检索结果-南通市图书馆

Testing noncommutative spacetimes and violations of the Pauli Exclusion Principle through underground experiments

在线全文

学校读者我要写书评

暂无评论

Chinese Physics C 2018年第9期42卷 79-86页

作者： Andrea Addazi Pierluigi Belli Rita Bernabei Antonino Marcianò Center for Field Theory and Particle Physics & Department of Physics Fudan University 200433 Shanghai China infn sezione Roma "Tor Vergata" I-00133 Rome Italy EU dipartimento di Fisica Universita di Roma "Tor Vergata" I-00133 Rome Italy EU

We propose to deploy limits that arise from different tests of the Pauli Exclusion Principle： i） to provide theories of quantum gravity with experimental guidance; ii） to distinguish, among the plethora of possible models, the ones that are already ruled out by current data; iii） to direct future attempts to be in accordance with experimental constraints. We first review experimental bounds on nuclear processes forbidden by the Pauli Exclusion Principle,which have been derived by several experimental collaborations making use of various detector materials. distinct features of the experimental devices entail sensitivities on the constraints hitherto achieved that may differ from one another by several orders of magnitude. We show that with choices of these limits, well-known examples of flat noncommutative space-time instantiations of quantum gravity can be heavily constrained, and eventually ruled out.We devote particular attention to the analysis of the κ-Minkowski and θ-Minkowski noncommutative spacetimes.These are deeply connected to some scenarios in string theory, loop quantum gravity, and noncommutative geometry.We emphasize that the severe constraints on these quantum spacetimes, although they cannot rule out theories of top-down quantum gravity to which they are connected in various ways, provide a powerful limitation for those models. Focus on this will be necessary in the future.

关键词： non-commutative space-times tests of violations of the Pauli Exclusion Principle theta-Minkowski kappa-Minkowski

Angular Momentum Minimal Magnetization of an Elementary Quantum Fermion System

在线全文

学校读者我要写书评

暂无评论

Journal of Modern Physics 2013年第5期4卷 638-643页

作者： C. Verzegnassi dipartimento di Fisica Università di Trieste INFN Sezione di Trieste Italy

I consider, in a Quantum Field Theory theoretical approach, the effects of an electromagnetic field on the components of the total angular momentum of an elementary fermion system, assuming the “minimal” form of the relative interaction. When the electromagnetic field can be treated as a classical one, these effects are particularly simple to be computed and exhibit a number of very general characteristic features in the case of a constant magnetic field. A qualitative possible analogy with similar features of an elementary organic system is finally proposed.

关键词： Organic

Search for the doubly heavy baryons Ωbc~0 and Ξbc~0 decaying to Λc~+π~- and Ξc~+π~-

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Physics C 2021年第9期45卷 14-25页

作者： R.Aaij C.Abellán Beteta T.Ackernley B.Adeva M.Adinolfi H.Afsharnia C.A.Aidala S.Aiola Z.Ajaltouni S.Akar J.Albrecht F.Alessio M.Alexander A.Alfonso Albero Z.Aliouche G.Alkhazov P.Alvarez Cartelle S.Amato Y.Amhis L.An L.Anderlini A.Andreianov M.Andreotti F.Archilli A.Artamonov M.Artuso K.Arzymatov E.Aslanides M.Atzeni B.Audurier S.Bachmann M.Bachmayer J.J.Back P.Baladron Rodriguez V.Balagura W.Baldini J.Baptista Leite R.J.Barlow S.Barsuk W.Barter M.Bartolini F.Baryshnikov J.M.Basels G.Bassi B.Batsukh A.Battig A.Bay M.Becker F.Bedeschi I.Bediaga A.Beiter V.Belavin S.Belin V.Bellee K.Belous I.Belov I.Belyaev G.Bencivenni E.Ben-Haim A.Berezhnoy *** D.Berninghoff H.C.Bernstein C.Bertella A.Bertolin C.Betancourt F.Betti Ia.Bezshyiko S.Bhasin J.Bhom L.Bian M.S.Bieker S.Bifani P.Billoir M.Birch F.C.R.Bishop A.Bitadze A.Bizzeti M.Bj?rn M.P.Blago T.Blake F.Blanc S.Blusk D.Bobulska J.A.Boelhauve O.Boente Garcia T.Boettcher A.Boldyrev A.Bondar N.Bondar S.Borghi M.Borisyak M.Borsato J.T.Borsuk S.A.Bouchiba T.J.V.Bowcock A.Boyer C.Bozzi M.J.Bradley S.Braun A.Brea Rodriguez M.Brodski J.Brodzicka A.Brossa Gonzalo D.Brundu A.Buonaura C.Burr A.Bursche A.Butkevich J.S.Butter J.Buytaert W.Byczynski S.Cadeddu H.Cai R.Calabrese L.Calefice L.Calero diaz S.Cali R.Calladine M.Calvi M.Calvo Gomez P.Camargo Magalhaes A.Camboni P.Campana A.F.Campoverde Quezada S.Capelli L.Capriotti A.Carbone G.Carboni R.Cardinale A.Cardini I.Carli P.Carniti L.Carus K.Carvalho Akiba A.Casais Vidal G.Casse M.Cattaneo G.Cavallero S.Celani J.Cerasoli A.J.Chadwick M.G.Chapman M.Charles Ph.Charpentier G.Chatzikonstantinidis C.A.Chavez Barajas M.Chefdeville C.Chen S.Chen A.Chernov V.Chobanova S.Cholak M.Chrzaszcz A.Chubykin V.Chulikov P.Ciambrone M.F.Cicala X.Cid Vidal G.Ciezarek P.E.L.Clarke M.Clemencic H.V.Cliff J.Closier J.L.Cobbledick V.Coco J.A.B.Coelho J.Cogan E.Cogneras L.Cojocariu P.Collins T.Colombo L.Congedo A.Contu N.Cooke G.Coombs G.Corti C.M.Costa Sobral B.Couturier D.C.Craik J.Crkovská M.Cruz Torres R.Currie C.L.Da Silva E.Dall’Occo J.Dalseno C.D’Amb AGH-University of Science and Technology Faculty of Computer Science Electronics and Telecommunications AGH-University of Science and Technology Faculty of Physics and Applied Computer Science Aix Marseille Univ CNRS/IN2P3 CPPM Budker Institute of Nuclear Physics (SB RAS) Cavendish Laboratory University of Cambridge Center for High Energy Physics Tsinghua University Centro Brasileiro de Pesquisas Físicas (CBPF) DS4DS La Salle Universitat Ramon Llull Departamento de Fisica Universidad Nacional de Colombia Department of Physics and Astronomy University of Manchester Department of Physics and Astronomy Uppsala University Department of Physics University of Oxford Department of Physics University of Warwick European Organization for Nuclear Research (CERN) Fakult?t Physik Technische Universit?t Dortmund Guangdong Provencial Key Laboratory of Nuclear Science Institute of Quantum Matter South China Normal University H.H. Wills Physics Laboratory University of Bristol Hangzhou Institute for Advanced Study UCAS Hanoi University of Science Henryk Niewodniczanski Institute of Nuclear Physics Polish Academy of Sciences Horia Hulubei National Institute of Physics and Nuclear Engineering I.Physikalisches Institut RWTH Aachen University ICCUB Universitat de Barcelona infn Laboratori Nazionali di Frascati infn sezione di Bari infn sezione di Bologna infn sezione di cagliari infn sezione di Ferrara infn sezione di Firenze infn sezione di Genova infn sezione di Milano infn sezione di Milano-Bicocca infn sezione di Perugia infn sezione di Pisa infn sezione di Roma La Sapienza infn sezione di Roma Tor Vergata Imperial College London Institut für Physik Universit?t Rostock Institute Of High Energy Physics (IHEP) Institute for High Energy Physics NRC Kurchatov Institute (IHEP NRC KI) Institute for Nuclear Research of the National Academy of Sciences (KINR) Institute for Nuclear Research of the Russian Academy of Sciences (INR RAS) Institute of Nuclear Physics Moscow State University (SINP MSU) Institute of Part

The first search for the doubly heavy Ωbc~0 baryon and a search for the Ξbc~0 baryon are performed using pp collision data collected via the LHCb experiment from 2016 to 2018 at a centre-of-mass energy of 13 TeV,corresponding to an integrated luminosity of 5.2 fb-1.The baryons are reconstructed via their decays to ∧c~+π~-andΞc~+π~-.No significant excess is found for invariant masses between 6700 and 7300 MeV/c2,in a rapidity range from2.0 to 4.5 and a transverse momentum range from 2 to 20 MeV/c.Upper limits are set on the ratio of the Ωbc~0 andΞbc~0 production cross-section times the branching fraction to ∧c~+π~-(Ξc~+π~-) relative to that of the ∧b~0(Ξb~0) baryon,for different lifetime hypotheses,at 95% confidence level.The upper limits range from 0.5×10-4to 2.5×10-4for theΩbc~0→∧c~+π~-(Ξbc~0→∧c~+π~-) decay,and from 1.4×10-3to 6.9×10-3for the Ωbc~0→Ξc~+π~-(Ξbc~0→Ξc~+π~-) decay,depending on the considered mass and lifetime of the Ωbc~0(Ξbc~0) baryon.

关键词： B physics quarkonium spectroscopy heavy quark production

A Quantum Field Theory Toy-Model for Magnetic Epigenetic

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Journal of Modern Physics 2013年第8期4卷 1133-1138页

作者： Fabio Burigana Euro Spallucci Claudio Verzegnassi AMEC (Association for Medicine and Complexity) Trieste Italy dipartimento di Fisica Sezione Teorica Università di Trieste and INFN Trieste Italy dipartimento di Fisica Sezione Teorica Università di Trieste and INFN Trieste Udine Italy

We consider the effects that a magnetic field has on the observable properties of an elementary one-fermion state, assumed for simplicity to be that of one electron. We show that for a weak intensity of the field these effects can be very simply computed in a quantum field theory theoretical framework, assuming the minimal form of the electromagnetic interaction and the validity of the dirac equation. The effects proceed via preliminary, magnetic field induced, modification of the four components of the spinor field. These generate consequent modifications of the various observable properties of the fermion, which can always be simply expressed in terms of the four spinor field components. A few general features of the various effects are discussed, and a number of possible analogies with the fascinating medical description of the epigenetic process for an organic cell are finally proposed.

关键词： Epigenetics Quantum Field Theory dirac Equation

Quantal symmetries in the non-linear σ model with Maxwell and non-Abelian Chern-Simons terms

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Physics C 2010年第5期34卷 535-538页

作者：王珂姜云国霍秋红 Department of Applied Physics Beijing University of Technology Department of Physics University of Pisa infn Sezione di PisaLargo Pontecorvo3.Ed.C56127 PisaItaly College of Materials Science and Engineering Beijing University of Technology

The quantal symmetry property of the CP1 nonlinear σ model with Maxwell non-Abelian ChernSimons terms in(2+1) dimension is studied.In the Coulomb gauge,the system is quantized by using the Faddeev-Senjanovic(FS) path-integral formalism.Based on the quantaum Noether theorem,the quantal conserved angular momentum is derived and the fractional spin at the quantum level in this system is presented.

关键词： non-linear sigma model non-Abelian Chern-Simons fractional spin

Holographic Duals of Quark Gluon Plasmas with Unquenched Flavors

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Communications in Theoretical Physics 2012年第3期57卷 364-386页

作者： Francesco Bigazzi Aldo Cotrone Javier Mas Daniel Mayerson Javier Tarrio dipartimento di Fisica e Astronomia Universita' di Firenze Via G.Sansone 1 I-50019 Sesto Fiorentino (Firenze)Italyand INFNSezione di PisaLargo B.Pontecorvo356127 PisaItaly dipartimento di Fisica Universita' di Torino and INFN Sezione di Torino Via P.Giuria 1 I-10125 TorinoItaly Departamento de F' sica de Part' culas Universidade de Santiago de Compostela and Instituto Galego de F' sica de Altas Enerx' as (IGFAE) E-15782 Santiago de CompostelaSpain Institute for Theoretical Physics University of AmsterdamScience Park 904Postbus 944851090 GL AmsterdamThe Netherlands Institute for Theoretical Physics Universiteit Utrecht3584 CEUtrechtThe Netherlands

We review the construction of gravitational solutions holographically dual to N=1 quiver gauge theories with dynamical flavor multiplets.We focus on the D3-D7 construction and consider the finite temperature,finite quark chemical potential case where there is a charged black hole in the dual solution.discussed physical outputs of the model include its thermodynamics (with susceptibilities) and general hydrodynamic properties.

关键词：夸克胶子等离子体全息口味淬灭水动力性能有限温度带电黑洞化学势

Holographic Bound in Quantum Field Energy Density and Cosmological Constant

在线全文

学校读者我要写书评

暂无评论

Journal of Modern Physics 2013年第6期4卷 807-811页

作者： Paolo Castorina dipartimento di Fisica Università di Catania and INFN Sezione di Catania Catania Italia

The cosmological constant problem is reanalyzed by imposing the limitation of the number of degrees of freedom (d.o.f.) due to entropy bounds directly in the calculation of the energy density of a field theory. It is shown that if a quantum field theory has to be consistent with gravity and holography, i.e. with an upper limit of storing information in a given area, the ultraviolet momentum cut-off is not the Planck mass, Mp, as naively expected, but where Nu is the number of d.o.f. of the universe. The energy density evaluation turns out completely consistent with Bousso’s bound on the cosmological constant value. The scale , that in the “fat graviton” theory corresponds to the graviton size, originates by a self-similar rearrangement of the elementary d.o.f. at different scales that can be seen as an infrared-ultraviolet connection.

关键词： Cosmological Constant Holography Quantum Fields

Energy and Heat Fluctuations in a Temperature Quench

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Communications in Theoretical Physics 2014年第10期61卷 555-570页

作者： M.Zannetti F.Corberi G.Gonnella A.Piscitelli dipartimento di Fisica "E.Caianiello" and CNISMUnità di SalernoUniversità di Salernovia Giovanni Paolo II 13284084 Fisciano (SA)Italy Kavli Institute for Theoretical Physics China the Chinese Academy of Sciences dipartimento di Fisica Università di Bari and INFNSezione di Barivia Amendola 17370126 BariItaly division of Physical Sciences School of Physical and Mathematical SciencesNanyang Technological University21 Nanyang Link637371Singapore

Fluctuations of energy and heat are investigated during the relaxation following the instantaneous temperature quench of an extended system. Results are obtained analytically for the Gaussian model and for the large N model quenched below the critical temperature TC. The main finding is that fluctuations exceeding a critical threshold do condense. Though driven by a mechanism similar to that of Bose–Einstein condensation, this phenomenon is an out-of-equilibrium feature produced by the breaking of energy equipartition occurring in the transient regime. The dynamical nature of the transition is illustrated by phase diagrams extending in the time direction.

关键词： fluctuations condensation temperature quench relaxation equipartition breaking

Containment effort reduction and regrowth patterns of the Covid-19 spreading

在线全文

学校读者我要写书评

暂无评论

Infectious disease Modelling 2021年第1期6卷 632-642页

作者： D.Lanteri D.Carco P.Castorina M.Ceccarelli B.Cacopardo infn Sezione di CataniaI-95123CataniaItaly dipartimento di Fisica e Astronomia Universita di CataniaItaly Istituto Oncologico del Mediterraneo ViagrandeItaly Faculty of Mathematics and Physics Charles UniversityV Holesovickach 218000Prague 8Czech Republic U.O.C.Malattie Infettive P.O.GaribaldiCataniaItaly dipartimento di Medicina clinica e sperimentale Universita di CataniaItaly

In all countries the political decisions aim to achieve an almost stable configuration with a small number of new infected individuals per day due to Covid-19.When such a condition is reached,the containment effort is usually reduced in favor of a gradual reopening of the social life and of the various economical sectors.However,in this new phase,the infection spread restarts and,moreover,possible mutations of the virus give rise to a large specific growth rate of the infected people.Therefore,a quantitative analysis of the regrowth pattern is very useful.We discuss a macroscopic approach which,on the basis of the collected data in the first lockdown,after few days from the beginning of the new phase,outlines different scenarios of the Covid-19 diffusion for longer time.The purpose of this paper is a demonstration-of-concept:one takes simple growth models,considers the available data and shows how the future trend of the spread can be obtained.The method applies a time dependent carrying capacity,analogously to many macroscopic growth laws in biology,economics and population dynamics.The illustrative cases of France,Italy and United Kingdom are analyzed.

关键词： Covid-19 spreading Mathematical models Macroscopic growth laws Carrying capacity