[Brahms-l] Fwd: STAR new paper on the observation of anti-alphas at RHIC

FYI
Flemming Videbaek
v

> From: Nu Xu <nxu_at_lbl.gov>
> Date: March 7, 2011 1:52:36 PM EST
> To: Barbara Jacak <jacak_at_skipper.physics.sunysb.edu>, Flemming Videbaek <videbaek_at_bnl.gov>, Wit Busza <busza_at_MIT.EDU>, Steven Vigdor <vigdor_at_bnl.gov>
> Cc: Nu Xu <NXu_at_lbl.gov>
> Subject: STAR new paper on the observation of anti-alphas at RHIC
> 
> Dear Barbara, Wit, Flemming and Steve,
> 
> I am pleased to announce that the STAR collaboration will submit to Nature Letter,  in one week's time,  a new paper on the observation of anti-alphas at RHIC. The title and abstract are included below.
> 
> Best regards,
> 
> Nu Xu
> 
> -----------------------------------------------------------------------
>  Nu Xu
> 
>  Build. 510A, I-181	    Phone:  (631)344-3471
>  P.O. Box 5000, BNL	    Fax:       (631)344-4206
>  Upton, NY11973		
>     	    				    Mobile: (510)289-8119
>  MS70R0319, NSD         Phone:  (510)495-2951
>  LBNL        			    Fax:       (510)486-4818
>  Berkeley, CA94720	    http://www-rnc.lbl.gov/~nxu		    
> -----------------------------------------------------------------------
> 
> Title: "Observation of the antimatter helium-4 nucleus"
> 
> Abstract: "High-energy nuclear collisions create an energy density similar to that of the universe microseconds after the Big Bang, and in both cases, matter and antimatter are formed with comparable abundance. However, the relatively short-lived expansion in nuclear collisions allows antimatter to decouple quickly from matter, and avoid annihilation. Thus, a high energy accelerator of heavy nuclei is an efficient means of producing and studying antimatter. The antimatter helium-4 nucleus ($^4\overline{He}), also known as the anti-$\alpha$ ($\overline{\alpha}$), consists of two antiprotons and two antineutrons (baryon number B=-4). It has not been observed previously, although the  particle was identified a century ago by Rutherford and is present in cosmic radiation at the 10% level. Antimatter nuclei with B < -1 have been observed only as rare products of interactions at particle accelerators, where the rate of antinucleus production in high-energy collisions decreases by about 1000 with each additional antinucleon. We present the observation of the antimatter helium-4 nucleus, the heaviest observed antinucleus. In total 18 $^4\overline{He}$ counts were detected at the STAR experiment at RHIC in 10$^9$ recorded Au+Au collisions at center-of-mass energies of 200 GeV and 62 GeV per nucleon-nucleon pair. The yield is consistent with expectations from thermodynamic and coalescent nucleosynthesis models, which has implications beyond nuclear physics."
> 
> Note: Nature has the following policy regarding publications: "Material submitted to Nature journals must not be discussed with the
> media, except in the case of accepted contributions, which can be discussed with the media no more than a week before the publication date under our embargo conditions. "



_______________________________________________
Brahms-l mailing list
Brahms-l_at_lists.bnl.gov
https://lists.bnl.gov/mailman/listinfo/brahms-l