Subscribe to the gold package and get unlimited access to Shamra Academy
Register a new userThermodynamically Anomalous Regions As A Mixed Phase Signal
98
0
0.0
(
0
)
Ask ChatGPT about the research
No Arabic abstract
Using the most advanced model of the hadron resonance gas we reveal, at chemical freeze-out, remarkable irregularities such as an abrupt change of the effective number of degrees of freedom and plateaus in the collision-energy dependence of the entropy per baryon, total pion number per baryon, and thermal pion number per baryon at laboratory energies 6.9-11.6 AGeV. On the basis of the generalized shock adiabat model we show that these plateaus give evidence for the thermodynamic anomalous properties of the mixed phase at its boundary to the quark-gluon plasma (QGP). A new signal for QGP formation is suggested and justified.
rate research
Read More
Using an advanced version of the hadron resonance gas model we have found indications for irregularities in data for hadrons produced in relativistic heavy-ion collisions. These include an abrupt change of the effective number of degrees of freedom, a change of the slope of the ratio of lambda hyperons to protons at laboratory energies 8.6--11.6 AGeV, as well as highly correlated plateaus in the collision-energy dependence of the entropy per baryon, total pion number per baryon, and thermal pion number per baryon at laboratory energies 6.9-11.6 AGeV. Also, we observe a sharp peak in the dimensionless trace anomaly at a laboratory energy of 11.6 AGeV. On the basis of the generalized shock-adiabat model we demonstrate that these observations give evidence for the anomalous thermodynamic properties of the mixed phase at its boundary to the quark-gluon plasma. We argue that the trace-anomaly peak and the local minimum of the generalized specific volume observed at a laboratory energy of 11.6 AGeV provide a signal for the formation of a mixed phase between the quark-gluon plasma and the hadron phase. This naturally explains the change of slope in the energy dependence of the yield of lambda hyperons per proton at a laboratory energy of 8.6 GeV.
It is argued that the experimentally observed baryon stopping indicates a non-monotonous behaviour as a function of the incident energy of colliding nuclei. This can be quantified by a midrapidity reduced curvature of the net-proton rapidity spectrum and reveals itself as a zigzag irregularity in the excitation function of this curvature. The three-fluid dynamic calculations with a hadronic equation of state (EoS) fail to reproduce this irregularity. At the same time, the same calculations with an EoS involving a first-order phase transition and a crossover one into the quark-gluon phase do reproduce this zigzag behaviour, however only qualitatively.
Assuming the Lorentz and CPT invariances we show that neutron-antineutron oscillation implies breaking of CP along with baryon number violation -- i.e. two of Sakharov conditions for baryogenesis. The oscillation is produced by the unique operator in the effective Hamiltonian. This operator mixing neutron and antineutron preserves charge conjugation C and breaks P and T. External magnetic field always leads to suppression of oscillations. Its presence does not lead to any new operator mixing neutron and antineutron.
The detected anomalous frequency drift acceleration in Pioneers radar data finds its explanation in a Berry phase that obtains the quantum state of a photon that propagates within an expanding space-time. The clock acceleration is just the adiabatic expansion rate and an analogy between the effect and Foucaults experiment is fully suggested. In this sense, light rays play a similar role in the expanding space than Foucaults Pendulum does while determining Earths rotation. On the other hand, one could speculate about a suitable future experiment at laboratory scales able to measure the local cosmological expansion rate using the procedure outlined in this paper.
Contrary to common expectation, a left-sneutrinos can occasionally be the lightest supersymmet- ric particle. This has important implications in both collider and dark matter studies. We show that same-sign tri-lepton (SS3L) events at the Large Hadron Collider, with any lepton having opposite sign vetoed, distinguish such scenarios, up to gluino masses exceeding 2 TeV. The jets + M ET signal rate is somewhat suppressed in this case, thus enhancing the scope of leptonic signals.
Log in to be able to interact and post comments
comments
Fetching comments
Sign in to be able to follow your search criteria
