Technion – Israel Institute of Technology

About: Technion – Israel Institute of Technology is a education organization based out in Haifa, Israel. It is known for research contribution in the topics: Population & Nonlinear system. The organization has 31714 authors who have published 79377 publications receiving 2603976 citations. The organization is also known as: Technion Israel Institute of Technology & Ṭekhniyon, Makhon ṭekhnologi le-Yiśraʼel.

Improved luminosity determination in pp collisions at root s=7 TeV using the ATLAS detector at the LHC

Abstract: The luminosity calibration for the ATLAS detector at the LHC during pp collisions at root s = 7 TeV in 2010 and 2011 is presented. Evaluation of the luminosity scale is performed using several luminosity-sensitive detectors, and comparisons are made of the long-term stability and accuracy of this calibration applied to the pp collisions at root s = 7 TeV. A luminosity uncertainty of delta L/L = +/- 3.5 % is obtained for the 47 pb(-1) of data delivered to ATLAS in 2010, and an uncertainty of delta L/L = +/- 1.8 % is obtained for the 5.5 fb(-1) delivered in 2011.

SNARKs for C : verifying program executions succinctly and in zero knowledge

Abstract: An argument system for NP is a proof system that allows efficient verification of NP statements, given proofs produced by an untrusted yet computationally-bounded prover. Such a system is non-interactive and publicly-verifiable if, after a trusted party publishes a proving key and a verification key, anyone can use the proving key to generate non-interactive proofs for adaptively-chosen NP statements, and proofs can be verified by anyone by using the verification key.

Automated Tag Clustering: Improving search and exploration in the tag space

Abstract: In this paper we discuss the use of clustering techniques to enhance the user experience and thus the success of collaborative tagging services. We show that clustering techniques can improve the user experience of current tagging services. We first describe current limitations of tagging services, second, we give an overview of existing approaches. We then describe the algorithms we used for tag clustering and give experimental results. Finally, we explore the use of several techniques to identify semantically related tags.

Search for neutral MSSM Higgs bosons at LEP

Abstract: The four LEP collaborations, ALEPH, DELPHI, L3 and OPAL, have searched for the neutral Higgs bosons which are predicted by the Minimal Supersymmetric standard model (MSSM). The data of the four collaborations are statistically combined and examined for their consistency with the background hypothesis and with a possible Higgs boson signal. The combined LEP data show no significant excess of events which would indicate the production of Higgs bosons. The search results are used to set upper bounds on the cross-sections of various Higgs-like event topologies. The results are interpreted within the MSSM in a number of “benchmark” models, including CP-conserving and CP-violating scenarios. These interpretations lead in all cases to large exclusions in the MSSM parameter space. Absolute limits are set on the parameter cosβ and, in some scenarios, on the masses of neutral Higgs bosons.

Reverberation Mapping of High-Luminosity Quasars: First Results

Abstract: Reverberation mapping of nearby active galactic nuclei (AGNs) has led to estimates of broad-line region (BLR) sizes and central object masses for some 37 objects to date. However, successful reverberation mapping has yet to be performed for quasars of either high luminosity (above Lopt ~ 1046 ergs s-1) or high redshift (z 0.3). Over the past 6 years, we have carried out, at the Hobby-Eberly Telescope, rest-frame ultraviolet spectrophotometric monitoring of a sample of six quasars at redshifts z = 2.2-3.2, with luminosities of Lopt ~ 1046.4-1047.6 ergs s-1, an order of magnitude greater than those of previously mapped quasars. The six quasars, together with an additional five having similar redshift and luminosity properties, were monitored photometrically at the Wise Observatory during the past decade. All 11 quasars monitored show significant continuum variations of order 10%-70%. This is about a factor of 2 smaller variability than for lower luminosity quasars monitored over the same rest-frame period. In the six objects that have been spectrophotometrically monitored, significant variability is detected in the C IV ?1550 broad emission line. In several cases the variations track the continuum variations in the same quasar, with amplitudes comparable to, or even greater than, those of the corresponding continua. In contrast, no significant Ly? variability is detected in any of the four objects in which it was observed. Thus, UV lines may have different variability trends in high-luminosity and low-luminosity AGNs. For one quasar, S5 0836+71 at z = 2.172, we measure a tentative delay of 595 days between C IV and UV continuum variations, corresponding to a rest-frame delay of 188 days and a central black hole mass of 2.6 ? 109 M?.