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The QCD-coupling is a necessary input in the computation of many observables, and the parametric error on input parameters can be a dominant source of uncertainty. The coupling can be extracted by comparing high order perturbative…

High Energy Physics - Lattice · Physics 2022-03-16 Leonardo Chimirri , Rainer Sommer

Under appropriate conditions controllable two-level systems can be used to detect the third moment of current fluctuations. We derive a Master Equation for a quantum system coupled to a bath valid to the third order in the coupling between…

Mesoscale and Nanoscale Physics · Physics 2009-11-11 Valentina Brosco , Rosario Fazio , F. W. J. Hekking , J. P. Pekola

We present details of our evaluation of the NNLO QCD corrections to BR(B -> X_s gamma) in the heavy charm limit m_c >> m_b/2. Results of this calculation have been essential for estimating O(alpha_s^2) effects in this branching ratio via…

High Energy Physics - Phenomenology · Physics 2014-11-21 Mikolaj Misiak , Matthias Steinhauser

In a series of three lectures, I review the theory and phenomenology of heavy quark masses and mixing angles and the status of their determination. In addition, I give an introduction to heavy quark symmetry, with the main emphasis on the…

High Energy Physics - Phenomenology · Physics 2016-10-26 M. Neubert

We have calculated the rate of the decay b -> clv to second order in alpha_s in the limit that the b and c quarks have equal masses. The results here confirm recent calculations done in the opposite limit where the c-quark is much lighter…

High Energy Physics - Phenomenology · Physics 2009-06-02 Matthew Dowling

We review the production of charm and bottom quarks in two-photon collisions at e+e- colliders. The next-to-leading order QCD predictions for total cross sections and differential distributions are compared with recent experimental results.

High Energy Physics - Phenomenology · Physics 2008-11-26 Stefano Frixione , Michael Krämer , Eric Laenen

The most recent recalculation of the two-loop correction to the static quark-antiquark potential gave the numerical value different from the previously known one. We comment on the effect this change produces on the numerical estimates of…

High Energy Physics - Phenomenology · Physics 2007-05-23 A. A. Penin , A. A. Pivovarov

We use overlap fermions as valence quarks to calculate meson masses in a wide quark mass range on the $2+1$-flavor domain-wall fermion gauge configurations generated by the RBC and UKQCD Collaborations. The well-defined quark masses in the…

We study the heavy quark mass dependence of the perturbative renormalization factors for the heavy-light currents involving Wilson, Clover, and NRQCD heavy quarks. We find that the one-loop Z-factor for the axial-vector current depends…

High Energy Physics - Lattice · Physics 2009-10-30 K-I. Ishikawa , S. Aoki , S. Hashimoto , H. Matsufuru , T. Onogi , N. Yamada

We simulate a theory with two dynamical O($a$) improved Wilson quarks whose mass $M$ ranges from a factor eight up to a factor two below the charm quark mass and at three values of the lattice spacing ranging from 0.066 to 0.034 fm. This…

High Energy Physics - Lattice · Physics 2014-11-06 Francesco Knechtli , Andreas Athenodorou , Mattia Bruno , Jacob Finkenrath , Björn Leder , Marina Marinkovic , Rainer Sommer

In this article we evaluate mass corrections up to $O((m^2/q^2)^6)$ to the three-loop polarization function induced by an axial-vector current. Special emphasis is put on the evaluation of the singlet diagram which is absent in the vector…

High Energy Physics - Phenomenology · Physics 2011-09-13 R. Harlander , M. Steinhauser

We compute the charm quark mass in lattice QCD and compare different formulations of the heavy quark, and quenched data to that with dynamical sea quarks. We take the continuum limit of the quenched data by extrapolating from three…

High Energy Physics - Lattice · Physics 2009-11-10 UKQCD Collaboration , A. Dougall , C. M. Maynard , C. McNeile

We study the phenomenology at the Large Hadron Collider of an exotic vector-like quark X with charge +5/3. We relax the assumption of a 100% branching into W t and allow for an arbitrary rate into W plus light quarks, thus covering all…

High Energy Physics - Phenomenology · Physics 2015-06-12 Giacomo Cacciapaglia , Aldo Deandrea , Luca Panizzi , Stephane Perries , Viola Sordini

We calculate the O(alpha_s^3 ln(alpha_s)) contributions to the heavy-quarkonium production and annihilation rates. Our result sheds new light on the structure of the high-order perturbative corrections and opens a new perspective for a…

High Energy Physics - Phenomenology · Physics 2009-11-07 Bernd A. Kniehl , Alexander A. Penin , Vladimir A. Smirnov , Matthias Steinhauser

We review the status of heavy quark physics at the Fermilab Tevatron collider by summarizing recent top quark and B physics results from CDF and DO. In particular, we discuss the measurement of the top quark mass and top production cross…

High Energy Physics - Experiment · Physics 2007-05-23 M. Paulini

Like many other models, Composite Higgs Models feature the existence of heavy vector-like quarks. Mixing effects between the Standard Model fields and the heavy states, which can be quite large in case of the top quark, imply deviations…

High Energy Physics - Phenomenology · Physics 2015-06-17 Marc Gillioz , Ramona Grober , Andreas Kapuvari , Margarete Muhlleitner

Decoupling of heavy quarks at low energies can be described by means of an effective theory as shown by S. Weinberg in Ref. [1]. We study the decoupling of the charm quark by lattice simulations. We simulate a model, QCD with two degenerate…

High Energy Physics - Lattice · Physics 2017-11-22 Francesco Knechtli , Tomasz Korzec , Björn Leder , Graham Moir

We present our calculation of the correlator $<T\{V_sV_s^\dag\} >$ between two external vector-currents with the quantum-numbers of a charged kaon. The renormalized expression to $O(p^6)$ in $SU(3) \times SU(3)$ standard chiral perturbation…

High Energy Physics - Phenomenology · Physics 2009-10-31 Stephan Dürr , Joachim Kambor

We present a review of the current understanding of the heavy quark distributions in the nucleon and their impact on collider physics. The origin of strange, charm and bottom quark pairs at high light-front (LF) momentum fractions in hadron…

High Energy Physics - Phenomenology · Physics 2017-03-08 S. J. Brodsky , V. A. Bednyakov , G. I. Lykasov , J. Smiesko , S. Tokar

New vectorlike fermions that mix with the third generation can significantly affect the tau and b Yukawa couplings. Consistent with precision electroweak measurements, the width of the Higgs boson to tau tau, b b can be reduced by O(1) with…

High Energy Physics - Phenomenology · Physics 2013-05-30 John Kearney , Aaron Pierce , Neal Weiner
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