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Related papers: Limits on Lorentz violation from charged-pion deca…

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Lorentz- and CPT-violating effects initiating two-body electromagnetic flavor-changing decays of charged leptons are studied in the framework of Lorentz-violating effective field theory. An analysis of data from experiments at the Paul…

High Energy Physics - Phenomenology · Physics 2022-07-12 Alan Kostelecky , E. Passemar , N. Sherrill

CPT and Lorentz violation in the photon sector is described within the minimal Standard-Model Extension by a dimension-3 Chern-Simons-like operator parametrized by a four-vector parameter $k_{AF}$ that has been very tightly bounded by…

High Energy Physics - Phenomenology · Physics 2017-11-13 D. Colladay , J. P. Noordmans , R. Potting

A parton-model description of high-energy hadronic interactions in the presence of Lorentz violation is presented. This approach is used to study lepton-hadron and hadron-hadron interactions at large momentum transfer. Cross sections for…

High Energy Physics - Phenomenology · Physics 2019-11-19 Nathan Sherrill

Recent evidence appears to confirm that the ultra-high-energy primary cosmic ray spectrum consists mostly of protons. The fact that these protons can traverse large distances to reach Earth allows us to place bounds on Lorentz violations.…

High Energy Physics - Phenomenology · Physics 2008-11-26 Brett Altschul

Surprisingly, until recently CP violation in pion decay was not ruled out experimentally even at the percent level. I have derived the first experimental limit, $-0.01<A_{CP}<0.02$, from old data on the anomalous magnetic moment $g-2$ of…

High Energy Physics - Phenomenology · Physics 2007-05-23 Daniel M. Kaplan

Constraints on possible Lorentz symmetry violation (LV) of order E/M_Planck for electrons and photons in the framework of effective field theory (EFT) are discussed. Using (i) the report of polarized MeV emission from GRB021206 and (ii) the…

Astrophysics · Physics 2009-11-10 T. Jacobson , S. Liberati , D. Mattingly , F. W. Stecker

We consider the possibility that Lorentz violation can generate differences between the limiting velocities of light and charged matter. Such effects would lead to efficient vacuum Cherenkov radiation or rapid photon decay. The absence of…

High Energy Physics - Phenomenology · Physics 2009-09-02 Michael A. Hohensee , Ralf Lehnert , David F. Phillips , Ronald L. Walsworth

These proceedings introduce the main techniques and ideas for a systematic effective field theory analysis of CP violation in the charged lepton sector. This study is required because the Standard Model of particle physics predicts a very…

High Energy Physics - Phenomenology · Physics 2022-09-21 Giovanni Marco Pruna

In this paper, we have investigated the charged kaons decay at the lowest order in the presence of a circularly polarized laser field. To be more precise, we have examined the leptonic decay of both positive (matter) and negative…

High Energy Physics - Phenomenology · Physics 2021-09-22 M. Baouahi , M. Ouali , M. Jakha , S. Mouslih , Y. Attaourti , B. Manaut , S. Taj

For the first time, a search for the rare decay of the W boson to three charged pions has been performed. Proton-proton collision data recorded by the CMS experiment at a center-of-mass energy of 13 TeV, corresponding to an integrated…

High Energy Physics - Experiment · Physics 2019-04-24 CMS Collaboration

Charged lepton flavor violation is an unambiguous signature for New Physics. Here we present a summary of the theoretical and experimental status of the search for charged lepton flavor violation in heavy particle decays, in particular in…

High Energy Physics - Phenomenology · Physics 2022-05-24 Wolfgang Altmannshofer , Cecile Caillol , Mogens Dam , Stefania Xella , Yongchao Zhang

If there is Lorentz symmetry violation in the $t$ quark sector of the standard model, changes to particles' dispersion relations might allow for the existence of stable top-flavored hadrons. Observations of the survival of high-energy…

High Energy Physics - Phenomenology · Physics 2020-10-14 Brett Altschul

Due to the large mass of top quark, CP violation in the top-quark decay is sensitive to the interactions mediated by Higgs bosons. We consider CP violation in $t\rightarrow W^+ b$ decay by calculating consistently in unitary gauge the…

High Energy Physics - Phenomenology · Physics 2009-09-25 Tsutom Hasuike , Toshihiko Hattori , Toshio Hayashi , Seiichi Wakaizumi

Below the electroweak scale, new physics that violates lepton number in two units ($\Delta L = 2$) and is mediated by heavy particle exchange can be parameterized by a dimension-9 low-energy effective Lagrangian. Operators in this…

High Energy Physics - Phenomenology · Physics 2025-03-11 Marcela González , Nicolás A. Neill

The lepton number violating process can be induced by introducing a fourth generation heavy Majorana neutrino, which is coupled to the charged leptons of Standard Model. There have been many previous studies on the leptonic number violating…

High Energy Physics - Phenomenology · Physics 2013-07-23 Hai-Rong Dong , Feng Feng , Hai-Bo Li

The NA48/2 experiment at CERN collected a large sample of charged kaon decays to final states with multiple charged particles in 2003--2004. A new upper limit on the rate of the lepton number violating decay…

High Energy Physics - Experiment · Physics 2017-03-24 2 collaboration

Inspired by the small mass-squared difference measured in the solar neutrino oscillation experiments and by the testability, we suggest that a limit of the partial mass degeneracy, in which masses of the first two generation fermions are…

High Energy Physics - Phenomenology · Physics 2014-05-07 Takeshi Araki , Hiroyuki Ishida

CP-violating effects in decays of B mesons offer a wide spectrum of probes for testing the phase structure of the quark-flavour sector of the Standard Model. After a brief discussion of the picture emerging from the current LHC data, the…

High Energy Physics - Phenomenology · Physics 2015-06-22 Robert Fleischer

In the presence of Lorentz violation, the Cerenkov-like process $\gamma\rightarrow\gamma+\pi^{0}$ may become allowed for sufficiently energetic photons. Photons above the threshold would lose energy rapidly through pion emission. The fact…

High Energy Physics - Phenomenology · Physics 2016-05-06 Brett Altschul

We derive constraints on the couplings of light vector particles to all first-generation Standard Model fermions using leptonic decays of the charged pion, $\pi^+\to e^+ \nu_e X_\mu$. In models where the net charge to which $X_\mu$ couples…

High Energy Physics - Phenomenology · Physics 2023-09-12 Matheus Hostert , Maxim Pospelov