Related papers: Rencontres de Moriond '98 -- QCD and Hadronic Inte…
This talk covers a selection of topics that were discussed at this meeting in the non-heavy-ion sessions: (a) The high $Q^{2}$ events at HERA and their theoretical interpretation. (b) The issues of how well we know the predictions of QCD,…
The study of the inelastic scattering of hadrons has progressed in the last decade. With the availability of high-statistics data sets from HERA and the Tevatron, our understanding of high energy and high jet multiplicity events has become…
The recently reported excess of events at HERA compared to QCD calculations impels us to examine all possible Standard Model explanations before invoking ``new physics''. We explore the possibility of adding an unusual, but small, component…
In the events of the type $e^+e^- \rightarrow W^+W^- \rightarrow$ 4 jets, $e^+e^- \rightarrow t\bar{t} \rightarrow bW^+\bar{b}W^-$, particle production could depend in a non-trivial way on the kinematics of the process. It is shown that QCD…
The HERA experiments H1 and ZEUS have recently presented a number of interesting results from studies of the hadronic final state produced in $ep$ collisions. These studies have focussed on deep inelastic scattering events and on the…
The Moriond conference on QCD and High Energy Interactions has been a most exciting and interesting event once more. This year's edition has been characterized by a very large amount of new results from the LHC experiments. However, also…
We consider $e e q q$ contact interactions as a possible origin of an excess of events above Standard Model predictions in $e^+ p \to e^+ jet$ at high $Q^2$ observed by the H1 and ZEUS collaborations at HERA. The HERA data prefer chirality…
A contact four-fermion interaction between light quarks and electrons has been evoked as a possible explanation for the excess of events observed by HERA at high-$Q^2$. We explore the 1-loop effects of such interaction in $\Gamma(Z^0 \to…
An excess of events with a rapidity gap between jets, over what would be expected from non-diffractive processes, has been observed at HERA. A process based on a perturbative QCD calculation of colour singlet exchange has been added to…
Theoretical talks and discussions at Rencontres de Moriond 2004 "QCD and Hadronic Interactions" are summarized. Following exciting recent experimental discoveries, theoretical developments were reported in the description of heavy ion…
We discuss the possibility of explaining the excess in the cross section at high-Q^2 recently found at HERA in terms of four-fermion effective interactions. To avoid the constraints from low-energy data, we select three special cases in…
New QCD results obtained by the H1 Collaboration are summarized. These results are based on data taken in $e^{\pm}p$ collisions at HERA I (1994-2002) and HERA II (2003-2007) corresponding to an integrated luminosity of almost $\rm 0.5…
Highlights of the experimental results presented at the 39th Rencontres du Moriond on ``QCD and High Energy Hadronic Interactions'', which was held in La Thuile, Italy on Mar. 28 - Apr. 4, 2004 are briefly summarised.
2008 was a vintage year for the QCD Moriond meeting. Plenty of new data from Tevatron, HERA, B-Factories and other experiments have been reported. Some brand new results became public just before or even during the conference. A few new…
Effective $eeqq$ contact interactions can enhance event rates in $e^+p$ scattering at HERA at high $Q^2$. Present constraints from atomic parity violation measurements and from Drell Yan events at the Tevatron are discussed.
We present a study of $W+$multijet events that compares the kinematics of the observed events with expectations from direct QCD $W+$jet production and from production and decay of top quark pairs. The data were collected in the 1992-93 run…
Recent results from CDF indicate that the inclusive cross section for jets with $E_T > 200$ GeV is significantly higher than that predicted by QCD. We describe here a simple flavor-universal variant of the ``coloron" model of Hill and Parke…
The results of complementary tests of perturbative QCD in DIS at large centre-of-mass energies at HERA are presented. The analysis of event shape variables allows for the investigation of approaches to understand aspects of non-perturbative…
We report measurements of forward jets produced in Cu+Au collisions at $\sqrt{s_{NN}}=200$ GeV at the Relativistic Heavy Ion Collider. The jet-energy distributions extend to energies much larger than expected by Feynman scaling. This…
I summarize highlights of the theory talks presented at the 37th Rencontres de Moriond on QCD and High Energy Hadronic Interactions.