What do we learn from the ρ-π puzzle

LI Xue-Qian

doi:10.1088/1674-1137/34/2/022

Chinese Physics C> 2010, Vol. 34> Issue(2) : 267-269 DOI: 10.1088/1674-1137/34/2/022

What do we learn from the ρ-π puzzle

LI Xue-Qian ^,

Department of Physics, Nankai University, Tianjin 300071, China

Abstract
HTML
Reference
Related

PDF

Abstract：
The experimental observation indicates that the branching ratio of ψ´→ρπ is very small while the ρ-π channel is a main one in J/ψ decays. To understand the puzzle, various interpretations have been proposed. Meanwhile according to the hadronic helicity selection rule, this decay mode should be suppressed. Numerical calculations are needed to determine how it is suppressed. We calculate the branching ratios of J/ψ→ρπ and ππ in the framework of QCD. The results show that the branching ratios are proportional to (m_u+m_d/M_J/ψ)² for the ρπ mode and (m_u+m_d/M_J/ψ)² for the ππ mode which is isospin violated. The theoretical prediction of the ratio of J/ψ→ρπ is smaller than data, but not too small to invoke a completely new mechanism. Thus the puzzle is still standing even though we learn much knowledge towards the puzzle and this will help to finally interpret the puzzle and then gain a deeper insight to the heavy quarkonia.

References

[1]

. Rosner J L. Phys. Rev. D, 2001, 64: 0940022. Suzuki M. Phys. Rev. D, 2001, 63: 054021, hep-ph/00062963. LI X Q, Bugg D V, ZOU B S. Phys. Rev. D, 1997, 55: 14214. LIU X, ZENG X, LI X. Phys. Rev. D, 2006, 74: 0740035. LI G, LI T, LI X, MA W. Nucl. Phys. B, 2008, 727: 301;LI T, ZHAO S, LI X. Nulc. Phys. A, 2009, 828: 1256. Brodsky S, Lepage G. Phys. Rev. D, 1981, 24: 2848; Bram-billa N et al. Heavy Quarkonium Physics, hep-ph/04121587. MO X H, YUAN C Z, WANG P. arXiv:hep-ph/06112148. ZHAO Q, LI G, CHANG C H. Phys. Lett. B, 2007, 645:173; LI G, ZHAO Q, CHANG C H. J. Phys. G, 2008, 35:055002; ZHAO Q. Talk given at "The Conference on Inter-disciplinary Fields of Particle Physics, Nuclear Physics and Cosmology", Tenchong, Yunnan, China, Aug. 2 to 4

[1]	Xing-Dao Guo , Dian-Yong Chen , Xue-Qian Li , Zhong-Yuan Yuan , Shijing Sang . Molecular components in J/ψ and ρ-π puzzle. Chinese Physics C, 2024, 48(5): 053110. doi: 10.1088/1674-1137/ad2a65
[2]	Dong-Liang Fang . What can we learn from recent 2νββ experiments?. Chinese Physics C, 2024, 48(3): 034101. doi: 10.1088/1674-1137/ad181b
[3]	Qing-Hong Cao , Hao-Lin Li , Ling-Xiao Xu , Jiang-Hao Yu . What can we learn from the total width of the Higgs boson?. Chinese Physics C, 2023, 47(3): 033101. doi: 10.1088/1674-1137/aca8f6
[4]	Zhen-Hua Zhang . Potential pollution of the Kπ-puzzle by the isospin-breaking π⁰-η-η' mixing effect. Chinese Physics C, 2022, 46(9): 093110. doi: 10.1088/1674-1137/ac7317
[5]	Hongpeng Wang , Chang-Zheng Yuan . New puzzle in charmonium decays. Chinese Physics C, 2022, 46(7): 071001. doi: 10.1088/1674-1137/ac5fa2
[6]	BAI Wei , LIU Min , FAN Ying-Ying , WANG Wen-Fei , CHENG Shan , XIAO Zhen-Jun . Revisiting the Kπ puzzle in the pQCD factorization approach. Chinese Physics C, 2014, 38(3): 033101. doi: 10.1088/1674-1137/38/3/033101
[7]	ZHAO Qiang , LI Gang , CHANG Chao-Hsi . Further insights into the ρπ puzzle. Chinese Physics C, 2010, 34(2): 299-304. doi: 10.1088/1674-1137/34/2/027
[8]	MO Xiao-Hu , YUAN Chang-Zheng , WANG Ping . Study of the ρπ Puzzle in Charmonium Decays. Chinese Physics C, 2007, 31(7): 686-701.
[9]	YU Hong . THE ι-E PUZZLE AND THE GENERALIZED MOMENT ANALYSIS. Chinese Physics C, 1989, 13(6): 574-576.
[10]	Yu Hong . The Ɩ/E Puzzle and the Moment Analysis. Chinese Physics C, 1989, 13(S2): 181-184.

Access

Get Citation

LI Xue-Qian. What do we learn from the ρ-π puzzle[J]. Chinese Physics C, 2010, 34(2): 267-269. doi: 10.1088/1674-1137/34/2/022

LI Xue-Qian. What do we learn from the ρ-π puzzle[J]. Chinese Physics C, 2010, 34(2): 267-269. doi: 10.1088/1674-1137/34/2/022 shu

RIS(for EndNote,Reference Manager,ProCite)

BibTex

Txt

Milestone

Received: 2009-09-02
Revised: 2009-09-25

Article Metric

Article Views(2858)
PDF Downloads(542)
Cited by(0)

Policy on re-use

To reuse of subscription content published by CPC, the users need to request permission from CPC, unless the content was published under an Open Access license which automatically permits that type of reuse.

通讯作者: 陈斌, bchen63@163.com

1.
沈阳化工大学材料科学与工程学院沈阳 110142

What do we learn from the ρ-π puzzle

LI Xue-Qian ^,

Corresponding author: LI Xue-Qian,

Department of Physics, Nankai University, Tianjin 300071, China

Received Date: 2009-09-02
Accepted Date: 2009-09-25
Available Online: 2010-02-05

Abstract:

The experimental observation indicates that the branching ratio of ψ´→ρπ is very small while the ρ-π channel is a main one in J/ψ decays. To understand the puzzle, various interpretations have been proposed. Meanwhile according to the hadronic helicity selection rule, this decay mode should be suppressed. Numerical calculations are needed to determine how it is suppressed. We calculate the branching ratios of J/ψ→ρπ and ππ in the framework of QCD. The results show that the branching ratios are proportional to (m_u+m_d/M_J/ψ)² for the ρπ mode and (m_u+m_d/M_J/ψ)² for the ππ mode which is isospin violated. The theoretical prediction of the ratio of J/ψ→ρπ is smaller than data, but not too small to invoke a completely new mechanism. Thus the puzzle is still standing even though we learn much knowledge towards the puzzle and this will help to finally interpret the puzzle and then gain a deeper insight to the heavy quarkonia.