Recent developments in high energy physics

Recent results from experiments with solar, atmospheric and accelerator neutrinos are presented. Some of the important results from the LEP and TEVATRON colliders are summarised. (20 refs)

Neutrinos and our Sun - part 3

In the concluding part of the article on Neutrinos and our Sun we discuss the detection of atmospheric neutrinos, their fluxes and zenith angle distributions. Here too one finds discrepancies with theoretical predictions. We discuss how the idea of neutrino oscillations helps resolve both the solar neutrino puzzle (discussed in Part 2) and the discrepancy observed in atmospheric neutrino fluxes. This is followed by a discussion of neutrino masses and the recent confirmation of the neutrino oscillations in the KamLAND experiment

The story of large electron positron collider: 1. Fundamental constituents of matter

This article does not have an abstract

Neutrinos and our Sun - part 2

In this part we describe the chain of nuclear reactions that fuse protons into helium nuclei in the centres of stars. Neutrinos play an important role in the proton-proton chain and detection of these neutrinos is important for a direct insight into the processes taking place at the centre of the sun. Experiments for the detection of solar neutrinos and the emerging result from them, known as the Solar Neutrino Puzzle, are described. The puzzle refused to go away even with very carefully designed experiments. Its solution came from physics, by reviving the idea of neutrino oscillations, speculated many decades ago. Recent experiments have confirmed these ideas and have enriched our knowledge of these fundamental particles

Correlation of charm particles from gluon-gluon fusion in hadronic collisions

In the framework of fusion process, ≈90% of which is g+g→c+ c-, we have calculated rapidity correlation and p T /2 of charm particles produced in hadronic collisions. The experimental observation of rapidity correlation by the LEBC-EHS Collaboration is in good agreement with the calculation. From the ratio of double to single charm production an estimate of fusion cross section is made

Study of hyperfragments. Part V. Analysis of light hyperfragments

464 non-mesic and 65 mesic decay of hyperfragments (HFs) produced by pions of momenta 3·5 GeV/c. and 17·2 GeV/c. and protons of momentum 23 GeV/c., have been used to obtain information on Q-, the ratio of non-mesic to π- mesic events and S, the ratio of neutron to proton stimulated events as a function of charge of HFs. Q- is found to increase rapidly with the increase in charge of HFs; the value of Q- for HFs of Z≥3 is 14·6±3·0 which is high compared to the theoretical value of about 4 to 5. The value of S is found to be >1 for all HFs of Z≥2

Study of hyperfragments. Part IV. Mechanism for production of hyperfragments

Hyperfragments (HFs) produced in interactions of high energy pions and protons with emulsion nuclei have been investigated to deduce information on their mechanism of production. From these studies it is concluded that (a) long-range HFs (R≥20µm.) which are due to fragments with mass number 15, are produced in the evaporation stage of the disintegrations of Ag and Br nuclei of emulsion, (b) short-range HFs (R≤10µm.) are mainly due to residues of the target nuclei and a small fraction (≈10%) of them in the range 5<RHF≤15µm. are due to fission type of processes that occur in high energy interactions and (c) the relative probability of sticking of Λ° to fragments with Z=2 to that with 3≤Z≤6 is roughly in the ratio 1:10