$B \to \rho \ell \bar{\nu}$ resonance form factors from $B \to \pi \pi \ell \bar{\nu}$ in lattice QCD

Leskovec, Luka (avtor), Meinel, Stefan (avtor), Petschlies, Marcus (avtor), Negele, John W. (avtor), Paul, Srijit (avtor), Pochinsky, Andrew (avtor)

The decay $B \to \rho \ell \bar{\nu}$ is an attractive process for determining the magnitude of the smallest Cabibbo-Kobayashi-Maskawa matrix element, $|V_{ub}|$, and can provide new insights into the origin of the longstanding exclusive-inclusive discrepancy in determinations of this standard-model parameter. This requires a nonperturbative QCD calculation of the $B \to \rho$ form factors $V$, $A_0$, $A_1$, and $A_{12}$. The unstable nature of the $\rho$ resonance has prevented precise lattice QCD calculations of these form factors to date. Here, we present the first lattice QCD calculation of the $B \to \rho$ form factors in which the $\rho$ is treated properly as a resonance in $P$-wave $\pi \pi$ scattering. To this end, we use the Lellouch-Lüscher finite-volume formalism to compute the $B \to \pi \pi$ form factors as a function of both momentum transfer and $\pi \pi$ invariant mass, and then analytically continue to the $\rho$ resonance pole. This calculation is performed with 2 + 1 dynamical quark flavors at a pion mass of approximately 320 MeV, and demonstrates a clear path toward results at the physical point.

• Jezik: Angleški jezik
• Ključne besede: physics of elementary particles, particle interactions, lattice QCD, form factors
• Vrsta gradiva: Članek v reviji
• Tipologija: 1.01 - Izvirni znanstveni članek
• Organizacija: FMF - Fakulteta za matematiko in fiziko
• Status publikacije: Objavljeno
• Različica publikacije: Objavljena publikacija
• Leto izida: 2025
• Št. strani: Str. 161901-1-161901-8
• Številčenje: Vol. 134, iss. 16
• PID: 20.500.12556/RUL-168786
• UDK: 539.120.811
• ISSN pri članku: 0031-9007
• DOI: 10.1103/PhysRevLett.134.161901
• COBISS.SI-ID: 234136323
• Datum objave v RUL: 24.04.2025

Gradivo je del revije

• Naslov: Physical review letters
• Skrajšan naslov: Phys. rev. lett.
• Založnik: American Physical Society
• ISSN: 0031-9007
• COBISS.SI-ID: 1282575

Licence

• Licenca: CC BY 4.0, Creative Commons Priznanje avtorstva 4.0 Mednarodna
• Povezava: http://creativecommons.org/licenses/by/4.0/deed.sl
• Opis: To je standardna licenca Creative Commons, ki daje uporabnikom največ možnosti za nadaljnjo uporabo dela, pri čemer morajo navesti avtorja.

Sekundarni jezik

• Jezik: Slovenski jezik
• Ključne besede: fizika osnovnih delcev, interakcije delcev, kvantna kromodinamika na mreži, oblikovni faktorji