ production at midrapidity in longitudinally polarized $p$$+$$p$ collisions

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 نشر من قبل Brant M. Johnson
 تاريخ النشر 2015
  مجال البحث
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We present measurements from the PHENIX experiment of large parity-violating single spin asymmetries of high transverse momentum electrons and positrons from $W^pm/Z$ decays, produced in longitudinally polarized $p$$+$$p$ collisions at center of mass energies of $sqrt{s}$=500 and 510~GeV. These asymmetries allow direct access to the anti-quark polarized parton distribution functions due to the parity-violating nature of the $W$-boson coupling to quarks and anti-quarks. The results presented are based on data collected in 2011, 2012, and 2013 with an integrated luminosity of 240 pb$^{-1}$, which exceeds previous PHENIX published results by a factor of more than 27. These high $Q^2$ data provide an important addition to our understanding of anti-quark parton helicity distribution functions.



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