Göttingen 2025 – scientific programme

Parts | Days | Selection | Search | Updates | Downloads | Help

T: Fachverband Teilchenphysik

T 74: Flavour Physics V

T 74.3: Talk

Thursday, April 3, 2025, 16:45–17:00, VG 1.104

Measurement of A_fs^s in B_s⁰→ D_s⁻π⁺ at the LHCb experiment in Run 2 — Johannes Albrecht¹, Jonathan Davies², Agnieszka Dziurda³, Conor Fitzpatrick², •James Andrew Gooding¹, Jairus Patoc⁴, and Nicole Skidmore⁵ — ¹TU Dortmund University, Dortmund, Germany — ²University of Manchester, Manchester, United Kingdom — ³Institute of Nuclear Physics PAS, Kraków, Poland — ⁴University of Oxford, Oxford, United Kingdom — ⁵University of Warwick, Coventry, United Kingdom

B_(s)⁰→ D_(s)^(∗)−h⁺ decays are considered a standard candle of the SM and central to measurements of the CKM angle γ. Recently, tensions between the predicted and measured values of B_(s)⁰→ D_(s)^(∗)−h⁺ branching fractions have emerged of up to 7σ. These tensions leave a possibility for new physics contributions which may enhance time-integrated CP asymmetries by up to 1%. In the SM, CP violation in flavour-specific B_s⁰→ D_s⁻π⁺ decays arises only from B_s⁰−B_s⁰ mixing, measured previously in semi-leptonic B_s⁰ decays as a_sl^s.

The high quality tracking and particle identification offered by the LHCb detector makes it well-equipped to reconstruct B_s⁰→ D_s⁻π⁺ decays in the D_s⁻→ K⁻K⁺π⁻,π⁻π⁺π⁻ decay modes, and thus to measure the time-integrated CP asymmetry A_fs^s. This measurement is performed for the first time using 5.9 fb⁻¹ of pp-collision data recorded at √s=13 TeV during Run 2 of the LHC.

In this contribution, the approach and current status of the analysis is presented. An overview of the sensitivity of this analysis and considerations of detection and production asymmetries is given.

Keywords: LHCb; tree-level; Run 2; LHC; B physics