Exclusive Production of Phi Vector Meson During HERA-II

The Hadron Electron Ring Accelerator (HERA) in Germany, which ran from 1992 to 2007, is to date the only high energy electron and proton collider. The ZEUS detector at HERA measured the collisions of 27.5 GeV electrons with 920 GeV protons. Elastic vector meson production was measured during the first phase of HERA (HERA-I) from 1992 to 2000 before HERA was upgraded in 2003 (HERA-II) with increased luminosity. The goal of this project was to analyze data collected during the HERA-II run to identify and quantify the exclusive production of the vector meson. Runs from the ZEUS experiment were taken from 2005, corresponding to an integrated luminosity of 136 pb-1 . The meson was detected with masses consistent with their theoretical and previously observed invariant masses and the ∗ cross section was measured in the kinematic range 5 ≤ 2 ≤ 702 . This is the first time the vector meson from HERA-II have been studied. Additional analysis to determine systematic errors is necessary to yield information relevant to physics interests. Given that the next highest priority in nuclear physics is the construction of an electron ion collider, resolving as much information from previous measurements at HERA-II will help to guide the research

Could we learn more about HERA high Q2Q^2 anomaly from LEP200 and TEVATRON? R-parity violation scenario

The excess of high $Q^2$ events at HERA reported in the early 1997 by H1 and ZEUS collaborations has become the subject of extensive studies in the framework of several models related to new physics. Here we concentrate on the most promising, from our point of view, model describing HERA anomaly. We update our previous analysis and take into account new HERA statistics of the 1997 year. HERA events are considered within the R-parity broken SUSY model for a specific scenario with several non-zero couplings. R-parity broken SUSY with several non-zero couplings could explain both high $Q^2 e^+ + jets$ and $\mu^+ + jets$ observed at HERA. The consequence of such a particular scenario is the excess of high $Q^2$ di- or tri-jet events at HERA. The relation of this scenario for LEP and TEVATRON colliders is considered. This study shows that if a squark resonance does take place at HERA, supersymmetry with broken R-parity can be revealed at either LEP200 or TEVATRON in the near future.Comment: 15 pages, LaTeX file with 9 eps figure

Zeus at HERA II

The ZEUS detector has been upgraded in a number of areas to prepare for the physics opportunities of HERA II. These upgrades, and their physics rationale and promise, are briefly outlined. The measurement of polarisation at HERA II, and its importance for the HERA II physics programme, is also discussed.Comment: 9 pages, 7 figure

Hydrogen Epoch of Reionization Array (HERA)

The Hydrogen Epoch of Reionization Array (HERA) is a staged experiment to measure 21 cm emission from the primordial intergalactic medium (IGM) throughout cosmic reionization ($z=6-12$), and to explore earlier epochs of our Cosmic Dawn ($z\sim30$). During these epochs, early stars and black holes heated and ionized the IGM, introducing fluctuations in 21 cm emission. HERA is designed to characterize the evolution of the 21 cm power spectrum to constrain the timing and morphology of reionization, the properties of the first galaxies, the evolution of large-scale structure, and the early sources of heating. The full HERA instrument will be a 350-element interferometer in South Africa consisting of 14-m parabolic dishes observing from 50 to 250 MHz. Currently, 19 dishes have been deployed on site and the next 18 are under construction. HERA has been designated as an SKA Precursor instrument. In this paper, we summarize HERA's scientific context and provide forecasts for its key science results. After reviewing the current state of the art in foreground mitigation, we use the delay-spectrum technique to motivate high-level performance requirements for the HERA instrument. Next, we present the HERA instrument design, along with the subsystem specifications that ensure that HERA meets its performance requirements. Finally, we summarize the schedule and status of the project. We conclude by suggesting that, given the realities of foreground contamination, current-generation 21 cm instruments are approaching their sensitivity limits. HERA is designed to bring both the sensitivity and the precision to deliver its primary science on the basis of proven foreground filtering techniques, while developing new subtraction techniques to unlock new capabilities. The result will be a major step toward realizing the widely recognized scientific potential of 21 cm cosmology.Comment: 26 pages, 24 figures, 2 table