A. Ghosh

Multiplicity Characteristics of Symmetric and Asymmetric Heavy-Ion Interactions at 4.5 A GeV/c

This letter presents a systematic analysis of multiplicity data in limited regions of phase space in symmetric (12C-C/N/O) and asymmetric (24Mg-Ag/Br) heavy-ion interactions at 4.5A GeV/c. It is observed that in both types of interactions the multiplicity distribution of produced charged particles can be well fitted to the newly prescribed negative binomial (NB) law, the detailed characteristics of which are also investigated. Also, for the first time a universality is observed in the behaviour of entropy production in symmetric and asymmetric nuclear collisions if the incident momentum per nucleon is kept constant.

Analysis ofPT spectrum of projectile fragments in heavy-ion interactions. Identification of collective flow of nuclear matter

SummaryTransverse-momentum data of the projectile fragments are analysed to identify the presence of collective flow of nuclear matter in symmetric (16O-CNO at 2.1A GeV and12C-CNO at 4.5A GeV/c) and asymmetric (24Mg−AgBr at 4.5A GeV/c) heavy-ion interactions, adapting the method proposed by Danielewicz and Odyniec. A comparison of the data with Monte-Carlo-simulated values gives a positive indication of collective flow in each case.

Investments in Clean Energy in South Asia: Visiting Barriers and Gaps from the Perspective of Policies and Politics

Many countries in South Asia are facing serious challenges concerning energy access. Robust infrastructure for generation, transmission and distribution are still lacking. Simultaneously, many of these countries have enormous potential for generating clean energy that can solve the problem of energy provisioning and transform their energy mix. It can further cushion them from dependence on fuel imports. However, investment in clean energy in most South Asian countries is far below what is expected and desired. In this perspective, it is important to investigate the evidences on existing constraints that are limiting investments in clean energy in South Asia. Transition in energy systems is essentially a long-term process—and involves changes in technology, economy (structure, efficiency), active policies, institutions, behaviour and belief systems. Mere formulation of policies and setting targets (policy goals) has been found to be insufficient for attracting investment in clean energy in most of these countries. There exists a gap in the literature regarding evidences on the barriers to investment in clean energy in South Asian countries. Following the Political Economy Analysis framework, in this article, the authors attempt to build up on evidence for answering the following questions:

Mean free paths and interaction cross-section of α-projectile fragments produced in oxygen-emulsion interaction at 60 GeV/n

SummaryThe work reports the results of the measurement of the mean free paths of α-particles emitted as the projectile fragment from16O-emulsion interactions at 60 GeV/n. From 357 primary peripheral events, 642 α-PFs are observed in a total track of 37 metres. The interaction mean free paths of the α-PFs have been found to be independent of the path length from their production points. Interaction cross-sections of the α-PFs are calculated from the experimentally determined mean free paths in terms of target particle concentration.

Multiplicity fluctuation in heavy-ion interaction and negative binomial distribution

SummaryThis paper presents an investigation on multiplicity distribution of charged secondary particles in different pseudorapidity windows with the assumption that they are coming out as a cluster ofkcor particles. The distributions in a particular pseudorapidity window for different values ofkcor (2 to 5) were compared with the negative binomial distributions with integer values ofk-parameter (kNBD=2 to 5) in order to search for a possible significance of the parameter using24Mg-emulsion interaction data at 4.5 GeV/c per nucleon.

Three-proton correlation in central24Mg−AgBr interactions at 4.5A GeV/c—Indication of sideward flow of nuclear matter

SummaryA different approach is presented to study the sideward flow of nuclear matter in high-energy nuclear collision. The method is essentially based on a comparison of experimental three-particle angular correlation with that of the Monte Carlo events, assuming an independent emission of the target protons. The method is applied to the central24Mg−AgBr interactions at 4.5 GeV/c per nucleon, and a statistically significant excess of the correlation values over those obtained from Monte Carlo events is observed. This indicates the occurrence of collective sideward flow of target protons emitted in an angular zone (emission angle within 55° to 90°).