Rho resonance parameters from lattice QCD

Journal Article · Mon Aug 01 00:00:00 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 (TJNAF), Newport News, VA (United States)
• Sponsoring Organization: USDOE Office of Science (SC), Nuclear Physics (NP)
• DOE Contract Number: PHY-1151648; PHY-1452055; 1415459
• OSTI ID: 1306424
• Report Number(s): JLAB-THY-16-2313; DOE/OR/23177-3912; arXiv:1605.03993; PRVDAQ
• Journal Information: Physical Review D, Vol. 94, Issue 3; Related Information: Jefferson Lab publications: https://misportal.jlab.org/ul/publications/view_pub.cfm?pub_id=14467; ISSN 2470-0010
• Country of Publication: United States
• Language: English