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origin of tiny neutrino masses and mixing is one of the most widely studied problems in modern day particle physics . since the standard model ( sm ) of particle physics fails to provide an explanation to neutrino masses and mixing , several well motivated beyond standard model ( bsm ) frameworks have been proposed to account for the tiny neutrino mass observed by several neutrino oscillation experiments @xcite . more recently , the neutrino oscillation experiments t2k @xcite , double chooz @xcite , daya - bay @xcite and reno @xcite have also confirmed the earlier results and also made the measurement of neutrino parameters more precise . the latest global fit values for @xmath3 range of neutrino oscillation parameters @xcite are shown in table [ tab : data1 ] . another global fit study @xcite reports the 3@xmath4 values as shown in table [ tab : data2 ] . .global fit @xmath3 values of neutrino oscillation parameters @xcite [ cols="^,^,^",options="header " , ]     [ table : deltacl ]     with charged lepton correction to scaling , scaledwidth=100.0% ]    in the second mechanism we adopt to give correction to the scaling neutrino mixing , we do not add corrections to the neutrino mass matrix originating from type i seesaw , but incorporate corrections to the neutrino mixing matrix originating from charged lepton mixing . diagonalizing the scaling neutrino mass matrix from type i seesaw matrix gives @xmath5 which is related to the leptonic mixing matrix @xmath6 through the charged lepton diagonalizing matrix @xmath7 . we first numerically evaluate @xmath5 by using the best fit values of neutrino mass squared differences and two mixing angles @xmath8 . we also substitute the best fit values of neutrino mixing angles in pmns mixing matrix and then compute the charged lepton diagonalizing matrix as @xmath9 we keep the dirac cp phase @xmath2 as free parameter so that @xmath10 is a function of it . the numerical form of @xmath7 for @xmath11 is shown in table [ table : ul ] . assuming the same diagonalizing matrix of charged leptons and dirac neutrino mass matrix ( a generic case in grand unified theories operating at high scale ) , we can write down the modified dirac neutrino mass matrix as @xmath12 where @xmath13 is the scaling type dirac neutrino mass matrix we choose earlier . we choose a diagonal form of @xmath14 while keeping the lightest right handed neutrino mass @xmath15 in the appropriate flavor regime of leptogenesis and varying the heavier right handed neutrino masses @xmath16 between @xmath15 and the grand unified theory scale @xmath17 gev . for such a choice of @xmath14 , we numerically evaluate the parameters in @xmath13 by equating the type i seesaw term @xmath18 to the numerically fitted type i scaling neutrino mass matrix . the numerical values of @xmath14 which give baryon asymmetry closest to the observed in each flavor regime are shown in table [ table : mrrcl ] . the numerical form of dirac neutrino mass matrices in each flavor regime for @xmath11 are shown in table [ table : mlrcl ] . the predictions for baryon asymmetry as a function of @xmath2 are shown in figure [ fig7 ] . the values of dirac cp phase which give rise to correct baryon asymmetry are listed in table [ table : deltacl ] . we have studied a specific type of neutrino mass matrix based on the idea of strong scaling ansatz where the ratio of neutrino mass matrix elements belonging to two different columns are equal . out of three such possibilities , we focus on a particular scaling neutrino mass matrix which predicts zero values of reactor mixing angle @xmath0 . this choice was motivated by several recent works where the leading order neutrino mass matrix obeying certain symmetries predict @xmath1 and suitable corrections to the neutrino mass matrix or leptonic mixing matrix give rise to small but non - zero values of @xmath0 . in this work , we have assumed type i seesaw to give rise to scaling neutrino mass matrix which ( in the diagonal charged lepton basis ) gives @xmath1 and inverted hiearchical mass pattern with @xmath19 . then we consider two different possible corrections to scaling : one with type ii seesaw which gives rise to deviations from both @xmath1 and @xmath19 , the other with charged lepton correction which gives non - zero @xmath0 while keeping @xmath19 . we also assume both the corrections to give rise to non - trivial dirac cp phase @xmath2 as well . in both the cases , we first numerically evaluate the type i seesaw scaling neutrino mass matrix by using the best fit values of neutrino mass squared differences and two mixing angles : solar and atmospheric . we then calculate the necessary corrections to scaling neutrino mass and mixing by keeping the dirac cp phase as free parameter . we further constrain the dirac cp phase by calculating the baryon asymmetry through the mechanism of leptogenesis and comparing with the observed baryon asymmetry . the important results we have obtained in the case of type ii seesaw correction to scaling can be summarized as :    * type ii seesaw correction to scaling neutrino mass matrix with @xmath20 can result in both normal as well as inverted hierarchy with non - zero @xmath0 as well as non - trivial dirac cp phase @xmath2 . * for inverted hierarchy with @xmath21 that is @xmath22 , correct values of baryon asymmetry is obtained through the mechanism of leptogenesis only when the lightest neutrino mass @xmath23 is of same order as the heavier ones @xmath24 . * for inverted hierarchy with @xmath25 that is @xmath26 , both large and mild hierarchy among neutrino masses give rise to correct baryon asymmetry through leptogenesis . * for normal hierarchy with @xmath22 , both large and mild hierarchy among neutrino masses can give rise to correct baryon asymmetry in the one flavor regime . in the two flavor regime however , the lightest neutrino mass @xmath23 should be of same order as @xmath27 to give correct baryon asymmetry . * for normal hierarchy with @xmath26 , the lightest neutrino mass @xmath23 should be of same order as @xmath27 to give correct baryon asymmetry in both one and two flavor regimes . * observed baryon asymmetry can not be generated in the three flavor regime of leptogenesis in this framework . similarly , the important results in the case of charged lepton correction to scaling are :    * charged lepton correction to scaling neutrino mixing predicts only inverted hierarchy with @xmath19 , but gives rise to correct values of @xmath0 and non - trivial @xmath2 . * correct baryon asymmetry can be obtained through leptogenesis for one , two and three flavor regimes if @xmath2 is restricted to certain range of values . since the dirac cp phase is restricted in all these cases discussed , from the demand of producing the correct baryon asymmetry , future determination of @xmath2 should be able to shed some light on these scenarios . future experiments may however , measure a different value of @xmath2 than the ones which give correct baryon asymmetry through the mechanism of leptogenesis in the models we have studied here . this will by no means rule out the neutrino mass models based on strong scaling ansatz we discuss , but will only hint at a different source of baryon asymmetry than the one discussed in our work . similarly , determination of neutrino mass hierarchy in neutrino oscillation experiments will further constrain the models and only charged lepton correction to scaling may not be sufficient to reproduce the correct neutrino data if inverted hierarchy gets disfavored by experiments . from theoretical point of view , such scaling neutrino mass matrix can find a dynamical origin within discrete flavor symmetry models as pointed out by @xcite . since scaling is not affected by renormalization group running , additional physics are required in order to produce correct low energy neutrino oscillation data . undisturbed by such running effects , scaling can be valid all the way from grand unified theory scale down to the tev scale , where new physics affects like higgs triplet in type ii seesaw can give rise to the necessary correction to scaling neutrino mass matrix . although we have studied only one particular type of scaling neutrino mass matrix giving @xmath20 , the other two possibile scaling mass matrices could also give rise to correct neutrino phenomenology if suitable corrections are incorporated , which is left for our future studies . the work of m. k. das is partially supported by the grant no . 42 - 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we study a very specific type of neutrino mass and mixing structure based on the idea of strong scaling ansatz ( ssa ) where the ratios of neutrino mass matrix elements belonging to two different columns are equal . 
 there are three such possibilities , all of which are disfavored by the latest neutrino oscillation data . 
 we focus on the specific scenario which predicts vanishing reactor mixing angle @xmath0 and inverted hierarchy with vanishing lightest neutrino mass . motivated by several recent attempts to explain non - zero @xmath0 by incorporating corrections to a leading order neutrino mass or mixing matrix giving @xmath1 , here we study the origin of non - zero @xmath0 as well as leptonic dirac cp phase @xmath2 by incorporating two different corrections to scaling neutrino mass and mixing : one where type ii seesaw acts as a correction to scaling neutrino mass matrix and the other with charged lepton correction to scaling neutrino mixing . 
 although scaling neutrino mass matrix originating from type i seesaw predicts inverted hierarchy , the total neutrino mass matrix after type ii seesaw correction can give rise to either normal or inverted hierarchy . 
 however , charged lepton corrections do not disturb the inverted hierarchy prediction of scaling neutrino mass matrix . 
 we further discriminate between neutrino hierarchies , different choices of lightest neutrino mass and dirac cp phase by calculating baryon asymmetry and comparing with the observations made by the planck experiment .