New photometry and spectroscopy for more than a hundred RR Lyrae stars in two fields located close to the bar of the Large Magellanic Cloud ( LMC ) are used to derive new accurate estimates of the average magnitude , the local reddening , the luminosity-metallicity relation , and of the distance to the LMC .
The average apparent luminosity of the RR Lyrae ’ s with complete V and B light curves is < V ( RR ) > = 19.412 \pm 0.019 ( \sigma =0.153 ) , < B ( RR ) > = 19.807 \pm 0.022 ( \sigma =0.172 ) in our field A ( 62 stars ) , and < V ( RR ) > = 19.320 \pm 0.023 ( \sigma =0.159 ) , < B ( RR ) > = 19.680 \pm 0.024 ( \sigma =0.163 ) in our field B ( 46 stars ) .
The average V apparent luminosity of the clump stars in the same areas is 0.108 and 0.029 mag brighter than the RR Lyrae level ( < V _ { clump } > = 19.304 \pm 0.002 and 19.291 \pm 0.003 , in field A : 6728 stars , and B : 3851 stars , respectively ) .
Metallicities from low resolution spectra obtained with the Very Large Telescope have been derived for 101 RR Lyrae stars , finding an average value of [ Fe/H ] = -1.48 \pm 0.03 ( \sigma =0.29 , on Harris 1996 metallicity scale ) .
An estimate of the reddening within the two fields was obtained ( i ) from Sturch ( 1966 ) method applied to the fundamental mode pulsators ( RRab ’ s ) with known metal abundance ; and ( ii ) from the colors of the edges of the instability strip defined by the full sample of RR Lyrae variable stars .
We obtained : E ( B - V ) =0.116 \pm 0.017 , and 0.086 \pm 0.017 mag in field A and B , respectively , with a clearcut indication of a 0.03 mag differential reddening betweeen the two fields .
We find that reddening in field A is 0.028 mag smaller than derived by OGLE-II in the same area .
On average , the new reddenings are also 0.035 mag larger than derived from Cepheids with projected distances within 2 degrees from the centers of our fields .
The new metallicities were combined with the apparent average V _ { 0 } luminosities to determine the slope of the luminosity-metallicity relation for the RR Lyrae stars .
We derived \Delta { M _ { V } ( RR ) } / \Delta [ Fe/H ] = 0.214 \pm 0.047 , with no clear evidence for the change in slope at [ Fe/H ] = -1.5 , recently suggested by evolutionary/pulsation and Horizontal Branch models .

The dereddened apparent average luminosity of the RR Lyrae ’ s defined by the present photometry is < V ( RR ) > _ { 0 } = 19.064 \pm 0.064 at [ Fe/H ] = -1.5 .

When coupled with the absolute magnitude derived from the Baade-Wesselink and the statistical parallaxes methods ( M _ { V } ( RR ) =0.68 \pm 0.15 and 0.76 \pm 0.13 mag at [ Fe/H ] = - 1.5 ) , both methods known to favour the short distance scale , this value leads to distance moduli for the LMC of \mu _ { { LMC } } =18.38 \pm 0.16 and \mu _ { { LMC } } =18.30 \pm 0.14 , respectively .
If we use instead the absolute magnitude from the new Main Sequence Fitting of Galactic globular clusters ( M _ { V } ( RR ) =0.61 \pm 0.07 mag at [ Fe/H ] = - 1.5 ; Gratton et al .
2002a ) we derive \mu _ { { LMC } } =18.45 \pm 0.09 .

The average I apparent luminosity of the clump stars derived by the present photometry is < I _ { clump } > = 18.319 \pm 0.002 and 18.307 \pm 0.003 , in field A ( \sigma =0.190 , 6728 stars ) and B ( \sigma =0.184 , 3851 stars ) , respectively .
These values once corrected for our new reddening estimates lead to < I > _ { 0 } =18.12 \pm 0.06 mag and move the clump distance modulus to the LMC to 18.42 \pm 0.07 and 18.45 \pm 0.07 , when Udalski [ 2000a , ApJ , 531 , L25 ] or Popowski [ 2000 , ApJ 528 , L9 ] metallicity- I luminosity relations for the clump stars are adopted .

All these values are only 1 \sigma shorter than provided by the Population I distance indicators , and allow to reconcile the short and long distance scale on a common value for the distance modulus of the LMC of \mu _ { { LMC } } =18.515 \pm 0.085 mag .