Central Exclusive Meson Pair Production in Perturbative Regime.

(based on works by V.Khoze, M. RYskin and W.J. STirling and L.

HArland-Lang)

(KRYSTHAL collaboration)

V.A. Khoze (IPPP, Durham & PNPI)

For more details see: ArXiV:1105.1626

CEP is reported by LHCb (DIS-11)

new CDF CEP results (Erik, low x-11)All measurements in agreement with Durham group (pre)dictions.

CEP-spin-parity filter (KMR-00,KKMR-03)

Prio

r to

thi

s W

orks

hop

Now 43 events

(now proved to be small)

(KMRS-04)(LKRS-10)

(M.Benayoun,V.Chernyak,-1990)

40 diagrams (4 basic)

(Mariola’s talk)

(explicit calculation)

is this easy to understand ?

is this easy to understand ?

currently popular (among the more formal community) MHV- technique

g

g

(KRYSTHAL coll.- 09-11)

New CDF data nicely confirm this ! (Erik’s talk)

(K-factor,..)

New CDF data confirm both Durham predictions for CEPand strong suppression of the

PT expectations if no proton tagging

Violation of

-momentum transfer through the ‘digluon Pomeron’

In the low mass region: is small.

Non-relativistic effects for spin 2.

Non-PT contribution ( for spin 1, still ~ ).

Spin-2 quarkonium suppression is easier to violate!

for CEP (KMRS-04)

ppY+X+Z