Quark cluster signatures in deuteron electromagnetic interactions

A suggestion is made for distinguishing 2N and 6q short range correlations within the deuteron. The suggestion depends upon observing high momentum backward nucleons emerging from inelastic electromagnetic scattering from a deuteron target. A simple model is worked out to see the size of effects that may be expected.Comment: 18 pages (3 figures available as hard copy), WM-94-10

Experimental and Theoretical Results for Weak Charge Current Backward Proton Production

In this paper, we do three things in the study of deuteron break-up by high energy neutrino beams. (1) We present previously unpublished data on neutrino induced backward protons from deuteron targets; (2) we calculate the contributions from both the two-nucleon (2N) and six-quark (6q) deuteron components, which depend upon the overall normalization of the part that is 6q; and (3) we suggest other signatures for distinguishing the 2N and 6q clusters. We conclude that the 6q cluster easily explains the shape of the high momentum backward proton spectrum, and its size is nicely explained if the amount of 6q is one or a few percent by normalization of the deuteron. There is a crossover, above which the 6q contribution is important or dominant, at 300--400 MeV/c backward proton momentum.Comment: 8 pages, 5 figure

Ikaros has a crucial role in regulation of B cell receptor signaling

transcription factor Ikaros, a key regulator of hematopoiesis, has an essential role in lymphocyte development. In mice, fetal lymphoid differentiation is blocked in the absence of Ikaros, and whereas T cells develop postnatally, B cells are totally absent. The significance of Ikaros in the B cell development is evident, but how Ikaros regulates B cell function has neither been established nor previously been studied with B cells that lack Ikaros expression. Here we show that disruption of Ikaros in the chicken B cell line DT40 induces a B cell receptor (BCR) signaling defect with reduced phospholipase C gamma 2 phosphorylation and impaired intracellular calcium mobilization, which is restored by Ikaros reintroduction. Furthermore, we show that lack of Ikaros induces hyperphosphorylation of Casitas B lymphoma protein subsequent to BCR activation. These results indicate that the absolute need of Ikaros for development, cell fate decisions and maintenance of B cells is due to the enhancement of BCR signaling

Enhancing Iowa High School Students\u27 Transition to College

We present our studies of the transitions of Iowa science students from high school to post-secondary colleges. Our report summarizes information and impressions from dealing with thousands of new students arriving at our six colleges, along with meetings and discussions with high school science teachers to add their viewpoints into our considerations. Feedback from community college, four year college, and high school science teachers highlighted the following five study issues and needs for improving student transitions from high school to college science: 1) Better math preparation is needed; 2) More work with inquiry-based learning rather than with facts and memorization is needed in both secondary and post-secondary courses; 3) Students must become aware of career choices earlier; 4) Misconceptions by teachers at both levels must be minimized; and 5) High school and college science educators must improve intercommunication. To address these issues differently, our team invited Nobel Laureate Leon Lederman to be keynote speaker at the Iowa Science Teachers Fall Conference in October 2004. Dr. Lederman has campaigned for revamping the high school curriculum to have mathematics and the sciences integrated into a coherent, logical, interconnected whole, with conceptual physics first, to enable students to learn with a minimum of memorization. Feedback from high school science teachers has been very positive. Several Iowa high schools expressed interest in adopting this approach, and one Iowa high school has incorporated, at submission time, this innovation into their high school curriculum

Inhibitor development in haemophilia according to concentrate Four-year results from the European HAemophilia Safety Surveillance (EUHASS) project

Inhibitor development represents the most serious side effect of haemophilia treatment. Any difference in risk of inhibitor formation depending on the product used might be of clinical relevance. It was this study's objective to assess inhibitor development according to clotting factor concentrate in severe haemophilia A and B. The European Haemophilia Safety Surveillance (EUHASS) was set up as a study monitoring adverse events overall and according to concentrate. Since October 2008, inhibitors were reported at least quarterly. Number of treated patients was reported annually, specifying the number of patients completing 50 exposure days (Previously Untreated Patients, PUPs) without inhibitor development. Cumulative incidence, incidence rates and 95 % confidence intervals (CI) were calculated. Data from October 1, 2008 to December 31, 2012 were analysed for 68 centres that validated their data. Inhibitors developed in 108/417 (26 %; CI 22-30 %) PUPs with severe haemophilia A and 5/72 (7 %; CI 2-16%) PUPs with severe haemophilia B. For Previously Treated Patients (PTPs), 26 inhibitors developed in 17,667 treatment years [0.15/100 treatment years; CI 0.10-0.22) for severe haemophilia A and 1/2836 (0.04/100; (CI 0.00-0.20) for severe haemophilia B. Differences between plasma-derived and recombinant concentrates, or among the different recombinant FVIII concentrates were investigated. In conclusion, while confirming the expected rates of inhibitors in PUPs and PTPs, no class or brand related differences were observed

The QCD/SM Working Group: Summary Report

This Report documents the results obtained by the Working Group on Quantum ChromoDynamics and the Standard Model for the Workshop ``Physics at TeV Colliders'', Les Houches, France, 21 May - 1 June 2001. The account of uncertainties in Parton Distribution Functions is reviewed. Progresses in the description of multiparton final states at Next-to-Leading Order and the extension of calculations for precision QCD observables beyond this order are summarized. Various issues concerning the relevance of resummation for observables at TeV colliders is examined. Improvements to algorithms of jet reconstruction are discussed and predictions for diphoton and photon pi-zero production at the LHC are made for kinematic variables of interest regarding searches for a Higgs boson decaying into two photons. Finally, several improvements implemented in Monte-Carlo event generators are documented

Status report of the JYFL-ECR ion sources

"Ion beam cocktails" are mixtures of ions with near-identical charge-to-mass ratios. In conjunction with the JYFL-ECRIS, the K130-cyclotron acts as a mass analyzer: the switch from one ion to another within the same cocktail is simple and fast. In the case of the first ion beam cocktail, the oxygen and argon gases were mixed into the gas feed line. At the same time the magnesium and iron ion beams were produced using the MIVOC method. Magnesocene and ferrocene compounds were both mixed into the MIVOC chamber. This capability is especially useful in the study of single event effects (SEE) in space electronics. All gaseous elements from H to Xe can be produced. The non-gaseous elements produced so far are C, Mg, Al, Si, S, Ca, Ti, Cr, Fe, Co, Ni, Cu, Zn and Ge. A major technical modification since the construction (in 1990) of the JYFL-ECRIS was made in January 98: a negatively biased disc replaces now the first plasma stage. After a couple of months experience with the modified source the change was found to be towards a correct direction. The source is now much easier to use and the good operating conditions are well repeated. A real advantage is the new magnetic field settings which are practically the same for all kind of beams, gaseous and solids. Due to the requirements of ion beams with higher charges and heavier elements than the present JYFL-ECRIS can produce, JYFL decided to begin a design and construction project of a new ECR ion source, called as ECRIS 2. The project aims to a source that is based mainly on the design of the 14 GHz AECR-U source at the LBNL. Some modifications made into the similar source under construction at the NSCL/MSU will be utilized here. The new source will be installed horizontally in the basement of the ECRIS laboratory. It requires a new beam-line from the source to the cyclotron injection line, since the old vertically located JYFL-ECRIS will be preserved in operation. The new source is planned to be operational during the year 2000

Three-pion exchange: a gap in the nucleon-nucleon potential

The leading contribution to the three-pion exchange nucleon-nucleon potential is calculated in the framework of chiral symmetry. It has pseudoscalar and axial components and is dominated by the former, which has a range of about 1.5 fm and tends to enhance the OPEP. The strength of this force does not depend on the pion mass and hence it survives in the chiral limit.Comment: 20 pages, 5 figures, 1 tabl

Principal-component analysis of two-particle azimuthal correlations in PbPb and pPb collisions at CMS

Peer reviewe