With the latest results of a large mixing angle $θ_{13}$ for neutrinos by the T2K, MINOS and Double Chooz experiments, we find that the self-complementarity (SC) relations agree with the data in some angle-phase parametrizations of the lepton mixing matrix. There are three kinds of self-complementarity relations: (1) $\vartheta_i+\vartheta_j=\vartheta_k=45^\circ$; (2) $\vartheta_i+\vartheta_j=\vartheta_k$; (3) $\vartheta_i+\vartheta_j=45^\circ$ (where $i$, $j$, $k$ denote the mixing angles in the angle-phase parametrizations). We present a detailed study on the self-complementarity relations in nine different angle-phase parametrizations, and also examine the explicit expressions in reparametrization-invariant form, as well as their deviations from global fit. These self-complementarity relations may lead to new perspective on the mixing pattern of neutrinos.
We explore the complementarity between LHC searches and neutrino experiments in probing neutrino non-standard interactions. Our study spans the theoretical frameworks of effective field theory, simplified model and an illustrative UV completion, highlighting the synergies and distinctive features in all cases. We show that besides constraining the allowed NSI parameter space, the LHC data can break important degeneracies present in oscillation experiments such as DUNE, while the latter play an important role in probing light and weakly coupled physics undetectable at the LHC.
We investigate a stability of leptonic self-complementarity such that sum of three mixing angles in lepton sector is 90 degrees. Renormalization group equations in a context of minimal supersymmetric standard model for the self-complementarity are analyzed. It is seen that one of Majorana phases plays an important role for the stability of self-complementarity. We find some stable solutions against quantum corrections at a low energy. An effective neutrino mass for neutrino-less double beta decay is also evaluated by the use of neutrino parameters giving rise to the stable solutions.
We discuss how the intensity and the energy frontiers provide complementary constraints within a minimal model of neutrino mass involving just one new field beyond the Standard Model at accessible energy, namely a doubly charged scalar $S^{++}$ and its antiparticle $S^{--}$. In particular we focus on the complementarity between high-energy LHC searches and low-energy probes such as lepton flavor violation. Our setting is a prime example of how high- and low-energy physics can cross-fertilize each other.
We study the complementarity between accelerator and reactor coherent elastic neutrino-nucleus elastic scattering (CE$ν$NS) experiments for constraining new physics in the form of non-standard neutrino interactions (NSI). Firstly, considering just data from the recent observation by the COHERENT experiment, we explore interpretive degeneracies that emerge when activating either two or four unknown NSI parameters. Next, we demonstrate that simultaneous treatment of reactor and accelerator experiments, each employing at least two distinct target materials, can break a degeneracy between up and d…
We study the complementarity between quark and lepton mixing angles (QLC), the sum of an angle in quark mixing and the corresponding angle in lepton mixing is $π/4$. Experimentally in the standard PDG parametrization, two such relations exist approximately. These QLC relations are accidental which only manifest themselves in the PDG parametrization. We propose reparametrization invariant expressions for the complementarity relations in terms of the magnitude of the elements in the quark and lepton mixing matrices. In the exact QLC limit, it is found that $|V_{us}/V_{ud}| + |V_{e2}/V_{e1}| + |V…
We examine how a parametrization of neutrino mixing matrix reflecting quark-lepton complementarity can be probed by considering phase-averaged oscillation probabilities, flavor composition of neutrino fluxes coming from atmospheric and astrophysical neutrinos and lepton flavor violating radiative decays. We discuss about some distinct features of the parametrization by comparing with the triminimal parametrization of perturbations to tri-bimaximal neutrino mixing matrix.
It is suggested that there is an underlying symmetry which relates the quark and lepton sectors. Namely, among the mixing matrix elements of CKM for quarks and PMNS for leptons there exist complementarity relations at a high energy scale (such as the see-saw or even the GUT scales). Assuming that the relations would remain during the matrix elements running down to the EW scale. Observable breaking of the rational relation is attributed to existence of sterile neutrinos which mix with the active neutrino to result in the observable PMNS matrix. We show that involvement of a sterile in the (3+1…
Although tribimaximal mixing (TBM) and quark-lepton complementarity (QLC) are both compatible with experimental data within one standard deviation ($ 1 σ$), the TBM and QLC assumptions are mutually exclusive by $56 σ$.
With the progress of increasingly precise measurements on the neutrino mixing angles, phenomenological relations such as quark-lepton complementarity (QLC) among mixing angles of quarks and leptons and self-complementarity (SC) among lepton mixing angles have been observed. Using the latest global fit results of the quark and lepton mixing angles in the standard Chau-Keung scheme, we calculate the mixing angles and CP-violating phases in the other eight different schemes. We check the dependence of these mixing angles on the CP-violating phases in different phase schemes. The dependence of QLC…
We study deviations from tri-bimaximality (TBM) and quark-lepton complementarity (QLC) in a model independent way. The current neutrino experimental data is well approximated by tri-bimaximal generation mixing but the QLC relations are not satisfied with each data of 1$σ$ level. This means that there exist deviations from the complementarity. The same fact for the TBM might be checked in the future neutrino experiments. We discuss such deviations from the TBM and QLC, simultaneously. A new ratio between the deviations is introduced, and some interesting points are presented. We also show predi…
We reiterate that there is significant complementarity between low-energy experiments and high-energy colliders in exploring new physics associated with neutrino properties and their mass generation mechanisms. Signals of the new physics in the two energy regimes may be correlated with each other from the same underlying dynamics. We demonstrate the complementary nature by presenting the physics reaches for the Seesaw models of Type I, II and III, and for general neutrino interactions in an effective field theory framework, and in a $Z'$ model.
A basis independent formulation of quark-lepton complementarity is implemented at a high scale for quasidegenerate Majorana neutrinos. It is shown that even with the renormalization group evolution in the minimal supersymmetric standard model, the scenario can be consistent with the data provided a nontrivial role is played by the Majorana phases. Correlated constraints are found on these phases and the neutrino mass scale using the current data. We also indicate how future accurate measurements of the mixing angles can serve as tests of this scenario and restrict the values of the Majorana ph…
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 $θ_{23}$, $δ_\text{CP}$, and the neutrino mass ordering by performing a Monte Carlo study of the long baseline accelerator and reactor data. We…
The neutrino oscillation data are well explained by the tri-bimaximal pattern. Recently a paper appeared showing that also the bimaximal pattern could be a very good starting point in order to describe the lepton mixing. In this paper I review both the flavour structures and then I present an explicit model based on the discrete symmetry group S4.
As a result of identification of the solution to the solar neutrino problem, a rather precise relation theta_{sun} + theta_C = pi/4 between the leptonic 1-2 mixing angle theta_{sun} and the Cabibbo angle has emerged. It would mean that the lepton and the quark mixing angles add up to the maximal, suggesting a deep structure by which quarks and leptons are interrelated. We refer the relation ``quark-lepton complementarity'' (QLC) in this paper. We formulate general conditions under which the QLC relation is realized. We then present several scenarios which lead to the relation and elaborate on …
We demonstrate that `Bimaximal + Democratic' type neutrino mass matrix can accommodate the deviation of $θ_\odot$ from its maximal value which referred in the literature as `quark-lepton complementarity' along with the other present day neutrino experimental results, namely, atmospheric, CHOOZ, neutrinoless double beta decay ($ββ_{0ν}$) and result obtained from WMAP experiment. We define a function $χ_p$ in terms of solar and atmospheric neutrino mass squared differences and solar neutrino mixing angle (obtained from different experiments and our proposed texture). The masses and mixing angles…
Complementarity between atmospheric and super-beam neutrinos at ESSnuSB
Consorcio ESS-bilbao（ESS-Bilbao联合体）；European Spallation Source（欧洲散裂源）；Center of Excellence for Advanced Materials and Sensing Devices, Ruđer Bošković Institute（先进材料与传感设备卓越中心，鲁德·博什科维奇研究所）；IPHC, Université de Strasbourg, CNRS/IN2P3（斯特拉斯堡大学物理与核子化学研究所，法国国家科学研究中心/欧洲粒子物理研究所）；Department of Physics, School of Engineering Sciences, KTH Royal Institute of Technology（皇家理工学院工程科学学院物理系）；The Oskar Klein Centre, AlbaNova University Center（奥斯卡·克莱因中心，阿尔巴诺瓦大学中心）；Sofia University St. Kliment Ohridski, Faculty of Physics（索非亚圣克利门特奥赫里德斯基大学物理学院）；University of Milano-Bicocca and INFN Sez. di Milano-Bicocca（米兰比可卡大学及意大利国家核物理研究所米兰比可卡分部）
The mixing among flavors in quarks or leptons in terms of a single rotation angle is defined such that three flavor eigenvectors are transformed into three mass eigenvectors by a single rotation about a common axis. We propose that a geometric complementarity condition exists between the complex angle of quarks and that of leptons in $\mathbb{C}^2$ space. The complementarity constraint has its rise in quark-lepton unification and is reduced to the correlation among $θ_{12}, θ_{23}, θ_{13}$ and the CP phase $δ$. The CP phase turns out to have a non-trivial dependence on all the other angles. We…
A summary of the parameter degeneracy issue for long baseline neutrino oscillations is presented and how a sequence of measurements can be used to resolve all degeneracies. Next, a comparison of the JHF and NuMI Off-Axis proposals is made with emphasis on how both experiments running neutrinos can distinguish between the normal and inverted hierarchies provided the E/L of NuMI is less than or equal to the E/L of JHF. Due to the space limitations of this proceedings only an executive style summary can be presented here, but the references and transparencies of the talk contain the detailed argu…
Starting from a new zeroth order basis for quark mixing (CKM) matrix based on the quark-lepton complementarity and the tri-bimaximal pattern of lepton mixing, we derive a triminimal parametrization of CKM matrix with three small angles and a CP-violating phase as its parameters. This new triminimal parametrization has the merits of fast convergence and simplicity in application. With the quark-lepton complementary relations, we derive relations between the two unified triminimal parametrizations for quark mixing obtained in this work and for lepton mixing obtained by Pakvasa-Rodejohann-Weiler.…
The residual $\mathbb Z^{23}_2$ ($\mathbb Z^{μτ}_2$) and $\mathbb Z^{12}_2$ ($\mathbb Z^s_2$ or $\overline{\mathbb Z}^s_2$) symmetries can not only apply to the lepton sector, but also explain the mainly $1$--$2$ mixing in the quark sector. With both up and down quarks subject to the same $\mathbb Z^{23}_2$ symmetry, which interchanges the second and third generations, the $1$--$3$ and $2$--$3$ mixing angles in CKM vanish while the Cabibbo angle is dictated by two residual $\mathbb Z^{12}_2$ symmetries. It turns out that the quark-lepton complementarity conditions are natural consequences of u…
We present a general formalism for extracting information on the fundamental parameters associated with neutrino masses and mixings from two or more long baseline neutrino oscillation experiments. This formalism is then applied to the current most likely experiments using neutrino beams from the Japan Hadron Facility (JHF) and Fermilab's NuMI beamline. Different combinations of muon neutrino or muon anti-neutrino running are considered. To extract the type of neutrino mass hierarchy we make use of the matter effect. Contrary to naive expectation, we find that both beams using neutrinos is more…
We analyze quantum correlations and quantum coherence in neutrino oscillations. To this end, we exploit complete complementarity relations (CCR) that fully characterize the interplay between different correlations encoded in a quantum system both for pure and mixed states. We consider the CCR for neutrino oscillations both in the case of plane-waves (pure state) and of wave packets (mixed state). In this last case we find a complex structure of correlations depending on the mixing angle, and we show the connection with the non local advantage of quantum coherence, a relevant quantifier of cohe…
Massive neutrinos and leptonic mixings have provided the first evidence of flavour violation in the lepton sector, opening a unique gateway to many new phenomena. Among the latter, one finds processes violating lepton number, charged lepton flavours, or even the universality of lepton flavours. These very rare transitions can be studied in high-intensity facilities, and if observed, constitute a clear sign of New Physics. After a brief review of the experimental status of dedicated searches, we comment on the prospects of several well-motivated models of neutrino mass generation to several of …
The complementarity between the quark and lepton mixing matrices is shown to provide a robust prediction for the neutrino mixing angle $θ_{13}^{PMNS}$. We obtain this prediction by first showing that the matrix $V_M$, product of the CKM and PMNS mixing matrices, may have a zero (1,3) entry which is favored by experimental data. Hence models with bimaximal or tribimaximal forms of the correlation matrix $V_M$ are quite possible. Any theoretical model with a vanishing (1,3) entry of $V_M$ that is in agreement with quark data, solar, and atmospheric mixing angle leads to $θ_{13}^{PMNS}=(9{^{+1}_{…
We consider the TeV scale left-right symmetric theory which can accommodate low scale seesaw mechanisms consistent with neutrino oscillation data and find new physics contributions to neutrinoless double beta decay. The model facilitates natural type-II seesaw dominance and the presence of extra particles make the Dirac neutrino mass matrix $M_D$ large that leads to large light heavy neutrino mixing. The spontaneous symmetry breaking through doublets, triplets and bidoublet scalars at TeV scale offers rich phenomenology accessible to LHC. From the numerical studies of the new physics contribut…
We compute the effect of non diagonal neutrino mass in l_i -> l_j gamma in SUSY theories with non trivial Quark-Lepton complementarity and a flavor symmetry. The correlation matrix V_M=U_{CKM}U_{PMNS} is such that its (1,3) entry, as preferred by the present experimental data, is zero. We do not assume that $V_M$ is bimaximal. Quark-Lepton complementarity and the flavor symmetry strongly constrain the theory and we obtain a clear prediction for the contribution to mu -> e gamma and the tau decays tau -> e gamma and tau -> mu gamma. If the Dirac neutrino Yukawa couplings are degenerate but the …
Neutrinoless double beta decay experiments constrain one combination of neutrino parameters, while cosmic surveys constrain another. This complementarity opens up an exciting range of possibilities. If neutrinos are Majorana particles, and the neutrino masses follow an inverted hierarchy, then the upcoming sets of both experiments will detect signals. The combined constraints will pin down not only the neutrino masses but also constrain one of the Majorana phases. If the hierarchy is normal, then a beta decay detection with the upcoming generation of experiments is unlikely, but cosmic surveys…
Direct detection dark matter experiments looking for WIMP-nucleus elastic scattering will soon be sensitive to an irreducible background from neutrinos which will drastically affect their discovery potential. Here we explore how the neutrino background will affect future ton-scale experiments considering both spin-dependent and spin-independent interactions. We show that combining data from experiments using different targets can improve the dark matter discovery potential due to target complementarity. We find that in the context of spin-dependent interactions, combining results from several …
After the successful investigation and confirmation of non zero $θ_{13}^{PMNS}$ by various experiments, we are standing at a square where we still encounter a number of issues, which are to be settled. In this paper, we have extended our recent work towards a precise prediction of the $θ_{23}^{PMNS}$ mixing angle, taking into account the neutrino mass hierarchy. We parameterize the non-trivial correlation between quark (CKM) and lepton (PMNS) mixing matrices in quark-lepton complementarity (QLC) model as $V_{c}= U_{CKM}. ψ. U_{PMNS}$, where $ψ$ is a diagonal phase matrix. Monte Carlo simulatio…
The recent experimental measurements of the solar neutrino mixing angle $θ_{sol}$ and the Cabibbo mixing angle $θ_C$ reveal a surprising relation, $ θ_{sol}+θ_C \simeq \fracπ{4}$. We note that the lepton mixing matrix derived from quark-lepton unification can lead to a shift of the complementarity relation at low energy. While the renormalization group effects generally lead to additive contribution on top of the shift, in this letter, we show that the threshold corrections which may exist in some intermediate scale new physics such as supersymmetric standard model can diminish it, so we can a…
We consider a rather minimal extension of the Standard Model involving just one extra particle, namely a single $SU(2)_L$ singlet scalar $S^{++}$ and its antiparticle $S^{--}$. We propose a model independent effective operator, which yields an effective coupling of $S^{\pm \pm}$ to pairs of same sign weak gauge bosons, $W^{\pm} W^{\pm}$. We also allow tree-level couplings of $S^{\pm \pm}$ to pairs of same sign right-handed charged leptons $l^{\pm}_Rl'^{\pm}_R$ of the same or different flavour. We calculate explicitly the resulting two-loop diagrams in the effective theory responsible for neutr…
We investigate the potential (small) deviations from the unitarity of the mixing matrix that are expected to occur, because of mass splittings, in the Quantum Field Theory of non-degenerate coupled systems. We extend our previous analysis concerning mixing angles, which led to a precise determination of the Cabibbo angle, to the case of three generations of fermions. We show that the same condition for neutral currents of mass eigenstates, i.e. that universality of diagonal currents is violated with the same strength as the absence of non-diagonal ones, is satisfied: on one hand, by the three …
The quark-lepton complementarity (QLC) relations indicate a deep structure that interrelates quarks and leptons. We propose new scenarios, in a seesaw framework with discrete $A_4$ flavor symmetry, which can accommodate the QLC relations and the nonzero neutrino mixing angle $θ_{13}$ together with all the available neutrino experimental data, in a consistent way to generate the Cabibbo-Kobayashi-Maskawa (CKM) matrix for the quark mixing. Certain effective dimension-5 operators are introduced, which induce a deviation of the lepton mixing matrix from the tribimaximal mixing (TBM) pattern and le…
In this talk we present our results on the sensitivity to the neutrino mass hierarchy, the octant of the mixing angle and the CP phase in the future long baseline experiments T2HK and DUNE as well as in the atmospheric neutrino observation at Hyperkamiokande (HK).
The scale at which supersymmetry (SUSY) breaks ($m_{s}$) is still unknown. The present article, following a top-down approach, endeavors to study the effect of varying $m_s$ on the radiative stability of the observational parameters associated with the neutrino mixing. These parameters get additional contributions in the minimal supersymmetric model,(MSSM). A variation in $m_s$ will influence the bounds for which the Standard Model,(SM) and MSSM work and hence will account for the different radiative contributions received from both sectors respectively, while running the renormalization group…
The measurements of the neutrino and quark mixing angles satisfy the empirical relations called Quark-Lepton Complementarity. These empirical relations suggest the existence of a correlation between the mixing matrices of leptons and quarks. In this work, we examine the possibility that this correlation between the mixing angles of quarks and leptons originates in the similar hierarchy of quarks and charged lepton masses and the seesaw mechanism type~I, that gives mass to the Majorana neutrinos. We assume that the similar mass hierarchies of charged lepton and quark masses allows us to represe…
We show that the next-to-leading order corrections in the quark-lepton complementarity are important to explain the observed pattern of neutrino mixing. In particular, the next-to-leading order corrections 1) lead to a deviation of θ_{23} from maximal mixing, 2) reduce the predicted value of $\sin^2 2θ_{13}$ by 9.8%, 3) provide the same value of $\sin^2 θ_{12}$ as that of the tri-bimaximal mixing. This is shown by calculating $\sin^2 2θ_{ij} (i,j=1,2,3)$ to ${\cal O}(λ^6)$ in the framework in which the product of the CKM and PMNS matrices is bimaximal.
The quark-lepton complementarity (QLC) is very suggestive in understanding possible relations between quark and lepton mixing matrices. We explore the QLC relations in all the possible angle-phase parametrizations and point out that they can approximately hold in five parametrizations. Furthermore, the vanishing of the smallest mixing angles in the CKM and PMNS matrices can make sure that the QLC relations exactly hold in those five parametrizations. Finally, the sensitivity of the QLC relations to radiative corrections is also discussed.
Composite-fermion models predict excited quarks and leptons with mass scales which can potentially be observed at high-energy colliders like the LHC; the most recent exclusion limits from the CMS and ATLAS Collaborations corner excited-fermion masses and the compositeness scale to the multi-TeV range. At the same time, hypothetical composite Majorana neutrinos would lead to observable effects in neutrinoless double beta decay ($0νββ$) experiments. In this work, we show that the current composite-neutrino exclusion limit $M_N>4.6$ TeV, as extracted from direct searches at the LHC, can indeed be…
Recent measurements of the neutrino solar mixing angle and the Cabibbo angle satisfy the empirical relation theta_{sol} + theta_{C} ~ 45^{o}. This relation suggests the existence of a correlation between the mixing matrices of leptons and quarks, the so called quark-lepton complementarity. Here, we examine the possibility that this correlation originates in the strong hierarchy in the mass spectra of quarks and charged leptons, and the seesaw mechanism that gives mass to the Majorana neutrinos. In a unified treatment of quarks and leptons in which the mass matrices of all fermions have a simil…
Complementarity Between Neutrino Neutral and Charged Current Events in the Search for New Physics
Colorado State University（科罗拉多州立大学）；National Centre for Nuclear Research（国家核研究中心）；Fermi National Accelerator Laboratory（费米国家加速器实验室）；Shanghai Jiao Tong University（上海交通大学）
Implications of the recent results on neutrino masses and mixing to underlying new physics are considered. Various approaches to physics behind neutrino mass are described which include the tri-bimaximal mixing and flavor symmetries, the quark-lepton complementarity and weak complementarity, the quark-lepton universality and unification. Some recent results from string phenomenology are discussed and the issue of model building versus "string engineering" is outlined.
Current experimental data indicate that two unitarity triangles of the CKM quark flavor mixing matrix V are almost the right triangles with α\approx 90^\circ. We find that α= 90^\circ actually points to {\rm Re}(V_{tb}V_{ud}V^*_{td}V^*_{ub}) = 0. Considering a very suggestive parametrization of V, we show that its CP-violating phase ϕis nearly equal to α(i.e., ϕ- α\approx 1.1^\circ). Both ϕand αare stable against the renormalizaton-group evolution from the electroweak scale M_Z to a superhigh energy scale M_X or vice versa, and thus it is impossible to obtain α= 90^\circ at M_Z from ϕ= 90^\cir…
The neutrino mixing parameters are thoroughly studied using renormalization-group evolution of Dirac neutrinos with recently proposed parametrization of the neutrino mixing angles referred as `high-scale mixing relations'. The correlations among all neutrino mixing and $CP$ violating observables are investigated. The predictions for the neutrino mixing angle $θ_{23}$ are precise, and could be easily tested by ongoing and future experiments. We observe that the high scale mixing unification hypothesis is incompatible with Dirac neutrinos due to updated experimental data.
The recent experimental measurements of the solar neutrino mixing angle $θ_{sol}$ and the Cabibbo mixing angle $θ_C$ reveal a surprising relation, $ θ_{sol}+θ_C \simeq \fracπ{4} $. We review that while this empirical relation has been interpreted as a support of the idea of grand unification, it may be merely accidental in the sense that reproducing the relation at a low energy in the framework of grand unification may depend strongly on the renormalization effects whose size can vary with the choice of parameter space. We note that the lepton mixing matrix derived from quark-lepton unificatio…
It has been recognized recently that there is a remarkable empirical relation between lepton and quark mixing angles, theta_{12} + theta_C \approx pi/4. If not accidental, it should testify for yet uncovered new relationship between the fundamental twin particles in nature which only differ in their ability to feel color. The nontrivial structure which is presumed to exist behind the empirical relation is named as ``quark-lepton complementarity''. In this talk, I review the idea at the kind request of the organizer. Starting from pedagogical discussions of bimaximal mixing, which likely to be …
We review the status of three-neutrino mixing and the results of global analyses of short-baseline neutrino oscillation data in 3+1 and 3+2 neutrino mixing schemes.
The present observations of Cabbibo angle and solar mixing angle satisfy the empirical relation called Quark-Lepton Complementarity(QLC), namely $θ_{12}^l\sim π/4-θ_C$. It suggests the existence of correlation between quarks and leptons which is supported by the idea of grand unification. We propose a specific ansatz for the structure of Yukawa matrices in SO(10) unified theory which leads to such relation if neutrinos get masses through type-II seesaw mechanism. Viability of this ansatz is discussed through detailed analysis of fermion masses and mixing angles all of which can be explained in…
We point out two simple but instructive possibilities to construct the charged lepton and neutrino mass matrices, from which the nearly bi-maximal neutrino mixing with large T violation can naturally emerge. The two lepton mixing scenarios are compatible very well with current experimental data on solar and atmospheric neutrino oscillations, and one of them may lead to an observable T-violating asymmetry between ν_μ--> ν_e and ν_e --> ν_μtransitions in the long-baseline neutrino oscillation experiments. Their implications on the neutrinoless double beta decay are also discussed.
We reexamine the quark-lepton complementarity (QLC) in nine angle-phase parametrizations with the latest result of a large lepton mixing angle $\vartheta_{13}$ from the T2K, MINOS and Double Chooz experiments. We find that there are still two QLC relations satisfied in P1, P4 and P6 parametrizations, whereas only one QLC relation holds in P2, P3, P5 and P9 parametrizations separately. We also work out the corresponding reparametrization-invariant forms of the QLC relations and check the resulting expressions with the experimental data. The results can be viewed as a check of the validity of th…
Similarity between the weak interaction properties of quarks and leptons has led to suggestions that the origin of lepton mixing angles may be related to those of quarks. In this paper, we present a gauge model based on $SU(2)_L \times SU(2)_R\times SU(4)_c$ group that leads to a new form for the quark lepton complementarity which predicts the solar neutrino mixing angle in terms of the Cabibbo angle for the case of inverted mass hierarchy for neutrinos. We also indicate how these ideas can be implemented in an $E_6$ inspired trinification $SU(3)_C \times SU(3)_L \times SU(3)_R$ model, which i…
We derive a new set of sum rules between the neutrino mass and mixing parameters in vacuum and their effective counterparts in matter. The moduli of nine genuine lepton mixing matrix elements can then be calculated in terms of the matter-corrected ones, and the latter can directly be determined from a variety of long-baseline neutrino oscillations. We show that it is possible to reconstruct the leptonic unitarity triangles and CP violation in a similar parametrization-independent way.
We have studied how observables of the neutrino mixing matrix can link up with the ones in the quark sector. The deviation from the bi-maximal flavor mixing is parameterized using a 3 x 3 unitary matrix. The neutrino mixings are investigated supposing this unitary matrix to be hierarchical like the quark mixing matrix. We obtain the remarkable prediction |U_{e3}| >= 0.03 from the experimentally allowed range tan^2 theta_{sol} = 0.24 ~ 0.89. The CP violation in neutrino oscillations is expected to be very small.
The complementarity between the quark and lepton mixing matrices is shown to provide robust predictions. We obtain these predictions by first showing that the matrix V_M, product of the quark (CKM) and lepton (PMNS) mixing matrices, may have a zero (1,3) entry which is favored by experimental data. We obtain that any theoretical model with a vanishing (1,3) entry of V_M that is in agreement with quark data, solar, and atmospheric mixing angle leads to $θ_{13}^{PMNS}=(9{^{+1}_{-2}})^\circ$. This value is consistent with the present 90% CL experimental upper limit. We also investigate the predic…
We investigate the blazar contribution to the cumulative neutrino intensity assuming a generic relationship between neutrino and gamma-ray luminosities, $L_ν\propto (L_{\rm ph})^{γ_{\rm lw}}$. Using the gamma-ray luminosity functions for blazars including flat spectrum radio quasars (FSRQs) and BL Lac objects, as well as the $Fermi$-LAT detection efficiency, we estimate contributions from {blazars resolved by $Fermi$-LAT as well as the unresolved counterpart.} Combining the existing upper limits from stacking analyses, the cumulative neutrino flux from all blazars ({including $Fermi$-LAT resol…
We systematically investigate the parameter space of neutrino and charged lepton mass matrices for textures motivated by an extended quark-lepton complementarity. As the basic hypothesis, we postulate that all mixing angles in U_l and U_nu be either maximal or described by powers of a single small quantity epsilon ~ theta_C. All mass hierarchies are described by this epsilon as well. In this study, we do not assume specific forms for U_l and U_nu, such as large mixing coming from the neutrino sector only. We perform a systematic scan of the 262,144 generated mixing matrices for being compatibl…
In this work we investigate the sensitivity to the neutrino mass hierarchy, the octant of the mixing angle $θ_{23}$ and the CP phase $δ_{CP}$ in the future long-baseline experiments T2HK and DUNE as well as in the atmospheric neutrino observation at Hyperkamiokande (HK). We show for the first time that the sensitivity is enhanced greatly if we combine these three experiments. Our results show that the hierarchy sensitivity of both T2HK and HK are limited due to the presence of parameter degeneracy. But this degeneracy is removed when T2HK and HK are added together. With T2HK+HK (DUNE), the neu…
Inspired by a new relation $θ_{13}^{\rm PMNS}={θ_C}/{\sqrt{2}}$ observed from the relatively large $θ_{13}^{\rm PMNS}$, we find that the combination of this relation with the quark-lepton complementarity and the self-complementarity results in correlations of the lepton mixing angles with the quark mixing angles. We find that the three mixing angles in the PMNS matrix are all related to the Wolfenstein parameter $λ$ in the quark mixing, so they are also correlated. Consequently, the PMNS matrix can be parameterized by $λ$, A, and a Dirac CP-violating phase $δ$. Such parametrizations for the PM…
