Gross Properties and Isotopic Phenomena in Spectator Fragmentation

A systematic study of isotopic effects in the break-up of projectile spectators at relativistic energies has been performed with the ALADiN spectrometer at the GSI laboratory. Searching for signals of criticality in the fragment production we have applied the model independent universal fluctuations theory already proposed to track criticality signals in multifragmentation to our data. The fluctuation of the largest fragment charge and of the asymmetry of the two and three largest fragments and their bimodal distribution have also been analysed.Comment: 6 pages, 4 figures, IX International Conference on Nucleus-Nucleus Collisions, Rio de Janeiro, Brazil, August 28 - September 1, 200

Mass and Isospin Effects in Multifragmentation

A systematic study of isospin effects in the breakup of projectile spectators at relativistic energies has been performed with the ALADiN spectrometer at the GSI laboratory (Darmstadt). Four different projectiles 197Au, 124La, 124Sn and 107Sn, all with an incident energy of 600 AMeV, have been used, thus allowing a study of various combinations of masses and N/Z ratios in the entrance channel. The measurement of the momentum vector and of the charge of all projectile fragments with Z>1 entering the acceptance of the ALADiN magnet has been performed with the high efficiency and resolution achieved with the TP-MUSIC IV detector. The Rise and Fall behavior of the mean multiplicity of IMFs as a function of Zbound and its dependence on the isotopic composition has been determined for the studied systems. Other observables investigated so far include mean N/Z values of the emitted light fragments and neutron multiplicities. Qualitative agreement has been obtained between the observed gross properties and the predictions of the Statistical Multifragmentation Model.Comment: 10 pages,7 figure, 18th Nuclear Physics Division Conference of the EPS, Prague, submitted to Nucl. Phys.

Mass measurement and isoscaling in 124^{124}Sn+Sn and 107^{107}Sn+Sn reactions at 600 AMeV

Isotopic effects in projectile spectator fragmentation at 600 AMeV have been investigated using data collected in recent experiments with SIS beams at the GSI laboratory and with the ALADiN forward-spectrometer. For this purpose, primary beams of 124Sn, as well as secondary beams of 124La and 107Sn produced at the FRS fragment separator have been used. Isoscaling in 124,107Sn+Sn reactions is investigated and results are compared with data taken with the INDRA multidetector for 12C+112,124Sn reactions

Approach to thermal equilibrium in an extended TDHF theory

An empirical research reveals how the users of an intranet relay chat in a company tend to develop personal, anonymous and communitarian relationships in a professional context. These relationships are structured thanks to a plurimodal communication induced by the use of the chat (phone calls, direct meetings, e-mails). In certain cases, chatting can help employees to fight against distress and isolation. The use of nicknames allows a freedom of expression in rupture with the way people usually communicate in firms. The anonymity of the users and the difficulty to legitimate the use of the chat in terms of productivity lead to a lack of trust in the relationships, because the users fear for their professional reputation. In order to restore this trust, they increase the efforts to gather and to check information on the identity of their interlocutors. The organizational context makes easier this restoration of trust relationships

Approach to thermal equilibrium in an extended TDHF theory

An empirical research reveals how the users of an intranet relay chat in a company tend to develop personal, anonymous and communitarian relationships in a professional context. These relationships are structured thanks to a plurimodal communication induced by the use of the chat (phone calls, direct meetings, e-mails). In certain cases, chatting can help employees to fight against distress and isolation. The use of nicknames allows a freedom of expression in rupture with the way people usually communicate in firms. The anonymity of the users and the difficulty to legitimate the use of the chat in terms of productivity lead to a lack of trust in the relationships, because the users fear for their professional reputation. In order to restore this trust, they increase the efforts to gather and to check information on the identity of their interlocutors. The organizational context makes easier this restoration of trust relationships