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Author Marquez-Martin, I.; Arnault, P.; Di Molfetta, G.; Perez, A. url  doi
openurl 
  Title Electromagnetic lattice gauge invariance in two-dimensional discrete-time quantum walks Type Journal Article
  Year 2018 Publication Physical Review A Abbreviated Journal Phys. Rev. A  
  Volume 98 Issue 3 Pages 032333 - 8pp  
  Keywords  
  Abstract Gauge invariance is one of the more important concepts in physics. We discuss this concept in connection with the unitary evolution of discrete-time quantum walks in one and two spatial dimensions, when they include the interaction with synthetic, external electromagnetic fields. One introduces this interaction as additional phases that play the role of gauge fields. Here, we present a way to incorporate those phases, which differs from previous works. Our proposal allows the discrete derivatives, that appear under a gauge transformation, to treat time and space on the same footing, in a way which is similar to standard lattice gauge theories. By considering two steps of the evolution, we define a density current which is gauge invariant and conserved. In the continuum limit, the dynamics of the particle, under a suitable choice of the parameters, becomes the Dirac equation and the conserved current satisfies the corresponding conservation equation.  
  Address [Marquez-Martin, Ivan; Arnault, Pablo; Di Molfetta, Giuseppe; Perez, Armando] Univ Valencia, Dept Fis Teor, Dr Moliner 50, E-46100 Burjassot, Spain, Email: ivan.marquez@uv.es;  
  Corporate Author Thesis  
  Publisher Amer Physical Soc Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN (down) 2469-9926 ISBN Medium  
  Area Expedition Conference  
  Notes WOS:000446163200006 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ pastor @ Serial 3750  
Permanent link to this record
 

 
Author Martone, G.I.; Larre, P.E.; Fabbri, A.; Pavloff, N. url  doi
openurl 
  Title Momentum distribution and coherence of a weakly interacting Bose gas after a quench Type Journal Article
  Year 2018 Publication Physical Review A Abbreviated Journal Phys. Rev. A  
  Volume 98 Issue 6 Pages 063617 - 21pp  
  Keywords  
  Abstract We consider a weakly interacting uniform atomic Bose gas with a time-dependent nonlinear coupling constant. By developing a suitable Bogoliubov treatment we investigate the time evolution of several observables, including the momentum distribution, the degree of coherence in the system, and their dependence on dimensionality and temperature. We rigorously prove that the low-momentum Bogoliubov modes remain frozen during the whole evolution, while the high-momentum ones adiabatically follow the change in time of the interaction strength. At intermediate momenta we point out the occurrence of oscillations, which are analogous to Sakharov oscillations. We identify two wide classes of time-dependent behaviors of the coupling for which an exact solution of the problem can be found, allowing for an analytic computation of all the relevant observables. A special emphasis is put on the study of the coherence property of the system in one spatial dimension. We show that the system exhibits a smooth “light-cone effect,” with typically no prethermalization.  
  Address [Martone, Giovanni I.; Pavloff, Nicolas] Univ Paris Saclay, Univ Paris Sud, CNRS, LPTMS,UMR 8626, F-91405 Orsay, France  
  Corporate Author Thesis  
  Publisher Amer Physical Soc Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN (down) 2469-9926 ISBN Medium  
  Area Expedition Conference  
  Notes WOS:000452949900009 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ pastor @ Serial 3841  
Permanent link to this record
 

 
Author Arnault, P.; Perez, A.; Arrighi, P.; Farrelly, T. url  doi
openurl 
  Title Discrete-time quantum walks as fermions of lattice gauge theory Type Journal Article
  Year 2019 Publication Physical Review A Abbreviated Journal Phys. Rev. A  
  Volume 99 Issue 3 Pages 032110 - 16pp  
  Keywords  
  Abstract It is shown that discrete-time quantum walks can be used to digitize, i.e., to time discretize fermionic models of continuous-time lattice gauge theory. The resulting discrete-time dynamics is thus not only manifestly unitary, but also ultralocal, i.e., the particle's speed is upper bounded, as in standard relativistic quantum field theories. The lattice chiral symmetry of staggered fermions, which corresponds to a translational invariance, is lost after the requirement of ultralocality of the evolution; this fact is an instance of Meyer's 1996 no-go results stating that no nontrivial scalar quantum cellular automaton can be translationally invariant [D. A. Meyer, J. Stat. Phys. 85, 551 (1996); Phys. Lett. A 223, 337 (1996)]. All results are presented in a single-particle framework and for a (1+1)-dimensional space-time.  
  Address [Arnault, Pablo; Perez, Armando] Univ Valencia, Dept Fis Teor, Dr Moliner 50, E-46100 Burjassot, Spain, Email: pablo.arnault@ific.uv.es  
  Corporate Author Thesis  
  Publisher Amer Physical Soc Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN (down) 2469-9926 ISBN Medium  
  Area Expedition Conference  
  Notes WOS:000461896700002 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ pastor @ Serial 3950  
Permanent link to this record
 

 
Author Guo, J.J.; Sun, F.X.; Zhu, D.Q.; Gessner, M.; He, Q.Y.; Fadel, M. url  doi
openurl 
  Title Detecting Einstein-Podolsky-Rosen steering in non-Gaussian spin states from conditional spin-squeezing parameters Type Journal Article
  Year 2023 Publication Physical Review A Abbreviated Journal Phys. Rev. A  
  Volume 108 Issue 1 Pages 012435 - 7pp  
  Keywords  
  Abstract We present an experimentally practical method to reveal Einstein-Podolsky-Rosen (EPR) steering in non-Gaussian spin states by exploiting a connection to quantum metrology. Our criterion is based on the quantum Fisher information, and uses bounds derived from generalized spin-squeezing parameters that involve measurements of higher-order moments. This leads us to introduce the concept of conditional spin-squeezing parameters, which quantify the metrological advantage provided by conditional states, as well as detect the presence of an EPR paradox.  
  Address [Guo, Jiajie; Sun, Feng-Xiao; Zhu, Daoquan; He, Qiongyi] Peking Univ, State Key Lab Mesoscop Phys, Sch Phys, Frontiers Sci Ctr Nanooptoelect, Beijing 100871, Peoples R China, Email: manuel.gessner@uv.es;  
  Corporate Author Thesis  
  Publisher Amer Physical Soc Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN (down) 2469-9926 ISBN Medium  
  Area Expedition Conference  
  Notes WOS:001130449100004 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ pastor @ Serial 5905  
Permanent link to this record
 

 
Author Argyropoulos, T.; Catalan-Lasheras, N.; Grudiev, A.; Mcmonagle, G.; Rodriguez-Castro, E.; Syrachev, I.; Wegner, R.; Woolley, B.; Wuensch, W.; Zha, H.; Dolgashev, V.; Bowden, G.; Haase, A.; Lucas, T.G.; Volpi, M.; Esperante-Pereira, D.; Rajamaki, R. doi  openurl
  Title Design, fabrication, and high-gradient testing of an X-band, traveling-wave accelerating structure milled from copper halves Type Journal Article
  Year 2018 Publication Physical Review Accelerators and Beams Abbreviated Journal Phys. Rev. Accel. Beams  
  Volume 21 Issue 6 Pages 061001 - 11pp  
  Keywords  
  Abstract A prototype 11.994 GHz, traveling-wave accelerating structure for the Compact Linear Collider has been built, using the novel technique of assembling the structure from milled halves. The use of milled halves has many advantages when compared to a structure made from individual disks. These include the potential for a reduction in cost, because there are fewer parts, as well as a greater freedom in choice of joining technology because there are no rf currents across the halves' joint. Here we present the rf design and fabrication of the prototype structure, followed by the results of the high-power test and post-test surface analysis. During high-power testing the structure reached an unloaded gradient of 100 MV/m at a rf breakdown rate of less than 1.5 x 10(-5) breakdowns/pulse/m with a 200 ns pulse. This structure has been designed for the CLIC testing program but construction from halves can be advantageous in a wide variety of applications.  
  Address [Argyropoulos, Theodoros; Catalan-Lasheras, Nuria; Grudiev, Alexej; Mcmonagle, Gerard; Rodriguez-Castro, Enrique; Syrachev, Igor; Wegner, Rolf; Woolley, Ben; Wuensch, Walter; Zha, Hao] CERN, European Org Nucl Res, CH-1211 Geneva, Switzerland, Email: thomas.geoffrey.lucas@cern.ch  
  Corporate Author Thesis  
  Publisher Amer Physical Soc Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN (down) 2469-9888 ISBN Medium  
  Area Expedition Conference  
  Notes WOS:000434469900001 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ pastor @ Serial 3608  
Permanent link to this record
 

 
Author Senes, E.; Argyropoulos, T.; Tecker, F.; Wuensch, W. doi  openurl
  Title Beam-loading effect on breakdown rate in high-gradient accelerating cavities: An experiment at the Compact Linear Collider Test Facility at CERN Type Journal Article
  Year 2018 Publication Physical Review Accelerators and Beams Abbreviated Journal Phys. Rev. Accel. Beams  
  Volume 21 Issue 10 Pages 102001 - 8pp  
  Keywords  
  Abstract Radio frequency breakdown rate is a crucial performance parameter that ensures that the design luminosity is achieved in the CLIC linear collider. The required low breakdown rate for CLIC, of the order of 10(-7) breakdown pulse(-1) m(-1), has been demonstrated in a number of 12 GHz CLIC prototype structures at gradients in excess of the design 100 MV/m accelerating gradient, however without the presence of the accelerated beam and associated beam loading. The beam loading induced by the approximately 1 A CLIC main beam significantly modifies the field distribution inside the structures, and the effect on breakdown rate is potentially significant so needs to be determined. A dedicated experiment has been carried out in the CLIC Test Facility CTF3 to measure this effect, and the results are presented.  
  Address [Senes, Eugenio] John Adams Inst, Denys Wilkinson Bldg,Keble Rd, Oxford OX1 3RH, England, Email: eugenio.senes@cern.ch  
  Corporate Author Thesis  
  Publisher Amer Physical Soc Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN (down) 2469-9888 ISBN Medium  
  Area Expedition Conference  
  Notes WOS:000447731900003 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ pastor @ Serial 3768  
Permanent link to this record
 

 
Author Vnuchenko, A.; Esperante Pereira, D.; Gimeno, B.; Benedetti, S.; Catalan Lasheras, N.; Garlasch, M.; Grudiev, A.; McMonagle, G.; Pitman, S.; Syratchev, I.; Timmins, M.; Wegner, R.; Woolley, B.; Wuensch, W.; Faus-Golfe, A. doi  openurl
  Title High-gradient testing of an S-band, normal-conducting low phase velocity accelerating structure Type Journal Article
  Year 2020 Publication Physical Review Accelerators and Beams Abbreviated Journal Phys. Rev. Accel. Beams  
  Volume 23 Issue 8 Pages 084801 - 13pp  
  Keywords  
  Abstract A novel high-gradient accelerating structure with low phase velocity, v/c = 0.38, has been designed, manufactured and high-power tested. The structure was designed and built using the methodology and technology developed for CLIC 100 MV/m high-gradient accelerating structures, which have speed of light phase velocity, but adapts them to a structure for nonrelativistic particles. The parameters of the structure were optimized for the compact proton therapy linac project, and specifically to 76 MeV energy protons, but the type of structure opens more generally the possibility of compact low phase velocity linacs. The structure operates in S-band, is backward traveling wave (BTW) with a phase advance of 150 degrees and has an active length of 19 cm. The main objective for designing and testing this structure was to demonstrate that low velocity particles, in particular protons, can be accelerated with high gradients. In addition, the performance of this structure compared to other type of structures provides insights into the factors that limit high gradient operation. The structure was conditioned successfully to high gradient using the same protocol as for CLIC X-band structures. However, after the high power test, data analysis realized that the structure had been installed backwards, that is, the input power had been fed into what is nominally the output end of the structure. This resulted in higher peak fields at the power feed end and a steeply decreasing field profile along the structure, rather than the intended near constant field and gradient profile. A local accelerating gradient of 81 MV/m near the input end was achieved at a pulse length of 1.2 μs and with a breakdown rate (BDR) of 7.2 x 10(-7) 1 /pulse/m. The reverse configuration was accidental but the operating with this field condition gave very important insights into high-gradient behaviour and a comprehensive analysis has been carried out. A particular attention was paid to the characterization of the distribution of BD positions along the structure and within a cell.  
  Address [Vnuchenko, A.; Esperante Pereira, D.; Gimeno Martinez, B.] Inst Fsica Corpuscular IFIC, Valencia 46980, Spain, Email: anna.vnuchenko@cern.ch  
  Corporate Author Thesis  
  Publisher Amer Physical Soc Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN (down) 2469-9888 ISBN Medium  
  Area Expedition Conference  
  Notes WOS:000582958800002 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ pastor @ Serial 4584  
Permanent link to this record
 

 
Author Woolley, B.; Burt, G.; Dexter, A.C.; Peacock, R.; Millar, W.L.; Catalan Lasheras, N.; Degiovanni, A.; Grudiev, A.; Mcmonagle, G.; Syratchev, I.; Wuensch, W.; Rodriguez Castro, E.; Giner Navarro, J. doi  openurl
  Title High-gradient behavior of a dipole-mode rf structure Type Journal Article
  Year 2020 Publication Physical Review Accelerators and Beams Abbreviated Journal Phys. Rev. Accel. Beams  
  Volume 23 Issue 12 Pages 122002 - 11pp  
  Keywords  
  Abstract A normal-conducting, X-band traveling wave structure operating in the dipole mode has been systematically high-gradient tested to gain insight into the maximum possible gradients in these types of structure. Measured structure conditioning, breakdown behavior, and achieved surface fields are reported as well as a postmortem analysis of the breakdown position and a scanning electron microscope analysis of the high-field surfaces. The results of these measurements are then compared to high-gradient results from monopole-mode cavities. Scaled to a breakdown rate of 10(-6), the cavities were found to operate at a peak electric field of 154 MV/m and a peak modified Poynting vector S-c of 5.48 MW/mm(2). The study provides important input for the further development of dipole-mode cavities for use in the Compact Linear Collider as a crab cavity and dipole-mode cavities for use in x-ray free-electron lasers as well as for studies of the fundamental processes in vacuum arcs. Of particular relevance are the unique field patterns in dipole cavities compared to monopole cavities, where the electric and magnetic fields peak in orthogonal planes, which allow the separation of the role of electric and magnetic fields in breakdown via postmortem damage observation. The azimuthal variation of breakdown crater density is measured and is fitted to sinusoidal functions. The best fit is a power law fit of exponent 6. This is significant, as it shows how breakdown probability varies over a surface area with a varying electric field after conditioning to a given peak field.  
  Address [Woolley, B.; Burt, G.; Dexter, A. C.; Peacock, R.; Millar, W. L.] Univ Lancaster, Lancaster LA1 4YW, England  
  Corporate Author Thesis  
  Publisher Amer Physical Soc Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN (down) 2469-9888 ISBN Medium  
  Area Expedition Conference  
  Notes WOS:000614886300002 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ pastor @ Serial 4696  
Permanent link to this record
 

 
Author Folgado, M.G.; Sanz, V. url  doi
openurl 
  Title Exploring the political pulse of a country using data science tools Type Journal Article
  Year 2022 Publication Journal of Computational Social Science Abbreviated Journal J. Comput. Soc. Sci.  
  Volume 5 Issue Pages 987-1000  
  Keywords Politics; Spain; Sentiment analysis; Artificial Intelligence; Machine learning; Neural networks; Natural Language Processing (NLP)  
  Abstract In this paper we illustrate the use of Data Science techniques to analyse complex human communication. In particular, we consider tweets from leaders of political parties as a dynamical proxy to political programmes and ideas. We also study the temporal evolution of their contents as a reaction to specific events. We analyse levels of positive and negative sentiment in the tweets using new tools adapted to social media. We also train a Fully-Connected Neural Network (FCNN) to recognise the political affiliation of a tweet. The FCNN is able to predict the origin of the tweet with a precision in the range of 71-75%, and the political leaning (left or right) with a precision of around 90%. This study is meant to be viewed as an example of how to use Twitter data and different types of Data Science tools for a political analysis.  
  Address [Folgado, Miguel G.; Sanz, Veronica] Univ Valencia, Inst Fis Corpuscular IFIC, CSIC, Valencia 46980, Spain, Email: migarfol@upvnet.upv.es;  
  Corporate Author Thesis  
  Publisher Springernature Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN (down) 2432-2717 ISBN Medium  
  Area Expedition Conference  
  Notes WOS:000742263500002 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ pastor @ Serial 5077  
Permanent link to this record
 

 
Author HAWC Collaboration (Abeysekara, A.U. et al); Salesa Greus, F. url  doi
openurl 
  Title HAWC observations of the acceleration of very-high-energy cosmic rays in the Cygnus Cocoon Type Journal Article
  Year 2021 Publication Nature Astronomy Abbreviated Journal Nat. Astron.  
  Volume 4 Issue Pages 465–471  
  Keywords  
  Abstract Cosmic rays with energies up to a few PeV are known to be accelerated within the Milky Way(1,2). Traditionally, it has been presumed that supernova remnants were the main source of these very-high-energy cosmic rays(3,4), but theoretically it is difficult to accelerate protons to PeV energies(5,6) and observationally there simply is no evidence of the remnants being sources of hadrons with energies above a few tens of TeV7,8. One possible source of protons with those energies is the Galactic Centre region(9). Here, we report observations of 1-100 TeV gamma rays coming from the 'Cygnus Cocoon'(10), which is a superbubble that surrounds a region of massive star formation. These gamma rays are likely produced by 10-1,000 TeV freshly accelerated cosmic rays that originate from the enclosed star-forming region Cyg OB2. Until now it was not known that such regions could accelerate particles to these energies. The measured flux likely originates from hadronic interactions. The spectral shape and the emission profile of the Cocoon changes from GeV to TeV energies, which reveals the transport of cosmic particles and historical activity in the superbubble.  
  Address [Abeysekara, A. U.; Hona, B.; Kieda, D.; Newbold, M.; Springer, R. W.] Univ Utah, Dept Phys & Astron, Salt Lake City, UT 84112 USA, Email: rdb3@stanford.edu;  
  Corporate Author Thesis  
  Publisher Nature Research Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN (down) 2397-3366 ISBN Medium  
  Area Expedition Conference  
  Notes WOS:000627714400002 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ pastor @ Serial 4763  
Permanent link to this record
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