Biblioteca Digital

Observation of the antimatter helium-4 nucleus

**Autoria(s):** AGAKISHIEV, H.; AGGARWAL, M. M.; AHAMMED, Z.; ALAKHVERDYANTS, A. V.; ALEKSEEV, I.; ALFORD, J.; ANDERSON, B. D.; ANSON, C. D.; ARKHIPKIN, D.; AVERICHEV, G. S.; BALEWSKI, J.; BEAVIS, D. R.; BEHERA, N. K.; BELLWIED, R.; BETANCOURT, M. J.; BETTS, R. R.; BHASIN, A.; BHATI, A. K.; BICHSEL, H.; BIELCIK, J.; BIELCIKOVA, J.; BIRITZ, B.; BLAND, L. C.; BORDYUZHIN, I. G.; BOROWSKI, W.; BOUCHET, J.; BRAIDOT, E.; BRANDIN, A. V.; BRIDGEMAN, A.; BROVKO, S. G.; BRUNA, E.; BUELTMANN, S.; BUNZAROV, I.; BURTON, T. P.; CAI, X. Z.; CAINES, H.; CALDERON, M.; CEBRA, D.; CENDEJAS, R.; CERVANTES, M. C.; CHAJECKI, Z.; CHALOUPKA, P.; CHATTOPADHYAY, S.; CHEN, H. F.; CHEN, J. H.; CHEN, J. Y.; CHEN, L.; CHENG, J.; CHERNEY, M.; CHIKANIAN, A.; CHOI, K. E.; CHRISTIE, W.; CHUNG, P.; CODRINGTON, M. J. M.; CORLISS, R.; CRAMER, J. G.; CRAWFORD, H. J.; LEYVA, A. Davila; SILVA, L. C. De; DEBBE, R. R.; DEDOVICH, T. G.; DEREVSCHIKOV, A. A.; SOUZA, R. Derradi de; DIDENKO, L.; DJAWOTHO, P.; DOGRA, S. M.; DONG, X.; DRACHENBERG, J. L.; DRAPER, J. E.; DUNLOP, C.; EFIMOV, L. G.; ELNIMR, M.; ENGELAGE, J.; EPPLEY, G.; ESTIENNE, M.; EUN, L.; EVDOKIMOV, O.; FATEMI, R.; FEDORISIN, J.; FERSCH, R. G.; FILIP, P.; FINCH, E.; FINE, V.; FISYAK, Y.; GAGLIARDI, C. A.; GANGADHARAN, D. R.; GEURTS, F.; GHOSH, P.; GORBUNOV, Y. N.; GORDON, A.; GREBENYUK, O. G.; GROSNICK, D.; GUERTIN, S. M.; GUPTA, A.; GUPTA, S.; GURYN, W.; HAAG, B.; HAJKOVA, O.; HAMED, A.; HAN, L-X.; HARRIS, J. W.; HAYS-WEHLE, J. P.; HEINZ, M.; HEPPELMANN, S.; HIRSCH, A.; HJORT, E.; HOFFMANN, G. W.; HOFMAN, D. J.; HUANG, B.; HUANG, H. Z.; HUMANIC, T. J.; HUO, L.; IGO, G.; JACOBS, P.; JACOBS, W.; JENA, C.; JIN, F.; JOSEPH, J.; JUDD, E. G.; KABANA, S.; KANG, K.; KAPITAN, J.; KAUDER, K.; KE, H. W.; KEANE, D.; KECHECHYAN, A.; KETTLER, D.; KIKOLA, D. P.; KIRYLUK, J.; KISIEL, A.; KIZKA, V.; KLEIN, S. R.; KNOSPE, A. G.; KOETKE, D. D.; KOLLEGGER, T.; KONZER, J.; KORALT, I.; KOROLEVA, L.; KORSCH, W.; KOTCHENDA, L.; KOUCHPIL, V.; KRAVTSOV, P.; KRUEGER, K.; KRUS, M.; KUMAR, L.; KURNADI, P.; LAMONT, M. A. C.; LANDGRAF, J. M.; LAPOINTE, S.; LAURET, J.; LEBEDEV, A.; LEDNICKY, R.; LEE, J. H.; LEIGHT, W.; LEVINE, M. J.; LI, C.; LI, L.; LI, N.; LI, W.; LI, X.; LI, X.; LI, Y.; LI, Z. M.; LISA, M. A.; LIU, F.; LIU, H.; LIU, J.; LJUBICIC, T.; LLOPE, W. J.; LONGACRE, R. S.; LOVE, W. A.; LU, Y.; LUKASHOV, E. V.; LUO, X.; MA, G. L.; MA, Y. G.; MAHAPATRA, D. P.; MAJKA, R.; MALL, O. I.; MANWEILER, R.; MARGETIS, S.; MARKERT, C.; MASUI, H.; MATIS, H. S.; MATULENKO, Yu A.; MCDONALD, D.; MCSHANE, T. S.; MESCHANIN, A.; MILNER, R.; MINAEV, N. G.; MIODUSZEWSKI, S.; MITROVSKI, M. K.; MOHAMMED, Y.; MOHANTY, B.; MONDAL, M. M.; MOROZOV, B.; MOROZOV, D. A.; Munhoz, Marcelo Gameiro; MUSTAFA, M. K.; NAGLIS, M.; NANDI, B. K.; NAYAK, T. K.; NETRAKANTI, P. K.; NOGACH, L. V.; NURUSHEV, S. B.; ODYNIEC, G.; OGAWA, A.; OH, K.; OHLSON, A.; OKOROKOV, V.; OLDAG, E. W.; OLSON, D.; PACHR, M.; PAGE, B. S.; PAL, S. K.; PANDIT, Y.; PANEBRATSEV, Y.; PAWLAK, T.; PEI, H.; PEITZMANN, T.; PERKINS, C.; PERYT, W.; PILE, P.; PLANINIC, M.; PLOSKON, M. A.; PLUTA, J.; PLYKU, D.; POLJAK, N.; PORTER, J.; POSKANZER, A. M.; POTUKUCHI, B. V. K. S.; POWELL, C. B.; PRINDLE, D.; PRUNEAU, C.; PRUTHI, N. K.; PUJAHARI, P. R.; PUTSCHKE, J.; QIU, H.; RANIWALA, R.; RANIWALA, S.; RAY, R. L.; REDWINE, R.; REED, R.; RITTER, H. G.; ROBERTS, J. B.; ROGACHEVSKIY, O. V.; ROMERO, J. L.; RUAN, L.; RUSNAK, J.; SAHOO, N. R.; SAKREJDA, I.; SALUR, S.; SANDWEISS, J.; SANGALINE, E.; SARKAR, A.; SCHAMBACH, J.; SCHARENBERG, R. P.; SCHMAH, A. M.; SCHMITZ, N.; SCHUSTER, T. R.; SEELE, J.; SEGER, J.; SELYUZHENKOV, I.; SEYBOTH, P.; SHAH, N.; SHAHALIEV, E.; SHAO, M.; SHARMA, M.; SHI, S. S.; SHOU, Q. Y.; SICHTERMANN, E. P.; SIMON, F.; SINGARAJU, R. N.; SKOBY, M. J.; SMIRNOV, N.; SOLANKI, D.; SORENSEN, P.; SPINKA, H. M.; SRIVASTAVA, B.; STANISLAUS, T. D. S.; STASZAK, D.; STEADMAN, S. G.; STEVENS, J. R.; STOCK, R.; STRIKHANOV, M.; STRINGFELLOW, B.; Suaide, Alexandre Alarcon do Passo; SUAREZ, M. C.; SUBBA, N. L.; SUMBERA, M.; SUN, X. M.; SUN, Y.; SUN, Z.; SURROW, B.; SVIRIDA, D. N.; SYMONS, T. J. M.; Szanto de Toledo, Alejandro; TAKAHASHI, J.; TANG, A. H.; TANG, Z.; TARINI, L. H.; TARNOWSKY, T.; THEIN, D.; THOMAS, J. H.; TIAN, J.; TIMMINS, A. R.; TLUSTY, D.; TOKAREV, M.; TRAINOR, T. A.; TRENTALANGE, S.; TRIBBLE, R. E.; TRIBEDY, P.; TSAI, O. D.; ULLRICH, T.; UNDERWOOD, D. G.; BUREN, G. Van; NIEUWENHUIZEN, G. van; VANFOSSEN JR., J. A.; VARMA, R.; VASCONCELOS, G. M. S.; VASILIEV, A. N.; VIDEBAEK, F.; VIYOGI, Y. P.; VOKAL, S.; VOLOSHIN, S. A.; WADA, M.; WALKER, M.; WANG, F.; WANG, G.; WANG, H.; WANG, J. S.; WANG, Q.; WANG, X. L.; WANG, Y.; WEBB, G.; WEBB, J. C.; WESTFALL, G. D.; WHITTEN JR., C.; WIEMAN, H.; WISSINK, S. W.; WITT, R.; WITZKE, W.; WU, Y. F.; XIAO, Z.; XIE, W.; XU, H.; XU, N.; XU, Q. H.; XU, W.; XU, Y.; XU, Z.; XUE, L.; YANG, Y.; YANG, Y.; YEPES, P.; YIP, K.; YOO, I-K.; ZAWISZA, M.; ZBROSZCZYK, H.; ZHAN, W.; ZHANG, J. B.; ZHANG, S.; ZHANG, W. M.; ZHANG, X. P.; ZHANG, Y.; ZHANG, Z. P.; ZHAO, F.; ZHAO, J.; ZHONG, C.; ZHOU, W.; ZHU, X.; ZHU, Y. H.; ZOULKARNEEV, R.; ZOULKARNEEVA, Y.; STAR Collaboration
Contribuinte(s)	UNIVERSIDADE DE SÃO PAULO
Data(s)	20/10/2012 20/10/2012 2011
Resumo	High-energy nuclear collisions create an energy density similar to that of the Universe microseconds after the Big Bang(1); 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 provides an efficient means of producing and studying antimatter. The antimatter helium-4 nucleus ((4)(He) over bar), also known as the anti-alpha ((alpha) over bar), consists of two antiprotons and two antineutrons (baryon number B = -4). It has not been observed previously, although the alpha-particle was identified a century ago by Rutherford and is present in cosmic radiation at the ten per cent level(2). 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 a factor of about 1,000 with each additional antinucleon(3-5). Here we report the observation of (4)<(He) over bar, the heaviest observed antinucleus to date. In total, 18 (4)(He) over bar counts were detected at the STAR experiment at the Relativistic Heavy Ion Collider (RHIC; ref. 6) in 10(9) recorded gold-on-gold (Au+Au) collisions at centre-of-mass energies of 200 GeV and 62 GeV per nucleon-nucleon pair. The yield is consistent with expectations from thermodynamic(7) and coalescent nucleosynthesis(8) models, providing an indication of the production rate of even heavier antimatter nuclei and a benchmark for possible future observations of (4)(He) over bar in cosmic radiation. RHIC Operations Group RHIC Operations Group RACF at BNL RACF at BNL NERSC Center at LBNL NERSC Center at LBNL Open Science Grid consortium Open Science Grid consortium U.S. Department of Energy (DOE) Offices of NP and HEP within the US DOE Office of Science U.S. National Science Foundation (NSF) US NSF Sloan Foundation Sloan Foundation DFG cluster of excellence `Origin and Structure of the Universe` of Germany Deutsche Forschungsgemeinschaf (DFG) CNRS/IN2P3 CNRS/IN2P3 Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) FAPESP CNPq of Brazil Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) Ministry of Education and Science of the Russian Federation Ministry of Education and Science of the Russian Federation NNSFC Natural Science Foundation of China Natural Science Foundation of China (NSFC) CAS of China Chinese Academy of Sciences (CAS) MoST of China MoST of China MoE of China MoE of China GA and MSMT of the Czech Republic GA and MSMT of the Czech Republic Foundation for Fundamental Research on Matter (FOM) Netherlands Organisation for Scientific Research (NWO) FOM and NWO of the Netherlands DAE, DST and CSIR of India DST and CSIR of India Department of Atomic Energy of India (DAE) Polish Ministry of Science and Higher Education Polish Ministry of Science and Higher Education Korea Research Foundation Korea Research Foundation Ministry of Science, Education and Sports of Croatia Ministry of Science, Education and Sports of Croatia RosAtom of Russia RosAtom of Russia
Identificador	NATURE, v.473, n.7347, p.353-356, 2011 0028-0836 http://producao.usp.br/handle/BDPI/29504 10.1038/nature10079 http://dx.doi.org/10.1038/nature10079
Idioma(s)	eng
Publicador	NATURE PUBLISHING GROUP
Relação	Nature
Direitos	restrictedAccess Copyright NATURE PUBLISHING GROUP
Palavras-Chave	#QUARK-GLUON PLASMA #ANTIPROTONS #COLLISIONS #ELECTRON #Multidisciplinary Sciences
Tipo	article original article publishedVersion

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