Over the past few decades, data from leading neutrino experiments have firmly established neutrino oscillation, implying non-zero neutrino masses and leptonic mixing and thereby providing confirmed evidence of physics beyond the Standard Model. On the backdrop of the precision era of neutrino oscillation, this thesis underscores its relevance by demonstrating the physics reach of the forthcoming long-baseline experiments -- Deep Underground Neutrino Experiment (DUNE) and Hyper-Kamiokande (Hyper-K) -- to establish non-maximal $θ_{23}$, resolve the correct $θ_{23}$ octant, and improve the precision on $θ_{23}$ and $Δm^2_{31}$ by efficiently breaking parameter degeneracies. This is enabled by DUNE's high-resolution LArTPC detector and its wide-band beam, achieving sensitivity at a high confidence level compared to the global fits of world neutrino data. The combined analysis of DUNE and Hyper-K not only significantly enhances sensitivity to these phenomenological studies but also demonstrates their capabilities at lower exposures when operated together, relative to their nominal individual exposures. In addition, we investigate the impact of flavor-dependent long-range interactions arising from anomaly-free U(1)' extensions of the Standard Model, showing that although subdominant long-range interactions can substantially influence the sensitivity and precision of oscillation parameter measurements, the complementary strengths of DUNE and Hyper-K mitigate these challenges to a large extent.
The first phase of the long-baseline neutrino experiment, LBNE10, will use a broadband, high-energy neutrino beam with a 10-kt liquid argon TPC at 1300 km to study neutrino oscillation. In this paper, we describe potential upgrades to LBNE10 that use Project X to produce high-intensity, low-energy neutrino beams. Simultaneous, high-power operation of 8- and 60-GeV beams with a 200-kt water Cerenkov detector would provide sensitivity to nu_mu to nu_e oscillations at the second oscillation maximum. We find that with ten years of data, it would be possible to measure sin2(2theta_13) with precisio…
I discuss some problems connected with the high precision study of neutrino oscillations. In the general case of $n$-neutrino mixing I derive a convenient expression for transition probability in which only independent terms (and mass-squared differences) enter. For three-neutrino mixing I discuss a problem of a definition of a large (atmospheric) neutrino mass-squared difference. I comment also possibilities to reveal the character of neutrino mass spectrum in future reactor neutrino experiments.
We discuss two theoretical motivations of precision measurements of oscillation parameters. One is the guidance for flavour model building with flavour symmetries, and the other is the connection with the origin of matter-antimatter asymmetry. We also present our recent progress in these aspects, a new approach of flavour model building based on cross coupling in the flavon potential and a novel mechanism of leptogenesis via phase transition.
Future neutrino oscillation experiments will lead to precision measurements of neutrino mass splittings and mixings. The flavour structure of the lepton sector will therefore at some point become better known than that of the quark sector. This article discusses the potential of future oscillation experiments on the basis of detailed simulations with an emphasis on experiments which can be done in about ten years. In addition, some theoretical implications for neutrino mass models will be briefly discussed.
Improved precision on 2-3 oscillation parameters using the synergy between DUNE and T2HK
Institute of Physics（印度物理研究所）；Homi Bhabha National Institute（霍米·巴巴国立学院）；Department of Physics & Wisconsin IceCube Particle Astrophysics Center, University of Wisconsin, Madison（威斯康星大学麦迪逊分校物理系与威斯康星冰立方粒子天体物理中心）；Department of Physics, Utkal University（乌塔卡尔大学物理系）
We present predictions of the distribution of groomed heavy jet mass in electron-positron collisions at the next-to-next-to-leading order accuracy matched with the resummation of large logarithms to next-to-next-to-next-to-leading logarithmic accuracy. Resummation at this accuracy is possible through extraction of necessary two-loop constants and three-loop anomalous dimensions from fixed-order codes.
With the discovery of a modest size for the mixing angle $θ_{13} \sim 9^\circ$ by the Daya Bay collaboration at $>$5 sigma (\cite{dayabay}) the science of neutrino oscillations has shifted to explicit demonstration of CP violation and precision determination of the CP phase in the 3-flavor framework. Any additional contributions from new physics to the oscillation channel $ν_μ\to ν_e$ could be uncovered by multiple constraints in the ($θ_{13}, δ_{CP}$) parameter space. In long-baseline experiments such constraints will require examination of the oscillation strength at higher $L/E$ where the e…
We review the current status of the neutrino mass and mixing parameters needed to reconstruct the neutrino mass matrix. A comparative study of the precision in the measurement of oscillation parameters expected from the next generation solar, atmospheric, reactor and accelerator based experiments is presented. We discuss the potential of $0νββ$ experiments in determining the neutrino mass hierarchy and the importance of a better $θ_{12}$ measurement for it.
Neutrino physics is now poised to move into the precision regime. Active attempts are under way to commence the era of precision neutrino measurement science which will surely widen the horizon of our knowledge about neutrinos. A number of high-precision neutrino oscillation experiments have been contrived to sharpen our understanding about these tiny particles. This is the right time to ask how different planned/proposed next generation experiments in the coming decades would perform to explicate the nature of neutrinos and our thrust for new physics. This thesis is an effort to have a look o…
Revealing precision bounds on neutrino oscillation parameters with quantum estimation theory
Institute of High Energy Physics, Chinese Academy of Sciences（中国科学院高能物理研究所）；School of Physical Sciences, University of Chinese Academy of Sciences（中国科学院大学物理科学学院）；KTH Royal Institute of Technology（皇家理工学院）
We consider the determination of the solar neutrino oscillation parameters $Δm^2_{21}$ and $θ_{12}$ by studying oscillations of reactor anti-neutrinos emitted by nuclear power plants (located mainly in France) with a detector installed in the Frejus underground laboratory. The performances of a water Cerenkov detector of 147 kt fiducial mass doped with 0.1% of Gadolinium (MEMPHYS-Gd) and of a 50 kt scale liquid scintillator detector (LENA) are compared. In both cases 3$σ$ uncertainties below 3% on $Δm^2_{21}$ and of about 20% on $\sin^2θ_{12}$ can be obtained after one year of data taking. The…
According to different effects on neutrino oscillations, the unitarity violation in the MNSP matrix can be classified into the direct unitarity violation and the indirect unitarity violation which are induced by the existence of the light and the heavy sterile neutrinos respectively. Of which sub-eV sterile neutrinos are of most interesting. We study in this paper the possibility of searching for sub-eV sterile neutrinos in the precision reactor antineutrino oscillation experiments with three different baselines at around 500 m, 2 km and 60 km. We find that the antineutrino survival probabilit…
I shortly review time period of twelve years, 1989-2000, which was devoted to a theoretical support of experiments at LEP and SLC at Z resonance and discuss several directions of possible future work in the field of precision theoretical calculations for experiments at future colliders.
We discuss to what extent future precision measurements of neutrino mixing observables will influence the information we can draw from a measurement of (or an improved limit on) neutrinoless double beta decay. Whereas the Delta m^2 corresponding to solar and atmospheric neutrino oscillations are expected to be known with good precision, the parameter theta_{12} will govern large part of the uncertainty. We focus in particular on the possibility of distinguishing the neutrino mass hierarchies and on setting a limit on the neutrino mass. We give the largest allowed values of the neutrino masses …
The 3X3 Maki-Nakagawa-Sakata-Pontecorvo (MNSP) lepton flavor mixing matrix may be slightly non-unitary if the three active neutrinos are coupled with sterile neutrinos. We show that it is in principle possible to test whether the relation |V_{e1}|^2 + |V_{e2}|^2 + |V_{e3}|^2 = 1 holds or not in a precision reactor antineutrino oscillation experiment, such as the recently proposed Daya Bay II experiment. We explore three categories of non-unitary effects on the 3X3 MNSP matrix: 1) the indirect effect in the (3+ 3) flavor mixing scenario where the three heavy sterile neutrinos do not take part i…
We present a calculation of slepton pair production at the LHC at next-to-next-to-leading logarithmic (NNLL) accuracy, matched to approximate next-to-next-to-leading order (aNNLO) QCD corrections. We collect the relevant analytical formulae, discuss the matching of logarithmically enhanced and fixed-order results and describe the transformation of parton densities and hadronic cross sections to and from Mellin space. Numerically, we find a moderate increase of invariant-mass distributions and total cross sections with respect to our previous results at next-to-leading logarithmic (NLL) accurac…
Starting with next-generation experiments, flavor physics fully enters the era of precision measurements. The focus shifts from testing the Standard Model to finding and characterizing new physics contributions. We review the opportunities offered by future flavor experiments, discussing the expected sensitivities of the most important measurements. We also present some examples of measurable deviations from the Standard Model in the flavor sector generated in a selection of new physics models, demonstrating the major contribution that precision flavor physics could give to the effort of going…
We discuss the physics potential of intermediate $L \sim 20 ÷30$ km baseline experiments at reactor facilities, assuming that the solar neutrino oscillation parameters $Δm^2_{\odot}$ and $θ_{\odot}$ lie in the high-LMA solution region. We show that such an intermediate baseline reactor experiment can determine both $Δm^2_{\odot}$ and $θ_{\odot}$ with a remarkably high precision. We perform also a detailed study of the sensitivity of the indicated experiment to $Δm^2_{\rm atm}$, which drives the dominant atmospheric $ν_μ$ ($\barν_μ$) oscillations, and to $θ$ - the neutrino mixing angle limited …
Impact of errors in the magnetic field measurement on the precision determination of neutrino oscillation parameters at the proposed ICAL detector at INO
We perform a comparison of the different future neutrino oscillation experiments based on the achievable precision in the determination of the fundamental parameters theta_{13} and the CP phase, delta, assuming that theta_{13} is in the range indicated by the recent Daya Bay measurement. We study the non-trivial dependence of the error on delta on its true value. When matter effects are small, the largest error is found at the points where CP violation is maximal, and the smallest at the CP conserving points. The situation is different when matter effects are sizable. As a result of this effec…
We review the potential of long and intermediate baseline reactor neutrino experiments in measuring the mass and mixing parameters. The KamLAND experiment can measure the solar mass squared difference very precisely. However it is not at the ideal baseline for measuring the solar neutrino mixing angle. If low-LMA is confirmed by the next results from KamLAND, a reactor experiment with a baseline of 70 km should be ideal to measure precisely the solar neutrino mixing angle. If on the contrary KamLAND re-establishes high-LMA as a viable solution, then a 20--30 km intermediate baseline reactor ex…
We revisit scalar leptoquark pair-production at hadron colliders and significantly improve the level of precision of the cross section calculations. Apart from QCD contributions, we include lepton t-channel exchange diagrams that turn out to be relevant in the light of the recent B-anomalies. We evaluate all contributions at next-to-leading-order accuracy in QCD and resum, in the threshold regime, soft-gluon radiation at next-to-next-to-leading logarithmic accuracy. Our predictions consist hence in the most precise leptoquark cross section calculations available to date, and are necessary for …
We compute the Next-to-Next-to-Leading Order (NNLO) QCD corrections to the partonic reaction that dominates top-pair production at the Tevatron. This is the first ever NNLO calculation of an observable with more than two colored partons, and/or massive fermions, at hadron colliders. Augmenting our fixed order calculation with soft-gluon resummation through Next-to-Next-to-Leading Logarithmic (NNLL) accuracy, we observe that the predicted total inclusive cross-section exhibits a very small perturbative uncertainty, estimated at +-2.7%. We expect that once all sub-dominant partonic reactions are…
The long baseline (LBL) neutrino experiments use heavy nuclear targets for neutrino scattering in which nuclear effects give rise to complications in measuring the neutrino oscillation parameters up to high precision. These nuclear effects are not yet fully understood and therefore need to be quantified as they contribute to the systematic uncertainties. Precision reconstruction of neutrino energy is one of the main components in measuring the oscillation parameters, and it is required that the neutrino energy is reconstructed with very high precision. In this work, we investigate the effects …
We present a resummation-improved prediction for $VH$ + 0 jets production at the Large Hadron Collider. We focus on highly-boosted final states in the presence of jet veto to suppress the $t{\bar t}$ background. In this case, conventional fixed-order calculations are plagued by the existence of large Sudakov logarithms $α_s^n \log^m (p_T^{veto}/Q)$ for $Q\sim m_V + m_H$ which lead to unreliable predictions as well as large theoretical uncertainties, and thus limit the accuracy when comparing experimental measurements to the Standard Model. In this work, we show that the resummation of Sudakov …
To deepen the search for beyond the Standard Model physics, the Large Hadron Collider is pushing to higher and higher luminosity. At high luminosity, precision physics becomes increasingly difficult due to contamination from additional proton collisions per bunch crossing called pile-up. In recent years, many methods have been developed to cull this excess mostly low-energy radiation away from important signal regions, but it has been unclear if these methods were amenable to systematically-improvable theoretical understanding. In this paper, it is shown that one such method, soft drop jet gro…
We present precise predictions for the Higgs boson rapidity distribution at the LHC in the gluon fusion production mode. Our approach relies on the fully analytic computation of six terms in a systematic expansion of the partonic differential cross section around the production threshold of the Higgs boson at next-to-next-to-next-to leading order (N$^3$LO) in QCD perturbation theory. We observe a mild correction compared to the previous perturbative order and a significant reduction of the dependence of the cross section on the perturbative scale throughout the entire rapidity range.
Modern proposed atmospheric neutrino oscillation experiments, such as PINGU in the Antarctic ice or ORCA in Mediterranean sea water, aim for precision measurements of the oscillation parameters including the ordering of the neutrino masses. They can, however, go far beyond that: Since neutrino oscillations are affected by the coherent forward scattering with matter, neutrinos can provide a new view on the interior of the earth. We show that the proposed atmospheric oscillation experiments can measure the lower mantle density of the earth with a precision at the level of a few percent, includin…
Future neutrino oscillation measurement focus, at first priority, on the discovery of sin^2(2 theta_13) describing the coupling between solar and atmospheric oscillations. In this talk, we briefly discuss the prospects to measure sin^2(2 theta_13) by future reactor and beam experiments, and we illustrate the usefulness of these measurements (and their precision) from the theoretical point of view with an example.
We explore the impact of the data from the KamLAND experiment in constraining neutrino mass and mixing angles involved in solar neutrino oscillations. In particular we discuss the precision with which we can determine the the mass squared difference $Δm^2_{solar}$ and the mixing angle $θ_{solar}$ from combined solar and KamLAND data. We show that the precision with which $Δm^_{solar}$ can be determined improves drastically with the KamLAND data but the sensitivity of KamLAND to the mixing angle is not as good. We study the effect of enhanced statistics in KamLAND as well as reduced systematics…
The direct photon spectrum is computed to the highest currently available precision and compared to ATLAS data from 8 TeV collisions at the LHC. The prediction includes threshold resummation at next-to-next-to-next-to-leading logarithmic order through the program PeTeR, matched to next-to-leading fixed order with fragmentation effects using JetPhox and includes the resummation of leading-logarithmic electroweak Sudakov effects. Remarkably, improved agreement with data can be seen when each component of the calculation is added successively. This comparison demonstrates the importance of both t…
The ``baseline setup'' for a possible, beyond T2K, next generation long baseline experiment along the J-PARC neutrino beam produced at Tokai, assumes two very large deep-underground Water Cerenkov imaging detectors of about 300 kton fiducial each, located one in Korea and the other in Kamioka but at the same off-axis angle. In this paper, we consider the physics performance of a similar setup but with a single and smaller, far detector, possibly at shallow depth, composed of a 100 kton next generation liquid Argon Time Projection Chamber. The potential location of the detector could be in the …
The O(alpha_s^2) contribution to the Energy-Energy Correlation function (EEC) of e+e- -> hadrons is calculated to high precision and the results are shown to be larger than previously reported. The consistency with the leading logarithm approximation and the accurate cancellation of infrared singularities exhibited by the new calculation suggest that it is reliable. We offer evidence that the source of the disagreement with previous results lies in the regulation of double singularities.
We review the current status of neutrino oscillations after 1258 days of Super-Kamiokande, assess their future prospects over the next 10 years as the next generation of experiments come on-line, and discuss the longer-term opportunities presented by a Neutrino Factory. We also give an introduction to the see-saw mechanism and its application to atmospheric and solar neutrinos.
The level of experimental precision that will be achieved with LHC Run-III data and in the forthcoming High Luminosity stage calls for equally accurate theoretical predictions to compare with. Here we present updated cross section calculations for the electroweak production of SUSY particles at the LHC with aNNLO+NNLL (approximate next-to-next-to-leading-order plus next-to-next-to-leading-logarithmic) accuracy. Results are shown for slepton pair production and for electroweakinos pair production in their mostly higgsino or gaugino configuration, finding a further significant reduction of the f…
The determination of the missing $U_{e3}$ element (magnitude and phase) of the PMNS neutrino mixing matrix is possible via the detection of $\numu\to\nue$ oscillations at a baseline $L$ and energy $E$ given by the atmospheric observations, corresponding to a mass squared difference $E/L \sim Δm^2\simeq 2.5\times 10^{-3} eV^2$. While the current optimization of the CNGS beam provides limited sensitivity to this reaction, we discuss in this document the physics potential of an intensity upgraded and energy re-optimized CNGS neutrino beam coupled to an off-axis detector. We show that improvements…
A High-Precision Numerical Framework for Time-Varying Solar Neutrino Flux with Full Earth Matter Oscillation Corrections for Global Underground Laboratories
We perform a phenomenological study of $Z$ plus jet, Higgs plus jet and di-jet production at the Large Hadron Collider. We investigate in particular the dependence of the leading jet cross section on the jet radius as a function of the jet transverse momentum. Theoretical predictions are obtained using perturbative QCD calculations at the next-to and next-to-next-to-leading order, using a range of renormalization and factorization scales. The fixed order predictions are compared to results obtained from matching next-to-leading order calculations to parton showers. A study of the scale depende…
We study to what extent upcoming precision neutrino oscillation experiments will be able to exclude one of the most predictive models of neutrino mass and mixing: the Littlest Seesaw. We show that this model provides a good fit to current data, predicting eight observables from two input parameters, and provide new assessments of its predictions and their correlations. We then assess the ability to exclude this model using simulations of upcoming neutrino oscillation experiments including the medium-distance reactor experiments JUNO and RENO-50 and the long-baseline accelerator experiments DUN…
Quantifying Information Hierarchy for Neutrino Oscillation Parameters at JUNO
Institute of High Energy Physics, Chinese Academy of Sciences（中国科学院高能物理研究所）；University of Chinese Academy of Sciences（中国科学院大学）；Kaiping Neutrino Research Center（开平中微子研究中心）
After the LHC Run 1, the standard model (SM) of particle physics has been completed. Yet, despite its successes, the SM has shortcomings vis-à-vis cosmological and other observations. At the same time, while the LHC restarts for Run 2 at 13 TeV, there is presently a lack of direct evidence for new physics phenomena at the accelerator energy frontier. From this state of affairs arises the need for a consistent theoretical framework in which deviations from the SM predictions can be calculated and compared to precision measurements. Such a framework should be able to comprehensively make use of …
Neutrino oscillations from a wide band beam of 1-6 GeV at CERN to LENA, a 50 kton liquid scintillator, at Pyhasalmi mine 2288 km apart are simulated. The performance is very promising and this can be considered as a realistic alternative for the next long baseline experiment. Different performance factors and baselines are compared and the studied setup is found to be sufficiently close to a realistic optimum.
KM3NeT, currently under construction in the abysses of the Mediterranean Sea, is a distributed research infrastructure that will host a km3-scale neutrino telescope (ARCA) for high-energy neutrino astronomy, and a megaton scale detector (ORCA) for neutrino oscillation studies of atmospheric neutrinos. ORCA is optimised for a measurement of the mass hierarchy, providing a sensitivity of 3σ after 3-4 years. It will also measure the atmospheric mixing parameters $Δm_{32}^2$ and $θ_{23}$ with a precision comparable to the NOvA and T2K experiments using both the muon neutrino disappearance and tau …
We present a neutrino oscillation analysis of two particular data sets from the Daya Bay and RENO reactor neutrino experiments aiming to study the increase in precision in the oscillation parameters $\sin^2{2θ}_{13}$ and the effective mass splitting $Δm^2_{ee}$ gained by combining two relatively simple to reproduce analyses available in the literature. For Daya Bay the data from 217 days between December 2011 and July 2012 were used. For RENO we used the data from 500 live days between August 2011 and January 2012. We reproduce reasonably well the results of the individual analyses, both, rate…
It is shown that the vector current contribution of neutrino interaction with electrons in ion gives rise to oscillating component, which is absent for the axial-vector contribution, when a single neutrino is detected in the recently proposed neutrino pair beam. CP violation measurements are thus possible with high precision along with determination of mass hierarchical patterns.
We present the constraints on neutrino oscillation parameters $Δm^2_{\odot}$ and $θ_{\odot}$ governing the solar neutrino oscillations from two generation analysis of solar and KamLAND data. We include the latest 766.3 ton year KamLAND data in our analysis. We also present the allowed values of parameters $Δm^2_{atm}$ and $\sin^2θ_{atm}$ from two generation oscillation analysis of SuperKamiokande atmospheric and K2K data. For both cases we discuss the precision achieved in the present set of experiments and also how the precision can be improved in future. We also obtain the bounds on $θ_{13}$…
The feasibility of a European next-generation very massive neutrino observatory in seven potential candidate sites located at distances from CERN ranging from 130 km to 2300 km, is being considered within the LAGUNA design study. The study is providing a coordinated technical design and assessment of the underground research infrastructure in the various sites, and its coherent cost estimation. It aims at a prioritization of the sites within summer 2010 and a start of operation around 2020. In addition to a rich non-accelerator based physics programme including the GUT-scale with proton decay …
Despite the dramatic progress made in neutrino oscillation studies recently, several fundamental neutrino parameters remain either unknown or poorly measured. We discuss in detail a method for their measurement by precision studies of oscillation-caused neutrino energy spectrum distortions, for which a large underwater inverse beta decay detector appears to be a perfect tool. Results determine optimal baselines and necessary exposures in the presence of systematic uncertainties and the unavoidable background from terrestrial antineutrinos.
We compare the generic physics potential of various combinations of conventional Wide Band or Neutrino Factory Beams with different detectors to determine several oscillation parameters in long baseline experiments. For each combination of beam and detector we show the precision which can be obtained for the leading oscillation parameters $\dm{31}$ and $\sin^2 2θ_{23}$. Furthermore we show the sensitivity to $\sin^2 2θ_{13}$ and the range in $\sin^2 2θ_{13}$ for which the sign of $\dm{31}$ can be extracted via matter effects. The results suggest that existing conventional Wide Band Beam and de…
For high energy long baseline neutrino oscillation experiments, we propose a Figure of Merit criterion to compare the statistical quality of experiments at various oscillation distances under the condition of identical detectors and a given neutrino beam. We take into account all possible experimental errors under general consideration. In this way the Figure of Merit is closely related to the usual statistical criterion of number of sigmas. We use a realistic neutrino beam for an entry level neutrino factory and a possible superbeam from a meson source and a 100 kt detector for the calculatio…
We derive the axion-nucleon interaction Lagrangian in heavy baryon chiral perturbation theory up to next-to-next-to-leading order. The effective axion-nucleon coupling is calculated to a few percent accuracy.
Precision searches for the electric dipole moment of protons in storage ring experiments call for beam-position monitoring in the picometer range. We present the relevant fully quantum mechanical derivation of radiofrequency-driven collective oscillations of a beam in a storage ring.
We study the prospects for testing classes of atmospheric mixing sum rules at precision neutrino facilities. Such sum rules, which correlate the atmospheric mixing angle theta23 with the recently measured reactor angle theta13 and the cosine of the oscillation phase delta, are predicted by a variety of semi-direct models based on discrete family symmetry, classified in terms of finite von Dyck groups. We perform a detailed simulation of the performance of the next generation of oscillation experiments, including the wide band superbeam and low-energy neutrino factory proposals, and compare the…
We briefly summarize the current status of perturbative calculations at next-to-next-to-leading-order (NNLO) accuracy in the \bar{B}\to X_sγdecay rate as well as that of non-perturbative power-corrections.
