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Related papers: The $Z$ decay width in the SMEFT: $y_t$ and $\lamb…

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At energies below the electroweak scale, baryon number $B$ and lepton number $L$ violating processes are of significant importance in identifying the nature of UV extensions of the Standard Model. The imprint of UV theories on low-energy…

High Energy Physics - Phenomenology · Physics 2021-10-15 Joydeep Chakrabortty , Suraj Prakash , Shakeel Ur Rahaman , Michael Spannowsky

A set of equations representing the $W/Z$ mass ratio and various observables of $Z$ decays in terms of $\bar\alpha \equiv\alpha (m_Z)$, $G_{\mu}$, $m_Z$, $m_t$, $m_H$, $\bar\alpha_{s} \equiv\alpha_{s} (m_Z)$, $m_b$ and $m_\tau$ (all other…

High Energy Physics - Phenomenology · Physics 2009-10-28 V. A. Novikov , L. B. Okun , A. N. Rozanov , M. I. Vysotsky , V. P. Yurov

We investigate constraints on couplings of Standard Model effective field theory (SMEFT) operators contributing to $Wtb$ effective vertex at tree level. We study the one-loop level impact of these couplings on the low-energy flavour…

High Energy Physics - Phenomenology · Physics 2025-10-15 Subhajit Kala , Lipika Kolay , Lopamudra Mukherjee , Soumitra Nandi

In this paper we present the complete one-loop matching conditions, up to dimension-six operators of the Standard Model effective field theory, resulting by integrating out the two scalar leptoquarks $S_{1}$ and $S_{3}$. This allows a…

High Energy Physics - Phenomenology · Physics 2021-11-17 Valerio Gherardi , David Marzocca , Elena Venturini

Effective field theories offer a rationale to classify new physics models based on the size of their contribution to the effective Lagrangian, and therefore to experimental observables. A complete classification can be obtained, at a fixed…

High Energy Physics - Phenomenology · Physics 2023-03-31 G. Guedes , P. Olgoso , J. Santiago

We study one loop supersymmetric corrections to precision observables. Adding LEP2 e ebar --> f fbar cross sections to the data-set removes previous hints for SUSY and the resulting constraints are in some cases stronger than direct bounds…

High Energy Physics - Phenomenology · Physics 2009-10-09 Guido Marandella , Christian Schappacher , Alessandro Strumia

The Standard Model Effective Field Theory (SMEFT) provides a robust framework for probing deviations in the couplings of Standard Model particles from their theoretical predictions. This framework relies on an expansion in…

High Energy Physics - Phenomenology · Physics 2025-01-22 Nilabhra Adhikary , Tisa Biswas , Joydeep Chakrabortty , Christoph Englert , Michael Spannowsky

The search for effective field theory deformations of the Standard Model (SM) is a major goal of particle physics that can benefit from a global approach in the framework of the Standard Model Effective Field Theory (SMEFT). For the first…

High Energy Physics - Phenomenology · Physics 2021-05-19 John Ellis , Maeve Madigan , Ken Mimasu , Veronica Sanz , Tevong You

Linear Standard Model (SM) extensions, defined as new particles that can couple linearly to SM fields, form a motivated and finite set of simplified models for exploring phenomenology Beyond the SM (BSM). Heavy BSM particles may be…

High Energy Physics - Phenomenology · Physics 2025-09-26 John Gargalionis , Jérémie Quevillon , Pham Ngoc Hoa Vuong , Tevong You

Precision observables are well known for constraining most of the Beyond Standard Model (BSM) scenarios tightly. We present here a simple and comprehensive fitting framework for various BSM scenarios to these observables. We start with the…

High Energy Physics - Phenomenology · Physics 2023-05-24 Mathew Thomas Arun , Kuldeep Deka , Tripurari Srivastava

We compute the next-to-leading order QCD and electroweak corrections to $Z$ and $W$ pole observables using the dimension-6 Standard Model effective field theory and present numerical results that can easily be included in global fitting…

High Energy Physics - Phenomenology · Physics 2022-09-28 Sally Dawson , Pier Paolo Giardino

The most important hint of physics beyond the Standard Model (SM) from the 1995 precision electroweak data is that the most precisely measured quantities, the total, leptonic and hadronic decay widths of the $Z$ and the effective weak…

High Energy Physics - Phenomenology · Physics 2010-11-23 Kaoru Hagiwara

Threshold corrections provide a universal link between experimentally measured broken-phase parameters and $\overline{\hbox{MS}}$ renormalised symmetric-phase parameters used in SMEFT renormalisation-group (RG) analyses and matching to…

High Energy Physics - Phenomenology · Physics 2026-01-23 Anke Biekötter , Livia E. G. Maskos , Benjamin D. Pecjak

The choice of an electroweak (EW) input scheme is an important component of perturbative calculations in Standard Model Effective Field Theory (SMEFT). In this paper we perform a systematic study of three different EW input schemes in…

High Energy Physics - Phenomenology · Physics 2023-08-02 Anke Biekötter , Benjamin D. Pecjak , Darren J. Scott , Tommy Smith

In the Standard Model Effective Field Theory (SMEFT), the $SU(2)_L\times U(1)_Y$ symmetry of the Standard Model is linearly realized. However, it is possible that more general effective field theories, such as the Higgs Effective Field…

High Energy Physics - Phenomenology · Physics 2024-06-04 Siddhartha Karmakar , Susobhan Chattopadhyay , Amol Dighe

The Standard Model Effective Field Theory (SMEFT) theoretical framework is increasingly used to interpret particle physics measurements and constrain physics beyond the Standard Model. We investigate the truncation of the effective-operator…

High Energy Physics - Phenomenology · Physics 2020-12-02 Chris Hays , Andreas Helset , Adam Martin , Michael Trott

This paper presents a computer code for analyzing electroweak precision data (EWPD) in the framework of the Standard Model Effective Field Theory (SMEFT), highlights the importance of recent ATLAS and CMS precision measurements, and…

High Energy Physics - Phenomenology · Physics 2026-05-14 Hannes Mildner

A model-independent anatomy of $\Delta F= 2$ transitions in the context of the Weak Effective Theory (WET) below the electroweak scale (EW) and the Standard Model Effective Field Theory (SMEFT) above the EW scale is discussed. Two master…

High Energy Physics - Phenomenology · Physics 2022-02-22 Jason Aebischer

Lepton-number-violating interactions occur in the Standard Model Effective Field Theory (SMEFT) at odd dimensions starting from the dimension-5 Weinberg operator. Although the operators at dimension-7 and higher are more suppressed by the…

High Energy Physics - Phenomenology · Physics 2025-10-09 Kåre Fridell , Lukáš Gráf , Julia Harz , Chandan Hati

Within the framework of the MSSM, we compute the complete set of electroweak one-loop supersymmetric quantum effects on the width $\Gamma_Z$ of the $Z$-boson in the on-shell renormalization scheme. Numerical analyses of the corrections to…

High Energy Physics - Phenomenology · Physics 2009-10-28 D. Garcia , R. A. Jimenez , J. Sola