1,625 research outputs found
Explosive Collisions at RHIC?
Motivated by experimental results from RHIC, we suggest how a condensate for
the Polyakov loop might produce explosive behavior at the QCD phase transition.
This is due to a rapid rollover of the condensate field below the transition
temperature
Fluctuations in the presence of fields -Phenomenological Gaussian approximation and a new class of thermodynamic inequalities-
The work approaches the study of the fluctuations for the thermodynamic
systems in the presence of the fields. The approach is of phenomenological
nature and developed in a Gaussian approximation. The study is exemplified on
the cases of a magnetizable continuum in a magnetoquasistatic field, as well as
for the so called discrete systems. In the last case one finds that the
fluctuations estimators depends both on the intrinsic properties of the system
and on the characteristics of the environment. Following some earlier ideas of
one of the authors we present a new class of thermodynamic inequalities for the
systems investigated in this paper. In the case of two variables the mentioned
inequalities are nothing but non-quantum analogues of the well known quantum
Heisenberg (''uncertainty'') relations. Also the obtained fluctuations
estimators support the idea that the Boltzmann's constant k has the
signification of a generic indicator of stochasticity for thermodynamic
systems.
Pacs number(s): 05.20.-y, 05.40.-a, 05.70.-a, 41.20.GzComment: preprint, 24 page
Nuclear collective dynamics within Vlasov approach
We discuss, in an investigation based on Vlasov equation, the properties of
the isovector modes in nuclear matter and atomic nuclei in relation with the
symmetry energy. We obtain numerically the dipole response and determine the
strength function for various systems, including a chain of Sn isotopes. We
consider for the symmetry energy three parametrizations with density providing
similar values at saturation but which manifest very different slopes around
this point. In this way we can explore how the slope affects the collective
response of finite nuclear systems. We focus first on the dipole polarizability
and show that while the model is able to describe the expected mass dependence,
A^{5/3}, it also demonstrates that this quantity is sensitive to the slope
parameter of the symmetry energy. Then, by considering the Sn isotopic chain,
we investigate the emergence of a collective mode, the Pygmy Dipole Resonance
(PDR), when the number of neutrons in excess increases. We show that the total
energy-weighted sum rule exhausted by this mode has a linear dependence with
the square of isospin I=(N-Z)/A, again sensitive to the slope of the symmetry
energy with density. Therefore the polarization effects in the isovector
density have to play an important role in the dynamics of PDR. These results
provide additional hints in the investigations aiming to extract the properties
of symmetry energy below saturation.Comment: 7 pages, 6 figure
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Influencing the physiology and decisions of groups: Physiological linkage during group decision-making
Many of the most important decisions in our society are made within groups, yet we know little about how the physiological responses of group members predict the decisions that groups make. In the current work, we examine whether physiological linkage from “senders” to “receivers”—which occurs when a sender’s physiological response predicts a receiver’s physiological response—is associated with senders’ success at persuading the group to make a decision in their favor. We also examine whether experimentally manipulated status—an important predictor of social behavior—is associated with physiological linkage. In groups of 5, we randomly assigned 1 person to be high status, 1 low status, and 3 middle status. Groups completed a collaborative decision-making task that required them to come to a consensus on a decision to hire 1 of 5 firms. Unbeknownst to the 3 middle-status members, high- and low-status members surreptitiously were told to each argue for different firms. We measured cardiac interbeat intervals of all group members throughout the decision-making process to assess physiological linkage. We found that the more receivers were physiologically linked to senders, the more likely groups were to make a decision in favor of the senders. We did not find that people were physiologically linked to their group members as a function of their fellow group members’ status. This work identifies physiological linkage as a novel correlate of persuasion and highlights the need to understand the relationship between group members’ physiological responses during group decision-making
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