First Observation of the P-Wave Spin-Singlet Bottomonium States h_b(1P) and h_b(2P)

Journal Article · Wed Jan 18 00:00:00 EST 2012 · Physical Review Letters

DOI:https://doi.org/10.1103/PhysRevLett.108.032001· OSTI ID:1092013

Adachi, I.; Aihara, H.; Arinstein, K.; Asner, David M.; Aushev, T.; Aziz, T.; Bakich, A. M.; Barberio, E.; Belous, K.; Bhardwaj, V.; Bhuyan, B.; Bondar, A.; Bracko, Marko; Brodzicka, J.; Browder, Thomas E.; Chang, P.; Chen, A.; Chen, P.; Cheon, B. G.; Chilikin, K. ; Chistov, R.; Cho, I- S.; Cho, K.; Choi, Y.; Dalseno, J.; Danilov, M.; Drasal, Z.; Drutskoy, A.; Eidelman, S.; Epifanov, D.; Esen, Sevda; Fast, James E.; Feindt, M.; Gaur, Vipin; Gabyshev, N.; Garmash, A.; Goh, Y. M.; Golob, B.; Hara, Takanori; Hayasaka, K.; Hayashii, H.; Hoshi, Y.; Hou, W. S.; Hsiung, Y. B.; Hyun, H. J.; Iijima, T.; Ishikawa, A.; Iwabuchi, M.; Iwasaki, Y.; Jaegle, Igal; Julius, T.; Kang, J. H.; Katayama, N.; Kawasaki, T.; Kichimi, H.; Kim, H. O.; Kim, J. B.; Kim, K. T.; Kim, M. J.; Kim, Y. J.; Kinoshita, Kay; Ko, Byeong Rok; Kobayashi, N.; Koblitz, S.; Korpar, S.; Krizan, P.; Kuhr, T.; Kumita, T.; Kuzmin, A.; Kwon, Y. J.; Lange, J. S.; Lee, S. H.; Li, J.; Libby, J.; Liu, C.; Liventsev, D.; Louvot, R.; Macnaughton, Jimmy N.; Matvienko, D.; McOnie, S.; Miyabayashi, K.; Miyata, H.; Miyazaki, Y.; Mizuk, R.; Mohanty, G. B.; Mussa, R.; Nagasaka, Y.; Nakano, E.; Nakao, M.; Nakazawa, H.; Natkaniec, Z.; Neubauer, S.; Nishida, S.; Nishimura, K.; Nitoh, O.; Nozaki, T.; Ohshima, T.; Okuno, S.; Olsen, Stephen L.; Onuki, Y.; Pakhlov, P.; Pakhlova, G.; Park, H.; Pedlar, Todd K.; Pestotnik, Rok; Petric, M.; Piilonen, Leo E.; Poluektov, A.; Ritter, M.; Rohrken, M.; Ryu, S.; Sahoo, Himansu B.; Sakai, Y.; Sanuki, T.; Schneider, O.; Schwanda, C.; Schwartz, A. J.; Senyo, K.; Seon, O.; Sevior, Martin E.; Shapkin, M.; Shebalin, V.; Shibata, T. A.; Shiu, Jing-Ge; Shwartz, B.; Simon, F.; Smerkol, P.; Sohn, Young-Soo; Sokolov, A.; Solovieva, E.; Stanic, S.; Stanic, M.; Sumihama, M.; Tatishvili, Gocha; Teramoto, Y.; Tikhomirov, I.; Trabelsi, K.; Uchida, M.; Uehara, S.; Uglov, T.; Unno, Y.; Uno, S.; Vahsen, S. E.; Varner, G.; Varvell, K. E.; Vinokurova, A.; Wang, C. H.; Wang, X. L.; Watanabe, Y.; Wicht, J.; Won, E.; Yabsley, B. D.; Yamashita, Y.; Yuan, C. Z.; Zhilich, V.; Zupanc, A.

We report the observation of the h_b(1P) and h_b(2P) spin-singlet bottomonium states produced in the reaction e⁺e⁻ → h_b(nP)π⁺π⁻ with significances of 5.5σ and 11.2σ, respectively. We find that M[h_b(1P)] = (9898.25±1.06+1.03 –1.07 )MeV/c² and M[h_b(2P)] = (10259.76±0.64+1.43 –1.03 )MeV/c², which correspond to measurements of the P-wave hyperfine splittings ΔM^HF = (1.62 ± 1.52)MeV/c² and (0.48+1.57 –1.22)MeV/c², respectively. We also report measurements of the cross sections for e⁺e⁻ → h_b(nP)π⁺π⁻ relative to the cross section for the e⁺e⁻ Υ(2S)π⁺π⁻ reaction. These results are obtained from a 121.4 fb⁻¹ data sample collected with the Belle detector near the Υ(5S) resonance at the KEKB asymmetric-energy e⁺e⁻ collider.

• Research Organization: Pacific Northwest National Lab. (PNNL), Richland, WA (United States). Environmental Molecular Sciences Lab. (EMSL)
• Sponsoring Organization: USDOE
• Contributing Organization: Belle Collaboration
• DOE Contract Number: AC05-76RL01830
• OSTI ID: 1092013
• Report Number(s): PNNL-SA-81589; 45392
• Journal Information: Physical Review Letters, Vol. 108, Issue 3; ISSN 0031-9007
• Publisher: American Physical Society (APS)
• Country of Publication: United States
• Language: English

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First observation of the hb(1P) and hb(2P) bottomonium states
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