\setlength{\textheight}{23cm} \setlength{\textwidth}{14cm} \setlength{\marginparwidth}{0pt} \def\beq{\begin{equation}} \def\eeq{\end{equation}} \def\bea{\begin{eqnarray}} \def\eea{\end{eqnarray}} \def\bq{\begin{quote}} \def\eq{\end{quote}} \def \lsim{\mathrel{\vcenter{\hbox{$<$}\nointerlineskip\hbox{$\sim$}}}} \def \gsim{\mathrel{\vcenter{\hbox{$>$}\nointerlineskip\hbox{$\sim$}}}} \def\gappeq{\mathrel{\rlap {\raise.5ex\hbox{$>$}}{\lower.5ex\hbox{$\sim$}}}} \def\lappeq{\mathrel{\rlap{\raise.5ex\hbox{$<$}}{\lower.5ex\hbox{$\sim$}}}} \def\simlt{\stackrel{<}{{}_\sim}} \def\simgt{\stackrel{>}{{}_\sim}} \def\msnu{m_{\tilde{\nu}}} \def\msnui{m_{\tilde{\nu}_i}} \def\msnuj{m_{\tilde{\nu}_j}} \def\msnuI{m_{\tilde{\nu}_I}} \def\msnuJ{m_{\tilde{\nu}_J}} \def\snu{\tilde{\nu}} \def\snuvi{\langle\tilde{\nu}_i\rangle} \def\Huv{\langle H_u \rangle} \def\mchi{m_{\chi}} \def\Rp{R_p} \def\Rpv{R_p \! \! \! \! \! \! /~~} \def\mnu{[m_{\nu}]_{ij}} \def\LI{$\{ L_I \} ~$} \def\vd{\vec{\delta}} \def\hd{\hat{\delta}} \def\ltap{\raisebox{-.4ex}{\rlap{$\sim$}} \raisebox{.4ex}{$<$}} \def\gtap{\raisebox{-.4ex}{\rlap{$\sim$}} \raisebox{.4ex}{$>$}} \newcommand{\Rsl}{{\not \! \!{R}}} \newcommand{\sqm}{m_{\tilde{q}}} \newcommand{\slm}{m_{\tilde{l}}} \newcommand{\ms}{\widetilde{m}} \newcommand{\sun}{\Delta m^2_{\rm solar}} \newcommand{\atm}{\Delta m^2_{\rm atm}} \newcommand{\lsnd}{\Delta m^2_{\rm LSND}} \def\bea{\begin{eqnarray}} \def\eea{\end{eqnarray}} \def\la{\mathrel{\mathchoice {\vcenter{\offinterlineskip\halign{\hfil$\displaystyle## $\hfil\cr<\cr\sim\cr}}} {\vcenter{\offinterlineskip\halign{\hfil$\textstyle## $\hfil\cr<\cr\sim\cr}}} {\vcenter{\offinterlineskip\halign{\hfil$\scriptstyle## $\hfil\cr<\cr\sim\cr}}} {\vcenter{\offinterlineskip\halign{\hfil$\scriptscriptstyle##$ \hfil\cr<\cr\sim\cr}}}}} % greater than or order of \ga \def\ga{\mathrel{\mathchoice {\vcenter{\offinterlineskip\halign{\hfil $\displaystyle##$\hfil\cr>\cr\sim\cr}}} {\vcenter{\offinterlineskip\halign{\hfil$\textstyle## $\hfil\cr>\cr\sim\cr}}} {\vcenter{\offinterlineskip\halign{\hfil$\scriptstyle## $\hfil\cr>\cr\sim\cr}}} {\vcenter{\offinterlineskip\halign{\hfil$\scriptscriptstyle##$ \hfil\cr>\cr\sim\cr}}}}}