Observation of the Antimatter Hypernucleus $^4_{\bar{\Lambda}}\overline{\hbox{H}}$
Abstract
At the origin of the Universe, asymmetry between the amount of created matter and antimatter led to the matter-dominated Universe as we know today. The origins of this asymmetry remain not completely understood yet. High-energy nuclear collisions create conditions similar to the Universe microseconds after the Big Bang, with comparable amounts of matter and antimatter. Much of the created antimatter escapes the rapidly expanding fireball without annihilating, making such collisions an effective experimental tool to create heavy antimatter nuclear objects and study their properties, hoping to shed some light on existing questions on the asymmetry between matter and antimatter. Here we report the first observation of the antimatter hypernucleus \hbox{}, composed of a , an antiproton and two antineutrons. The discovery was made through its two-body decay after production in ultrarelativistic heavy-ion collisions by the STAR experiment at the Relativistic Heavy Ion Collider. In total, 15.6 candidate \hbox{} antimatter hypernuclei are obtained with an estimated background count of 6.4. The lifetimes of the antihypernuclei \hbox{} and \hbox{} are measured and compared with the lifetimes of their corresponding hypernuclei, testing the symmetry between matter and antimatter. Various production yield ratios among (anti)hypernuclei and (anti)nuclei are also measured and compared with theoretical model predictions, shedding light on their production mechanisms.
Cite
@article{arxiv.2310.12674,
title = {Observation of the Antimatter Hypernucleus $^4_{\bar{\Lambda}}\overline{\hbox{H}}$},
author = {STAR Collaboration and M. I. Abdulhamid and B. E. Aboona and J. Adam and L. Adamczyk and J. R. Adams and I. Aggarwal and M. M. Aggarwal and Z. Ahammed and E. C. Aschenauer and S. Aslam and J. Atchison and V. Bairathi and J. G. Ball Cap and K. Barish and R. Bellwied and P. Bhagat and A. Bhasin and S. Bhatta and S. R. Bhosale and J. Bielcik and J. Bielcikova and J. D. Brandenburg and C. Broodo and X. Z. Cai and H. Caines and M. Calderón de la Barca Sánchez and D. Cebra and J. Ceska and I. Chakaberia and P. Chaloupka and B. K. Chan and Z. Chang and A. Chatterjee and D. Chen and J. Chen and J. H. Chen and Z. Chen and J. Cheng and Y. Cheng and S. Choudhury and W. Christie and X. Chu and H. J. Crawford and M. Csanád and G. Dale-Gau and A. Das and I. M. Deppner and A. Dhamija and P. Dixit and X. Dong and J. L. Drachenberg and E. Duckworth and J. C. Dunlop and J. Engelage and G. Eppley and S. Esumi and O. Evdokimov and O. Eyser and R. Fatemi and S. Fazio and C. J. Feng and Y. Feng and E. Finch and Y. Fisyak and F. A. Flor and C. Fu and C. A. Gagliardi and T. Galatyuk and T. Gao and F. Geurts and N. Ghimire and A. Gibson and K. Gopal and X. Gou and D. Grosnick and A. Gupta and W. Guryn and A. Hamed and Y. Han and S. Harabasz and M. D. Harasty and J. W. Harris and H. Harrison-Smith and W. He and X. H. He and Y. He and N. Herrmann and L. Holub and C. Hu and Q. Hu and Y. Hu and H. Huang and H. Z. Huang and S. L. Huang and T. Huang and X. Huang and Y. Huang and Y. Huang and T. J. Humanic and M. Isshiki and W. W. Jacobs and A. Jalotra and C. Jena and A. Jentsch and Y. Ji and J. Jia and C. Jin and X. Ju and E. G. Judd and S. Kabana and D. Kalinkin and K. Kang and D. Kapukchyan and K. Kauder and D. Keane and A. Khanal and Y. V. Khyzhniak and D. P. Kikoła and D. Kincses and I. Kisel and A. Kiselev and A. G. Knospe and H. S. Ko and L. K. Kosarzewski and L. Kumar and M. C. Labonte and R. Lacey and J. M. Landgraf and J. Lauret and A. Lebedev and J. H. Lee and Y. H. Leung and N. Lewis and C. Li and D. Li and H-S. Li and H. Li and W. Li and X. Li and Y. Li and Y. Li and Z. Li and X. Liang and Y. Liang and R. Licenik and T. Lin and Y. Lin and M. A. Lisa and C. Liu and G. Liu and H. Liu and L. Liu and T. Liu and X. Liu and Y. Liu and Z. Liu and T. Ljubicic and O. Lomicky and R. S. Longacre and E. M. Loyd and T. Lu and J. Luo and X. F. Luo and L. Ma and R. Ma and Y. G. Ma and N. Magdy and D. Mallick and R. Manikandhan and S. Margetis and C. Markert and G. McNamara and O. Mezhanska and K. Mi and S. Mioduszewski and B. Mohanty and M. M. Mondal and I. Mooney and J. Mrazkova and M. I. Nagy and A. S. Nain and J. D. Nam and M. Nasim and D. Neff and J. M. Nelson and D. B. Nemes and M. Nie and G. Nigmatkulov and T. Niida and T. Nonaka and G. Odyniec and A. Ogawa and S. Oh and K. Okubo and B. S. Page and R. Pak and S. Pal and A. Pandav and A. K. Pandey and T. Pani and A. Paul and B. Pawlik and D. Pawlowska and C. Perkins and J. Pluta and B. R. Pokhrel and M. Posik and T. Protzman and V. Prozorova and N. K. Pruthi and M. Przybycien and J. Putschke and Z. Qin and H. Qiu and C. Racz and S. K. Radhakrishnan and A. Rana and R. L. Ray and R. Reed and C. W. Robertson and M. Robotkova and M. A. Rosales Aguilar and D. Roy and P. Roy Chowdhury and L. Ruan and A. K. Sahoo and N. R. Sahoo and H. Sako and S. Salur and S. Sato and B. C. Schaefer and W. B. Schmidke and N. Schmitz and F-J. Seck and J. Seger and R. Seto and P. Seyboth and N. Shah and P. V. Shanmuganathan and T. Shao and M. Sharma and N. Sharma and R. Sharma and S. R. Sharma and A. I. Sheikh and D. Shen and D. Y. Shen and K. Shen and S. S. Shi and Y. Shi and Q. Y. Shou and F. Si and J. Singh and S. Singha and P. Sinha and M. J. Skoby and N. Smirnov and Y. Söhngen and Y. Song and B. Srivastava and T. D. S. Stanislaus and M. Stefaniak and D. J. Stewart and Y. Su and M. Sumbera and C. Sun and X. Sun and Y. Sun and Y. Sun and B. Surrow and M. Svoboda and Z. W. Sweger and A. C. Tamis and A. H. Tang and Z. Tang and T. Tarnowsky and J. H. Thomas and A. R. Timmins and D. Tlusty and T. Todoroki and S. Trentalange and P. Tribedy and S. K. Tripathy and T. Truhlar and B. A. Trzeciak and O. D. Tsai and C. Y. Tsang and Z. Tu and J. Tyler and T. Ullrich and D. G. Underwood and I. Upsal and G. Van Buren and J. Vanek and I. Vassiliev and V. Verkest and F. Videbæk and S. A. Voloshin and F. Wang and G. Wang and J. S. Wang and J. Wang and K. Wang and X. Wang and Y. Wang and Y. Wang and Y. Wang and Z. Wang and J. C. Webb and P. C. Weidenkaff and G. D. Westfall and D. Wielanek and H. Wieman and G. Wilks and S. W. Wissink and R. Witt and J. Wu and J. Wu and X. Wu and X. Wu and B. Xi and Z. G. Xiao and G. Xie and W. Xie and H. Xu and N. Xu and Q. H. Xu and Y. Xu and Y. Xu and Z. Xu and Z. Xu and G. Yan and Z. Yan and C. Yang and Q. Yang and S. Yang and Y. Yang and Z. Ye and Z. Ye and L. Yi and K. Yip and Y. Yu and H. Zbroszczyk and W. Zha and C. Zhang and D. Zhang and J. Zhang and S. Zhang and W. Zhang and X. Zhang and Y. Zhang and Y. Zhang and Y. Zhang and Y. Zhang and Z. J. Zhang and Z. Zhang and Z. Zhang and F. Zhao and J. Zhao and M. Zhao and J. Zhou and S. Zhou and Y. Zhou and X. Zhu and M. Zurek and M. Zyzak},
journal= {arXiv preprint arXiv:2310.12674},
year = {2024}
}
Comments
28 pages, 5 figures in the main paper; 16 pages, 5 figures in the methods part