Related papers: Workshop Summary: Experiment
The W Mass and QCD Working Group discussed a wide variety of topics relating to present and future measurements of M(W) at LEP2, including QCD backgrounds to W+W- production. Particular attention was focused on experimental issues…
We estimate the high-energy behavior of the $\Theta^+$ and $\Lambda(1520)$ production cross sections in inclusive $pp$ collisions using the $K$ exchange diagram. We show that the cross section of the $\Theta^+$-production is suppressed…
We examine cross sections for the processes $\gamma N\to NK\bar{K}$ in the framework of a phenomenological Lagrangian. We include contributions from $\Lambda$ and $\Sigma$ resonances up to spin 3/2, as well as those from an exotic…
In the post-LEP era the high energy frontier is reachable only by large scale collaborations and laboratories, while the present lepton colliders operating at low and intermediate energies are planning major upgrades aimed at increasing…
Preliminary results of measurements of fermion-pair production at LEP2 are used to derive limits on new physics phenomena. Combinations of the cross sections and asymmetrie of the 4 LEP collaborations are interpreted in terms four-fermion…
A search for the \thp in the reaction $\gamma d \to pK^-K^+n$ was completed using the CLAS detector at Jefferson Lab. A study of the same reaction, published earlier, reported the observation of a narrow \thp resonance. The present…
A summary of experimental contributions to HSQCD 2005 is given. This includes results from the four HERA experiments H1, ZEUS, HERMES and HERA-B, as well as results from the Tevatron (D0), the CERN hyperon beam (WA98), from RHIC (PHENIX),…
The reaction pp->p K0 pi+ Lambda has been studied with the ANKE spectrometer at COSY-Juelich at a beam momentum of 3.65 GeV/c in order to search for a possible signal of the pentaquark Theta+(1540), decaying into the p K0 system. By…
Signals of physics beyond the Standard Model at HERA have been searched for by the H1 and ZEUS collaborations. Results are reported about searches of contact interaction effects, leptoquarks, R-parity violating squarks, excited fermions and…
Is there a theory or good experimental evidence? Bj's question: Pentaquark is created by $e^+e^-$. $2q + q \to$ Baryon $; ~ ~ ~ 2q + \bar q \to $ Triquark$ ; ~ ~ ~ 2q + $Triquark $ \to $Pentaquark Does it live long onough to be observable?…
We present a consistent color-flavor-spin-orbital wave function for a positive parity Theta^+ that naturally explains the observed narrowness of the state. The wave function is totally symmetric in its flavor-spin part and totally…
We report on a study of the pentaquark Theta^+(1540), using a variety of different interpolating fields. We use Chirally Improved fermions in combination with Jacobi smeared quark sources to improve the signal and get reliable results even…
We summarize the activities of the New Particles Subgroup at the 1996 Snowmass Workshop. We present the expectations for discovery or exclusion of leptoquarks at hadron and lepton colliders in the pair production and single production…
Selected topics on precision tests of the Standard Model of the Electroweak and the Strong Interaction at the LEP $e^+e^-$ collider are presented, including an update of the world summary of measurements of $\alpha_s$, representing the…
The report from the working group on '\gamma\gamma Event Generators' of the LEP 2 workshop
The existence of an anti-decuplet of pentaquark particles has been predicted some year ago within the chiral soliton model. In the last year, several experimental groups have reported evidence for a S=+1 baryon resonance, with mass ranging…
Spin structure of the reaction ${\vec p}{\vec n}\to {\vec \Lambda^0} {\vec \Theta}$ is analysed at the threshold in a model independent way under assumption that the $\Theta^+$ is an isosinglet. We found that the sign of the spin-spin…
The structure of the pentaquark state uudd-sbar is studied in the chiral SU(3) quark model as well as in the extended chiral SU(3) quark model, in which the vector meson exchanges are included. Four configurations of JP=1/2- and four of…
Recent results on searches for new particles at the electron-proton collider HERA are reported. Based on roughly 100pb-1 of e^+p data and 16pb-1 of e^-p data per experiment, taken in the years 1994-2000, the H1 and ZEUS collaborations have…
We investigate theoretically the $K^{0} p$ invariant mass spectrum of the $K^{+} d \to K^{0} p p$ reaction and scrutinize how the signal of the "$\Theta ^{+}$" pentaquark, if it exists, emerges in the $K^{0} p$ spectrum. The most prominent…