Robert Klanner - DESY 1 DESY, HERA and the US contribution HERA and DESY HERA status ZEUS and the US groups HERA and particle physics

Robert Klanner - DESY 2 HERA and DESY DESY priorities for Particle Physics: –HERA is the first priority of DESY until mid 2007 –Limited R&D on Linear Collider is also foreseen in this period. –Linear Collider becomes the priority after mid HERA status: –The background problems at the experiments have been solved (a heroic effort + a model for excellent collaboration between experiments and machine). –Longitudinal polarization of > 50% has been achieved for all 3 HERA experiments. (a true first for a large electron accelerator). –With the first ~20 pb -1 of data with polarized positrons, ZEUS and H1 have shown first preliminary physics results  the detectors, particularly the upgrades—forward tracking, microvertex detector, the second luminosity system, and the upgraded trigger (most with significant intellectual and hardware contributions by US groups) demonstrate design performance.

Robert Klanner - DESY 3 HERA and DESY (2) HERA status (cont.): –Luminosity projection: 750 pb-1 shared approximately uniformly over electrons/positrons of both helicities. –Since 2002 DESY has embarked on a major preventive maintenance program, which is showing the first fruits towards increased efficiency. –At present, >1/3 of DESY’s resources are devoted to HERA and the HERA experiments (350 FTE’s). Support will remain at a similar level until the end of HERA data taking. –HERA is DESY’s first priority — the success of HERA is of utmost importance for the lab. –The evaluation of the Particle Physics Programme of the Helmholtz association (Jan. 2004, chair: H. Montgomery) has given highest marks to the HERA programme and has — beyond the base programme described above — recommended some additional resources to further increase the luminosity performance of HERA.

Robert Klanner - DESY 4 ZEUS and the US groups From the conception of ZEUS, the US groups have played and play a leading role in all aspects of ZEUS: detector design, detector construction, running and physics. Both in leadership and physics productivity, the US contributions have been outstanding: –2 spokespersons –7 component coordinator –2 physics chairs –15 physics coordinators US physicist have been leaders in the most visible physics analyses: –Precision structure function –Diffraction –Searches beyond the Standard Model –QCD and hadronic final states US participation will continue to be vital for the excellent performance of the ZEUS detector (in particular responsibilities for the Calorimeter (CAL), CAL trigger, CAL trigger processor, Barrel presampler, Straw tube tracker and the new luminosity spectrometer.

Robert Klanner - DESY 5 HERA and particle physics HERA I has brought new and unexpected insights, in particular in the field of QCD. This is seen also in the high number of citations. HERA I has been a pioneer in instrumentation for colliders with short bunch distances — many of the LHC detector concepts have been developed at HERA. HERA has formed a large number of students (128 PhD’s in 2003) and post-docs (106 in 2003), several of whom now have leading roles in Tevatron, LHC and other experiments. HERA II is now well under way — as one of the two running high energy colliders worldwide, HERA II promises yet another rich physics harvest. Together with the Tevatron run IIa, HERA II is the present large step in Particle Physics at high energies before the start of LHC. The US groups have an essential role also for HERA II.