H1 ReportSteve Maxfield

• 920 GeV protons on 27.6 GeV electrons or positrons→318 GeV centre of mass

H1 (was) in the HERA ep ring at DESY

Data taking ended in July 2007… HERA-I HERA-II

e- ~20 pb-1 ~290 pb-1

e+ ~100 pb-1 ~270 pb-1

~1 fb-1 collected by H1+ZEUS

Finale: Low Energy Run 460-575 GeV to measure FL structure function.

Meanwhile…

H1 Liverpool has grown! John Dainton Erwin Gabathuler Tim Greenshaw Max Klein Thomas Kluge Paul Laycock Steve Maxfield Andy Mehta Girish Patel AJ Rahmat

…and H1 remains Active:

•Huge amount of data still to be analysed.•Program to produce combined H1+ZEUS results underway

H1 Publications in 2007: Three- and Four-jet Production at Low x at HERA Measurement of Isolated Photon Production in Deep-Inelastic Scattering at HERA Measurement of Deeply Virtual Compton Scattering and its t-dependence at HERA Dijet Cross Sections and Parton Densities in Diffractive DIS at HERA Measurement of Inclusive Jet Production in Deep-Inelastic Scattering at High

Q2and Determination of the Strong Coupling Charged Particle Production in High Q2 Deep-Inelastic Scattering at HERA Search for Baryonic Resonances Decaying to Xi pi in Deep-Inelastic Scattering at

HERA Tests of QCD Factorisation in the Diffractive Production of Dijets in Deep-Inelastic

Scattering and Photoproduction at HERA Search for Lepton Flavour Violation in ep collisions at HERA

A few recent and/or ongoing analyses…

Cross section at Low Q2 and x•(Preliminary) Reduced Cross section at Low Q2

•Uses normal and shifted vertex data•Uses events with ISR. Mom conservation and careful track validation with the BST.•Will be Final results for Q2<~1GeV2

• more to come for higher Q2

•Precursor to FL measurement at low Q2

•Other measurements underway:•σ at high Q2, y 920 GeV beam →FL high Q2

•‘Bulk’ 2000 data: highest precision F2 data in range Q2 12 – 100 GeV2

•NC high Q2: • dσ/dQ2 :all HERA data (I+II)• Poln asymmetry: 0304e+ / 0405e-

• xF3 : 0304e+ / 0405e-

•Analysis of 460 / 575 GeV data started

Results out next year

aS determination from Inclusive jets in DIS

•Use ratio of incl. jet to NC cross sections →reduced systematic, pdf errors

•Dominating theory error still scale uncertainty

•(can reduce at expense of increased stat errors by limiting Q2 range. ‘Best’ result:

Charm and Beauty Measurements – an ongoing analysis

/ /l l

Now:Combining info from track and secondary vertex significances using Neural Net

•S1, S2, S3, NTRACK, PT TRACK1, PT

TRACK2 , PT

Jet, SV Sig., SV Mult.•Very good b/c discriminationResults with full 06/07 data out next year

Prelim result in 2007

FTDMajor Improvements in track reconstruction FTD segment linking cuts tuned. Use beam line constraint for 1-module

tracks. Pick up more clusters in the Kalman filter step. Outlier rejection implemented in Kalman

filter track fit. Primary vertex fit cuts tuned.

70% more vertex-fitted tracks!

“use FTD tracks in the HFS”

FTD finally ‘comes of age’:

So where is it now?

Is that Irony or Ironmongery?

HERA=H1+ZEUS

•Combine H1 and ZEUS analyses•2x statistics ~1fb-1

•Improved systematics•Make combined fits

best possible precision for seminal HERA results

e.g. aS from inclusive jets in DIS

N ext gp

NC e+p NB still only HERA I!

Multi-lepton final states…

ConclusionsH1 data taking has finished but the

exploitation phase is in full swing and the highest precision results are still to come.

H1+ZEUS →HERA results beginning to appear.

Effort will still be needed – this is good physics cheap at the price.

May not be the end of ep collider physics…

For now…we note that:

H1 in 2007Took its last data on 30th

June…

…in the capable hands of experts from Liverpool…

…

H1 legacy to Liverpool: Knowledge Transfer via people…

already

soon

…including some with extremely useful skills:

(The ‘Christmas Tree’ Nebula)

Happy Christmas!