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Related papers: Unitarising Matrix Element + Parton Shower merging

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Starting from a new zeroth order basis for quark mixing (CKM) matrix based on the quark-lepton complementarity and the tri-bimaximal pattern of lepton mixing, we derive a triminimal parametrization of CKM matrix with three small angles and…

High Energy Physics - Phenomenology · Physics 2008-12-30 Xiao-Gang He , Shi-Wen Li , Bo-Qiang Ma

The Matrix Element Method is a promising multi-variate analysis tool which offers an optimal approach to compare theory and experiment according to the Neyman-Pearson lemma. However, until recently its usage has been limited by the fact…

High Energy Physics - Phenomenology · Physics 2020-10-01 Till Martini , Manfred Kraus , Sascha Peitzsch , Peter Uwer

A new model of QCD parton shower is proposed which is dedicated to two-photon process in $e^+ e^-$ scattering. When hadron jets are produced, the photon may resolve into quark-antiquark pairs so that the structure functions of the photon…

High Energy Physics - Phenomenology · Physics 2014-11-17 T. Munehisa , P. Aurenche , J. -Ph. Guillet , M. Fontannaz , Y. Shimizu

We propose a method to examine how a parton shower sums large logarithms. In this method, one works with an appropriate integral transform of the distribution for the observable of interest. Then, one reformulates the parton shower so as to…

High Energy Physics - Phenomenology · Physics 2021-10-04 Zoltan Nagy , Davison E. Soper

We introduce multi-jet merging for deep inelastic scattering in the Vincia parton shower in the Monte Carlo event generator Pythia 8. Merging combines event samples of different parton multiplicities with logarithmically enhanced…

High Energy Physics - Phenomenology · Physics 2025-06-10 Ilkka Helenius , Joni O. Laulainen , Christian T. Preuss

We show how the use of a see-saw mechanism based on a $3 \times 3$ neutrino mass matrix texture can considerably simplify Higgs sectors for quark-lepton symmetric models (and for Standard Model extensions generally). The main theory we…

High Energy Physics - Phenomenology · Physics 2009-10-28 R. Foot , R. R. Volkas

We investigate the possibility that quarks and leptons are unified at a low energy scale much smaller than the grand unified scale. A simple theory for quark-lepton unification based on the gauge group SU(4)_C X SU(2)_L X U(1)_R is…

High Energy Physics - Phenomenology · Physics 2021-04-27 Pavel Fileviez Perez , Mark B. Wise

Standard dipole parton showers are known to yield incorrect subleading-colour contributions to the leading (double) logarithmic terms for a variety of observables. In this work, concentrating on final-state showers, we present two simple,…

High Energy Physics - Phenomenology · Physics 2021-07-29 Keith Hamilton , Rok Medves , Gavin P. Salam , Ludovic Scyboz , Gregory Soyez

We aim to improve the modelling of deep inelastic scattering by implementing multi-jet merging capabilities in Vincia parton shower in the general-purpose Monte Carlo event generator, Pythia. Merging allows to combine event samples of…

High Energy Physics - Phenomenology · Physics 2024-08-16 Joni Laulainen , Ilkka Helenius , Christian T. Preuss

Recent works show that the original Kobayashi-Maskawa (KM) form of fermion mixing matrix exhibits some advantages, especially when discussing problems such as unitarity boomerangs and maximal CP violation hypothesis. Therefore, the KM form…

High Energy Physics - Phenomenology · Physics 2011-03-23 Nan Qin , Bo-Qiang Ma

The comparison of the CKM mixing angles with the leptonic mixings implied by the recent atmospheric and solar neutrino data exhibits an interesting complementarity. This pattern can be understood in the context of the SU(5) grand…

High Energy Physics - Phenomenology · Physics 2009-10-31 Zurab Berezhiani , Anna Rossi

Layer factorization has emerged as a widely used technique for training memory-efficient neural networks. However, layer factorization methods face several challenges, particularly a lack of robustness during the training process. To…

Numerical Analysis · Mathematics 2025-02-06 Jonas Kusch , Steffen Schotthöfer , Alexandra Walter

General-purpose Monte Carlo event generators have become important tools in particle physics, allowing the simulation of exclusive hadronic final states. In this article we examine the Pythia 8 generator, in particular focusing on its…

High Energy Physics - Phenomenology · Physics 2011-03-18 Richard Corke , Torbjörn Sjöstrand

We study hadron production in jets by applying quark recombination to jet shower partons. With the jet showers obtained from PYTHIA and augmented by additional non-perturbative effects, we compute hadron spectra in e+ + e-collisions at…

Nuclear Theory · Physics 2015-06-11 Kyong Chol Han , Rainer J Fries , Che Ming Ko

We report several recent updates from the BABAR Collaboration on the matrix elements $|V_{cb}|$, $|V_{ub}|$, and $|V_{td}|$ of the Cabibbo-Kobayashi-Maskawa (CKM) quark-mixing matrix, and the angles $\beta$ and $\alpha$ of the unitarity…

High Energy Physics - Experiment · Physics 2010-04-21 Chih-hsiang Cheng

We construct quark mixing matrices within a group theoretic framework which is easily applicable to any number of generations. Familiar cases are retrieved and related, and it is hoped that our viewpoint may have advantages both…

High Energy Physics - Phenomenology · Physics 2019-08-17 K. J. Barnes , O. J. Senior , N. D. Virgo

We discuss possible signatures of the tree level FCNC, which results from the non-unitarity of CKM matrix. We first define the unitaity step-by-step, and possible test of the non-unitaity through the 4-value-KM parametrization. We, then,…

High Energy Physics - Phenomenology · Physics 2008-12-18 C. S. Kim , Amol Dighe

We first obtain the most general and compact parametrization of the unitary transformation diagonalizing any 3 by 3 hermitian matrix H, as a function of its elements and eigenvalues. We then study a special class of fermion mass matrices,…

High Energy Physics - Phenomenology · Physics 2010-04-06 Gilles Couture , Cherif Hamzaoui , Steven S. Y. Lu , Manuel Toharia

In this work we present a new subtraction method for next-to-leading order calculations that is particularly convenient even when narrow resonances are present. The method is particularly suitable for the implementation of next-to-leading…

High Energy Physics - Phenomenology · Physics 2016-01-27 Tomáš Ježo , Paolo Nason

This contribution outlines the implementation of the matrix element method (MEM) in the search for $\text{t}\bar{\text{t}}$H, H $\rightarrow \text{b}\bar{\text{b}}$ events. In particular, the evaluation of the transfer functions, which…

High Energy Physics - Experiment · Physics 2018-12-21 Maren Meinhard