We propose a novel detection concept for neutrinoless double-beta decay searches. This concept is based on a Time Projection Chamber (TPC) filled with high-pressure gaseous xenon, and with separated-function capabilities for calorimetry and tracking. Thanks to its excellent energy resolution, together with its powerful background rejection provided by the distinct double-beta decay topological signature, the design discussed in this Letter Of Intent promises to be competitive and possibly out-perform existing proposals for next-generation neutrinoless double-beta decay experiments. We discuss the detection principles, design specifications, physics potential and R&D plans to construct a detector with 100 kg fiducial mass in the double-beta decay emitting isotope Xe(136), to be installed in the Canfranc Underground Laboratory.

The NEXT Collaboration F. Granena T. Lux F. Nova J. Rico F. Sanchez D. R. Nygren J. A. S. Barata F. I. G. M. Borges C. A. N. Conde T. H. V. T. Dias L. M. P. Fernandes E. D. C. Freitas J. A. M. Lopes C. M. B. Monteiro J. M. F. dos Santos F. P. Santos L. M. N. Tavora J. F. C. A. Veloso E. Calvo I. Gil-Botella P. Novella C. Palomares A. Verdugo I. Giomataris E. Ferrer-Ribas J. A. Hernando-Morata D. Martinez X. Cid M. Ball S. Carcel A. Cervera J. Diaz A. Gil J. J. Gomez-Cadenas J. Martin-Albo F. Monrabal J. Munoz-Vidal L. Serra M. Sorel N. Yahlali R. Esteve Bosch C. W. Lerche J. D. Martinez F. J. Mora A. Sebastia A. Tarazona J. F. Toledo M. Lazaro J. L. Perez L. Ripoll J. M. Carmona S. Cebrian T. Dafni J. Galan H. Gomez F. J. Iguaz I. G. Irastorza G. Luzon J. Morales A. Rodriguez J. Ruz A. Tomas J. A. Villar

We report the first theoretical model for the alkali fluids which yields a liquid-vapor phase coexistence with the experimentally observed features and electrical conductivity estimates which are also in accord with observations. We have carried out a Monte Carlo simulation for a lattice gas model which allows an integrated study of the structural, thermodynamic, and electronic properties of metal-atom fluids. Although such a technique is applicable to both metallic and nonmetallic fluids, non-additive interactions due to valence electron delocalization are a crucial feature of the present model.

P. Tarazona E. Chacon J. P. Hernandez

Thermodynamic and electronic properties are obtained for a lattice-gas model fluid with self-consistent, partial, occupation of its sites; the self consistency consists in obtaining ionic configurations from grand-canonical Monte Carlo simulations based on fits to the exact, electronic, tight-binding energies of isothermal ensembles of those same ionic configurations. The energy of an ion is found to be a concave-up function of its local coordination. Liquid-vapor coexistence densities and the electrical conductivity, which shows a metal-nonmetal transition, have been obtained.

M. Reinaldo-Falagan P. Tarazona E. Chacon J. P. Hernandez

We present a derivation of the recently proposed eighth order phase field crystal model [Jaatinen et al., Phys. Rev. E 80, 031602 (2009)] for the crystallization of a solid from an undercooled melt. The model is used to study the planar growth of a two dimensional hexagonal crystal, and the results are compared against similar results from dynamical density functional theory of Marconi and Tarazona, as well as other phase field crystal models. We find that among the phase field crystal models studied, the eighth order fitting scheme gives results in good agreement with the density functional theory for both static and dynamic properties, suggesting it is an accurate and computationally efficient approximation to the density functional theory.

A. Jaatinen T. Ala-Nissila

The Dynamic Density Functional (DDF) theory and standard Brownian dynamics simulations (BDS) are used to study the drifting effects of a colloidal particle in a polymer solution, both for ideal and interacting polymers. The structure of the stationary density distributions and the total induced current are analyzed for different drifting rates. We find good agreement with the BDS, which gives support to the assumptions of the DDF theory. The qualitative aspect of the density distribution are discussed and compared to recent results for driven colloids in one-dimensional channels and to analytical expansions for the ideal solution limit.

F. Penna J. Dzubiella P. Tarazona

In several frameworks for leptons-sectors of two Higgs doublet models, we calculate the magnetic dipole moment for the different flavor types of neutrino. Computations are carried out by assuming a normal hierarchy for neutrino masses, and analyzing the process $\nu \rightarrow \nu \gamma $ with a charged Higgs boson into the loop. The analysis was performed by sweeping the charged Higgs mass and taking into account the experimental constraints for relevant parameters in Two Higgs Doublet Models with and without flavor changing neutral currents; obtaining magnetic dipole moments close to the experimental thresholds for tau neutrinos in type II and Lepton-specific cases. In the neutrino-specific scenario, the contribution of new physics could be sizeable to the current measurement for flavor magnetic dipole moment. This fact leads to excluding possible zones in the parameter space of charged Higgs mass and vacuum expectation value of the second doublet.

Carlos G. Tarazona Rodolfo A. Diaz John Morales Andres Castillo

The Muon (g-2) Experiment, E989 at Fermilab, will measure the muon anomalous magnetic moment a factor-of-four more precisely than was done in E821 at the Brookhaven National Laboratory AGS. The E821 result appears to be greater than the Standard-Model prediction by more than three standard deviations. When combined with expected improvement in the Standard-Model hadronic contributions, E989 should be able to determine definitively whether or not the E821 result is evidence for physics beyond the Standard Model. After a review of the physics motivation and the basic technique, which will use the muon storage ring built at BNL and now relocated to Fermilab, the design of the new experiment is presented. This document was created in partial fulfillment of the requirements necessary to obtain DOE CD-2/3 approval.

J. Grange V. Guarino P. Winter K. Wood H. Zhao R. M. Carey D. Gastler E. Hazen N. Kinnaird J. P. Miller J. Mott B. L. Roberts J. Benante J. Crnkovic W. M. Morse H. Sayed V. Tishchenko V. P. Druzhinin B. I. Khazin I. A. Koop I. Logashenko Y. M. Shatunov E. Solodov M. Korostelev D. Newton A. Wolski A. Chapelain R. Bjorkquist N. Eggert A. Frankenthal L. Gibbons S. Kim A. Mikhailichenko Y. Orlov D. Rubin D. Sweigart D. Allspach G. Annala E. Barzi K. Bourland G. Brown B. C. K. Casey S. Chappa M. E. Convery B. Drendel H. Friedsam T. Gadfort K. Hardin S. Hawke S. Hayes W. Jaskierny C. Johnstone J. Johnstone V. Kashikhin C. Kendziora B. Kiburg A. Klebaner I. Kourbanis J. Kyle N. Larson A. Leveling A. L. Lyon D. Markley D. McArthur K. W. Merritt N. Mokhov J. P. Morgan H. Nguyen J-F. Ostiguy A. Para C. C. Polly M. Popovic E. Ramberg M. Rominsky D. Schoo R. Schultz D. Still A. K. Soha S. Strigonov G. Tassotto D. Turrioni E. Villegas E. Voirin G. Velev L. Welty-Rieger D. Wolff C. Worel J-Y. Wu R. Zifko K. Jungmann C. J. G. Onderwater P. T. Debevec S. Ganguly M. Kasten S. Leo K. Pitts C. Schlesier M. Gaisser S. Haciomeroglu Y-I. Kim S. Lee M-J Lee Y. K. Semertzidis K. Giovanetti V. A. Baranov V. N. Duginov N. V. Khomutov V. A. Krylov N. A. Kuchinskiy V. P. Volnykh C. Crawford R. Fatemi W. P. Gohn T. P. Gorringe W. Korsch B. Plaster A. Anastasi D. Babusci S. Dabagov C. Ferrari A. Fioretti C. Gabbanini D. Hampai A. Palladino G. Venanzoni T. Bowcock J. Carroll B. King S. Maxfield K. McCormick J. Price D. Sim A. Smith T. Teubner W. Turner M. Whitley M. Wormald R. Chislett S. Kilani M. Lancaster E. Motuk T. Stuttard M. Warren D. Flay D. Kawall Z. Meadows T. Chupp R. Raymond A. Tewlsey-Booth M. J. Syphers D. Tarazona S. Catalonotti R. Di Stefano M. Iacovacci S. Mastroianni S. Chattopadhyay M. Eads M. Fortner D. Hedin N. Pohlman A. de Gouvea H. Schellman L. Welty-Rieger F. Azfar S. Henry G. D. Alkhazov V. L. Golovtsov P. V. Neustroev L. N. Uvarov A. A. Vasilyev A. A. Vorobyov M. B. Zhalov L. Cerrito F. Gray G. Di Sciascio D. Moricciani C. Fu X. Ji L. Li H. Yang D. Stöckinger G. Cantatore D. Cauz M. Karuza G. Pauletta L. Santi S. Baeßler M. Bychkov E. Frlez D. Pocanic L. P. Alonzi M. Fertl A. Fienberg N. Froemming A. Garcia D. W. Hertzog J. Kaspar P. Kammel R. Osofsky M. Smith E. Swanson T. van Wechel K. Lynch

Adding a small amount of passive (Brownian) particles to a two-dimensional dense suspension of repulsive active Brownian particles does not affect the appearance of a motility-induced phase separation into a dense and a dilute phase, caused by the persistence of the active particles' direction of motion. Unlike a purely active suspension, the dense slab formed in an elongated system of a passive-active mixture may show, over long periods of time, a stable and well-defined propagation of the interfaces, because of the symmetry breaking caused by the depletion of passive particles on one side of the slab. We investigate these dynamical structures via average density profile calculations, revealing an asymmetry between the two interfaces, and enabling a kinetic analysis of the slab movement. The apparent movement of the dense slab is not a pure source/sink effect, nor a rigid displacement of all the particles, but a self-sustained combination of both effects. Furthermore, we analyse the specific fluctuations that produce, cancel and abruptly reverse the slab motion.

Rodrigo Fernández-Quevedo García Enrique Chacón Pedro Tarazona Chantal Valeriani

We obtain a fundamental measure density functional for mixtures of parallel hard cylinders. To this purpose we first generalize to multicomponent mixtures the fundamental measure functional proposed by Tarazona and Rosenfeld for a one-component hard disk fluid, through a method alternative to the cavity formalism of these authors. We show the equivalence of both methods when applied to two-dimensional fluids. The density functional so obtained reduces to the exact density functional for one-dimensional mixtures of hard rods when applied to one-dimensional profiles. In a second step we apply an idea put forward some time ago by two of us, based again on a dimensional reduction of the system, and derive a density functional for mixtures of parallel hard cylinders. We explore some features of this functional by determining the fluid-fluid demixing spinodals for a binary mixture of cylinders with the same volume, and by calculating the direct correlation functions.

Yuri Martinez-Raton Jose A. Capitan Jose A. Cuesta

The authors present a study of the non equilibrium statistical properties of a one dimensional hard-rod fluid dissipating energy via inelastic collisions and subject to the action of a Gaussian heat bath, simulating an external driving mechanism. They show that the description of the fluid based on the one-particle phase-space reduced distribution function, in principle necessary because of the presence of velocity dependent collisional dissipation, can be contracted to a simpler description in configurational space. Indeed, by means of a multiple-time scale method the authors derive a self-consistent governing equation for the particle density distribution function. This equation is similar to the dynamic density functional equation employed in the study of colloids, but contains additional terms taking into account the inelastic nature of the fluid. Such terms cannot be derived from a Liapunov generating functional and contribute not only to the relaxational properties, but also to the non equilibrium steady state properties. A validation of the theory against molecular dynamics simulations is presented in a series of cases, and good agreement is found.

Umberto Marini-Bettolo-Marconi Pedro Tarazona Fabio Cecconi