Diffractive Higgs Production at the Tevatron and LHC

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Diffractive Higgs Production at the Tevatron and
LHC
Workshop on low x physics, Antwerp 2002
Brian Cox, Jeff Forshaw and Beate Heinemann
Phys. Lett. B 540 (2002) 263-268

• Do we all disagree, and, if so, why?
• How sensitive are the predictions to the
  parameters of the pomeron trajectory?
• Can we check the LHC predictions in Run II?

http//www.pomwig.com
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WHAT IS POMWIG ?

• No doubt that Ingelman Schlein works at HERA
• Pomwig uses measured structure functions and
  flux from H1 OR user defined structure functions
  / flux PLUS all HERWIG hard sub-processes /
  hadronisation etc.

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What do we calculate?
Inclusive (Central-inelastic) process pp
p gap H X gap p
Khoze, Martin Ryskin, hep-ph/0207313
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What do we calculate?
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Results
Enberg 2 fb
CDF measured ? ? 44 ? 20 nb
S2 0.1
S2 0.02
s 6 fb
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Higgs cross sections
IP IR, ?IP 1.20, ?IR0.57 (POMWIG defaults) ,
? ? 0.1
MH 115 GeV
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What effect does the intercept have?
H1 fit 2
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S2 0.02
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Are these diagrams as large a contribution as
KMR calculate?
S2 0.1 (CDF data) Theory S2 0.05
Khoze, Martin Ryskin, hep-ph/0207313
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Can we see the exclusive contribution in the data?
POMWIG does well at differential distributions
Appleby Forshaw, Phys.Lett.B451 108-114 (2002)
Mass dist. similar (KMR hep-ph/0207313)
Exclusive limit 3.7 nb CDF Phys. Rev. Lett
85 4215 (2000)
Exclusive calculation 1 nb (Khoze, Martin
Ryskin, hep-ph/0111078, 0006005)
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Exclusive vs. C.inel
IPIR
IPIR
IP
IP

• Cross section depends critically on invariant
  mass of diffractive system (and available phase
  space for emission)

consistent with CDF data
CDF cuts 0.035 lt ? lt 0.095 0.01 lt ? lt 0.03
KMR cuts Dh lt 2
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Summary
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• KMR and CFH agree, but CFH miss out LO piece,
  accounted for by larger gap survival factor
• BDPR very large cant be accounted for by lower
  IP intercept

• crucial (and possible) to observe exclusive
  dijet production in different mass ranges (1 nb
  ET gt 7 GeV) at Run II to check these conclusions.