Search

We perform a global analysis of most up-to-date solar neutrino data and KamLAND reactor antineutrino data in the framework of the 3+1 sterile neutrino mixing scenario (invoked to explain the results of the Gallium source experiments) with the aim of quantifying the dependence of the (in)compatibility of the required mixing with assumptions on the initial fluxes. The analysis of solar data is performed in two alternative ways: using the flux predicted by the latest standard solar models, and in a model independent approach where the solar fluxes are also determined by the fit. The dependence on the normalization of the capture rate in the solar Gallium experiments is also quantified. Similarly, in the KamLAND analysis we consider both the case where the reactor flux normalization is assumed to be known a priori, as well as a normalization free case which relies solely on available neutrino data. Using a parameter goodness of fit test, we find that in most cases the compatibility between Gallium and solar+KamLAND data only occur at the $3\sigma$ level or higher. We also discuss the implications of enforcing better compatibility by tweaking the mechanism for the energy production in the Sun., Comment: 9 pages, 3 figures, 1 table. Matches published version

In this note, we give a definitive basis for the dimension-eight operators leading to quartic -- but no cubic -- interactions among electroweak gauge bosons. These are often called anomalous quartic gauge couplings, or aQGCs. We distinguish in particular the CP-even ones from their CP-odd counterparts., Comment: LHC Effective Field Theory Working Group Note, 8 pages, 3 tables

We present an updated global analysis of neutrino oscillation data as of September 2024. The parameters $\theta_{12}$, $\theta_{13}$, $\Delta m^2_{21}$, and $|\Delta m^2_{3\ell}|$ ($\ell = 1,2$) are well-determined with relative precision at $3\sigma$ of about 13\%, 8\%, 15\%, and 6\%, respectively. The third mixing angle $\theta_{23}$ still suffers from the octant ambiguity, with no clear indication of whether it is larger or smaller than $45^\circ$. The determination of the leptonic CP phase $\delta_{CP}$ depends on the neutrino mass ordering: for normal ordering the global fit is consistent with CP conservation within $1\sigma$, whereas for inverted ordering CP-violating values of $\delta_{CP}$ around $270^\circ$ are favored against CP conservation at more than $3.6\sigma$. While the present data has in principle $2.5$--$3\sigma$ sensitivity to the neutrino mass ordering, there are different tendencies in the global data that reduce the discrimination power: T2K and NOvA appearance data individually favor normal ordering, but they are more consistent with each other for inverted ordering. Conversely, the joint determination of $|\Delta m^2_{3\ell}|$ from global disappearance data prefers normal ordering. Altogether, the global fit including long-baseline, reactor and IceCube atmospheric data results into an almost equally good fit for both orderings. Only when the $\chi^2$ table for atmospheric neutrino data from Super-Kamiokande is added to our $\chi^2$, the global fit prefers normal ordering with $\Delta\chi^2 = 6.1$. We provide also updated ranges and correlations for the effective parameters sensitive to the absolute neutrino mass from $\beta$-decay, neutrinoless double-beta decay, and cosmology.

We quantify the effects of light spin-zero particles with pseudoscalar couplings to leptons and scalar couplings to nucleons on the evolution of solar neutrinos. In this scenario the matter potential sourced by the nucleons in the Sun's matter gives rise to spin precession of the relativistic neutrino ensemble. As such the effects in the solar observables are different if neutrinos are Dirac or Majorana particles. For Dirac neutrinos the spin-flavour precession results into left-handed neutrino to right-handed neutrino (i.e., active-sterile) oscillations, while for Majorana neutrinos it results into left-handed neutrino to right-handed antineutrino (i.e., active-active) oscillations. In both cases this leads to distortions in the solar neutrino spectrum which we use to derive constraints on the allowed values of the mediator mass and couplings via a global analysis of the solar neutrino data. In addition for Majorana neutrinos spin-flavour precession results into a potentially observable flux of solar electron antineutrinos at the Earth which we quantify and constrain with the existing bounds from Borexino and KamLAND., Comment: 22 pages, 5 figures, 1 table. Matches published version

We present the basis of dimension-eight operators associated with universal theories. We first derive a complete list of independent dimension-eight operators formed with the Standard Model bosonic fields characteristic of such universal new physics scenarios. Without imposing C or P symmetries the basis contains 175 operators -- that is, the assumption of Universality reduces the number of independent SMEFT coefficients at dimension eight from 44807 to 175. 89 of the 175 universal operators are included in the general dimension-eight operator basis in the literature. The 86 additional operators involve higher derivatives of the Standard Model bosonic fields and can be rotated in favor of operators involving fermions using the Standard Model equations of motion for the bosonic fields. By doing so we obtain the allowed fermionic operators generated in this class of models which we map into the corresponding 86 independent combinations of operators in the dimension-eight basis of Ref. arXiv:2005.00059, Comment: 38 pages, 9 Tables; added a new section with few examples of UV completions, typos corrected, references added

We determine the solar neutrino fluxes from the global analysis of the most up-to-date terrestrial and solar neutrino data including the final results of the three phases of Borexino. The analysis are performed in the framework of three-neutrino mixing with and without accounting for the solar luminosity constraint. We discuss the independence of the results on the input from the Gallium experiments. The determined fluxes are then compared with the predictions provided by the latest Standard Solar Models. We quantify the dependence of the model comparison with the assumptions about the normalization of the solar neutrino fluxes produced in the CNO-cycle as well as on the particular set of fluxes employed for the model testing., Comment: 34 pages, 12 figures, 2 tables. Matches published version

Precision measurements of anomalous quartic couplings of electroweak gauge bosons allow us to search for deviations of the Standard Model predictions and signals of new physics. Here, we obtain the constraints on anomalous quartic gauge couplings using the presently available data on the production of gauge-boson pairs via vector boson fusion. We work in the Higgs effective theory framework and obtain the present bounds on the operator's Wilson coefficients. Anomalous quartic gauge boson couplings lead to rapidly growing cross sections and we discuss the impact of a unitarization procedure on the attainable limits.

We derive new constraints on effective four-fermion neutrino non-standard interactions with both quarks and electrons. This is done through the global analysis of neutrino oscillation data and measurements of coherent elastic neutrino-nucleus scattering (CEvNS) obtained with different nuclei. In doing so, we include not only the effects of new physics on neutrino propagation but also on the detection cross section in neutrino experiments which are sensitive to the new physics. We consider both vector and axial-vector neutral-current neutrino interactions and, for each case, we include simultaneously all allowed effective operators in flavour space. To this end, we use the most general parametrization for their Wilson coefficients under the assumption that their neutrino flavour structure is independent of the charged fermion participating in the interaction. The status of the LMA-D solution is assessed for the first time in the case of new interactions taking place simultaneously with up quarks, down quarks, and electrons. One of the main results of our work are the presently allowed regions for the effective combinations of non-standard neutrino couplings, relevant for long-baseline and atmospheric neutrino oscillation experiments., Comment: 43 pages, 9 figures, 5 tables. This work updates and extends arXiv:1805.04530 and arXiv:2204.03011. V2 matches accepted version

Particle physics today faces the challenge of explaining the mystery of dark matter, the origin of matter over anti-matter in the Universe, the origin of the neutrino masses, the apparent fine-tuning of the electro-weak scale, and many other aspects of fundamental physics. Perhaps the most striking frontier to emerge in the search for answers involves new physics at mass scales comparable to familiar matter, below the GeV-scale, or even radically below, down to sub-eV scales, and with very feeble interaction strength. New theoretical ideas to address dark matter and other fundamental questions predict such feebly interacting particles (FIPs) at these scales, and indeed, existing data provide numerous hints for such possibility. A vibrant experimental program to discover such physics is under way, guided by a systematic theoretical approach firmly grounded on the underlying principles of the Standard Model. This document represents the report of the FIPs 2022 workshop, held at CERN between the 17 and 21 October 2022 and aims to give an overview of these efforts, their motivations, and the decadal goals that animate the community involved in the search for FIPs., Comment: 383 pp, 176 figures

We perform a complete study of the electroweak precision observables and electroweak gauge boson pair production in terms of the SMEFT up to ${\cal O}(1/\Lambda^4)$ under the assumption of universal, C and P conserving new physics. We show that the analysis of data from those two sectors allows us to obtain closed constraints in the relevant parameter space in this scenario. In particular we find that the Large Hadron Collider data can independently constrain the Wilson coefficients of the dimension-six and -eight operators directly contributing to the triple gauge boson vertices. Our results show that the impact of dimension-eight operators in the study of triple gauge couplings is small., Comment: 17 pages and 3 figures

The exchange of a pair of neutrinos with Standard Model weak interactions generates a long-range force between fermions. The associated potential is extremely feeble, $\propto G_F^2/r^5$ for massless neutrinos, whichrenders it far from observable even in the most sensitive experiments testing fifth forces. The presence of a neutrino background has been argued to induce a correction to the neutrino propagator that enhances the potential by orders of magnitude. In this brief note, we point out that such modified propagators are invalid if the background neutrino wavepackets have a finite width. By reevaluating the 2--$\nu$ exchange potential in the presence of a neutrino background including finite width effects, we find that the background-induced enhancement is reduced by several orders of magnitude. Unfortunately, this pushes the resulting 2--$\nu$ exchange potential away from present and near-future sensitivity of tests of new long-range forces., Comment: 11 pages, 3 figures. Results unchanged. Added Note. v3: Matches version published in JHEP. v4: Typo corrected

We analyze the impact of the recently released CDF-II measurement of $W$ mass on the SMEFT analyses of the electroweak precision data as well as Higgs and electroweak diboson productions. We work in the Hagiwara, Ishihara, Szalapski, and Zeppenfeld basis in which eight generation-independent operators enter in the electroweak precision data at tree level and, unlike in the Warsaw basis, the analysis of that set of data constrains all the eight Wilson coefficients, without the need of combination with Higgs or electroweak diboson data results. We show that in the global analysis the determination of the coefficients of all operators which do not enter the electroweak precision data are barely affected by the new $M_W$ determination., Comment: 6 pages, 3 figures

We present a detailed analysis of the spectral data of Borexino Phase II, with the aim of exploiting its full potential to constrain scenarios beyond the Standard Model. In particular, we quantify the constraints imposed on neutrino magnetic moments, neutrino non-standard interactions, and several simplified models with light scalar, pseudoscalar or vector mediators. Our analysis shows perfect agreement with those performed by the collaboration on neutrino magnetic moments and neutrino non-standard interactions in the same restricted cases and expands beyond those, stressing the interplay between flavour oscillations and flavour non-diagonal interaction effects for the correct evaluation of the event rates. For simplified models with light mediators we show the power of the spectral data to obtain robust limits beyond those previously estimated in the literature., Comment: 35 pages, 9 figures, 4 tables. Corrected a factor of two in the bound derived for GEMMA. Conclusions unchanged

Coherent elastic neutrino-nucleus scattering was first experimentally established five years ago by the COHERENT experiment using neutrinos from the spallation neutron source at Oak Ridge National Laboratory. The first evidence of observation of coherent elastic neutrino-nucleus scattering with reactor antineutrinos has now been reported by the Dresden-II reactor experiment, using a germanium detector. In this paper, we present constraints on a variety of beyond the Standard Model scenarios using the new Dresden-II data. In particular, we explore the constraints imposed on neutrino non-standard interactions, neutrino magnetic moments, and several models with light scalar or light vector mediators. We also quantify the impact of their combination with COHERENT (CsI and Ar) data. In doing so, we highlight the synergies between spallation neutron source and nuclear reactor experiments regarding beyond the Standard Model searches, as well as the advantages of combining data obtained with different nuclear targets. We also study the possible signal from beyond the Standard Model scenarios due to elastic scattering off electrons (which would pass selection cuts of the COHERENT CsI and the Dresden-II experiments) and find more stringent constraints in certain parts of the parameter space than those obtained considering coherent elastic neutrino-nucleus scattering., Comment: 33 pages, 6 figures. Matches published version, but further updates some references and corrects a plotting bug in fig.1

We analyze the electroweak interactions in the framework of the Higgs effective field theory using the available Higgs and electroweak diboson production results from LHC run 2 as well as the electroweak precision data. Assuming universality of the weak current, our study considers 25 possible anomalous couplings. To unveil the nature of the Higgs boson, i.e. isosinglet versus part of SU(2)L doublet, we explore the correlation effects between observables that are predicted to exist in the linear realization of the electroweak gauge symmetry but not in its non-linear counterpart. This improves previous studies aimed at investigating the Higgs nature and the origin of the electroweak symmetry breaking., Comment: 19 pages, 7 figures

In this contribution, we summarise the determination of neutrino masses and mixing arising from global analysis of data from atmospheric, solar, reactor, and accelerator neutrino experiments performed in the framework of three-neutrino mixing and obtained in the context of the NuFIT collaboration. Apart from presenting the latest status as of autumn 2021, we discuss the evolution of global-fit results over the last 10 years, and mention various pending issues (and their resolution) that occurred during that period in the global analyses., Comment: Matches published version. Invited review prepared for the Special Issue of Universe on "Studying the Universe from Spain"

We present a comprehensive study of the electroweak interactions using the available Higgs and electroweak diboson production results from LHC Runs 1 and 2 as well as the electroweak precision data, in terms of the dimension-six operators. Under the assumption that no new tree level sources of flavor violation nor violation of universality of the weak current is introduced, the analysis involves 21 operators. We assess the impact of the data on kinematic distributions for the Higgs production at the LHC by comparing the results obtained including the simplified template cross section data with those in which only total Higgs signal strengths are considered. We also compare the results obtained when including the dimension-six anomalous contributions to order $1/\Lambda^2$ and to order $1/\Lambda^4$. As an illustration of the LHC potential to indirectly learn about specific forms of new physics, we adapt the analysis to constrain the parameter space for a few simple extensions of the standard model which generate a subset of the dimension-six operators at tree level., Comment: version to appear in PRD with updates and corrections

We derive partial-wave unitarity constraints on gauge-invariant interactions of an Axion-Like Particle (ALP) up to dimension-6 from all allowed $2\to2$ scattering processes in the limit of large center-of-mass energy. We find that the strongest bounds stem from scattering amplitudes with one external ALP and only apply to the coupling to a pair of $SU(2)_L$ gauge bosons. Couplings to $U(1)_Y$ and $SU(3)_C$ gauge bosons and to fermions are more loosely constrained., Comment: 11 pages, 1 figure, 5 tables. Version published in PRD

We quantify the effect of gauge bosons from a weakly coupled lepton flavor dependent $U(1)'$ interaction on the matter background in the evolution of solar, atmospheric, reactor and long-baseline accelerator neutrinos in the global analysis of oscillation data. The analysis is performed for interaction lengths ranging from the Sun-Earth distance to effective contact neutrino interactions. We survey $\sim 10000$ set of models characterized by the six relevant fermion $U(1)'$ charges and find that in all cases, constraints on the coupling and mass of the $Z'$ can be derived. We also find that about 5% of the $U(1)'$ model charges lead to a viable LMA-D solution but this is only possible in the contact interaction limit. We explicitly quantify the constraints for a variety of models including $U(1)_{B-3L_e}$, $U(1)_{B-3L_\mu}$, $U(1)_{B-3L_\tau}$, $U(1)_{B-\frac{3}{2}(L_\mu+L_\tau)}$, $U(1)_{L_e-L_\mu}$, $U(1)_{L_e-L_\tau}$, $U(1)_{L_e-\frac{1}{2}(L_\mu+L_\tau)}$. We compare the constraints imposed by our oscillation analysis with the strongest bounds from fifth force searches, violation of equivalence principle as well as bounds from scattering experiments and white dwarf cooling. Our results show that generically, the oscillation analysis improves over the existing bounds from gravity tests for $Z'$ lighter than $\sim 10^{-11}$ eV. In the contact interaction limit, we find that for most models listed above there are values of $g'$ and $M_{Z'}$ for which the oscillation analysis provides constraints beyond those imposed by laboratory experiments. Finally we illustrate the range of $Z'$ and couplings leading to a viable LMA-D solution for two sets of models., Comment: 31 pages, 4 figures, 3 tables. Corrected the VEP bounds for some models in Fig.2 and Fig.4. Conclusions unchanged

The off-shell Higgs production in pp -> ZZ at LHC provides at present the most direct measurement of the Higgs width in the absence of beyond the standard model contributions. Here, we analyze the impact of anomalous Z couplings to fermions on the Higgs width determination. We show that, despite these couplings being strongly constrained by the available electroweak precision data, they can substantially affect the Higgs width determination at the LHC Runs 2 and 3. Conversely, in larger integrated luminosities runs, such as those foreseen at the high luminosity LHC and high energy LHC setups, the effect of such anomalous interactions in the Higgs width measurement is minimal., Comment: 10 pages, 4 figures, 1 table

Our herein described combined analysis of the latest neutrino oscillation data presented at the Neutrino2020 conference shows that previous hints for the neutrino mass ordering have significantly decreased, and normal ordering (NO) is favored only at the $1.6\sigma$ level. Combined with the $\chi^2$ map provided by Super-Kamiokande for their atmospheric neutrino data analysis the hint for NO is at $2.7\sigma$. The CP conserving value $\delta_\text{CP} = 180^\circ$ is within $0.6\sigma$ of the global best fit point. Only if we restrict to inverted mass ordering, CP violation is favored at the $\sim 3\sigma$ level. We discuss the origin of these results - which are driven by the new data from the T2K and NOvA long-baseline experiments -, and the relevance of the LBL-reactor oscillation frequency complementarity. The previous $2.2\sigma$ tension in $\Delta m^2_{21}$ preferred by KamLAND and solar experiments is also reduced to the $1.1\sigma$ level after the inclusion of the latest Super-Kamiokande solar neutrino results. Finally we present updated allowed ranges for the oscillation parameters and for the leptonic Jarlskog determinant from the global analysis., Comment: 16 pages, 8 figures. arXiv admin note: text overlap with arXiv:1811.05487

Coherent elastic neutrino-nucleus scattering (CE$\nu$NS), a process recently measured for the first time at ORNL's Spallation Neutron Source, is directly sensitive to the weak form factor of the nucleus. The European Spallation Source (ESS), presently under construction, will generate the most intense pulsed neutrino flux suitable for the detection of CE$\nu$NS. In this paper we quantify its potential to determine the root mean square radius of the point-neutron distribution, for a variety of target nuclei and a suite of detectors. To put our results in context we also derive, for the first time, a constraint on this parameter from the analysis of the energy and timing data of the CsI detector at the COHERENT experiment., Comment: 16 pages, 4 figures. Minor text changes and references added. Matches version accepted by JHEP

We obtain the partial-wave unitarity constraints on the lowest-dimension effective operators which generate anomalous quartic gauge couplings but leave the triple gauge couplings unaffected. We consider operator expansions with linear and nonlinear realizations of the electroweak symmetry and explore the multidimensional parameter space of the coefficients of the relevant operators: 20 dimension-eight operators in the linear expansion and 5 ${\cal O}(p^4)$ operators in the derivative expansion. We study two-to-two scattering of electroweak gauge bosons and Higgs bosons taking into account all coupled channels and all possible helicity amplitudes for the $J=0,1$ partial waves. In general, the bounds degrade by factors of a few when several operator coefficients are considered non-vanishing simultaneously. However, this requires to consider constraints from both $J=0$ and $J=1$ partial waves for some sets of operators., Comment: typos corrected and two additional operators included in the analyses

In a recent work by Capozzi et al (arXiv:1908.06992), it is observed that the introduction of non-standard neutrino-matter interactions considerably relaxes the preference of T2K and NO$\nu$A for normal over inverted mass ordering observed in the standard three-neutrino scenario. Motivated by this, in this note we update our previous global fit to investigate whether such result still holds once the information of solar, atmospheric and reactor experiments is taken into account. We find that the non-standard parameters responsible for the improvement of the inverted ordering fit to T2K and NO$\nu$A data are not compatible with the other oscillation experiments, and that the preference for NO is restored., Comment: 5 pages, 2 figures

We perform a global fit to neutrino oscillation and coherent neutrino-nucleus scattering data, using both timing and energy information from the COHERENT experiment. The results are used to set model-independent bounds on four-fermion effective operators inducing non-standard neutral-current neutrino interactions. We quantify the allowed ranges for their Wilson coefficients, as well as the status of the LMA-D solution, for a wide class of new physics models with arbitrary ratios between the strength of the operators involving up and down quarks. Our results are presented for the COHERENT experiment alone, as well as in combination with the global data from oscillation experiments. We also quantify the dependence of our results for COHERENT with respect to the choice of quenching factor, nuclear form factor, and the treatment of the backgrounds., Comment: 25 pages, 9 figures, 2 tables. Added an appendix with updated results accounting for the data available in July 2020

The European Spallation Source (ESS), presently well on its way to completion, will soon provide the most intense neutron beams for multi-disciplinary science. Fortuitously, it will also generate the largest pulsed neutrino flux suitable for the detection of Coherent Elastic Neutrino-Nucleus Scattering (CE$\nu$NS), a process recently measured for the first time at ORNL's Spallation Neutron Source. We describe innovative detector technologies maximally able to profit from the order-of-magnitude increase in neutrino flux provided by the ESS, along with their sensitivity to a rich particle physics phenomenology accessible through high-statistics, precision CE$\nu$NS measurements., Comment: 21 pages, 15 figures. v2: Minor changes, typo corrected in Fig 6. Version accepted for publication in JHEP

We perform a global analysis of neutrino data in the framework of three massive neutrinos with non-standard neutrino interactions which affect their evolution in the matter background. We focus on the effect of NSI in the present observables sensitive to leptonic CP violation and to the mass ordering. We consider complex neutral current neutrino interactions with quarks whose lepton-flavor structure is independent of the quark type. We quantify the status of the "hints" for CP violation, the mass-ordering and non-maximality of $\theta_{23}$ in these scenarios. We also present a parametrization-invariant formalism for leptonic CP violation in presence of a generalized matter potential induced by NSI., Comment: 24 pages, 4 figures

We study the effect of operators generating dipole couplings of the light quarks to electroweak gauge bosons on several observables at LHC. We start by demonstrating that the determination of the gauge boson self-couplings from electroweak diboson production at LHC is robust under the inclusion of those quark dipole operators even when let them totally unconstrained in the analysis. Conversely, we determine the bounds that the diboson data imposes on the light-quark dipole couplings and show that they represent a significant improvement over the limits arising from Z and W electroweak precision measurements. We also explore the sensitivity of the Drell-Yan cross section determination at LHC Run 1, and the results on resonance searches in high invariant-mass lepton pair production at Run 2 to further constrain the electroweak dipole couplings of the light quarks., Comment: 13 pages, 5 figures

In this talk I present my personal summary of the progress on the determination of the masses of the neutrinos and of the leptonic flavour mixing from the combined analysis of the experimental results., Comment: Invited Talk at the "History of Neutrino" Conference, September 2018, Paris

We perform a comprehensive study of the Higgs couplings, gauge-boson couplings to fermions and triple gauge boson vertices. We work in the framework of effective theories including the effects of the dimension-six operators contributing to these observables. We determine the presently allowed range for the coefficients of these operators via a 20 parameter global fit to the electroweak precision data, as well as electroweak diboson and Higgs production data from LHC Run 1 and 2. We quantify the improvement on the determination of the 20 Wilson coefficients by the inclusion of the Run 2 results. In particular we present a novel analysis of the ATLAS Run 2 36.1 $\rm fb^{-1}$ data on the transverse mass distribution of $W^+W^-$ and $W^\pm Z$ in the leptonic channel which allow for stronger tests of the triple gauge boson vertices. We discuss the discrete (quasi)-degeneracies existing in the parameter space of operator coefficients relevant for the Higgs couplings to fermions and gauge bosons. In particular we show how the inclusion of the incipient $tH$ data can break those degeneracies in the determination of the top-Higgs coupling. We also discuss and quantify the effect of keeping the terms quadratic in the Wilson coefficients in the analysis and we show the importance of the Higgs data to constrain some of the operators that modify the triple gauge boson couplings in the linear regime., Comment: 19 pages, 7 figures, 3 tables

We present the results of a global analysis of the neutrino oscillation data available as of fall 2018 in the framework of three massive mixed neutrinos with the goal at determining the ranges of allowed values for the six relevant parameters. We describe the complementarity and quantify the tensions among the results of the different data samples contributing to the determination of each parameter. We also show how those vary when combining our global likelihood with the chi^2 map provided by Super-Kamiokande for their atmospheric neutrino data analysis in the same framework. The best fit of the analysis is for the normal mass ordering with inverted ordering being disfavoured with a Delta_chi^2 = 4.7 (9.3) without (with) SK-atm. We find a preference for the second octant of theta_23, disfavouring the first octant with Delta_chi^2 = 4.4 (6.0) without (with) SK-atm. The best fit for the complex phase is Delta_CP = 215_deg with CP conservation being allowed at Delta_chi^2 = 1.5 (1.8). As a byproduct we quantify the correlated ranges for the laboratory observables sensitive to the absolute neutrino mass scale in beta decay, m_nu_e, and neutrino-less double beta decay, m_ee, and the total mass of the neutrinos, Sigma, which is most relevant in Cosmology., Comment: 35 pages, 14 figures, 2 tables. Updated results of the global fit will be available at http://www.nu-fit.org

We revisit the extraction of the triple electroweak gauge boson couplings from the Large Hadron Collider Run I data on the $W^+W^-$ and $W^\pm Z$ productions when the analysis also contains additional operators that modify the couplings of the gauge bosons to light quarks and the gauge boson self-energies. We work in the framework of effective Lagrangians where we consider dimension-six operators and perform a global fit to consistently take into account the bounds on these additional operators originating from the electroweak precision data. We show that the constraints on the Wilson coefficients $f_B/\Lambda^2$ and $f_W/\Lambda^2$ are modified when we include the additional operators while the limits on $f_{WWW}/\Lambda^2$ remain unchanged., Comment: 14 pages, 7 figures, 2 tables. Figures updated, acknowledgments included

In this work we revisit the question of whether Cosmology can be made compatible with scenarios with light sterile neutrinos, as invoked to explain the SBL anomalies, in the presence of self-interaction among sterile neutrinos mediated by massive gauge bosons. We examine this proposal by deriving the cosmological predictions of the model in a wide range of the model parameters including the effective interaction strength $G_X$, sterile neutrino mass $m_{\rm st}$ and active-sterile mixings. With those we perform a statistical analysis of the cosmological data from BBN, CMB, and BAO data to infer the posterior probabilities of the sterile self-interaction model parameters. BBN mostly provides information about the effective interaction strength and we find that $\log_{10}(G_X/G_F)\geq 3.6$ can describe the primordial abundances at 95% CL. Our analysis of CMB and BAO data show that when allowing a wide prior for the sterile neutrino mass its posterior is bounded to $m_{\rm st}\leq 0.91~{\rm eV}$ (95% CL) considering CMB data only and $m_{\rm st}\leq 0.37~{\rm eV}$ (95% CL) when adding the BAO information. So the mass bounds are slighly relaxed compared with that of a non-interacting sterile neutrino model but a sterile neutrino mass of 1 eV is still excluded at more than $2\sigma$ CL. Conversely if fixing the sterile neutrino mass and mixing to the values prefered by short baseline data we find that while that CMB data alone favors the self-interacting scenario, including the BAO information severly degrades the agreement with the model. Altogether we conclude then that adding the self-interaction can alleviate the tension between eV sterile neutrinos and CMB data, but when including also the BAO results the self-interacting sterile neutrino model cannot lead to a satisfactory description of the data., Comment: 26 pages, 10 figures, 3 tables; Corrected assumption of entropy conservation. Added explicit comparison with previous results obtained with entropy conservation assumption. Qualitative results unchanged. Version accepted in JCAP

We quantify our present knowledge of the size and flavor structure of non-standard neutrino interactions which affect the matter background in the evolution of solar, atmospheric, reactor and long-baseline accelerator neutrinos as determined by a global analysis of oscillation data - both alone and in combination with the results on coherent neutrino-nucleus scattering from the COHERENT experiment. We consider general neutral current neutrino interactions with quarks whose lepton-flavor structure is independent of the quark type. We study the dependence of the allowed ranges of non-standard interaction coefficients, the status of the LMA-D solution, and the determination of the oscillation parameters on the relative strength of the non-standard couplings to up and down quarks. Generically we find that the conclusions are robust for a broad spectrum of up-to-down strengths, and we identify and quantify the exceptional cases related to couplings whose effect in neutrino propagation in the Earth or in the Sun is severely suppressed. As a result of the study we provide explicit constraints on the effective couplings which parametrize the non-standard Earth matter potential relevant for long-baseline experiments., Comment: 38 pages, 12 figures, 2 tables. Added an appendix with updated results accounting for the data available in July 2020

The detection of coherent neutrino-nucleus scattering by the COHERENT collaboration has set on quantitative grounds the existence of an irreducible neutrino background in direct detection searches of Weakly Interacting Massive Dark Matter candidates. This background leads to an ultimate discovery limit for these experiments: a minimum Dark Matter interaction cross section below which events produced by the coherent neutrino scattering will mimic the Dark Matter signal, the so-called \emph{neutrino floor}. In this work we study the modification of such neutrino floor induced by non-standard neutrino interactions within their presently allowed values by the global analysis of oscillation and COHERENT data. By using the full likelihood information of such global analysis we consistently account for the correlated effects of non-standard neutrino interactions both in the neutrino propagation in matter and in its interaction in the detector. We quantify their impact on the neutrino floor for five future experiments: DARWIN (Xe), ARGO (Ar), Super-CDMS HV (Ge and Si) and CRESST phase III (CaWO$_4$). Quantitatively, we find that non-standard neutrino interactions allowed at the $3\sigma$ level can result in an increase of the neutrino floor of up to a factor $\sim 5$ with respect to the Standard Model expectations and impact the expected sensitivities of the ARGO, CRESST phase III and DARWIN experiments., Comment: 21 pages, 4 figures. Matches version published in the JHEP. Corrected exposure and results for CRESST phase III

In this work we use Bayesian inference to quantitatively reconstruct the solar properties most relevant to the solar composition problem using as inputs the information provided by helioseismic and solar neutrino data. In particular, we use a Gaussian process to model the functional shape of the opacity uncertainty to gain flexibility and become as free as possible from prejudice in this regard. With these tools we first readdress the statistical significance of the solar composition problem. Furthermore, starting from a composition unbiased set of standard solar models we are able to statistically select those with solar chemical composition and other solar inputs which better describe the helioseismic and neutrino observations. In particular, we are able to reconstruct the solar opacity profile in a data driven fashion, independently of any reference opacity tables, obtaining a 4% uncertainty at the base of the convective envelope and 0.8% at the solar core. When systematic uncertainties are included, results are 7.5% and 2% respectively. In addition we find that the values of most of the other inputs of the standard solar models required to better describe the helioseismic and neutrino data are in good agreement with those adopted as the standard priors, with the exception of the astrophysical factor $S_{11}$ and the microscopic diffusion rates, for which data suggests a 1% and 30% reduction respectively. As an output of the study we derive the corresponding data driven predictions for the solar neutrino fluxes., Comment: 17 pages, 10 figures, 6 tables

We study the bounds on minimal lepton flavour violation in the context of Type-III see-saw imposed by LHC Run I search for events which contain two charged leptons (either electron or muons of equal or opposite sign), two jets from a hadronically decaying $W$ boson and large missing transverse momentum. In this scenario the flavour structure of the couplings of the triplet fermions to the Standard Model leptons can be reconstructed from the neutrino mass matrix and lepton number violation is very suppressed. We find that using the information on charge and flavour of the leptons in the above final state it is possible to unambiguously rule out this scenario with triplet masses lighter than 300 GeV at 95% CL. The same analysis allows to exclude triplet masses masses up to 480 GeV at 95% CL for normal ordering of neutrino masses and specific values of a Majorana CP phase currently undetermined by neutrino physics., Comment: 21 pages, 6 figures

In the presence of non-standard neutrino interactions (NSI), oscillation data are affected by a degeneracy which allows the solar mixing angle to be in the second octant (aka the dark side) and implies a sign flip of the atmospheric mass-squared difference. This leads to an ambiguity in the determination of the ordering of neutrino masses, one of the main goals of the current and future experimental neutrino program. We show that the recent observation of coherent neutrino--nucleus scattering by the COHERENT experiment, in combination with global oscillation data, excludes the NSI degeneracy at the $3.1\sigma$ ($3.6\sigma$) CL for NSI with up (down) quarks., Comment: 5 pages, 3 figures

We analyze the scattering of fermions, Higgs and electroweak gauge bosons in order to obtain the partial-wave unitarity bounds on dimension-six effective operators, including those involving fermions. We also quantify whether, at the LHC energies, the dimension-six operators lead to unitarity violation after taking into account the presently available constraints on their Wilson coefficients. Our results show that for most dimension-six operators relevant for the LHC physics there is no unitarity violation at the LHC energies, and consequently, there is no need for the introduction of form factors in the experimental and phenomenological analyses, making them model independent. We also identify two operators for which unitarity violation is still an issue at the LHC Run-II., Comment: 17 Pages, 8 Tables

In presence of non-standard neutrino interactions the neutrino flavor evolution equation is affected by a degeneracy which leads to the so-called LMA-Dark solution. It requires a solar mixing angle in the second octant and implies an ambiguity in the neutrino mass ordering. Non-oscillation experiments are required to break this degeneracy. We perform a combined analysis of data from oscillation experiments with the neutrino scattering experiments CHARM and NuTeV. We find that the degeneracy can be lifted if the non-standard neutrino interactions take place with down quarks, but it remains for up quarks. However, CHARM and NuTeV constraints apply only if the new interactions take place through mediators not much lighter than the electroweak scale. For light mediators we consider the possibility to resolve the degeneracy by using data from future coherent neutrino-nucleus scattering experiments. We find that, for an experiment using a stopped-pion neutrino source, the LMA-Dark degeneracy will either be resolved, or the presence of new interactions in the neutrino sector will be established with high significance., Comment: 33 pages, 9 figures. Minor modifications. Version accepted for publication in JHEP

We perform a combined fit to global neutrino oscillation data available as of fall 2016 in the scenario of three-neutrino oscillations and present updated allowed ranges of the six oscillation parameters. We discuss the differences arising between the consistent combination of the data samples from accelerator and reactor experiments compared to partial combinations. We quantify the confidence in the determination of the less precisely known parameters $\theta_{23}$, $\delta_\text{CP}$, and the neutrino mass ordering by performing a Monte Carlo study of the long baseline accelerator and reactor data. We find that the sensitivity to the mass ordering and the $\theta_{23}$ octant is below $1\sigma$. Maximal $\theta_{23}$ mixing is allowed at slightly more than 90% CL. The best fit for the CP violating phase is around $270^\circ$, CP conservation is allowed at slightly above $1\sigma$, and values of $\delta_\text{CP} \simeq 90^\circ$ are disfavored at around 99% CL for normal ordering and higher CL for inverted ordering., Comment: 31 pages, 13 figures, 5 tables. Matches journal version. Updated results of the global fit will be available at http://www.nu-fit.org/. arXiv admin note: text overlap with arXiv:1409.5439

We study the modification of the detected flavor content of ultra high-energy astrophysical neutrinos in the presence of non-standard interactions of neutrinos with the Earth matter. Unlike the case of new physics affecting the propagation from the source to the Earth, non-standard Earth matter effects induce a dependence of the flavor content on the arrival direction of the neutrino. We find that, within the current limits on non-standard neutrino interaction parameters, large deviations from the standard 3-nu oscillation predictions can be expected, in particular for fluxes dominated by one flavor at the source. Conversely they do not give sizable corrections to the expectation of equalized flavors in the Earth for sources dominated by production via pion-muon decay-chain., Comment: 12 pages, 6 figures

The complete effective chiral Lagrangian for a dynamical Higgs is presented and constrained by means of a global analysis including electroweak precision data together with Higgs and triple gauge boson coupling data from the LHC Run~I. The operators' basis up to next-to-leading order in the expansion consists of 148 (188 considering right-handed neutrinos) flavour universal terms and it is presented here making explicit the custodial nature of the operators. This effective Lagrangian provides the most general description of the physical Higgs couplings once the electroweak symmetry is assumed, and it allows for deviations from the $SU(2)_L$ doublet nature of the Standard Model Higgs. The comparison with the effective linear Lagrangian constructed with an exact $SU(2)_L$ doublet Higgs and considering operators with at most canonical dimension six is presented. A promising strategy to disentangle the two descriptions consists in analysing i) anomalous signals present only in the chiral Lagrangian and not expected in the linear one, that are potentially relevant for LHC searches, and ii) decorrelation effects between observables that are predicted to be correlated in the linear case and not in the chiral one. The global analysis presented here, that includes several kinematic distributions, is crucial for reducing the allowed parameter space and for controlling the correlations between parameters. This improves previous studies aimed at investigating the Higgs Nature and the origin of the electroweak symmetry breaking., Comment: Minor corrections to Feynman rules appendix and Eq. 2.21

The larger center-of-mass energy of the Large Hadron Collider Run 2 opens up the possibility of a more detailed study of the quartic vertices of the electroweak gauge bosons. Our goal in this work is to classify all operators possessing quartic interactions among the electroweak gauge bosons that do not exhibit triple gauge-boson vertices associated to them. We obtain all relevant operators in the non-linear and linear realizations of the $SU(2)_L \otimes U(1)_Y$ gauge symmetry., Comment: 17 pages

The effective Lagrangian expansion provides a framework to study effects of new physics at the electroweak scale. To make full use of LHC data in constraining higher-dimensional operators we need to include both the Higgs and the electroweak gauge sector in our study. We first present an analysis of the relevant di-boson production LHC results to update constraints on triple gauge boson couplings. Our bounds are several times stronger than those obtained from LEP data. Next, we show how in combination with Higgs measurements the triple gauge vertices lead to a significant improvement in the entire set of operators, including operators describing Higgs couplings., Comment: 14 pages, 6 figures; version to be submitted to the journal

We present a comprehensive review of keV-scale sterile neutrino Dark Matter, collecting views and insights from all disciplines involved - cosmology, astrophysics, nuclear, and particle physics - in each case viewed from both theoretical and experimental/observational perspectives. After reviewing the role of active neutrinos in particle physics, astrophysics, and cosmology, we focus on sterile neutrinos in the context of the Dark Matter puzzle. Here, we first review the physics motivation for sterile neutrino Dark Matter, based on challenges and tensions in purely cold Dark Matter scenarios. We then round out the discussion by critically summarizing all known constraints on sterile neutrino Dark Matter arising from astrophysical observations, laboratory experiments, and theoretical considerations. In this context, we provide a balanced discourse on the possibly positive signal from X-ray observations. Another focus of the paper concerns the construction of particle physics models, aiming to explain how sterile neutrinos of keV-scale masses could arise in concrete settings beyond the Standard Model of elementary particle physics. The paper ends with an extensive review of current and future astrophysical and laboratory searches, highlighting new ideas and their experimental challenges, as well as future perspectives for the discovery of sterile neutrinos., Comment: v2: 257 pages, 57 figures, content matches published version [JCAP01(2017)025]; over 100 authors from several different communities

We present an update of the determination of the solar neutrino fluxes from a global analysis of the solar and terrestrial neutrino data in the framework of three-neutrino mixing. Using a Bayesian analysis we reconstruct the posterior probability distribution function for the eight normalization parameters of the solar neutrino fluxes plus the relevant masses and mixing, with and without imposing the luminosity constraint. We then use these results to compare the description provided by different Standard Solar Models. Our results show that, at present, both models with low and high metallicity can describe the data with equivalent statistical agreement. We also argue that even with the present experimental precision the solar neutrino data have the potential to improve the accuracy of the solar model predictions., Comment: 20 pages, 2 tables, 5 figures. arXiv admin note: substantial text overlap with arXiv:0910.4584

We summarize the determination of some neutrino properties from the global analysis of solar, atmospheric, reactor, and accelerator neutrino data in the framework of three-neutrino mixing as well as in some extended scenarios such as the mixing with eV-scale sterile neutrinos invoked for the interpretation of the short baseline anomalies, and the presence of non-standard neutrino interactions., Comment: 16 pages, 7 figures, 2 tables. Review prepared for the Nuclear Physics B Special Issue on "Neutrino Oscillations" celebrating the Nobel Prize in Physics 2015

The photon spectrum in macrocoherent atomic de-excitation via radiative emission of neutrino pairs (RENP) has been proposed as a sensitive probe of the neutrino mass spectrum, capable of competing with conventional neutrino experiments. In this paper we revisit this intriguing technique in order to quantify the requirements for statistical determination of some of the properties of the neutrino spectrum, in particular the neutrino mass scale and the mass ordering. Our results are sobering. We find that, even under ideal conditions, the determination of neutrino parameters needs experimental live times of the order of days to years for several laser frequencies, assuming a target of volume of order 100 cm3 containing about 10^21 atoms per cubic centimeter in a totally coherent state with maximum value of the electric field in the target. Such conditions seem to be, as of today, way beyond the reach of our current technology., Comment: 11 pages, 5 figures

We explore the use of the Inverse Amplitude Method for unitarization of scattering amplitudes to derive the existence and properties of possible new heavy states associated with perturbative extensions of the electroweak breaking sector of the Standard Model starting from the low energy effective theory. We use a toy effective theory generated by integrating out a heavy singlet scalar and compare the pole mass and width of the unitarized amplitudes with those of the original model. Our results show that the Inverse Amplitude Method reproduces correctly the singlet mass up to factors of O(1-3), but its width is overestimated., Comment: 11 pages with 2 figures