3,430 research outputs found
Large Momenta Fluctuations Of Charm Quarks In The Quark-Gluon Plasma
We show that large fluctuations of D mesons kinetic energy (or momentum)
distributions might be a signature of a phase transition to the quark gluon
plasma (QGP). In particular, a jump in the variance of the momenta or kinetic
energy, as a function of a control parameter (temperature or Fermi energy at
finite baryon densities) might be a signature for a first order phase
transition to the QGP. This behaviour is completely consistent with the order
parameter defined for a system of interacting quarks at zero temperature and
finite baryon densities which shows a jump in correspondance to a first order
phase transition to the QGP. The shows exactly the same behavior of
the order parameter and of the variance of the D mesons. We discuss
implications for relativistic heavy ion collisions within the framework of a
transport model and possible hints for experimental data.Comment: 4 pages 3 figure
An infrared origin of leptonic mixing and its test at DeepCore
Fermion mixing is generally believed to be a low-energy manifestation of an
underlying theory whose energy scale is much larger than the electroweak scale.
In this paper we investigate the possibility that the parameters describing
lepton mixing actually arise from the low-energy behavior of the neutrino
interacting fields. In particular, we conjecture that the measured value of the
mixing angles for a given process depends on the number of unobservable flavor
states at the energy of the process. We provide a covariant implementation of
such conjecture, draw its consequences in a two neutrino family approximation
and compare these findings with current experimental data. Finally we show that
this infrared origin of mixing will be manifest at the Ice Cube DeepCore array,
which measures atmospheric oscillations at energies much larger than the tau
lepton mass; it will hence be experimentally tested in a short time scale.Comment: 14 pages, 1 figure; version to appear in Int.J.Mod.Phys.
CP violation and mass hierarchy at medium baselines in the large theta(13) era
The large value of theta(13) recently measured by rector and accelerator
experiments opens unprecedented opportunities for precision oscillation
physics. In this paper, we reconsider the physics reach of medium baseline
superbeams. For theta(13) ~ 9 degree we show that facilities at medium
baselines -- i.e. L ~ O(1000 km) -- remain optimal for the study of CP
violation in the leptonic sector, although their ultimate precision strongly
depends on experimental systematics. This is demonstrated in particular for
facilities of practical interest in Europe: a CERN to Gran Sasso and CERN to
Phyasalmi nu_mu beam based on the present SPS and on new high power 50 GeV
proton driver. Due to the large value of theta(13), spectral information can be
employed at medium baselines to resolve the sign ambiguity and determine the
neutrino mass hierarchy. However, longer baselines, where matter effects
dominate the nu_mu->nu_e transition, can achieve much stronger sensitivity to
sign(Delta m^2) even at moderate exposures.Comment: 14 pages, 14 figures, version to appear in EPJ
Three-flavour oscillations with accelerator neutrino beams
The three-flavor neutrino oscillation paradigm is well established in
particle physics thanks to the crucial contribution of accelerator neutrino
beam experiments. In this paper we review the most important contributions of
these experiments to the physics of massive neutrinos after the discovery of
and future perspectives in such a lively field of research.
Special emphasis is given to the technical challenges of high power beams and
the oscillation results of T2K, OPERA, ICARUS and NOA. We discuss in
details the role of accelerator neutrino experiments in the precision era of
neutrino physics in view of DUNE and Hyper-Kamiokande, the programme of
systematic uncertainty reduction and the development of new beam facilities.Comment: 31 pages, 12 fugures. To appear in Univers
Experimental prospects to observe the g − 2 muon anomaly in the electron sector
The long-standing difference between the experimental measurement and the standard model prediction for the muon’s anomalous magnetic moment, aμ = (gμ − 2)/2, can be due to new particles flowing in loop contributions: such
discrepancy might thus signal the presence of new physics at the TeV scale. The vast majority of models explaining the muon discrepancy in terms of new physics (NP) predict sizable effects in ae = (ge−2)/2, too. We discuss the experimental prospects to reach sub-ppb precision on ae and test the NP origin of the muon anomaly in its electron counterpart
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