Luminosity measures the density of collisions at the LHC and is a key parameter for both physics analyses and accelerator operations. Its calibration is performed annually through a series of scans called the Van der Meer program (VdM). This project presents a preliminary analysis of the variable length scale scan, from the 2024 VdM program. The main goal is to determine the correction to the luminosity calibration constant related to the VLS method. For this purpose, a methodology developed for the Run 2 Analysis by the Luminosity CMS group was adapted to the specific conditions of the 2024 dataset. The method relies on using reconstructed vertices from the pixel detector during the mini-scans to determine the position of maximum overlap and compare it with the nominal position given by the accelerator control system. The comparison allows the determination of the VLS correction and its uncertainty. The results show a correction for each beam in both directions (x and y). The analysis indicates that the correction in x for the first beam and in y for both beans is of the order of 1%, while the correction in x for the second beam is about 2%. These corrections contribute to the determination of the normalization uncertainty in luminosity measurements.

Luminosity measures the density of collisions at the LHC and is a key parameter for both physics analyses and accelerator operations. Its calibration is performed annually through a series of scans called the Van der Meer program (VdM). This project presents a preliminary analysis of the variable length scale scan, from the 2024 VdM program. The main goal is to determine the correction to the luminosity calibration constant related to the VLS method. For this purpose, a methodology developed for the Run 2 Analysis by the Luminosity CMS group was adapted to the specific conditions of the 2024 dataset. The method relies on using reconstructed vertices from the pixel detector during the mini-scans to determine the position of maximum overlap and compare it with the nominal position given by the accelerator control system. The comparison allows the determination of the VLS correction and its uncertainty. The results show a correction for each beam in both directions (x and y). The analysis indicates that the correction in x for the first beam and in y for both beans is of the order of 1%, while the correction in x for the second beam is about 2%. These corrections contribute to the determination of the normalization uncertainty in luminosity measurements.