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Related papers: B-physics with $N_f=2$ Wilson fermions

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We present a lattice QCD determination of the $b$-quark mass and of the $f_{B_s}$ and $f_B$ decay constants performed with $N_f = 2 + 1 + 1$ twisted mass Wilson fermions. We have used simulations at three values of the lattice spacing…

High Energy Physics - Lattice · Physics 2014-10-06 N. Carrasco , P. Dimopoulos , R. Frezzotti , V. Giménez , P. Lami , V. Lubicz , E. Picca , L. Riggio , G. C. Rossi , F. Sanfilippo , S. Simula , C. Tarantino

We present an accurate lattice QCD computation of the b-quark mass, the B and Bs decay constants, the B-mixing bag-parameters for the full four-fermion operator basis, as well as estimates for \xi and f_{Bq}\sqrt{B_q} extrapolated to the…

We present a lattice QCD determination of the b quark mass and of the B and B_s decay constants, performed with N_f=2 twisted mass Wilson fermions, by simulating at four values of the lattice spacing. In order to study the b quark on the…

We present results for the matrix elements of the additional $\Delta S=2$ operators that appear in models of physics beyond the Standard Model (BSM), expressed in terms of four BSM $B$-parameters. Combined with experimental results for…

With Wilson quarks, on-shell O($a$) improvement of the lattice QCD action is achieved by including the Sheikholeslami-Wohlert term and two further operators of mass dimension 5, which amount to a mass-dependent rescaling of the bare…

High Energy Physics - Lattice · Physics 2024-02-02 Mattia Dalla Brida , Roman Höllwieser , Francesco Knechtli , Tomasz Korzec , Stefan Sint , Rainer Sommer

We report calculations of B_K using two flavours of dynamical clover-improved Wilson lattice fermions and look for dependence on the dynamical quark mass at fixed lattice spacing. We see some evidence for dynamical quark effects. In…

High Energy Physics - Lattice · Physics 2019-08-14 J. M. Flynn , F. Mescia , A. S. B. Tariq

First results are obtained for B mesons using a heavy propagator calculated using NRQCD, and a light Wilson propagator. Results from 13 quenched configurations of size 16^3 x 48 at \beta = 6.0 give a value for f_{B} of less than 200 Mev and…

High Energy Physics - Lattice · Physics 2012-08-27 UKQCD Collaboration

The anomalies in rare $B$ decays endure. We present results of an updated global analysis that takes into account the latest experimental input -- in particular the recent results on $R_K$ and BR$(B_s \to \mu^+\mu^-)$ -- and that…

High Energy Physics - Phenomenology · Physics 2021-11-17 Wolfgang Altmannshofer , Peter Stangl

We propose a method to improve lattice operators composed of Wilson fermions which allows the removal of all corrections of $O(a)$, including those proportional to the quark mass, leaving only errors of $O(a^2)$. The method exploits the…

High Energy Physics - Lattice · Physics 2009-10-09 G. Martinelli , G. C. Rossi , C. T. Sachrajda , S. Sharpe , M. Talevi , M. Testa

We report calculations of the parameter B_K appearing in the Delta S=2 neutral kaon mixing matrix element, whose uncertainty limits the power of unitarity triangle constraints for testing the standard model or looking for new physics. We…

High Energy Physics - Lattice · Physics 2010-02-03 UKQCD collaboration , J. M. Flynn , F. Mescia , A. S. B. Tariq

We present a lattice QCD calculation of the heavy-light decay constants f_B and f_Bs performed with Nf=2 maximally twisted Wilson fermions, at four values of the lattice spacing. The decay constants have been also computed in the static…

We present results for the strange contribution to the electromagnetic form factors of the nucleon computed on the CLS ensembles with $N_f=2+1$ flavors of $\mathcal{O}(a)$-improved Wilson fermions and an $\mathcal{O}(a)$-improved vector…

High Energy Physics - Lattice · Physics 2019-12-10 Dalibor Djukanovic , Konstantin Ottnad , Jonas Wilhelm , Hartmut Wittig

We compute the $O(\alpha_s)$ corrections to the Wilson coefficient of the chromomagnetic operator in inclusive semileptonic B decays. The results are employed to evaluate the complete $O(\alpha_s \Lambda^2/m_b^2)$ correction to the…

High Energy Physics - Phenomenology · Physics 2015-06-18 Andrea Alberti , Paolo Gambino , Soumitra Nandi

I consider the recent proposal by R. Frezzotti and G. Rossi to chirally improve Wilson fermions in such a way that mixings among operators of different chirality can be excluded. The method, which is based on the use of twisted mass QCD…

High Energy Physics - Lattice · Physics 2009-11-10 Michele Della Morte

We present new results for light quark masses. The calculations are performed using two flavours of $O(a)$ improved Wilson fermions. We have reached lattice spacings as small as $a \sim 0.07$fm and pion masses down to $m_{\pi} \sim 340$MeV…

High Energy Physics - Lattice · Physics 2008-11-26 M. Göckeler , R. Horsley , Y. Nakamura , D. Pleiter , P. E. L. Rakow , G. Schierholz , T. Streuer , H. Stüben , J. M. Zanotti

We calculate the B-meson decay constants f_B, f_Bs, and their ratio in unquenched lattice QCD using domain-wall light quarks and relativistic b-quarks. We use gauge-field ensembles generated by the RBC and UKQCD collaborations using the…

The measurement of lepton universality parameters $R_{K^{(*)}}$ was updated by LHCb in December 2022, which indicated that the well-known anomalies in flavor-changing neutral current (FCNC) processes of B meson decays have faded away.…

High Energy Physics - Phenomenology · Physics 2023-10-31 Qiaoyi Wen , Fanrong Xu

We determine non-perturbatively the normalisation constant Z_m*Z_P/Z_A as well as the Symanzik coefficients b_m and b_A-b_P, required in O(a) improved quark mass renormalisation with Wilson fermions. The strategy underlying their…

We present the status of our updated D- and B-meson decay-constant analysis, based on the MILC $N_f = 2+1$ asqtad gauge ensembles. Heavy quarks are incorporated using the Wilson clover action with the Fermilab interpretation. This analysis…

High Energy Physics - Lattice · Physics 2019-08-15 Andreas S. Kronfeld , Ethan T. Neil , James N. Simone , Ruth S. Van de Water

We present {\it preliminary} results for the spectrum and decay constants of B mesons using NRQCD heavy and Wilson light quarks on configurations at $\beta=5.6$ with two dynamical flavours of staggered fermions. All terms to order $1/M_Q$…

High Energy Physics - Lattice · Physics 2010-11-01 A. Ali Khan , S. Collins , C. T. H. Davies , U. M. Heller , J. Shigemitsu , J. H. Sloan