[Brahms-l] Fwd: New PHENIX paper on W's in 500 GeV p+p collisions

FYI

> From: Barbara Jacak <jacak_at_skipper.physics.sunysb.edu>
> Date: August 27, 2010 12:13:21 PM EDT
> To: Nu Xu <NXu_at_lbl.gov>, "Videbaek, Flemming" <videbaek_at_bnl.gov>,  
> Wit Busza <busza_at_mit.edu>, "Vigdor, Steven" <vigdor_at_bnl.gov>
> Subject: New PHENIX paper on W's in 500 GeV p+p collisions
>
> Dear Nu, Wit, Flemming and Steve,
>
> I am happy to announce that in one week's time, the
> PHENIX Collaboration will submit a paper to Phys.Rev.
> Letters on the topic indicated in the subject line. Please
> find the title and abstract below.
>
> best regards,
> Barbara
>
> -----------------------------------------------------
> Title:
> Cross Section and Parity Violating Spin Asymmetries of W^{\pm}
> Boson Production in Polarized pp Collisions at \sqrt{s}=500 GeV
>
> Abstract:
> Large parity violating longitudinal single spin asymmetries
> A^{e^-}_L= -0.86^{+0.14}_{-0.30} and A^{e^+}_L= 0.88^{+0.12}_{-0.71}
> are observed for inclusive high transverse momentum electrons
> and positrons in polarized pp collisions at a center of mass energy
> of \sqrt{s}=500\ GeV with the PHENIX detector at RHIC. These
> e^{\pm} come mainly from the decay of W^{\pm} and Z^0 bosons,
> and the asymmetries directly demonstrate parity violation in the  
> couplings
> of the W^{\pm} to the light quarks. The observed electron and positron
> yields were used to estimate W^\pm boson production cross sections
> equal to
> \sigma(pp\!\rightarrow\!W^{+}X)\times
> BR(W^+\!\rightarrow\!l^+\nu)=144.1\pm
> 21.2(stat)^{+3.4}_{-10.3}(syst)\pm15\%(norm) pb,
> and
> \sigma(pp\!\rightarrow\!W^{-}X)\times BR(W^-\!\rightarrow\!l^- 
> \bar{\nu})=31
> .7\pm 12.1(stat)^{+10.1}_{-8.2}(syst)\pm15\%(norm) pb.



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