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Related papers: A tmQCD mixed-action approach to flavour physics

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We investigate a new class of improved relativistic fermion action on the lattice with a criterion to give excellent energy-momentum dispersion relation as well as to be consistent with tree-level $O\left(a^{2}\right)$-improvement. Main…

High Energy Physics - Lattice · Physics 2013-12-18 Yong-Gwi Cho , Shoji Hashimoto , Jun-Ichi Noaki , Andreas Jüttner , Marina Marinkovic

Quantum Chromodynamics on a lattice with Wilson fermions and a chirally twisted mass term is considered in the framework of chiral perturbation theory. For two and three numbers of quark flavours, respectively, with non-degenerate quark…

High Energy Physics - Lattice · Physics 2010-12-23 Gernot Münster , Tobias Sudmann

We consider O(a) improvement for two flavor lattice QCD. The improvement term in the action is computed non-perturbatively for a large range of the bare coupling. The position of the critical line and higher order lattice artifacts…

High Energy Physics - Lattice · Physics 2009-10-31 Karl Jansen , Rainer Sommer

The effect of sea quark electromagnetic charge on meson masses is investigated, and first results for full QED+QCD low-energy constants are presented. The electromagnetic charge for sea quarks is incorporated in quenched QED+full QCD…

High Energy Physics - Lattice · Physics 2012-08-21 Tomomi Ishikawa , Thomas Blum , Masashi Hayakawa , Taku Izubuchi , Chulwoo Jung , Ran Zhou

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 study hadron properties near the deconfining transition in the quenched lattice QCD simulation. This paper focuses on the heavy quarkonium states, such as $J/\psi$ meson. In order to treat heavy quarks at $T>0$, we adopt the $O(a)$…

High Energy Physics - Lattice · Physics 2009-10-31 T. Umeda , R. Katayama , O. Miyamura , H. Matsufuru

Perturbative and non-perturbative results are presented on the renormalization constants of the quark field and the vector, axial-vector, pseudoscalar, scalar and tensor currents. The perturbative computation, carried out at one-loop level…

High Energy Physics - Lattice · Physics 2013-05-30 C. Alexandrou , M. Constantinou , T. Korzec , H. Panagopoulos , F. Stylianou

We report on the status of our study towards the equation of state in 2+1 flavor QCD with improved Wilson quarks. To reduce the computational cost which is quite demanding for Wilson-type quarks, we adopt the fixed scale approach, i.e. the…

High Energy Physics - Lattice · Physics 2010-11-05 K. Kanaya , S. Aoki , H. Ohno , T. Umeda , S. Ejiri , T. Hatsuda , N. Ishii , Y. Maezawa

Leptoquarks (LQs) provide very promising solutions to the tensions between the experimental measurements and the SM predictions of $b\to s\ell^+\ell^-$ and $b\to c\tau\nu$ processes. In this case the LQ masses are in general at the TeV…

High Energy Physics - Phenomenology · Physics 2019-03-13 Jason Aebischer , Andreas Crivellin , Christoph Greub

We consider QCD with valence and sea quarks obeying different boundary conditions. We point out that the energy of low lying two hadron states do not depend on the boundary condition of the sea quarks (up to exponentially small…

High Energy Physics - Lattice · Physics 2010-04-05 Paulo F. Bedaque , Jiunn-Wei Chen

We test the reweighting of the quark determinant of O(a) improved Wilson fermions in the domain-decomposed hybrid Monte-Carlo algorithm. Specifically, we implement a reweighting in a twisted-mass parameter proposed by Palombi and L\"uscher…

High Energy Physics - Lattice · Physics 2011-11-17 Chuan Miao , Harvey B. Meyer , Hartmut Wittig

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 study the equation of state in 2+1 flavor QCD with nonperturbatively improved Wilson quarks coupled with the RG-improved Iwasaki glue. We apply the $T$-integration method to nonperturbatively calculate the equation of state by the…

High Energy Physics - Lattice · Physics 2012-06-20 T. Umeda , S. Aoki , S. Ejiri , T. Hatsuda , K. Kanaya , Y. Maezawa , H. Ohno

We present results for $f_B$, $f_{B_s}$, $f_D$, $f_{D_s}$ and their ratios in the presence of two flavors of light sea quarks ($N_f=2$). We use Wilson light valence quarks and Wilson and static heavy valence quarks; the sea quarks are…

High Energy Physics - Lattice · Physics 2008-11-26 The MILC Collaboration , C. Bernard , S. Datta , T. DeGrand , C. DeTar , Steven Gottlieb , Urs M. Heller , C. McNeile , K. Orginos , R. Sugar , D. Toussaint

We present a calculation of the B and D meson decay constants in lattice QCD with two (Nf=2) flavours of light dynamical quarks, using an O(a)-improved Wilson action for both light and heavy quarks and a renormalization-group improved gauge…

We present results for the spectrum of light and strange mesons on configurations with two flavors of mass-degenerate Chirally Improved sea quarks. The calculations are performed on seven ensembles of lattice size 16^3x32 at three different…

High Energy Physics - Lattice · Physics 2015-06-03 Georg P. Engel , C. B. Lang , Markus Limmer , Daniel Mohler , Andreas Schaefer

Lattice QCD simulations at small lattice spacings and quark masses close to their physical values are technically challenging. In particular, the simulations can get trapped in the topological charge sectors of field space or may run into…

High Energy Physics - Lattice · Physics 2015-06-05 Martin Lüscher , Stefan Schaefer

We give a progress report on studies of B_s and B_d mixing with valence NRQCD b quarks and asqtad light quarks on the MILC configurations including the effect of 2+1 flavours of sea quarks. We explore methods for reducing statistical and…

High Energy Physics - Lattice · Physics 2011-03-23 Elvira Gamiz , Christine T. H. Davies , G. Peter Lepage , Junko Shigemitsu , Matthew Wingate

We determine the non-perturbatively renormalized axial current for O($a$) improved lattice QCD with Wilson quarks. Our strategy is based on the chirally rotated Schr\"odinger functional and can be generalized to other finite (ratios of)…

High Energy Physics - Lattice · Physics 2019-01-16 Mattia Dalla Brida , Tomasz Korzec , Stefan Sint , Pol Vilaseca

We present preliminary results from UKQCD simulations at light quark masses using two flavours of non-pertubatively improved Wilson fermions. We report on the performance of the standard HMC algorithm at these quark masses where m_pi/m_rho…

High Energy Physics - Lattice · Physics 2015-06-25 A. C. Irving , UKQCD Collaboration