NeuProbes neutrino and other probes for new physics
Neutrino physics holds the keys to the understanding of the origin of masses and matter
This project has received funding from the European Union’s Seventh Framework Programme for research, technological development and demonstration under grant agreement no PCIG11-GA-2012-321582 © Josu Hernandez
THE PROJECT The Standard Model (SM) of particle physics is an extremely successful theory that summarizes our understanding of the elementary particles that form the Universe. However, there a few experimental results that indicate that the SM needs to be extended with new physics to be discovered. Namely, the evidence for neutrino masses from the "neutrino oscillation phenomenon" and the existence of "dark matter" (DM), a new form of matter not present in the SM content. The study of these two sectors to explore new physics beyond the SM is the principal goal of the NeuProbes project. In 2011 the SM underwent a revolution, not only the Higgs particle was discovered completing the particle content of the SM, but also "theta13", a fundamental parameter describing neutrino interactions, was measured. This measurement opens the window to probing an even more fundamental unknown quantity in the neutrino sector "delta", that could be related to the existence of the observed matter-antimatter asymmetry in the Universe and, thus, ultimately responsible for our existence. A principal line of research in NeuProbes is the analysis and simulation of neutrino oscillation data so as to probe for and optimize the searches for delta. The discovery of theta13 revolutionized the field and allowed us to propose a new search strategy, which has been adopted by a new-formed experimental collaboration proposing a new facility based on the ESS under construction at Lund to determine the value of delta. Within the context of NewProbes we have also performed studies of the sensitivity that future neutrino oscillation searches will have to delta, conditioned to the presently available information from existing experiments. Currently we are also performing analysis aiming to optimize the two proposed neutrino oscillation facilities which will likely comprise the next generation in this field: T2HK in Japan and DUNE in the USA. Another line of research where NeuProbes has had a significant impact in the community is the probe of theories aiming at the explanation of the observed neutrino masses beyond the SM context. In particular, the most popular and widely accepted theory predicts the existence of extra neutrinos with extremely small interactions with the rest of the observable Universe. In NeuProbes we have analyzed present laboratory data as well as cosmological observations so as to constrain these very feeble interactions and probe for the existence of these hypothetical new particles. Finally, within NeuProbes, we have also probed for the interactions between DM and the visible Universe combining existing data. In this context, we have also developed a new alternative theory to explain DM production in the early Universe. These scientific results have been possible thanks to the NeuProbes grant that allowed to fund the ongoing career of a PhD student as well as some equipment and travel budget for the dissemination of the results. In turn this has enabled the NeuProbes principal investigator to successfully integrate within a broader working group in his research institution with good prospects for stabilization in the future.
This project has received funding from the European Union’s Seventh Framework Programme for research, technological development and demonstration under grant agreement no PCIG11-GA-2012-321582 © Josu Hernandez
Seminars & Talks
• Radiative corrections to Mh within the MSSM-Seesaw from 3 generations of neutrinos and sneutrinos V CPAN days. 25-27 November 2013. Santiago de Compostela, Spain. • CP violation and oscillation parameter precision measurements ICFA European Neutrino meeting, 8-10 January 2014. Paris, France. • The search for leptonic CP violation News in Neutrino Physics, 7 April-2 May 2014. Stockholm, Sweden • The search for leptonic CP violation GDR Neutrino Meeting 2014, 16-17 June. Orsay, France. • WG1 Summary talk NuFact14 Workshop, 15-30 August. Glasgow, UK. • The measurement of leptonic CP violation NOW 2014, 7-14 September 2014. Otranto, Italy. • The search for leptonic CP violation Seminar at the INFN Genova, 2 March 2015. Genova, Italy. • Complete bounds on right-handed neutrino mixing Invisibles Workshop 2015. 22-26 June 2015. Madrid, Spain. • The quest for leptonic CP violation Nu@Fermilab, 21-25 July 2015. Fermilab, Illinois, USA. • Discussion leader on neutrino oscillation experiments Neutrinos from Space and on Earth, 26 July-16 August 2015. Aspen, Colorado, USA. • Global fit to right-handed neutrino mixing at 1 loop EPS HEP 2015. 22-29 July 2015. Vienna, Austria.
  • Freeze-in through portals
    Mattias Blennow, Enrique Fernandez-Martínez and Bryan Zaldívar The popular freeze-out paradigm for Dark Matter (DM) production, relies on DM-baryon couplings of the order of the weak interactions. However, different search strategies for DM have failed to provide a conclusive evidence of such (non-gravitational) interactions, while greatly reducing the parameter space of many representative models. This motivates the study of alternative mechanisms for DM genesis. In the freeze-in framework, the DM is slowly populated from the thermal bath while never reaching equilibrium. In this work, we analyse in detail the possibility of producing a frozen-in DM via a mediator particle which acts as a portal. We give analytical estimates of different freeze-in regimes and support them with full numerical analyses, taking into account the proper distribution functions of bath particles. Finally, we constrain the parameter space of generic models by requiring agreement with DM relic abundance observations. JCAP 1401 (2013) 003 arXiv:1309.7348 [hep-ph]
  • Searching for sterile neutrinos at the ESSνSB
    Mattias Blennow, Pilar Coloma and Enrique Fernandez-Martinez The ESSνSB project is a proposed neutrino oscillation experiment based on the European Spallation Source with the search for leptonic CP as its main aim. In this letter we show that a near detector at around 1 km distance from the beamline is not only very desirable for keeping the systematic errors affecting the CP search under control, but would also provide a significant sensitivity probe for sterile neutrino oscillations in the region of the parameter space favored by the long-standing LSND anomaly. We find that the effective mixing angle θμe can be probed down to sin2(2θμe)≃2(8)⋅10−3 at 5σ assuming 15% bin-to-bin (un)correlated systematics. JHEP 1412 (2014) 120 arXiv:1407.1317 [hep-ph]
  • Reassessing the sensitivity to leptonic CP violation
    Mattias Blennow, Pilar Coloma and Enrique Fernandez-Martinez We address the validity of the usual procedure to determine the sensitivity of neutrino oscillation experiments to CP violation. An explicit calibration of the test statistic is performed through Monte Carlo simulations for several experimental setups. We find that significant deviations from a χ2 distribution with one degree of freedom occur for experimental setups with low sensitivity to δ. In particular, when the allowed region to which δ is constrained at a given confidence level is comparable to the whole allowed range, the cyclic nature of the variable manifests and the premises of Wilk's theorem are violated. This leads to values of the test statistic significantly lower than a χ2 distribution at that confidence level. On the other hand, for facilities which can place better constraints on δ the cyclic nature of the variable is hidden and, as the potential of the facility improves, the values of the test statistics first become slightly higher than and then approach asymptotically a χ2 distribution. The role of sign degeneracies is also discussed. JHEP 1503 (2015) 005 arXiv:1407.3274 [hep-ph]
  • Revisiting cosmological bounds on sterile neutrinos
    Aaron C. Vincent, Enrique Fernandez-Martinez, Pilar Hernandez, Massimiliano Lattanzi and Olga Mena We employ state-of-the art cosmological observables including supernova surveys and BAO information to provide constraints on the mass and mixing angle of a non-resonantly produced sterile neutrino species, showing that cosmology can effectively rule out sterile neutrinos which decay between BBN and the present day. The decoupling of an additional heavy neutrino species can modify the time dependence of the Universe's expansion between BBN and recombination and, in extreme cases, lead to an additional matter-dominated period; while this could naively lead to a younger Universe with a larger Hubble parameter, it could later be compensated by the extra radiation expected in the form of neutrinos from sterile decay. However, recombination-era observables including the Cosmic Microwave Background (CMB), the shift parameter RCMB and the sound horizon rs from Baryon Acoustic Oscillations (BAO) severely constrain this scenario. We self-consistently include the full time-evolution of the coupled sterile neutrino and standard model sectors in an MCMC, showing that if decay occurs after BBN, the sterile neutrino is essentially bounded by the constraint sin2θ≲0.026(ms/eV)−2. JCAP 1504 (2015) 006 arXiv:1408.1956 [astro-ph.CO]
  • Radiative corrections to Mh from three generations of Majorana neutrinos and sneutrinos
    Sven Heinemeyer, Josu Hernandez-Garcia, Maria Jose Herrero, Xabier Marcano, Ana Maria Rodriguez-Sanchez In this work we study the radiative corrections to the mass of the lightest Higgs boson of the MSSM from three generations of Majorana neutrinos and sneutrinos. The spectrum of the MSSM is augmented by three right handed neutrinos and their supersymmetric partners. A seesaw mechanism of type I is used to generate the physical neutrino masses and oscillations that we require to be in agreement with present neutrino data. We present a full one-loop computation of these Higgs mass corrections, and analyze in full detail their numerical size in terms of both the MSSM and the new (s)neutrino parameters. A critical discussion on the different possible renormalization schemes and their implications is included. Adv. High Energy Phys. 2015, 152394 (2015) arXiv:1407.1083 [hep-ph]
  • Loop level constraints on Seesaw neutrino mixing
    Enrique Fernandez-Martinez, Josu Hernandez-Garcia, Jacobo Lopez-Pavon and Michele Lucente We perform a detailed study of the importance of loop corrections when deriving bounds on heavy-active neutrino mixing in the context of general Seesaw mechanisms with extra heavy right-handed neutrinos. We find that, for low-scale Seesaws with an approximate B−L symmetry characterized by electroweak scale Majorana masses and large Yukawas, loop corrections could indeed become relevant in a small part of the parameter space. Previous results in the literature showed that a partial cancellation between these important loop corrections and the tree level contributions could relax some constraints and lead to qualitatively different results upon their inclusion. However, we find that this cancellation can only take place in presence of large violations of the B−L symmetry, that lead to unacceptably large contributions to the light neutrino masses at loop level. Thus, when we restrict our analysis of the key observables to an approximate B−L symmetry so as to recover the correct values for neutrino masses, we always find loop corrections to be negligible in the regions of the parameter space preferred by data. arXiv:1508.03051 [hep-ph]
  • Global constraints on vector-like WIMP effective interactions
    Mattias Blennow, Pilar Coloma, Enrique Fernandez-Martinez, Pedro A. N. Machado and Bryan Zaldivar In this work we combine information from relic abundance, direct detection, cosmic microwave background, positron fraction, gamma rays, and colliders to explore the existing constraints on effective couplings between Dark Matter and Standard Model constituents when no underlying model or correlation is assumed. Our results show that Dark Matter masses below 20 GeV are disfavoured at the 3σ level by tension between the relic abundance requirement and upper constraints on the Dark Matter couplings. Furthermore, large couplings are typically only allowed in combinations which avoid effective couplings to the nuclei used in direct detection experiments. arXiv:1509.01587 [hep-ph]
  • A Very Intense Neutrino Super Beam Experiment for Leptonic CP Violation Discovery based on the European Spallation Source Linac: A Snowmass 2013 White Paper
    E.Baussan, M.Blennow, M.Bogomilov, E.Bouquerel, J.Cederkall, P.Christiansen, P.Coloma, P.Cupial, H.Danared, C.Densham, M.Dracos, T.Ekelof, M.Eshraqi, E.Fernandez Martinez, G.Gaudiot, R.Hall-Wilton, J.-P.Koutchouk, M.Lindroos, R.Matev, D.McGinnis, M.Mezzetto, R.Miyamoto, L.Mosca, T.Ohlsson, H.Ohman, F.Osswald, S.Peggs, P.Poussot, R.Ruber, J.Y.Tang, R.Tsenov, G.Vankova-Kirilova, N.Vassilopoulos, E.Wildner, J.Wurtz Very intense neutrino beams and large neutrino detectors will be needed in order to enable the discovery of CP violation in the leptonic sector. We propose to use the proton linac of the European Spallation Source currently under construction in Lund, Sweden to deliver, in parallel with the spallation neutron production, a very intense, cost effective and high performance neutrino beam. The baseline program for the European Spallation Source linac is that it will be fully operational at 5 MW average power by 2022, producing 2 GeV 2.86 ms long proton pulses at a rate of 14 Hz. Our proposal is to upgrade the linac to 10 MW average power and 28 Hz, producing 14 pulses/s for neutron production and 14 pulses/s for neutrino production. Furthermore, because of the high current required in the pulsed neutrino horn, the length of the pulses used for neutrino production needs to be compressed to a few μs with the aid of an accumulator ring. A long baseline experiment using this Super Beam and a megaton underground Water Cherenkov detector located in existing mines 300-600 km from Lund will make it possible to discover leptonic CP violation at 5 σ significance level in up to 50% of the leptonic Dirac CP-violating phase range. This experiment could also determine the neutrino mass hierarchy at a significance level of more than 3 σ if this issue will not already have been settled by other experiments by then. The mass hierarchy performance could be increased by combining the neutrino beam results with those obtained from atmospheric neutrinos detected by the same large volume detector. This detector will also be used to measure the proton lifetime, detect cosmological neutrinos and neutrinos from supernova explosions. Results on the sensitivity to leptonic CP violation and the neutrino mass hierarchy are presented. Nuclear Physics B, Volume 885, August 2014, Pages 127-149 arXiv:1309.7022 [hep-ex]
• Course on Standard Model of elementary particles II (SMII)
Notebook 1 Notebook 2 Notebook 3
This project has received funding from the European Union’s Seventh Framework Programme for research, technological development and demonstration under grant agreement no PCIG11-GA-2012-321582 © Josu Hernandez
OUTREACH • Outreach talk: “Las Misteriosas Propiedades de los Neutrinos” La frontera de la fisica fundamental, 14 November 2013. Madrid, Spain.
Our body is by crossed by millions on neutrinos every second. The fascinating properties of these particles, they almost have no interaction with matter and their mass is millions times less than that of the other elementary particles, will be covered along this talk. • International Masterclass: hands on particle physics IPPO International Masterclasses 2014 and 2015. IFT Madrid, Spain. "Each year about 10.000 high school students in 42 countries come to one of about 200 nearby universities or research centres for one day in order to unravel the mysteries of particle physics. Lectures from active scientists give insight in topics and methods of basic research at the fundaments of matter and forces, enabling the students to perform measurements on real data from particle physics experiments themselves. At the end of each day, like in an international research collaboration, the participants join in a video conference for discussion and combination of their results." Visit the page here for more information. • Outreach events: “Semana de la Ciencia Madrid” Every November. Madrid, Spain. "The Madrid Science Week is an outreach initiative of science, technology and innovation addressed to all audiences of all ages and scientific levels that takes place throughout the Region of Madrid." More information here. • IFT UAM-CSIC Outreach Webpage "In these page you will find information about elementary particles and fundamental interactions, neutrinos, the Higgs boson, the origin and energy content of the Universe, dark matter and dark energy, black holes, and many other fascinating topics in the frontier of knowledge." Visit the page here. • CERN Outreach Webpage "Come and learn about fundamental research and see inside the world's largest particle physics laboratory. Feel free to visit our permanent exhibitions and experience CERN's scientific adventure on your own. Book and take part at one of our guided tours and discover the secrets of matter." Find here more information. • Paco Yndurain Colloquia Once a month at the Facultad de Ciencias. Universidad Autonoma de Madrid, Spain. "Since the academic course 2010-2011, the Department of Theoretical Physics holds every year the Paco Yndurain colloquia. These colloquia are intended to be of very high quality and very general and non-technical, targeting all specialties of our Department and well beyond." The slides and videos are available here.
This project has received funding from the European Union’s Seventh Framework Programme for research, technological development and demonstration under grant agreement no PCIG11-GA-2012-321582 © Josu Hernandez
MEMBERS email: institution: Universidad Autónoma de Madrid - IFT email: institution: Universidad Autónoma de Madrid - IFT • Enrique Fernandez Martinez • Josu Hernandez Garcia
This project has received funding from the European Union’s Seventh Framework Programme for research, technological development and demonstration under grant agreement no PCIG11-GA-2012-321582 © Josu Hernandez