1. Observation of the antimatter helium-4 nucleus
- Author
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H. Xu, M. Wada, B. Haag, I. G. Alekseev, B. Stringfellow, Donika Plyku, Zhigang Xiao, Zhuang Li, A. Hamed, Yaping Wang, M. A. Lisa, W. Korsch, N. G. Minaev, G. Igo, D. Staszak, E. Sangaline, Subhasis Chattopadhyay, W. Peryt, J. Joseph, O. D. Tsai, R. Corliss, Jana Bielcikova, J. Bouchet, N. Li, Zhi Ping Xu, Brian Page, Gene-Jack Wang, Elena Bruna, T. D.S. Stanislaus, Jorn Henning Putschke, C. Perkins, W. W. Jacobs, P. K. Netrakanti, Jie Zhao, V. Kouchpil, A. Szanto de Toledo, A. V. Brandin, H. M. Spinka, J. Kapitan, N. K. Behera, T. J.M. Symons, H. Agakishiev, T. Pawlak, R. Witt, A. V. Alakhverdyants, J. H. Thomas, S. Mioduszewski, L. H. Tarini, T. A. Trainor, P. R. Pujahari, P. Filip, J. Alford, Jaroslav Bielcik, G. D. Westfall, W. Christie, M. Sharma, H. Wieman, L. Ruan, M. K. Mustafa, M. Sumbera, J. H. Lee, C. D. Anson, O. I. Mall, I. Koralt, V. Fine, S. Bueltmann, J. Schambach, J. Fedorisin, Xiaofeng Luo, D. Tlusty, Yang Wu, P. Pile, S. M. Guertin, Alexandre Alarcon Do Passo Suaide, Z. Tang, Abhishek Sarkar, S. M. Dogra, G. S. Averichev, A. M. Poskanzer, L. Eun, H. S. Matis, R. Majka, Bedangadas Mohanty, D. P. Mahapatra, Y. Lu, T. Ljubicic, N. K. Pruthi, H. Z. Huang, F. Videbaek, N. L. Subba, R. G. Fersch, A. Kechechyan, M. Elnimr, J. Balewski, J. E. Draper, Frank Jm Geurts, Rashmi Raniwala, T. Tarnowsky, E. Hjort, Shenghui Zhang, P. Djawotho, S. Heppelmann, A. R. Timmins, Claude Andre Pruneau, M. Planinic, He Liu, L. Li, G. Van Buren, L. Kotchenda, Jake Y. Chen, C. Li, L. Huo, A. M. Schmah, L. Koroleva, Mitali Mondal, O. V. Rogachevskiy, M. Krus, R. Cendejas, H. Wang, William Axel Leight, C. Zhong, A. Lebedev, D. Prindle, M. K. Mitrovski, I. G. Bordyuzhin, M. Calderon, D. Cebra, T. Ullrich, Zhi-Jun Sun, I. Sakrejda, S. Voloshin, C. B. Powell, L. C. De Silva, Li-Zhu Chen, E. Finch, Y. Sun, R. Zoulkarneev, J. Seger, K. Oh, D. J. Hofman, S. Vokal, Wei Xie, D. R. Beavis, Hanna Paulina Zbroszczyk, S. Margetis, P. Kurnadi, Nilay Shah, X. L. Wang, Bernd Surrow, D. Solanki, M. Strikhanov, A. P. Meschanin, K. E. Choi, S. S. Shi, Xianglei Zhu, Hank Crawford, G. W. Hoffmann, A. A. Derevschikov, B. D. Anderson, Jing-Han Chen, A. G. Knospe, F. Jin, D. Keane, I. K. Yoo, C. A. Gagliardi, M. Pachr, G. Webb, K. Yip, E. W. Oldag, L. V. Nogach, Andreas Hirsch, R. Lednicky, H. W. Ke, A. Chikanian, R. R. Debbe, Jinbao Liu, G. Van Nieuwenhuizen, M. C. Suarez, Baoyu Huang, X. Dong, Y. N. Gorbunov, Madan M. Aggarwal, H. Bichsel, T. Kollegger, Y. Zoulkarneeva, G. L. Ma, Fuqiang Wang, M. Tokarev, M. G. Munhoz, S. G. Brovko, Justin Stevens, O. Hajkova, P. Kravtsov, Y. Yang, W. J. Llope, I. Selyuzhenkov, J. Takahashi, D. A. Morozov, S. Lapointe, L. X. Han, G. Eppley, Xu Cai, J. Pluta, E. Braidot, W. Li, W. Witzke, K. Krueger, Peter Martin Jacobs, S. Salur, R. Stock, P. Chung, M. Ploskon, Adam Ryszard Kisiel, P. Chaloupka, Rama Narayana Singaraju, Ron Longacre, M. A.C. Lamont, Q. Wang, W. L. Zhan, S. B. Nurushev, R. P. Scharenberg, Frank Simon, A. Ohlson, R. Fatemi, Michael Joseph Betancourt, Y. H. Zhu, R. E. Tribble, S. Trentalange, H. F. Chen, F. Liu, Sudhir Raniwala, Jianping Cheng, A. K. Bhati, J. Konzer, Z. Chajecki, A. Gordon, Nikolai Smirnov, M. Estienne, J. C. Webb, T. G. Dedovich, Xiaoping Zhang, Thomas Peitzmann, J. Sandweiss, J. Tian, D. McDonald, P. Sorensen, M. Zawisza, L. G. Efimov, M. Naglis, J. Seele, C. W.C. Whitten, J. Rusnak, R. Bellwied, M. Cherney, F. Zhao, N. R. Sahoo, B. V.K.S. Potukuchi, T. K. Nayak, Yu-Gang Ma, P. Seyboth, E. V. Lukashov, N. Schmitz, M. J. Skoby, Y. Fisyak, W. M. Zhang, L. C. Bland, T. R. Schuster, L. Didenko, Y. Zhang, G. M.S. Vasconcelos, J. B. Zhang, A. Ogawa, Y. Panebratsev, D. Grosnick, X. M. Sun, M. Shao, J. W. Harris, W. Zhou, O. G. Grebenyuk, W. Borowski, Y. Mohammed, J. A. Vanfossen, P. Yepes, A. Davila Leyva, D. Arkhipkin, A. H. Tang, J. Lauret, S. G. Steadman, I. Bunzarov, R. Manweiler, M. Heinz, Dave Underwood, D. N. Svirida, S. Pal, R. L. Ray, W. A. Love, Y. Xu, H. G. Ritter, J. Porter, S. Gupta, H. Pei, Andrey Vasiliev, M. C. Cervantes, Lokesh Kumar, Nu Xu, E. P. Sichtermann, D. D. Koetke, B. Morozov, N. Poljak, W. Xu, J. Kiryluk, Anju Bhasin, C. Jena, Basanta Kumar Nandi, D. Kettler, T. P. Burton, R. P. Redwine, H. Masui, K. Kang, R. Derradi de Souza, E. G. Judd, R. R. Betts, V. A. Okorokov, E. Shahaliev, J. C. Dunlop, Zubayer Ahammed, H. Qiu, Jian-Song Wang, Q. Y. Shou, M. J. Levine, R. Milner, B. Biritz, J. L. Romero, Xiao Li, Prithwish Tribedy, B. K. Srivastava, A. Gupta, Z. P. Zhang, J. L. Drachenberg, Liang Xue, Olga Evdokimov, J. Engelage, Jay Roberts, A. Bridgeman, Premomoy Ghosh, D. Olson, W. Guryn, H. Caines, D. Thein, Christina Markert, V. Kizka, J. G. Cramer, G. Odyniec, R. Reed, S. W. Wissink, Matthew Walker, S. R. Klein, Q. H. Xu, Y. P. Viyogi, Yanjun Li, Y. Pandit, S. Kabana, R. Varma, James Prewitt Hays-Wehle, Yu A. Matulenko, D. P. Kikola, T. S. McShane, K. Kauder, J. M. Landgraf, M. J.M. Codrington, Thomas Humanic, D. R. Gangadharan, Massachusetts Institute of Technology. Laboratory for Nuclear Science, Massachusetts Institute of Technology. Department of Physics, Massachusetts Institute of Technology. Department of Materials Science and Engineering, Laboratoire SUBATECH Nantes (SUBATECH), Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université de Nantes (UN)-Mines Nantes (Mines Nantes), and STAR
- Subjects
Particle physics ,Physics::General Physics ,media_common.quotation_subject ,Nuclear Theory ,FOS: Physical sciences ,Cosmic ray ,[PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex] ,7. Clean energy ,01 natural sciences ,Nuclear physics ,Nucleosynthesis ,0103 physical sciences ,Nuclear Experiment (nucl-ex) ,010306 general physics ,Antihydrogen ,Nuclear Experiment ,media_common ,Physics ,Multidisciplinary ,Annihilation ,010308 nuclear & particles physics ,Universe ,13. Climate action ,Antiproton ,Antimatter ,Relativistic Heavy Ion Collider - 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 ($^4\bar{He}$), also known as the anti-{\alpha} ($\bar{\alpha}$), 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 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 $^4\bar{He}$ 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., Comment: 19 pages, 4 figures. Submitted to Nature. Under media embargo
- Published
- 2011
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