A N f = 2 + 1 + 1 “twisted” determination of the b-quark mass, f B and f B s N. Carrasco (a,b) , P. Dimopoulos (c,d) , R. Frezzotti (d) , V. Giménez (a) , P. Lami (e,b) , V. Lubicz (e,b) , E. Picca ∗ (e,b) , L. Riggio (e,b) , G.C. Rossi (d) , F. Sanﬁlippo ( f ) , S. Simula (b) , C. Tarantino (e,b) (a) Departament de Física Teòrica and IFIC, Univ. de València-CSIC, Av. Dr. Moliner 50, E-46100 València, Spain, E-mail: nuria.carrasco@uv.es, vincente.gimenez@uv.es (b) INFN, Sezione di Roma Tre, Via della Vasca Navale 84, I-00146 Rome, Italy, E-mail: simula@roma3.infn.it (c) Centro Fermi - Museo storico della Fisica e Centro Studi e Ricerche Enrico Fermi, Compendio del Viminale, Piazza del Viminale 1, I-00184 Rome, Italy (d) Dipartimento di Fisica, Università di Roma “Tor Vergata” and INFN Sezione “Tor Vergata”, Via della Ricerca Scientiﬁca 1, I-00133 Rome, Italy, E-mail: dimopoulos@roma2.infn.it, frezzotti@roma2.infn.it, rossig@roma2.infn.it (e) Dipartimento di Matematica e Fisica, Università Roma Tre, Via della Vasca Navale 84, I-00146 Rome, Italy, Email: lamipaolo@gmail.com, lubicz@fis.uniroma3.it, e.picca88@gmail.com, lorenzo.riggio@gmail.com, tarantino@fis.uniroma3.it ( f ) Laboratoire de Physique Théorique (B ˆ at. 210), Université Paris Sud, F-91405 Orsay-Cedex, France, Email: francesco.sanfilippo@th.u-psud.fr For the ETM Collaboration We present a lattice QCD determination of the b-quark mass and of the f B s and f B decay con- stants performed with N f = 2 + 1 + 1 twisted mass Wilson fermions. We have used simulations at three values of the lattice spacing generated by ETMC with pion masses ranging from 210 to 440 MeV. To obtain physical quantities we performed a combined chiral and continuum limit and an extrapolation in the heavy quark mass from the charm to the b-quark region using suit- able ratios calculated at nearby heavy-quark masses having an exactly known static limit. Our results are: m b (m b )= 4.29(13) GeV, f B = 196(9) MeV, f B s = 235(9) MeV, f B s / f B = 1.201(25), ( f B s / f B )/( f K / f π )= 1.007(16) and ( f B s / f B )/( f D s / f D )= 1.008(13). 31st International Symposium on Lattice Field Theory LATTICE 2013 July 29 - August 3, 2013 Mainz, Germany ∗ Speaker. c  Copyright owned by the author(s) under the terms of the Creative Commons Attribution-NonCommercial-ShareAlike Licence. http://pos.sissa.it/