English
Related papers

Related papers: Top mixing in effective theories

200 papers

Light and heavy-light (b) hadrons are among the most interesting and among the most challenging quantities to calculate in lattice gauge theory. One would like to avoid discretization effects from very heavy quarks and to calculate chiral…

High Energy Physics - Lattice · Physics 2007-05-23 A. Ali Khan

If the LHC should fail to observe direct signals for new physics, it may become necessary to look for new physics effects in rare events such as flavour-changing decays of the top quark, which, in the Standard Model, are predicted to be too…

High Energy Physics - Phenomenology · Physics 2016-08-09 Debjyoti Bardhan , Gautam Bhattacharyya , Diptimoy Ghosh , Monalisa Patra , Sreerup Raychaudhuri

We consider constraints on models in which a top quark mass is generated through unenhanced extended technicolor interactions. The deviation in the $\rho$ parameter from unity and $B$--$\overline{B}$ mixing could be large, but given the…

High Energy Physics - Phenomenology · Physics 2009-09-15 L. Randall

We apply the relativistic chiral Lagrangian to the nuclear equation of state. An effective chiral power expansion scheme, which is constructed to work around nuclear saturation density, is presented. The leading and subleading terms are…

Nuclear Theory · Physics 2007-05-23 Matthias Lutz

An effective field theory of quarks, gluons, and pions, with the number $N$ of colors treated as large, is proposed as a basis for calculations of hadronic phenomena at moderate energies. The qualitative consequences of the large $N$ limit…

High Energy Physics - Phenomenology · Physics 2010-12-28 Steven Weinberg

We construct an effective Lagrangian which illustrates why color deconfines when chiral symmetry is restored in hot gauge theories with quarks in the fundamental representation. For quarks in the adjoint representation we show that while…

High Energy Physics - Phenomenology · Physics 2008-11-26 Agnes Mocsy , Francesco Sannino , Kimmo Tuominen

As a first step towards the construction of a general electroweak effective Lagrangian incorporating heavy states, we present here a simplified version where only vector and axial-vector spin-1 triplets are involved. We adopt an effective…

High Energy Physics - Phenomenology · Physics 2019-01-29 Joaquín Santos , Ignasi Rosell , Antonio Pich , Juan José Sanz-Cillero

Highlights of measurements of the properties of the top quark at the LHC are presented. The measurements probe a range of the properties of the top quark, including the structure of the $Wtb$ vertex, the top-Z coupling and the top-quark…

High Energy Physics - Experiment · Physics 2017-05-26 Mark Owen

We present a class of models in which the top quark, by mixing with new physics at a higher energy scale, is naturally heavier than the other standard model particles. We take this new physics to be extended color. Our models contain new…

High Energy Physics - Phenomenology · Physics 2007-05-23 Oscar F. Hernandez

Lattice gauge theory simulations are our principal probe of the masses of the light quarks. Results from such computations are the primary evidence against the $m_u=0$ solution to the strong CP problem. The large-$N$ approximation offers an…

High Energy Physics - Phenomenology · Physics 2022-02-02 Daniel Davies , Michael Dine , Benjamin V. Lehmann

In this paper we explore the coupling of a light axion-like particle (ALP) to top quarks. We use high-energy LHC probes, and examine both the direct probe to this coupling in associated production of a top-pair with an ALP, and the indirect…

High Energy Physics - Phenomenology · Physics 2023-10-11 Fabian Esser , Maeve Madigan , Veronica Sanz , Maria Ubiali

The top quark mass plays an important role in a variety of discussions both within and beyond the Standard Model. However, a precise determination of a theoretically well-defined top quark mass is still missing. Towards a precise…

High Energy Physics - Phenomenology · Physics 2015-11-11 Sayaka Kawabata

If supersymmetry is discovered at the LHC, the measured spectrum of superpartner masses and couplings will allow us to probe the origins of supersymmetry breaking. However, to connect the collider-scale Lagrangian soft parameters to the…

High Energy Physics - Phenomenology · Physics 2008-11-26 Gordon L. Kane , Piyush Kumar , David E. Morrissey , Manuel Toharia

Present and future expected limits on interactions between dark matter and various quarks are thoroughly investigated in a model-independent way. In particular, the constraints on the interactions from the Large Hadron Collider (LHC)…

High Energy Physics - Phenomenology · Physics 2013-04-22 Biplob Bhattacherjee , Debajyoti Choudhury , Keisuke Harigaya , Shigeki Matsumoto , Mihoko M. Nojiri

We study top quark pair production to probe new physics at the LHC. We propose reconstruction methods for $t\bar{t}$ semileptonic events and use them to reconstruct the $t\bar{t}$ invariant mass. The angular distribution of top quarks in…

High Energy Physics - Phenomenology · Physics 2008-11-26 Vernon Barger , Tao Han , Devin G. E. Walker

We obtain the constraints on scalar leptoquarks coming from radiative corrections to $Z$ physics. We perform a global fitting to the LEP data including the contributions of the most general effective Lagrangian for scalar leptoquarks, which…

High Energy Physics - Phenomenology · Physics 2008-02-03 Oscar J. P. Eboli

The effective quark Lagrangian is derived from the QCD action by means of averaging over the vacuum fields. In the limit of large N_c and keeping for simplicity the lowest order gluonic correlator one obtains nonlinear equations for the…

High Energy Physics - Phenomenology · Physics 2009-10-30 Yu. A. Simonov

We derive a microscopic relativistic point-coupling model of nuclear many-body dynamics constrained by in-medium QCD sum rules and chiral symmetry. The effective Lagrangian is characterized by density dependent coupling strengths,…

Nuclear Theory · Physics 2009-11-10 P. Finelli , N. Kaiser , D. Vretenar , W. Weise

We propose a rather general description of residual New Physics (NP) effects on the top quark couplings. These effects are described in terms of 20 gauge invariant $dim=6$ operators involving gauge and Higgs bosons as well as quarks of the…

High Energy Physics - Phenomenology · Physics 2009-10-28 G. J. Gounaris , M. Kuroda , F. M. Renard