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\begin{document}
\vspace*{4cm}
\title{A Light Higgs Boson Explanation for the $g-2$ Crisis \footnote{Talk
given at the XXXVIth Rencontres de Moriond  
``Electroweak Interactions and Unified Theories'',
Les Arcs 1800,  March 10-17, 2001.  }}

\author{ A. Dedes$^1$ and H. E. Haber$^2$ }

\address{$^1$Physikalisches Institut der Universit\"at Bonn,\\ 
 Nu\ss allee 12, D-53115 Bonn, Germany}
%E-mail: \email{dedes@th.physik.uni-bonn.de}

\address{$^2$Santa Cruz Institute for Particle Physics\\ 
University of California, Santa Cruz, CA, 95064 USA }



\maketitle\abstracts{ We have shown in hep-ph/0102297
 that a light CP-even Higgs
boson with a mass of around 10 GeV could explain the recent 
BNL measurement of the muon anomalous magnetic moment. This observation
is based on
a general two Higgs 
doublet extension of the Standard Model with neither CP violating nor
 tree level 
flavour changing neutral current couplings.  The
Higgs mass is constraint from CESR and LEP experiments 
to be less than twice the lightest B-meson mass
and greater than the Upsilon mass. LEP and CLEO would be able 
to exclude or discover such a possibility by using their
existing data.}



%\newpage
\section{A possibility for New physics from the $g-2$ measurement at BNL E821}
Based on Davier-H\"ocker calculation for the hadronic contributions
to the muon anomalous magnetic moment, BNL~\cite{bnl}
 reports a 2.6$\sigma$ deviation
from the Standard Model(SM) prediction. There are four possibilities
to interpret this discrepancy~\cite{ond} :
\begin{itemize}

\item a statistical fluctuation with 0.9\% probability.

\item something is ``wrong'' with the experiment : this
is going to  be resolved soon (by Christmas~\cite{ond}) since 
there is four times more data to be analyzed, and  the measurement
on $\mu^-$ which is in progress at the moment.

\item something is ``wrong'' with the hadronic contributions to
the muon anomalous magnetic moment, $a_\mu^{had}$. However, there
is a lot more data from Novorsibirsk and BES to appear and there 
is an intense effort from both theory and experimental
groups~\cite{hocker,erler,ynd,narison}
towards to that direction.

\item the by far most exciting possibility : there is a New Physics
beyond the SM, $\amu$. At 90\% CL this is~\cite{marciano,hocker,narison} 
%%%%%%%%%%%%%%%%%%%%%%%
\begin{eqnarray}
215 \times 10^{-11} \lsim &\amu & \lsim 637 \times 10^{-11}~~~ 
[{\rm Davier-Hocker (98)}]\;, \label{dh}\\
159 \times 10^{-11} \lsim &\amu & \lsim 599 \times 10^{-11}~~~ 
[{\rm Narison (01)}] \label{nar}
\end{eqnarray}
%%%%%%%%%%%%%%%%%%%%%%%%%
The above different bounds are based on the most recent independent
evaluations of the hadronic vacuum polarization contributions to
$a_\mu$. 

\end{itemize}
In what follows, we assume  the fourth possibility as an explanation
to the discrepancy under discussion. Two remarks on (\ref{dh},\ref{nar})
are in order~\cite{marciano} :
{\it i)} the contribution from the New Physics is positive, $\amu >0$,
and {\it ii)},  is of the order of the Electroweak (EW) contributions,
{\it i.e.,} $\amu \propto \frac{G_F m_\mu^2}{4\pi^2\sqrt{2}}$.     

\subsection{Why not from the Higgs sector?}
In the SM, the 1-loop Higgs boson contribution to the muon anomalous 
magnetic moment is suppressed by a factor of $m_\mu^2/m_h^2$, since the
SM Higgs mass is bounded from LEP to be greater than 113.5 GeV.
The situation is different if we extend the SM by adding an extra 
Higgs doublet~\cite{hunters}. The idea that a light Higgs boson 
could enhanced the predicted value of $a_\mu$ has been recently 
employed in Ref~\cite{dedhab,kraw}. Here we strictly follow the 
discussion of Ref~\cite{dedhab}~\footnote{For the purposes of this presentation
we refer to the Two Higgs Doublet Model (II) [2HDM(II)]. For the Model~I
see the discussion in Ref~\cite{dedhab} and for Model~III see 
Ref~\cite{2hdm3}.}.
 The enhancement arises from the Higgs sector is twofold:
{\it i)} the coupling of the muon  to the light CP-even Higgs (h),
 CP-Odd Higgs (A) and charged higgs ($H^\pm$)
 is proportional to $\tan\beta$ (the ratio
of the two vacuum expectation values), and hence $\amu \propto
\tan^2\beta$
 {\it ii}) the higgs coupling
to the Z-boson  can be set to zero, {\it i.e.,} $\sinbma=0$, ($\alpha$
is the mixing angle between the two CP-even Higgs bosons)
and thus LEP constraints from
$e^+e^-\rightarrow hZ$
cannot be applied~\cite{sin2}. In this case the Higgs
mass can be as light as $\sim 10$ GeV.  



\section{Model~II Higgs boson corrections to $a_\mu$}

The first calculation of the one-loop electroweak corrections to the muon
anomalous magnetic moment was presented by Weinberg and
Jackiw~\cite{Jackiw:1972jz} and 
by Fujikawa, Lee and Sanda~\cite{Fujikawa:1972fe}.  A very useful
compendium of formulae for the one-loop corrections to $g-2$
in a general electroweak model was
given in \cite{Leveille:1978rc}, 
and applied to the 2HDM in \cite{haber}.
In the 2HDM, both neutral and charged Higgs bosons contribute to $g-2$.
 One can derive approximate results 
by expanding the loop integrals in terms of the parameters
$R_{h,H,A,H^\pm}\equiv m_\mu^2/m_{h,H,A,H^\pm}^2$,
$R_\nu\equiv m_\nu^2/m_{H^\pm}^2$ (here we neglect the neutrino mass).

\subsection{Non-decoupling limit: $\sin(\beta-\alpha)=0$}

In section 1, we argued that the most significant Higgs contribution
to $\amu$ (consistent with the LEP SM Higgs search) arises in the
parameter regime in which $\sinbma\simeq 0$ and $\tanb\gg 1$.  
Setting  $\sinbma=0$ and keeping only the leading terms in 
$R$ when evaluating the above integrals, 
the total Higgs sector
 contribution to $a_\mu$ at 1-loop\footnote{Part  of
the dominant two-loop corrections have been discussed in
Ref.~\cite{2loop}.}
is given by:
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%5
\begin{eqnarray}
&& \delta a_\mu^{\rm Higgs}=  \delta a_\mu^h+\delta a_\mu^H
+\delta a_\mu^A+
\delta a_\mu^{H^\pm}  \nonumber \\[5pt]
&& \qquad\simeq\frac{G_Fm_\mu^2}{4\pi^2 \sqrt{2}}
\tan^2\beta \bigg \{
\frac{m_\mu^2}{\mhl^2} \biggl[\ln\left(\frac{\mhl^2}{m_\mu^2}\right)
-\frac{7}{6} \biggr] -\frac{m_\mu^2}{\mha^2} \biggl[
\ln\left(\frac{\mha^2}{m_\mu^2}\right) -\frac{11}{6}\biggr]-
\frac{m_\mu^2}{6m_{H^{\pm}}^2} \biggr \} \;. 
\label{hfull}
\end{eqnarray}
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
Note that the 
logarithms appearing in (\ref{hfull}) always dominate the corresponding
constant terms when the Higgs masses are larger than 1 GeV.
It is then clear that $\ha$ and $\hpm$ exchange contribute a
negative value to $\amu$ and thus cannot explain   the BNL $g-2$
measurement which suggests a positive value for $\amu$. In addition,
we  should take
$\mha$ and $\mhpm$ large (masses above 100~GeV are sufficient)
in order that the corresponding
$\ha$ and $\hpm$ negative contributions are 
neglibly small. If $\amu$ is to 
be a consequence of the Higgs sector, it must be entirely
due to the contribution of the light CP-even Higgs boson.
Note that the heavier
CP-even Higgs, $\hh$, does not give a contribution proportional to
$\tan\beta$ ; hence its contribution
to $\amu$ can be neglected in (\ref{hfull}). 
Thus, to a good approximation,

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
\begin{equation}
\delta a_{\mu}^{\rm Higgs}\simeq 
\delta a_\mu^{{\hl}} \simeq \frac{G_Fm_\mu^2}{4\pi^2 \sqrt{2}}
\left(\frac{m_\mu^2}{\mhl^2}\right) \tan^2\beta
\bigg[
\ln\left(\frac{\mhl^2}{m_\mu^2}\right)-\frac{7}{6} \biggr ] \;.
\label{app1}
\end{equation}
%%%%%%%%%%%%%%%%%%%%%%%

One can check that a light Higgs boson with a mass of
around 10 GeV and with $\tan\beta=35$ gives $\delta a_{\mu}^{\rm
Higgs}\simeq 280 \times 10^{-11}$, which is within the
90\%~CL allowed range for $\amu$ quoted in (\ref{dh},\ref{nar}).
Contour lines corresponding to a full numerical 
evaluation of the Higgs sector one-loop 
contribution to $\delta
a_\mu^{\rm Higgs}$ [in units of $10^{-11}$] are exhibited
in fig.~1a, for $\sinbma=0$ and $\mhh=\mha=\mhpm=200$~GeV.\footnote{% 
The results are insensitive to the values of the heavy Higgs masses
above 100~GeV.}
The relevant experimental bounds are also displayed
in fig.~1; [see discussion below].
A careful inspection of the excluded region in the $\mhl$ {\it vs.}
$\tanb$ parameter space shows that a light
Higgs boson of around 10 GeV mass and $25\lsim \tan\beta \lsim 35$
is permitted depending on the lower bound of Eq.(\ref{dh},\ref{nar}).
In this parameter regime, we obtain
a value for $\amu$ within the $90\%$~CL allowed range of
(\ref{dh}).  However, the central values of $\amu$ given
in Refs~\cite{marciano,narison} lie within the excluded regions of fig.~1a.  



%%%%%%%%%%%%%%%%%% FIG 1 %%%%%%%%%%%%%%%%%%%%%%%%%%%%
\begin{figure}
\rule{5cm}{0.2mm}\hfill\rule{5cm}{0.2mm}
\vskip 2.5cm
\hbox{\centerline{\psfig{figure=non_decoup_up.ps,height=3.2in,angle=90}
\psfig{figure=decoup.ps,height=3.2in,angle=90}}}
\caption{{\bf a)}
Contours of the  predicted one-loop Higgs sector contribution
to the muon anomalous magnetic moment, 
$\delta \alpha_\mu^{\rm Higgs}$ (in units of $10^{-11}$)
in the 2HDM, assuming that $\sin(\beta-\alpha)=0$, 
and $\mhh=\mha=\mhpm=200$~GeV
(there is little sensitivity to the heavier Higgs masses).
The dashed line contours correspond to the central value of
$\delta a_\mu\equiv a_\mu^{\rm exp}-a_\mu^{\rm SM}$, as reported 
by Brown {\it et.al} and by Narison.
The contour lines marked 215 and 637 correspond to 90\%~CL limits
for the contribution of new physics to $a_\mu$ (\ref{dh}). The contour
159 corresponds to the lower bound on $\amu$ given in (\ref{nar}).
The dark-shaded (red) region is excluded 
by the CUSB Collaboration search for $\Upsilon\to\hl\gamma$ 
at CESR.  The light-shaded (yellow) region 
is excluded at $95\%$~CL by the ALEPH and DELPHI searches
for $e^+e^-\to \hl f\bar f$ ($f=b$ or $\tau$) at LEP.
In the small hatched region (green) nestled between the 
two experimentally excluded
shaded regions, above the 159 contour line and 
centered around $\mhl\simeq 10$~GeV, the Higgs sector
contribution to $\amu$ lies within the 90\% CL allowed range
(\ref{dh},\ref{nar}). {\bf b)} Contour plot of the   
Higgs 1-loop contributions
to the muon $g-2$ anomalous magnetic moment $\delta a_\mu^{\rm Higgs}$
(in units of $10^{-14}$), on a plane $M_A-\tan\beta$, 
in the decoupling limit, {\it i.e.,} $\sin(\beta-\alpha)=1$.
The light Higgs boson mass has been fixed to be just above the current
experimental bound, 
$M_h=115$ GeV. The heavy CP-even and the charged Higgses are
taken to be equal to $M_A$. Note the residual enhancement with the 
$\tan\beta$ even in the (``decoupled'') region  of large $M_A$.}
\end{figure}
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%


\subsection{Decoupling limit: $\sin(\beta-\alpha)=1$}

In the decoupling limit, where $\sinbma\simeq 1$ and $\mha\gg\mz$,
the couplings of the light Higgs boson,
$\hl$, are (nearly) identical to those of the SM Higgs boson.
As a result, the LEP SM Higgs mass bound of $\mhl\gsim 113.5$~GeV applies.
For $\sinbma=1$, the $\hh$ couplings to down-type fermion pairs are 
enhanced by $\tanb$.
Thus, the Higgs sector contribution to $\amu$ is given by
(\ref{hfull}), with $\mhl$ replaced by $\mhh$.  In the decoupling limit,
$\mhh\simeq\mha\simeq \mhpm$ [the mass differences are of ${\cal
O}(\mz^2/\mha)$].  Setting $\sinbma=1$ and $\mhh=\mha=\mhpm$, we find
%%%%%%%%%%%%%%%%%%%%%%%%%%%%
\begin{eqnarray}
\delta a_\mu^{\rm Higgs} \simeq  \frac{G_Fm_\mu^2}{4 \pi^2\sqrt{2}}
\left(\frac{m_\mu^2}{\mha^2}\right)\tan^2\beta \biggl[
\frac{1}{2}-\left(\frac{2m_\mu^2}{\mha^2}\right) 
\ln\left(\frac{\mha^2}{m_\mu^2}\right)
 \biggr ]\;.
\label{app2}
\end{eqnarray}
%%%%%%%%%%%%%%%%%%%%%%%%%%%
The contribution of $\hl$ is not $\tanb$--enhanced and is thus
negligible.  It is interesting to note that for values of
$\mha\lsim\mhl\tanb$, the heavier (``decoupled'')
Higgs bosons actually dominate in the Higgs sector contribution
to $\amu$.\footnote{If we formally take $\mha\to\infty$, we recover
the Standard Model Higgs contribution to $a_\mu$.}
However, for 100~GeV $<\mha< 1000$~GeV, and $30<\tanb<100$,
the Higgs sector contribution to $a_\mu$ ranges from about $3\times
10^{-12}$ to $3\times 10^{-14}$, which is
three to five orders of magnitude below what
is needed to explain the BNL measurement of $a_\mu$ [see fig.1b].  


\subsection{Experimental constraints from CESR and LEP}

Let us consider the 2HDM in which $\sinbma=0$, $\tanb\gg 1$
and $\mhl\sim {\cal O}(10$~GeV), which are necessary conditions
if the Higgs sector is to be the source for $\amu$ in the range
given by Eq.(\ref{dh},\ref{nar}).
The $\hl\ha Z$ coupling is maximal , so we 
must assume that $\mha$ is large enough so that
$e^+e^-\to \hl\ha$ is not observed at LEP.
The tree-level $\hl ZZ$ coupling is absent, which implies that
the LEP SM Higgs search based on $e^+e^-\to Z\to Z\hl$ does not impose
any significant constraints on $\mhl$.\footnote{Presumably,
radiative corrections would lead to a small effective value for
$\sinbma$.  The LEP Higgs search yields an excluded region in the 
$\sinbma$ {\it vs.} $\mhl$ plane, and implies that for $\mhl\sim 10$~GeV, 
$|\sinbma|\lsim 0.06$ is not excluded
at 95\%~CL~\cite{Janot,Sopczak:1995zy}.}  
However, there are a number of constraints on light Higgs masses 
that do not rely on the $\hl ZZ$ coupling.  For Higgs bosons with
$\mhl\lsim 5$~GeV, the SM Higgs boson was ruled out by a
variety of arguments that were summarized in \cite{hunters}.  For
5~GeV $\lsim\mhl\lsim 10$~GeV, the relevant
Higgs boson constraint can be derived 
from the absence of Higgs production in $\Upsilon\to\hl\gamma$ [see
red region in Fig.1a].
A second bound on $\mhl$ can be derived from the non-observation of 
Higgs bosons at LEP  via the 
process $e^+e^-\to \hl f\bar f$ ($f=b$, $\tau$). However, only preliminary results have appeared so far
by DELPHI~\cite{delphi} and ALEPH~\cite{aleph} [see yellow region in
Fig.1a].
One noteworthy consequence of $\mhl\sim 10$~GeV is
the possibility of mixing
between the $\hl$ and the $0^{++}$ $b\bar b$ bound states
$\chi\ls{b0}(1P)$ and $\chi\ls{b0}(2P)$, as
discussed in \cite{haber,egns}.  As a result, the decay
$\chi\ls{b0}\to\tau^+\tau^-$ should be prominent. For more details
see Ref.\cite{dedhab}.


\section{Results}

If we combine the experimental bounds on the Higgs mass discussed in
section 2, 
we conclude that a light Higgs boson
can be responsible for the observed
$2.6\sigma$ deviation of the BNL measurement of the muon 
anomalous magnetic moment at the 90\%~CL in the framework of a
two-Higgs-doublet model with Model~II Higgs-fermion Yukawa couplings 
only if the model parameters satisfy the
following requirements:
%%%%%%%%%%%%%%%%%%
\begin{eqnarray}
&& m_{\Upsilon}\lsim \mhl \lsim 2 m_B \;, \nonumber \\
&& \sinbma\simeq 0 \;, \nonumber \\
&& 30\lsim\tanb\lsim 35~~~{\rm [Davier-Hocker (98)]} \;, \nonumber \\
&& 25\lsim\tanb\lsim 35~~~{\rm [Narison (01)]} \;.
\label{result}
\end{eqnarray}
%%%%%%%%%%%%%%%%%%
In addition, the other Higgs bosons should be heavy enough 
to satisfy the LEP bounds. Although, the parameter space 
is highly constraint we think that LEP (and maybe CLEO) 
ought to search for such a possibility.


To justify the word ``Crisis'' in the title, is enough to
indicate the enormous activity~\cite{susy,tecni,lepto,exotic,modelind}
 and excitement on a possible
Physics Beyond the SM from the BNL muon anomalous magnetic moment
measurements.



%\begin{figure}
%\rule{5cm}{0.2mm}\hfill\rule{5cm}{0.2mm}
%\vskip 2.5cm
%\rule{5cm}{0.2mm}\hfill\rule{5cm}{0.2mm}
%\psfig{figure=filename.ps,height=1.5in}
%\caption{Radiative (off-shell, off-page and out-to-lunch) SUSY Higglets.
%\label{fig:radish}}
%\end{figure}

\section*{Acknowledgments}

AD would like to thank A. H\"ocker, G. Onderwater, M. Schumacher, 
P. Teixeira Dias, W. Murray, R. Teuscher, P. Janot, J.M. Frere, 
E. Tournefier, A. Sanda for 
illuminating discussions on the muon $g-2$, Higgs and EW searches, and also
the organizers of this excellent workshop.
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
\section*{References}
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H.~N.~Brown {\it et al.}  [Muon $g-2$ Collaboration],
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hep-ex/0102017.
%%CITATION = HEP-EX 0102017;%%

\bibitem{ond}
See talk by G. Onderwater, these proceedings.

\bibitem{marciano}
For a review see A.~Czarnecki and W.~J.~Marciano,
%``The muon anomalous magnetic moment: A harbinger for 'new physics',''
hep-ph/0102122; see also talk by A.~Czarnecki, these proceedings.
%%CITATION = HEP-PH 0102122;%%


\bibitem{hocker}
M.~Davier and A.~H\"ocker,
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%\cite{Yndurain:2001qw}
\bibitem{ynd}
F.~J.~Yndurain,
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%%CITATION = HEP-PH 0102312;%%


\bibitem{erler}
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hep-ph/0101010.
%%CITATION = HEP-PH 0101010;%%

\bibitem{narison}
S.~Narison,
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%%CITATION = HEP-PH 0103199;%%

\bibitem{hunters}
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A.~Dedes and H.~E.~Haber,
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%%CITATION = HEP-PH 0102297;%%


\bibitem{kraw}
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%%CITATION = HEP-PH 0103223;%%

\bibitem{2hdm3}
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%%CITATION = HEP-PH 0103083;%%
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%%CITATION = HEP-PH 0103105;%%
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hep-ph/0103064.
%%CITATION = HEP-PH 0103064;%%




\bibitem{sin2}
See the LEP~I plot in : {\tt http://scipp.ucsc.edu/$\sim$haber/sba94.gif} .


\bibitem{Jackiw:1972jz}
R.~Jackiw and S.~Weinberg,
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Phys.\ Rev.\ D {\bf 5} (1972) 2396.
%%CITATION = PHRVA,D5,2396;%%

%\cite{Fujikawa:1972fe}
\bibitem{Fujikawa:1972fe}
K.~Fujikawa, B.W.~Lee and A.I.~Sanda,
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Phys.\ Rev.\ D {\bf 6} (1972) 2923.
%%CITATION = PHRVA,D6,2923;%%

\bibitem{Leveille:1978rc}
J.P.~Leveille,
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%%CITATION = NUPHA,B137,63;%%


\bibitem{haber}
H.E.~Haber, G.L.~Kane and T.Sterling,
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%%CITATION = NUPHA,B161,493;%%


\bibitem{2loop}
K.~Cheung, C.~Chou and O.~C.~Kong,
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hep-ph/0103183.
%%CITATION = HEP-PH 0103183;%%


\bibitem{Janot} P.~Janot, private communication.  Previous bounds have
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\bibitem{Sopczak:1995zy}
A.~Sopczak,
%``Status of Higgs hunting at LEP: Five years of progress,''
hep-ph/9504300.
%%CITATION = HEP-PH 9504300;%%


\bibitem{delphi}
J.~Kurowska, O.~Grajek and P.~Zalewski  [DELPHI Collaboration],
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\bibitem{aleph}
J.B.~de Vivie and P.~Janot [ALEPH Collaboration], ``Search for a Light
Higgs Boson in the Yukawa Process,'' PA13-027 contribution to the
International Conference on High Energy Physics, Warsaw, Poland,
25--31 July 1996.


\bibitem{egns}
J.~Ellis, M.K.~Gaillard, D.V.~Nanopoulos and C.T.~Sachrajda,
%``Is the Mass of the Higgs Boson about 10~GeV?,''
Phys.\ Lett.\ B {\bf 83} (1979) 339.
%%CITATION = PHLTA,B83,339;%%






\bibitem{susy} Supersymmetric models :
L.~Everett, G.~L.~Kane, S.~Rigolin and L.~Wang,
%``Implications of muon g-2 for supersymmetry and for discovering  superpartners directly,''
hep-ph/0102145;
%%CITATION = HEP-PH 0102145;%%
J.~L.~Feng and K.~T.~Matchev,
%``Supersymmetry and the anomalous anomalous magnetic moment of the muon,''
hep-ph/0102146;
%%CITATION = HEP-PH 0102146;%%
E.~A.~Baltz and P.~Gondolo,
%``Implications of muon anomalous magnetic moment for supersymmetric dark  matter,''
hep-ph/0102147.
%%CITATION = HEP-PH 0102147;%%
U.~Chattopadhyay and P.~Nath,
%``Upper limits on sparticle masses from g-2 and the possibility for  discovery of SUSY at colliders and in dark matter searches,''
hep-ph/0102157.
%%CITATION = HEP-PH 0102157;%%
J.~Ellis, D.~V.~Nanopoulos and K.~A.~Olive,
%``Combining the muon anomalous magnetic moment with other constraints on  the CMSSM,''
hep-ph/0102331.
%%CITATION = HEP-PH 0102331;%%
R.~Arnowitt, B.~Dutta, B.~Hu and Y.~Santoso,
%``Muon g-2, dark matter detection and accelerator physics,''
hep-ph/0102344.
%%CITATION = HEP-PH 0102344;%%
J.~E.~Kim, B.~Kyae and H.~M.~Lee,
%``Effective supersymmetric theory and (g-2)(mu) with R parity violation,''
hep-ph/0103054.
%%CITATION = HEP-PH 0103054;%%
S.~P.~Martin and J.~D.~Wells,
%``Muon anomalous magnetic dipole moment in supersymmetric theories,''
hep-ph/0103067.
%%CITATION = HEP-PH 0103067;%%
S.~Baek, P.~Ko and H.~S.~Lee,
%``Muon anomalous magnetic moment, $B\to X_s \gamma$ and dark matter detection in the string models with dilaton domination,''
hep-ph/0103218.
%%CITATION = HEP-PH 0103218;%%
K.~Choi, K.~Hwang, S.~K.~Kang, K.~Y.~Lee and W.~Y.~Song,
%``Probing the messenger of supersymmetry breaking by the muon anomalous  magnetic moment,''
hep-ph/0103048.
%%CITATION = HEP-PH 0103048;%%
S.~Komine, T.~Moroi and M.~Yamaguchi,
%``Recent result from E821 experiment on muon g-2 and unconstrained  minimal supersymemtric standard model,''
hep-ph/0102204.
%%CITATION = HEP-PH 0102204;%%
S.~Komine, T.~Moroi and M.~Yamaguchi,
%``No-Scale Scenarios in the Light of New Measurement of Muon Anomalous Magnetic Moment,''
hep-ph/0103182.
%%CITATION = HEP-PH 0103182;%%
T.~Ibrahim, U.~Chattopadhyay and P.~Nath,
%``Constraints on explicit CP violation from the Brookhaven muon g-2  experiment,''
hep-ph/0102324.
%%CITATION = HEP-PH 0102324;%%






\bibitem{tecni} Technicolor Models :
P.~Das, S.~Kumar Rai and S.~Raychaudhuri,
%``Anomalous magnetic moment of the muon in a composite model,''
hep-ph/0102242.
%%CITATION = HEP-PH 0102242;%%
Z.~Xiong and J.~M.~Yang,
%``Muon anomalous magnetic moment in technicolor models,''
hep-ph/0102259.
%%CITATION = HEP-PH 0102259;%%
C.~Yue, Q.~Xu and G.~Liu,
%``Topcolor assisted technicolor models and muon anomalous magnetic  moment,''
hep-ph/0103084.
%%CITATION = HEP-PH 0103084;%%







\bibitem{lepto} Leptoquarks :
D.~Chakraverty, D.~Choudhury and A.~Datta,
%``A nonsupersymmetric resolution of the anomalous muon magnetic moment,''
hep-ph/0102180.
%%CITATION = HEP-PH 0102180;%%
K.~Cheung,
%``Muon anomalous magnetic moment and leptoquark solutions,''
hep-ph/0102238.
%%CITATION = HEP-PH 0102238;%%

\bibitem{exotic} Lepton Flavour violation, exotic fermions and gauge
  bosons,
and extra dimensions :
T.~Huang, Z.~H.~Lin, L.~Y.~Shan and X.~Zhang,
%``Muon anomalous magnetic moment and lepton flavor violation,''
hep-ph/0102193.
%%CITATION = HEP-PH 0102193;%%
D.~Choudhury, B.~Mukhopadhyaya and S.~Rakshit,
%``Muon anomalous magnetic moment confronts exotic fermions and gauge  bosons,''
hep-ph/0102199.
%%CITATION = HEP-PH 0102199;%%
S.~N.~Gninenko and N.~V.~Krasnikov,
%``The muon anomalous magnetic moment and a new light gauge boson,''
hep-ph/0102222.
%%CITATION = HEP-PH 0102222;%%
T.~W.~Kephart and H.~Pas,
%``Muon anomalous magnetic moment in string inspired extended family  models,''
hep-ph/0102243.
%%CITATION = HEP-PH 0102243;%%
E.~Ma and M.~Raidal,
%``Neutrino mass, muon anomalous magnetic moment, and lepton flavor  nonconservation,''
hep-ph/0102255.
%%CITATION = HEP-PH 0102255;%%
Z.~Xing,
%``Nearly bi-maximal neutrino mixing, muon g-2 anomaly and  lepton-flavor-violating processes,''
hep-ph/0102304.
%%CITATION = HEP-PH 0102304;%%
J.~Hisano and K.~Tobe,
%``Neutrino masses, muon g-2, and lepton-flavour violation in the  supersymmetric see-saw model,''
hep-ph/0102315.
%%CITATION = HEP-PH 0102315;%%
X.~Calmet, H.~Fritzsch and D.~Holtmannspotter,
%``The anomalous magnetic moment of the muon and radiative lepton decays,''
hep-ph/0103012.
%%CITATION = HEP-PH 0103012;%%
S.~Rajpoot,
%``Muon anomalous magnetic moment in models with singlet fermions,''
hep-ph/0103069.
%%CITATION = HEP-PH 0103069;%%
S.~C.~Park and H.~S.~Song,
%``Muon anomalous magnetic moment and the stabilized Randall-Sundrum  scenario,''
hep-ph/0103072.
%%CITATION = HEP-PH 0103072;%%
D.~A.~Dicus, H.~He and J.~N.~Ng,
%``Neutrino-lepton masses, zee scalars and muon g-2,''
hep-ph/0103126.
%%CITATION = HEP-PH 0103126;%%
K.~Agashe, N.~G.~Deshpande and G.~H.~Wu,
%``Can extra dimensions accessible to the SM explain the recent measurement of anomalous magnetic moment of the muon?,''
hep-ph/0103235.
%%CITATION = HEP-PH 0103235;%%
C.~S.~Kim, J.~D.~Kim and J.~Song,
%``Muon anomalous magnetic moment (g-2)mu and the Randall-Sundrum model,''
hep-ph/0103127.
%%CITATION = HEP-PH 0103127;%%


\bibitem{modelind} Model independent analysis :
M.~B.~Einhorn and J.~Wudka,
%``Model-independent analysis of g(mu)-2,''
hep-ph/0103034.
%%CITATION = HEP-PH 0103034;%%







\end{thebibliography}

\end{document}

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