120997555
ADDENDUM TO THE CLOUD PROPOSAL
119975740
CLOUD: An Atmospheric research facility at CERN
124660642
A study of the link between cosmic rays and clouds with a cloud chamber at the CERN PS
A STUDY OF THE LINK BETWEEN COSMIC RAYS AND CLOUDS WITH A CLOUD CHAMBER AT THE CERN PS B. Fastrup, E. Pedersen University of Aarhus, Institute of Physics and Astronomy, Aarhus, Denmark E. Lillestol, E. Thorn University of Bergen, Institute of Physics, Bergen, Norway M. Bosteels, A. Gonidec, G. Harigel, J. Kirkby*, S. Mele, P. Minginette, B. Nicquevert, D. Schinzel, W. Seidl CERN, Geneva, Switzerland P. Grundsøe, N. Marsh, J. Polny, H. Svensmark Danish Space Research Institute, Copenhagen, Denmark Y. Viisanen Finnish Meteorological Institute, Helsinki, Finland K. Kurvinen, R. Orava University of Helsinki, Institute of Physics, Helsinki, Finland K. Hämeri, M. Kulmala, L. Laakso, J.M. Mäkelä, C.D. O’Dowd University of Helsinki, Lab. of Aerosol and Environmental Physics, Helsinki, Finland V. Afrosimov, A. Basalaev, M. Panov Ioffe Physical Technical Institute, Dept. of Fusion Technology, St. Petersburg, Russia A. Laaksonen, J. Joutsensaari University of Kuopio, Department of Applied Physics, Kuopio, Finland V. Ermakov, V. Makhmutov, O. Maksumov, P. Pokrevsky, Y. Stozhkov, N. Svirzhevsky Lebedev Physical Institute, Solar and Cosmic Ray Research Laboratory, Moscow, Russia K. Carslaw, Y. Yin University of Leeds, School of the Environment, Leeds, United Kingdom T. Trautmann University of Mainz, Institute for Atmospheric Physics, Mainz, Germany F. Arnold, K.-H. Wohlfrom Max-Planck Institute for Nuclear Physics (MPIK), Atmospheric Physics Division, Heidelberg, Germany D. Hagen, J. Schmitt, P. Whitefield University of Missouri-Rolla, Cloud and Aerosol Sciences Laboratory, Rolla, USA K. Aplin, R.G. Harrison University of Reading, Department of Meteorology, Reading, United Kingdom R. Bingham, F. Close, C. Gibbins, A. Irving, B. Kellett, M. Lockwood Rutherford Appleton Laboratory, Space Science & Particle Physics Depts., Chilton, United Kingdom D. Petersen, W.W. Szymanski, P.E. Wagner, A. Vrtala University of Vienna, Institute for Experimental Physics, Vienna, Austria CLOUD† Collaboration
1617188
Lorentz invariance in chiral kinetic theory.
We show that Lorentz invariance is realized nontrivially in the classical action of a massless spin-1/2 particle with definite helicity. We find that the ordinary Lorentz transformation is modified by a shift orthogonal to the boost vector and the particle momentum. The shift ensures angular momentum conservation in particle collisions and implies a nonlocality of the collision term in the Lorentz-invariant kinetic theory due to side jumps. We show that 2/3 of the chiral-vortical effect for a uniformly rotating particle distribution can be attributed to the magnetic moment coupling required by the Lorentz invariance. We also show how the classical action can be obtained by taking the classical limit of the path integral for a Weyl particle.
119270513
Realistic Implementation of Chiral Magnetic Wave in Heavy Ion Collisions
Chiral Magnetic Wave (CMW) is a gapless collective excitation of chiral charges along the direction of magnetic field in the Quark-Gluon Plasma that arises from the triangle anomaly of QCD. We perform reliable study of the CMW in the realistic simulation of heavy ion collisions, and find that the CMW contributions to the charge dependent elliptic flow of pions, $\Delta v_2 = v_2(\pi^-)-v_2(\pi^+)$, linearly depending on the net charge asymmetry $A_\pm\equiv (N_+-N_-)/(N_++N_-)$ with a positive slope $r$, is comparable to the recent experimental results from RHIC. We identify "Freezeout Hole Effect", which is a direct consequence of the propagation of CMW during the realistic evolution of fireball, as the dominant physics effect responsible for a sizable contribution from the CMW to the slope parameter $r$, and emphasize that a proper treatment of the freeze out condition is crucial in any reliable computation of the CMW contribution to the slope parameter $r$. We also implement chiral phase transition effect in our study, which illustrates the sensitivity of the results to chiral phase transition temperature, and suggest that the CMW can be an important probe of QCD chiral phase transition. Our results on the impact parameter dependence compare well with the RHIC experiments. We also give predictions for the LHC energy.
119225950
Electrical conductivity of the quark-gluon plasma and soft photon spectrum in heavy-ion collisions
We extract the electrical conductivity σ0 of the quark gluon plasma (QGP) and study the effects of magnetic field and chiral anomaly on soft photon azimuthal anisotropy, v₂, based on the thermal photon spectrum at 0.4GeV < p⊥< 0.6GeV at the RHIC energy. As a basis for my analysis, we derive the behavior of retarded photon self-energy of a strongly interacting neutral plasma in hydrodynamic regime in the presence of magnetic field and chiral anomaly. By evolving the resulting soft thermal photon production rate over the realistic hydrodynamic background and comparing the results with the data from the PHENIX Collaboration, I found that the electrical conductivity at QGP temperature is in the range: 0.4 < σ₀/(e²T) < 1.1, which is comparable with recent studies on lattice. I also compare the contribution from the magnetic field and chiral anomaly to soft thermal photon v₂ with the data. I argue that at the CERN Large Hadron Collider, the chiral magnetic wave would give negative contribution to photon v₂.
119015824
Conductivity and quasinormal modes in holographic theories
A bstractWe show that in field theories with a holographic dual the retarded Green’s function of a conserved current can be represented as a convergent sum over the quasinormal modes. We find that the zero-frequency conductivity is related to the sum over quasinormal modes and their high-frequency asymptotics via a sum rule. We derive the asymptotics of the quasinormal mode frequencies and their residues using the phase-integral (WKB) approach and provide analytic insight into the existing numerical observations concerning the asymptotic behavior of the spectral densities.
2503433
Chiral kinetic theory.
We derive the nonequilibrium kinetic equation describing the motion of chiral massless particles in the regime where it can be considered classically. We show that the Berry monopole which appears at the origin of the momentum space due to level crossing is responsible for the chiral magnetic and vortical effects.