Search for etab decay into J/psi J/psi

Search for &eta_b decay into J/&psi J/&psi at CDF

This web page summarizes the results for the search of &eta_b decay into J/&psi J/&psi, based upon 1.1 fb^-1 of data.
The results have been approved as of June 15, 2006.

We measure:

Using the results from PRD71, 032001 (2005)

it corresponds to

A more detailed summary of the results can be found in this public note.

CDF Run I search results can be found at
[]CDF Collaboration, J. Tseng, in Proceedings of the 5th International Conference on Quark Confinement and the Hadron Spectrum V, edited by N. Brambilla and G. M. Prosperi (World Scientific, Singapore, 2003).

7 candidates with 1.8 events are expected as background
The statistical significance is 2.2 &sigma
The production limit is set to be &sigma_{&eta_b}(|y|<0.4) · Br(&eta_b&rarr J/&psi J/&psi) · [Br(J/&psi &rarr &mu&mu)]² < 18 pb

Recent Nonrelativistic QCD (NRQCD) calculations predict the production times branching fractions to be Br· d&sigma/dy = 0.3 x 10^{± 1} pb [1].
[1] E. Braaten et al., Phys. Rev. D 63, 094006 (2001)

The mass splitting between &eta_b and &Upsilon(1S) is estimated to be 30 - 160 MeV range. [2-8]

[2] E. J. Eichten and C. Quiggs, Phys. Rev. D 49, 5845 (1994)
[3] X. Liao and T. Manke, Phys. Rev. D 65, 074508 (2002)
[4] S. Recksiegel and Y. Sumino, Phys. Lett. B 578, 369 (2004)
[5] D. Ebert, R. N. Faustov, and V. O. Galkin, Phys. Rev. D 67, 014027 (2003)
[6] V. Lengyel, Y. Fekete, I. Haysak, and A. Shpenik, Eur. Phys. J. C 21, 355 (2001)
[7] B. A. Kniehl, A. A. Penin, A. Pineda, V. A. Smirnov, and M. Steinhauser Phys. Rev. Lett. 92, 242001 (2004)
[8] F. Maltoni and A. D. Polosa, Phys. Rev. D 70, 054014 (2004)

Some other references :

Measurement of the J/&psi Meson and b-Hadron Production Cross Section in pp collisions at &radic s = 1960 GeV,
[9] D. Acosta et al., Phys. Rev. D 71, 032002 (2005)

Upsilon Production and Polarization in pp Collisions at &radic s = 1.8 TeV
[10] D. Acosta et al., Phys. Rev. Lett. 88, 161802 (2002)

Below are the eps or gif versions of all figures meant for downloads.

Table 1 : J/&psi yield table for inclusive and B for full data set [gif]
Table 2 : Systematics table in [jpg] and [png]

Figure 1 : J/&psi mass spectrum and projection from ML fit for 3.0 < Pt < 3.25 GeV, in [eps] and [gif]
Figure 2 : J/&psi mass spectrum and projection from ML fit for 3.0 < Pt < 3.25 GeV, in [eps] and [gif]
Figure 3 : differential J/&psi yield vs pt in [eps] and [gif]
Figure 4 : J/&psi mass fit for 50 < Pt < 70 GeV events in [eps] and [gif]
Figure 5 : &eta_b mass spectrum in SEARCH analysis [eps] and [gif]
Figure 6 : &eta_b significance scan in SEARCH analysis [eps] and [gif]
Figure 7 : &eta_b mass spectrum in UL analysis [eps] and [gif]
Figure 8 : &eta_b 95% CL excluded yield limit in [eps] and [gif]