Rho resonance parameters from lattice QCD

Journal Article · Mon Aug 01 04:00:00 EDT 2016 · Physical Review D

DOI:https://doi.org/10.1103/PhysRevD.94.034501· OSTI ID:1306424

Guo, Dehua; Alexandru, Andrei; Molina, Raquel; Döring, Michael

We perform a high-precision calculation of the phase shifts for $$\pi$$-$$\pi$$ scattering in the I = 1, J = 1 channel in the elastic region using elongated lattices with two mass-degenerate quark favors ($$N_f = 2$$). We extract the $$\rho$$ resonance parameters using a Breit-Wigner fit at two different quark masses, corresponding to $$m_{\pi} = 226$$MeV and $$m_{\pi} = 315$$MeV, and perform an extrapolation to the physical point. The extrapolation is based on a unitarized chiral perturbation theory model that describes well the phase-shifts around the resonance for both quark masses. We find that the extrapolated value, $$m_{\rho} = 720(1)(15)$$MeV, is significantly lower that the physical rho mass and we argue that this shift could be due to the absence of the strange quark in our calculation.

• Research Organization: Thomas Jefferson National Accelerator Facility, Newport News, VA (United States)
• Sponsoring Organization: USDOE; USDOE Office of Science (SC), Nuclear Physics (NP) (SC-26)
• OSTI ID: 1306424
• Report Number(s): JLAB-THY-16-2313; DOE/OR/23177-3912; arXiv:1605.03993
• Journal Information: Physical Review D, Journal Name: Physical Review D Journal Issue: 3 Vol. 94; ISSN PRVDAQ; ISSN 2470-0010
• Country of Publication: United States
• Language: English