Summary of the QCDHFS group

1
Summary of the QCD/HFS group
S.Chekanov (ANL)
J.Terron, M.Sutton, N.Brook (ext.)
ZEUS Collaboration Meeting, October 17, 2002
S.Chekanov (ANL), ZEUS Collaboration Meeting, Oct
2002
2
Group structure

• Coordinators J.Terron, M.Sutton, N.Brook (ext),
  S.Chekanov
• DQM Steven Hanlon
• Funnel Andy Ziegler
• Trigger Sabine Lammers

Meetings Every Thursday, 13.30, SR 3
Subgroup meetings Jets in DIS
Wednesday, 16.00 Particle
production Monday,
13.00 Instantons
Friday, 11.00
S.Chekanov (ANL), ZEUS Collaboration Meeting, Oct
2002
3
ICHEP02 papers

• 839 One- and two-dimensional Bose-Einstein
  effect L.Zawiejski,
  K.Olkiewicz, S.Chekanov,M.Derrick
• 843 Scaling violations in PHP at HERA
  
  C.Glasman, A.Lupi
  
• 845 Jet production in charged current DIS
  
  C.Glasman, M. Vazquez
• 846 K0s and Lambda production in PHP
  
  M.Sutton, S.Boogert
• 848 Multijet production in DIS
  
  N.Krumnack, S. Chekanov, L.Li
• 849 Multijets in photoproduction
  
  C.Gwenlan, M.Sutton, J.Butterworth
• 850 Inclusive phi (1020) production in
  DIS
  S.Chekanov, M.Derrick,B.Levchenko, J.Repond
• 851 Observation of prompt photons in DIS
  (not sent)
  M.Bell, D.Saxon
• 852 Rapidity gaps in photoproduction
  
  C.Gwenlan,
  M.Sutton
• 853 Inclusive strange baryons (not sent)
  
  A.Ziegler,
  B.Levchenko
• 855 Inclusive jet cross sections in
  neutral current DIS
  O.Gonzalez, J.Terron, H.Raach
• 854 Virtual-photon structure from dijets
  production
  A.Lupi, D.Kcira, H.Labes
• 857 Dijets in PHP and the photon structure
  (published) M.Wing, E.Heaphy,
  J.Terron, A.Ochs, J.Butterworth
• 858 High-mass dijets in photoproduction
  (published)
  C.Glasman, J.Terron
• 859 Dijet production in neutral current
  DIS (published) D.Chapin,
  M.Przybycien, C.Foudas, M.Wing

13 papers sent, 6 papers contain completely
new results
S.Chekanov (ANL), ZEUS Collaboration Meeting, Oct
2002
4
Jets in PHP
?
?
P
P
Scaling violation and determination
1st EB
C.Glasman, A.Lupi
C.Gwenlan, M.Sutton
Rapidity gaps in PHP
ICHEP02
C.Gwenlan,M.Sutton, J.Butterworth
Multijets in PHP
ICHEP02
M.Kowal
Work on cross sections and improvements of MC
statistics
S.Chekanov (ANL), ZEUS Collaboration Meeting, Oct
2002
5
Jets in PHP
New additions after ICHEP02
S.Chekanov (ANL), ZEUS Collaboration Meeting, Oct
2002
6
Jets in PHP rapidity gaps
New results for ICHEP02 (M.Sutton, C.Gwenlan)
HERWIG gives better description of the data than
PYHIA
Large difference between HERWIG and PYTHIA
without color singlet exchange
This precludes definite conclusions
7
Hard QCD at low


?
?
P
P
A.Lupi, D.Kcira,H.Labes
Low dijets and the photon structure
1st EB
Anna has left the group, thanks for her effort to
finish this paper!
S.Chekanov (ANL), ZEUS Collaboration Meeting, Oct
2002
8
Hard QCD at high
G.Glasman, A.Lupi, Jets in PHP
E
T

?
O.Gonzalez, H.Reach, J.Terron
Inclusive jets and determination
accepted for publication
sent
Azimuthal asymmetry from inclusive jets
S.Chekanov (ANL), ZEUS Collaboration Meeting, Oct
2002
9
Hard QCD at high
E
T

?
TEVATRON
S.Chekanov (ANL), ZEUS Collaboration Meeting, Oct
2002
10
Hard QCD jets in CC DIS
E
M.Vazquez, C.Glasman Inclusive jets and
dijets in CC DIS
T
/-
W
Paper draft is available
M.Vazquez
Paper presentation
Separation of quark and gluon jets in NC DIS
N.Brook, T.Namsoo apply a neural-net approach
to study jets
S.Chekanov (ANL), ZEUS Collaboration Meeting, Oct
2002
11
Azimuthal asymmetry in DIS
T.Tymieniecka, A.Ukleja Azimuthal asymmetry
in DIS

• Energy-flow method
• Look at average angles
• Use ZUFOs
• Increase statistics using 99/00 data

S.Chekanov (ANL), ZEUS Collaboration Meeting, Oct
2002
12
Multi-jet Production in DIS
P
N.Krumnack, L.Lee, S.Chekanov Exclusive
multijets in DIS
ICHEP02
L.Lee, N.Krumnack dependence for 3/2
-jet ratio
A.Morgan, S.Chekanov
and dependence for 1-4 jets
Nils Krumnack
Presentation
S.Chekanov (ANL), ZEUS Collaboration Meeting, Oct
2002
13
Prompt photons in DIS
NLO QCD
M.Bell, D.Saxon Prompt photons in DIS
New preliminary
J.Hamilton, P.Bussey Prompt photons in PHP
S.Magill, B.Musgrave work on the
signal/background ratio using BPRE
S.Chekanov (ANL), ZEUS Collaboration Meeting, Oct
2002
14
Forward jets and low-x physics
S.Lammers, J.Terron, S.Magill
Dijets at low
S.Lammers
Presentation
A. Benen
Jet production in DIS with FPC
Presentation
A.Benen
Search for instantons in DIS
S Hillert, B.Levchenko, A. Barakbaev
Presentation
S.Hillert
S.Chekanov (ANL), ZEUS Collaboration Meeting, Oct
2002
15
Interplay between hard and soft QCD
Hadronisation (higher - order pQCD effects?)

C. McCance, I.Skillicorn, P.Bussey Event shapes
in DIS
Paper reading October 15
S.Hanlon has started the analysis with the new
99/00 data
W.Yan will join soon
S.Chekanov (ANL), ZEUS Collaboration Meeting, Oct
2002
16
Using soft physics to study hard QCD

S
F(1020)
B.Levchenko, J.Repond, M.Derrick,
S.Chekanov Observation of the strange sea via
phi(1020)
Post-reading version
S.Chekanov (ANL), ZEUS Collaboration Meeting, Oct
2002
17
Strange particle production in DIS and PHP
A.Ziegler, Z.Ren, J.Lainesse Cascade and Sigma
production in DIS
L

Presentation
K0
S.Paganis, M.Barbi, A.Raval K0sK0s production in
DIS
s
Presentation
Paper draft for the group very soon
Ar.Ziegler, M.Barbi, A.Raval Strange particle
production (K0s, Lambda) in inclusive DIS
Presentation
M.Sutton, S.Boogert K0s and Lambda in PHP
ICHEP02
S.Chekanov (ANL), ZEUS Collaboration Meeting, Oct
2002
18
The final step in the particle production
L.Zawiejski, K.Olkiewicz, M.Derrick,
S.Chekanov 1D and 2D BE effect in DIS
BEC radius is independent of BEC is
longitudinally elongated BPC data point for the
final paper
Paper draft for the group very soon
S.Chekanov (ANL), ZEUS Collaboration Meeting, Oct
2002
19
More data is needed
The mainstream of the studies
is to increase statistics
and to decrease systematics
Studies suffering from too low statistics

• High-Et cross sections in DIS/PHP (Etgt40 GeV)
• Multi-jet production (Etgt10 GeV for 3rd jet)
• High-Pt strange mesons (for most interesting
  phase-space regions)
• K0s K0s studies in DIS
• 2D and 3D BE effects (no statistics for the
  measurement!)
• Prompt photons in DIS (very low statistics
  everywhere!)
• More differential jet studies require better
  statistics

S.Chekanov (ANL), ZEUS Collaboration Meeting, Oct
2002
20
What new components can be used
MVD

• An improvement in the reconstruction of
  ?

STT

• Strange baryons and mesons in the forward region
• Charged multiplicities in the forward
• Fragmentation functions in the target
  fragmentation region
• Possible improvement for ZUFOs reconstruction
  for jet physics

S.Chekanov (ANL), ZEUS Collaboration Meeting, Oct
2002
21
What data we need

• CAL CTD, HV 100
• CAL CTD, HV 90 (for vertex)
• CAL MVD (for vertex)

• High-luminosity data is not expected (with CTD
  HV 100)
• Low-luminosity data has no significant impact
  on the future measurements
• No much time left before the shutdown

So far there was no much interest in this data
We need to investigate the potential of new
components
(MVD/STT) as soon as possible!
Please join!
S.Chekanov (ANL), ZEUS Collaboration Meeting, Oct
2002