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Related papers: CP tests for high-$p_T$ multi-leptons

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If CP is violated in any decay process involving leptons it will signify the existense of a new force (called the X boson) responsible for CP violation that may be the key to understanding matter-antimatter asymmetry in the universe. We…

High Energy Physics - Phenomenology · Physics 2015-06-25 Yung Su Tsai

We investigate CP-violating effects in electroweak interactions at future high-energy muon colliders within the Standard Model Effective Field Theory (SMEFT) framework. Focusing on four dimension-six CP-odd operators -- $…

High Energy Physics - Phenomenology · Physics 2026-03-02 Qing-Hong Cao , Jian-Nan Ding , Yandong Liu , Jin-Long Yuan

Analytic expressions for the angular distributions of the $b$-quarks associated with single $t$-quark production in $p \bar p \to W^* \to t \bar b \to b \bar b W$ and of the leptons from the subsequent decay $W \to l\nu$ are obtained in the…

High Energy Physics - Phenomenology · Physics 2009-11-07 E. Christova , S. Fichtinger , S. Kraml , W. Majerotto

Some models of leptogenesis involve a nearly-degenerate pair of heavy Majorana neutrinos $N_{1,2}$ whose masses can be small, $O({\rm GeV})$. There can be heavy-light neutrino mixing parametrized by $|B_{\ell N}|^2 = 10^{-5}$, which leads…

High Energy Physics - Phenomenology · Physics 2021-04-27 David London

In the standard model, we study CP violating rate asymmetries in the decay b->d l^+ l^- when one of the leptons is polarised. We find an asymmetry of (5 -- 15)% in the polarised decay spectrum which is comparable to known results for the…

High Energy Physics - Phenomenology · Physics 2009-11-10 K. S. Babu , K. R. S. Balaji , I. Schienbein

We consider various integrated lepton charge-energy asymmetries and azimuthal asymmetries as tests of CP violation in the process $e^-e^+ \to W^-W^+$. These asymmetries are sensitive to different linear combinations of the CP violating form…

High Energy Physics - Phenomenology · Physics 2009-09-01 Darwin Chang , Wai-Yee Keung , Ivan Phillips

A search for the violation of the charge-parity ($CP$) symmetry in the production of top quarks in association with Z bosons is presented, using events with at least three charged leptons and additional jets. The search is performed in a…

High Energy Physics - Experiment · Physics 2026-01-08 CMS Collaboration

Experimental data on rare $B$-meson decays indicate deviations from Standard Model predictions. In studies of these decays, possible new sources of CP violation are often neglected. We discuss CP violation in the rare $B$-meson decays $B\to…

High Energy Physics - Phenomenology · Physics 2024-04-12 Robert Fleischer , Eleftheria Malami , Anders Rehult , K. Keri Vos

An inclusive search for nonresonant signatures of beyond the standard model (SM) phenomena in events with three or more charged leptons, including hadronically decaying $\tau$ leptons, is presented. The analysis is based on a data sample…

High Energy Physics - Experiment · Physics 2022-06-23 CMS Collaboration

We propose a model-independent test of CP violation in the scalar sector. We consider a heavy neutral scalar $h_2$ with tree-level couplings at the $h_2 V V$ and $h_2 h_1 Z$ vertices (with $V=W^{\pm},Z$), alongside the 125~GeV SM-like Higgs…

High Energy Physics - Phenomenology · Physics 2026-05-01 Qianxi Li , Ying-nan Mao , Kechen Wang

We study a CP and T violating triple (spin) correlation in the muon to electron conversion in nuclei in the context of the seesaw mechanism. After concluding that the results are negative for all three seesaw types, we turn to the…

High Energy Physics - Phenomenology · Physics 2010-03-03 Borut Bajc , Miha Nemevsek , Goran Senjanovic

We review the information on the CKM matrix elements, unitarity triangle and CP-violating phases $\alpha, \beta$ and $\gamma$ in the standard model which will be measured in the forthcoming experiments at B factories, HERA-B and hadron…

High Energy Physics - Phenomenology · Physics 2007-05-23 A. Ali

We investigate the possibilities of searching for non-standard CP violation in $pp\to t\bar{t}X$ at multiple TeV collision energies. A general kinematic analysis of the underlying partonic production processes $gg\to t\bar{t}$ and…

High Energy Physics - Phenomenology · Physics 2014-11-17 W. Bernreuther , A. Brandenburg

Lepton flavor violation can be induced in supersymmetry by the mixing of two or more of the leptonic scalar partners, Krashnikov and Arkani-Hamed et al. pointed out that this effect may be observable at the Next Linear Collider, through…

High Energy Physics - Phenomenology · Physics 2009-09-01 David Bowser-Chao , Wai-Yee Keung

In terms of flavor invariants, we establish the intimate connection between leptonic CP violation in the canonical seesaw model for neutrino masses and that in the seesaw effective field theory (SEFT). For the first time, we calculate the…

High Energy Physics - Phenomenology · Physics 2022-09-13 Bingrong Yu , Shun Zhou

We obtain the Boltzmann equations for leptogenesis including decay and scattering processes with two and three body initial or final states. We present an explicit computation of the CP violating scattering asymmetries. We analyze their…

High Energy Physics - Phenomenology · Physics 2008-11-26 Enrico Nardi , Juan Racker , Esteban Roulet

Scalar interactions (in effective Hamiltonian) can give significant variation of various experimental observables, as comparted to their respective Standard Model values, in dileptonic decays of B-meson. Also the quark level transition $b…

High Energy Physics - Phenomenology · Physics 2007-05-23 S. Rai Choudhury , Naveen Gaur

We study the contributions of supersymmetric models with a $U(1)$ horizontal symmetry and only spontaneous CP breaking to various lepton flavor observables, such as $\mu \to e\gamma$ and the electron electric dipole moment. We show that…

High Energy Physics - Phenomenology · Physics 2021-12-16 Daniel Aloni , Pouya Asadi , Yuichiro Nakai , Matthew Reece , Motoo Suzuki

Some yet unknown dynamics is expected to be at work behind the flavor puzzles of the Standard Model. Speculations exist that this may manifest itself in significant strength at the terascale. One consequence may be lepton flavor violation…

High Energy Physics - Phenomenology · Physics 2015-06-04 Dilip Kumar Ghosh , Probir Roy , Sourov Roy

The CP violating asymmetries in the (b -> d l^+ l^-) decay, when one of the leptons is polarized, is investigated using the most general form of the effective Hamiltonian. The sensitivity of the CP violating asymmetries on the new Wilson…

High Energy Physics - Phenomenology · Physics 2014-11-17 T. M. Aliev , V. Bashiry , M. Savci