Neutron-Antineutron oscillation as a test of a New Interaction

We propose to search Neutron-Antineutron transitions, in condition of strong magnetic field rather than suppressed one. It is commonly accepted that such an oscillation has to be searched in no magnetic field conditions (for instance, the experiment have to be shielded by the Earth’s magnetic field). But, Neutron(and Antineutron) could be coupled to a 5th force spin-independent background Φ generated by the Earth, as eV Φ¯nγ0n. The background condensate simulates a difference in neutron and antineutron masses, in other words a CPT violation. Compatible with Equivalence Principle (EP) limits for a neutron inside nuclei, the 5th force background could be as high as Φ ∼ 10−11 ÷ 10−10 eV. As consequence, the transition probability is amplified rather than suppressed with a magnetic field of B ∼ 1–10 Gauss, if we consider neutrons immersed in a background saturating the EP limit. There are intriguing connections among: the existence of a Majorana neutron, Baryon violations Beyond the Standard Model, the Matter-Antimatter asymmetry in our Universe (Baryogenesis and Leptogenesis), the possibility of a new fifth force interaction, the possible apparent violation of the Equivalence Principle and the CPT. These strongly motivate an improvement of our current best limits in n-¯n physics

String completion of an SU(3)c⊗SU(3)L⊗U(1)X\mathrm{SU(3)_c \otimes SU(3)_L \otimes U(1)_X} electroweak model

The extended electroweak $\mathrm{SU(3)_c \otimes SU(3)_L \otimes U(1)_X}$ symmetry framework "explaining" the number of fermion families is revisited. While $331$-based schemes can not easily be unified within the conventional field theory sense, we show how to do it within an approach based on D-branes and (un)oriented open strings, on Calabi-Yau singularities. We show how the theory can be UV-completed in a quiver setup, free of gauge and string anomalies. Lepton and baryon numbers are perturbatively conserved, so neutrinos are Dirac-type, and their lightness results from a novel TeV scale seesaw mechanism. Dynamical violation of baryon number by exotic instantons could induce neutron-antineutron oscillations, with proton decay and other dangerous R-parity violating processes strictly forbidden.Comment: 12 pages, 2 figures, published versio

DAMA annual modulation effect and asymmetric mirror matter

The long-standing model-independent annual modulation effect measured by DAMA Collaboration is examined in the context of asymmetric mirror dark matter, assuming that dark atoms interact with target nuclei in the detector via kinetic mixing between mirror and ordinary photons, both being massless. The relevant ranges for the kinetic mixing parameter are obtained taking into account various existing uncertainties in nuclear and particle physics quantities as well as characteristic density and velocity distributions of dark matter in different halo models.Comment: 27 pages, 5 figures, 2 tables; version in publication on Eur. Phys. J.

Un-oriented Quiver Theories for Majorana Neutrons

In the context of un-oriented open string theories, we identify quivers whereby a Majorana mass for the neutron is indirectly generated by exotic instantons. We discuss two classes of (Susy) Standard Model like quivers, depending on the embedding of SU(2)_W in the Chan-Paton group. In both cases, the main mechanism involves a vector-like pair mixing through a non-perturbative mass term. We also discuss possible relations between the phenomenology of Neutron-Antineutron oscillations and LHC physics in these models. In particular, a vector-like pair of color-triplet scalars or color-triplet fermions could be directly detected at LHC, compatibly with n-\bar{n} limits. Finally we briefly comment on Pati-Salam extensions of our models.Comment: More comments on phenomenology and fluxes, Re-discussion of SM-quivers compatible with n-cycles conditions Version accepted by JHE

Quantum gravity phenomenology at the dawn of the multi-messenger era—A review

The exploration of the universe has recently entered a new era thanks to the multimessenger paradigm, characterized by a continuous increase in the quantity and quality of experimental data that is obtained by the detection of the various cosmic messengers (photons, neutrinos, cosmic rays and gravitational waves) from numerous origins. They give us information about their sources in the universe and the properties of the intergalactic medium. Moreover, multi-messenger astronomy opens up the possibility to search for phenomenological signatures of quantum gravity. On the one hand, the most energetic events allow us to test our physical theories at energy regimes which are not directly accessible in accelerators; on the other hand, tiny effects in the propagation of very high energy particles could be amplified by cosmological distances. After decades of merely theoretical investigations, the possibility of obtaining phenomenological indications of Planck-scale effects is a revolutionary step in the quest for a quantum theory of gravity, but it requires cooperation between different communities of physicists (both theoretical and experimental). This review, prepared within the COST Action CA18108 ‘‘Quantum gravity phenomenology in the multi-messenger approach", is aimed at promoting this cooperation by giving a state-of-the art account of the interdisciplinary expertise that is needed in the effective search of quantum gravity footprints in the production, propagation and detection of cosmic messengers.Talent Scientific Research Program of College of Physics, Sichuan University 1082204112427Fostering Program in Disciplines Possessing Novel Features for Natural Science of Sichuan University 2020SCUNL2091000 Talent program of Sichuan province 2021Xunta de GaliciaEuropean Commission European Union ERDF, "Maria de Maeztu'' Units of Excellence program MDM-2016-0692Red Tematica Nacional de Astroparticulas RED2018-102661-TLa Caixa Foundation 100010434European Commission 847648 LCF/BQ/PI21/11830030 754510Ministry of Education, Science & Technological Development, Serbia 451-03-9/2021-14/200124FSR Incoming Postdoctoral Fellowship Ministry of Education, Science and Technological Development, Serbia 451-03-9/2021-14/200124University of Rijeka grant uniri-prirod-18-48Croatian Science Foundation (HRZZ) IP-2016-06-9782Villum Fonden 29405 DGA-FSE 2020-E2117REuropean Regional Development Fund through the Center of Excellence (TK133) "The Dark Side of the Universe'' European Regional Development Fund (ESIF/ERDF)Ministry of Education, Youth & Sports - Czech Republic CoGraDS-CZ.02.1.01/0.0/0.0/15 003/0000437Blavatnik grantBasque Government IT-97916 Basque Foundation for Science (IKERBASQUE)European Space Agency C4000120711 4000132310FNRS (Belgian Fund for Research)Programa de Apoyo a Proyectos de Investigacion e Innovacion Tecnologica (PAPIIT)Universidad Nacional Autonoma de Mexico TA100122National University of La Plata X909 DICYT 042131GRNational Research, Development & Innovation Office (NRDIO) - Hungary 123996FQXiSwiss National Science Foundation (SNSF)European Commission 181461 199307Netherlands Organization for Scientific Research (NWO) 680-91-119 15MV71Ministry of Education, Culture, Sports, Science and Technology, Japan (MEXT) Japan Society for the Promotion of ScienceGrants-in-Aid for Scientific Research (KAKENHI) 20H01899 20H05853 JP21F21789Estonian Research Council PRG356Julian Schwinger FoundationGeneralitat Valenciana Excellence PROMETEO-II/2017/033 PROMETEO/2018/165Istituto Nazionale di Fisica Nucleare (INFN)European ITN project HIDDeN H2020-MSCA-ITN-2019//860881-HIDDeNSwedish Research CouncilEuropean Commission 2016-05996 European Research Council (ERC) European Commission 668679Advanced ERC grant TReXMinistry of Education, Universities and Research (MIUR) 2017X7X85KFonds de la Recherche Scientifique - FNRS 4.4501.18Ministry of Research, Innovation and Digitization - Romania PN19-030102-INCDFM PN-III-P4ID-PCE-2020-2374United States Department of Energy (DOE) DE-SC0020262Ministry of Science, ICT & Future Planning, Republic of Korea 075-15-2020-778German Academic Scholarship Foundation German Research Foundation (DFG) 408049454 420243324 425333893 445990517 Germany's Excellence Strategy (EXC 2121 "Quantum Universe'') 390833306 390837967 Federal Ministry of Education & Research (BMBF) 05 A20GU2 05 A20PX1Centro de Excelencia "Severo Ochoa'' SEV-2016-0588CERCA program of the Generalitat de CatalunyaAgencia de Gestio D'Ajuts Universitaris de Recerca Agaur (AGAUR) Generalitat de Catalunya 2017-SGR-1469 2017-SGR-929 ICCUB CEX2019-000918-MNational Science Centre, Poland 2019/33/B/ST2/00050 2017/27/B/ST2/01902Conselho Nacional de Desenvolvimento Cientifico e Tecnologico (CNPQ) 306414/2020-1Dicyt-USACH 041931MFNational Science Fund of Bulgaria KP-06-N 38/11 RCN ROMFORSK 302640Comunidad de Madrid 2018-T1/TIC-10431 2019-T1/TIC-13177 S2018/NMT-4291UK Research & Innovation (UKRI)Science & Technology Facilities Council (STFC) ST/T000759/1 ST/P000258/1 ST/T000732/1 ST/V005596/1Portuguese Foundation for Science and Technology UIDB/00618/2020 UIDB/00777/2020 UIDP/00777/2020 CERN/FIS-PAR/0004/2019 PTDC/FIS-PAR/29436/2017 PTDC/FISPAR/31938/2017 PTDC/FIS-OUT/29048/2017 SFRH/BD/137127/2018Centre National de la Recherche Scientifique (CNRS), LabEx UnivEarthS ANR-10-LABX-0023 ANR18-IDEX-0001Junta de Andalucia European Commission A-FQM-053-UGR18Natural Sciences and Engineering Research Council of Canada (NSERC) RGPIN-2021-03644National Science Centre Poland Sonata Bis 2019/33/B/ST2/00050 DEC-2017/26/E/ST2/00763Natural Sciences and Engineering Research Council of Canada (NSERC) DGIID-DGA 2015-E24/2Spanish Research State Agency and Ministerio de Ciencia e Innovacion MCIN/AEI PID2019-104114RB-C32 PID2019-105544GB-I00 PID2019-105614GB-C21 PID2019106515GB-I00 PID2019-106802GB-I00 PID2019-107394GB-I00 PID2019-107844GB-C21 PID2019-107847RB-C41 MCIN/AEI PGC2018-095328-B-I00 PGC2018-094856-B-I00 PGC2018-096663-B-C41 PGC2018-096663-B-C44 PGC2018-094626-BC21 PGC2018-101858-B-I00 FPA2017-84543-P FPA2016-76005-C2-1-PSpanish 'Ministerio de Universidades' BG20/00228 Spanish Government PID2020-115845GBI00 Generalitat de Catalunya Comunidad de Madrid S2018/NMT-4291 Spanish Government PID2019-105544GB-I00Perimeter Institute for Theoretical PhysicsGovernment of Canada through the Department of Innovation, Science and Economic DevelopmentProvince of Ontario through the Ministry of Colleges and UniversitiesIstituto Nazionale di Fisica Nucleare (INFN)Centre National de la Recherche Scientifique (CNRS)Netherlands Organization for Scientific Research (NWO)Fundamental Questions Institute (FQXi)European Cooperation in Science and Technology (COST) CA18108Research Council of University of GuilanIniziativa Specifica TEONGRAV Iniziativa Specifica QGSKY Iniziativa Specifica QUAGRAP Iniziativa Specifica GeoSymQFTthe Spanish Research State Agency and Ministerio de Ciencia e Innovacion MCIN/AEI PID2020-115845GBI00 PID2019-108485GB-I00 PID2020-113334GB-I00 PID2020-113701GB-I00 PID2020-113775GB-I00 PID2020-118159GB-C41 PID2020-118159GA-C42 PRE2019-089024Rothchild grant UID/MAT/00212/2020 FPU18/0457

DAMA annual modulation and mirror Dark Matter

The DAMA experiment using ultra low background NaI(Tl) crystal scintillators has measured an annual modulation effect in the keV region which satisfies all the peculiarities of an effect induced by Dark Matter particles. In this paper we analyze this annual modulation effect in terms of mirror Dark Matter, an exact duplicate of ordinary matter from parallel hidden sector, which chemical composition is dominated by mirror helium while it can also contain significant fractions of heavier elements as Carbon and Oxygen. Dark mirror atoms are considered to interact with the target nuclei in the detector via Rutherford-like scattering induced by kinetic mixing between mirror and ordinary photons, both being massless. In the present analysis we consider various possible scenarios for the mirror matter chemical composition. For all the scenarios, the relevant ranges for the kinetic mixing parameter have been obtained taking also into account various existing uncertainties in nuclear and particle physics quantities

D-brane Instantons as Gauge Instantons in Orientifolds of Chiral Quiver Theories

Systems of D3-branes at orientifold singularities can receive non-perturbative D-brane instanton corrections, inducing field theory operators in the 4d effective theory. In certain non-chiral examples, these systems have been realized as the infrared endpoint of a Seiberg duality cascade, in which the D-brane instanton effects arise from strong gauge theory dynamics. We present the first UV duality cascade completion of chiral D3-brane theories, in which the D-brane instantons arise from gauge theory dynamics. Chiral examples are interesting because the instanton fermion zero mode sector is topologically protected, and therefore lead to more robust setups. As an application of our results, we provide a UV completion of certain D-brane orientifold systems recently claimed to produce conformal field theories with conformal invariance broken only by D-brane instantons.Comment: 50 pages, 32 figures. v2: version published in JHEP with references adde

New High-Sensitivity Searches for Neutrons Converting into Antineutrons And/or Sterile Neutrons at the HIBEAM/NNBAR Experiment at the European Spallation Source

The violation of baryon number, is an essential ingredient for the preferential creation of matter over antimatter needed to account for the observed baryon asymmetry in the Universe. However, such a process has yet to be experimentally observed. The HIBEAM/NNBAR program is a proposed two-stage experiment at the European Spallation Source to search for baryon number violation. The program will include high-sensitivity searches for processes that violate baryon number by one or two units: free neutron-antineutron oscillation via mixing, neutron-antineutron oscillation via regeneration from a sterile neutron state , and neutron disappearance (n → n′); the effective process of neutron regeneration is also possible. The program can be used to discover and characterize mixing in the neutron, antineutron and sterile neutron sectors. The experiment addresses topical open questions such as the origins of baryogenesis and the nature of dark matter, and is sensitive to scales of new physics substantially in excess of those available at colliders. A goal of the program is to open a discovery window to neutron conversion probabilities (sensitivities) by up to three orders of magnitude compared with previous searches. The opportunity to make such a leap in sensitivity tests should not be squandered. The experiment pulls together a diverse international team of physicists from the particle (collider and low energy) and nuclear physics communities, while also including specialists in neutronics and magnetics