de.mpg.escidoc.pubman.appbase.FacesBean
English

# Item

ITEM ACTIONSEXPORT

Released

Journal Article

#### Observation of charmonium pairs produced exclusively in pp collisions

##### MPS-Authors
http://pubman.mpdl.mpg.de/cone/persons/resource/persons30313

Blouw,  J.
Division Prof. Dr. Werner Hofmann, MPI for Nuclear Physics, Max Planck Society;

http://pubman.mpdl.mpg.de/cone/persons/resource/persons30339

Britsch,  M.
Division Prof. Dr. Werner Hofmann, MPI for Nuclear Physics, Max Planck Society;

http://pubman.mpdl.mpg.de/cone/persons/resource/persons37734

Fontana,  M.
Division Prof. Dr. Werner Hofmann, MPI for Nuclear Physics, Max Planck Society;

http://pubman.mpdl.mpg.de/cone/persons/resource/persons37740

Popov,  D.
Division Prof. Dr. Werner Hofmann, MPI for Nuclear Physics, Max Planck Society;

http://pubman.mpdl.mpg.de/cone/persons/resource/persons30992

Schmelling,  M.
Division Prof. Dr. Werner Hofmann, MPI for Nuclear Physics, Max Planck Society;

http://pubman.mpdl.mpg.de/cone/persons/resource/persons37744

Volyanskyy,  D.
Division Prof. Dr. Werner Hofmann, MPI for Nuclear Physics, Max Planck Society;

http://pubman.mpdl.mpg.de/cone/persons/resource/persons31150

Voss,  H.
Division Prof. Dr. Werner Hofmann, MPI for Nuclear Physics, Max Planck Society;

http://pubman.mpdl.mpg.de/cone/persons/resource/persons31206

Zavertyaev,  M.
Division Prof. Dr. Werner Hofmann, MPI for Nuclear Physics, Max Planck Society;

##### Fulltext (public)

1407.5973.pdf
(Preprint), 575KB

##### Supplementary Material (public)
There is no public supplementary material available
##### Citation

LHcb Collaboration, Aaij, R., Adeva, B., Adinolfi, M., Affolder, A., Ajaltouni, Z., et al. (2014). Observation of charmonium pairs produced exclusively in pp collisions. Journal of Physics G: Nuclear and Particle Physics, 41: 115002. doi:10.1088/0954-3899/41/11/115002.

Cite as: http://hdl.handle.net/11858/00-001M-0000-0024-8098-2
##### Abstract
A search is performed for the central exclusive production of pairs of charmonia produced in proton-proton collisions. Using data corresponding to an integrated luminosity of $3{\rm\ fb}^{-1}$ collected at centre-of-mass energies of 7 and 8 TeV, $J/\psi J/\psi$ and $J/\psi\psi(2S)$ pairs are observed, which have been produced in the absence of any other activity inside the LHCb acceptance that is sensitive to charged particles in the pseudorapidity ranges $(-3.5,-1.5)$ and $(1.5,5.0)$. Searches are also performed for pairs of P-wave charmonia and limits are set on their production. The cross-sections for these processes, where the dimeson system has a rapidity between 2.0 and 4.5, are measured to be $$\begin{array}{rl} \sigma^{J/\psi J/\psi} &= 58\pm10{(\rm stat)} \pm 6{(\rm syst)} {\rm\ pb} , \\ \sigma^{J/\psi\psi(2S)} &= 63 ^{+27}_{-18}{(\rm stat)}\pm 10{(\rm syst)} {\rm\ pb} , \\ \sigma^{\psi(2S)\psi(2S)} &< 237 {\rm\ pb}, \\ \sigma^{\chi_{c0}\chi_{c0}} &< 69 {\rm\ nb}, \\ \sigma^{\chi_{c1}\chi_{c1}} &< 45 {\rm\ pb}, \\ \sigma^{\chi_{c2}\chi_{c2}} &< 141 {\rm\ pb}, \\ \end{array}$$ where the upper limits are set at the 90% confidence level. The measured $J/\psi J/\psi$ and $J/\psi\psi(2S)$ cross-sections are consistent with theoretical expectations.