Preliminary results from India-based neutrino observatory detector R&D programme

We are currently developing and studying the performance of glass RPC prototypes, under the INO detector R&D programme. While we were successful in building and characterising a large number of chambers using local glass, these have met with severe aging problems after a few months of continuous operation. We have then built a couple of RPCs using a Japanese glass. We report in this paper on our long term stability tests of these RPCs. We also present some of our recent results on tracking of cosmic ray muons in a stack of glass RPCs

INO prototype detector and data acquisition system

India-based Neutrino Observatory (INO) collaboration is proposing to build a 50 kton magnetised iron calorimetric (ICAL) detector in an underground laboratory to be located in South India. Glass resistive plate chambers (RPCs) of about 2 m x 2 m in size will be used as active elements for the ICAL detector. As a first step towards building the ICAL detector, a 35 ton prototype of the same is being set up over ground to track cosmic muons. Design and construction details of the prototype detector and its data acquisition system will be discussed. Some of the preliminary results from the detector stack will also be highlighted. (C) 2009 Elsevier B.V. All rights reserved

A New Boson with a Mass of 125 GeV Observed with the CMS Experiment at the Large Hadron Collider

The Higgs boson was postulated nearly five decades ago within the framework of the standard model of particle physics and has been the subject of numerous searches at accelerators around the world. Its discovery would verify the existence of a complex scalar field thought to give mass to three of the carriers of the electroweak force-the W+, W-, and Z 0 bosons-as well as to the fundamental quarks and leptons. The CMS Collaboration has observed, with a statistical significance of five standard deviations, a new particle produced in proton-proton collisions at the Large Hadron Collider at CERN. The evidence is strongest in the diphoton and four-lepton (electrons and/or muons) final states, which provide the best mass resolution in the CMS detector. The probability of the observed signal being due to a random fluctuation of the background is about 1 in 3 x 106. The new particle is a boson with spin not equal to 1 and has a mass of about 1.25 giga-electron volts. Although its measured properties are, within the uncertainties of the present data, consistent with those expected of the Higgs boson, more data are needed to elucidate the precise nature of the new particle