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Related papers: Forward-Backward Asymmetry in $B\to X_d e^+e^-$

200 papers

We review the orientation of e+e- \to q\bar q g events in terms of the polar and azimuthal angles of the event plane w.r.t. the electron beam direction. The asymmetry of the azimuthal-angle distribution is, like the left-right…

High Energy Physics - Phenomenology · Physics 2007-05-23 P. N. Burrows , P. Osland

We present branching fraction and CP asymmetry measurements as well as angular studies of B to phi phi K decays using 464 x 10^6 BBbar events collected by the BaBar experiment. The branching fractions are measured in the phi phi invariant…

High Energy Physics - Experiment · Physics 2011-08-04 The BABAR Collaboration , J. P. Lees

We report the first observation of a manifestly CP violating effect in the K(L)->pi+pi-e+e- decay mode. A large asymmetry was observed in the distribution of these decays in the CP-odd and T-odd angle phi between the decay planes of the…

High Energy Physics - Experiment · Physics 2012-08-27 KTeV Collaboration

CP violation in the decays $t \to \ell^+\nu b$ and $\bar t \to \ell^-\bar\nu \bar b$ from the production process $e^-e^+ \to \ttbar$ is discussed. Since the asymmetry proposed as a measure of CP violation vanishes even at the one-loop level…

High Energy Physics - Phenomenology · Physics 2009-09-01 Bohdan Grzadkowski , Wai-Yee Keung

We study the doubly-polarized lepton pair forward-backward asymmetries in (Lambda_b -> Lambda l^+ l^-) decay using a general, model independent form of the effective Hamiltonian. We present the general expression for nine…

High Energy Physics - Phenomenology · Physics 2009-11-10 T. M. Aliev , V. Bashiry , M. Savci

We study $CP$ violation in the process $e^+e^- \to t\bar{t} \nu\bar{\nu}$ at an $e^+e^-$-TeV collider. As the source of $CP$ violation we assume a two-Higgs doublet model with an explicitly $CP$-noninvariant Higgs potential. Sizeable…

High Energy Physics - Phenomenology · Physics 2010-11-01 A. Pilaftsis , M. Nowakowski

The polarization asymmetries of $t$, $\bar t$ quarks can be used in the reaction $e^+e^-\to t\bar t\nu_e\bar\nu_e$ to measure the Higgs width, in the Standard Model or in its extensions, and to search for non-standard CP violating phases.…

High Energy Physics - Phenomenology · Physics 2007-05-23 David Atwood , Amarjit Soni

Measurements are presented of R_b, the ratio of the b bbar cross-section to the q qbar cross-section in e+e- collisions, and the forward-backward asymmetry A^b_FB at twelve energy points in the range sqrt(s) = 130-207 GeV. These results are…

High Energy Physics - Experiment · Physics 2009-04-08 DELPHI Collaboration , J. Abdallah

We propose T-odd and CP-odd odd asymmetries in order to analyze the impact of CP violating phases in neutralino production and subsequent leptonic two-body decays. We present numerical results of these asymmetries and of the cross sections…

High Energy Physics - Phenomenology · Physics 2007-05-23 O. Kittel

We investigate the possible sizes of all the CP-violating asymmetries offered by the angular distribution of rare decay $\Lambda_b\rightarrow \Lambda(\to p \pi^-) \ell^+\ell^-$ in the Standard Model and new physics scenarios motivated by…

High Energy Physics - Phenomenology · Physics 2023-07-21 Diganta Das , Jaydeb Das , Girish Kumar , Niladribihari Sahoo

The charge asymmetry in the process $e^+e^-\to \pi^+\pi^-\pi^0$ is studied taking into account a longitudinal polarization of electrons (positrons). The asymmetry arises due to interference of amplitudes corresponding to production of pions…

High Energy Physics - Phenomenology · Physics 2024-11-21 I. V. Obraztsov , A. S. Rudenko , A. I. Milstein

The recent forward-backward asymmetry recorded by the CDF Collaboration for the top and anti-top quark pair production indicates more than $2\sigma$ deviation from the Standard Model prediction, while its total production cross section…

High Energy Physics - Phenomenology · Physics 2009-12-04 Kingman Cheung , Wai-Yee Keung , Tzu-Chiang Yuan

Recent experimental limits for the direct CP asymmetries in $B^0 \to K^+ \pi^-$, $B^+ \to K^+ \pi^0$, $B^+ \to K^0 \pi^+$, and $B^0 \to \pi^+ \pi^-$, and for the indirect CP asymmetry in $B^0 \to \pi^+ \pi^-$, are combined with information…

High Energy Physics - Phenomenology · Physics 2014-11-17 Michael Gronau , Jonathan L. Rosner

The forward-backward (FB) asymmetry of $b$ quarks in $e^+e^-$ collisions at the Z pole measured at LEP, $A_\text{FB}^{0,b} = 0.0992\pm0.0016$, remains today one of the electroweak precision observables with the largest disagreement…

High Energy Physics - Phenomenology · Physics 2025-08-18 David d'Enterria , Cynthia Yan

We discuss a method to construct observables protected against QCD uncertainties based on the angular distribution of the exclusive Bd -> K(*0}(-> Kpi) l+ l- decay. We focus on the identification and the interpretation of all the symmetries…

High Energy Physics - Phenomenology · Physics 2010-12-22 Ulrik Egede , Tobias Hurth , Joaquim Matias , Marc Ramon , Will Reece

The decay $b\to d e^+e^-$ has an amplitude containing comparable contributions proportional to $V_{tb}V_{td}^{*}$, $V_{cb}V_{cd}^{*}$ and $V_{ub}V_{ud}^{*}$. These pieces involve different unitarity phases produced by $c\bar{c}$ and…

High Energy Physics - Phenomenology · Physics 2016-08-24 F. Krüger , L. M. Sehgal

We summarize the results of two papers in which we have studied CP violation in inclusive and exclusive decays b -> d e^+e^-. Two CP-violating effects are calculated: the partial rate asymmetry between b and \bar{b} decay, and the asymmetry…

High Energy Physics - Phenomenology · Physics 2007-05-23 F. Krüger , L. M. Sehgal

Angular and energy distributions for leptons and bottom quarks in the process e+e- --> t tbar --> l/b ... have been calculated assuming the most general top-quark couplings. The double distributions depend both on modification of the…

High Energy Physics - Phenomenology · Physics 2016-11-03 B. Grzadkowski , Z. Hioki

BaBar collaboration announced that they observed time reversal (T) asymmetry through $B$ meson system. In the experiment, time dependencies of two distinctive processes, $B_- \rightarrow \bar{B^0}$ and $\bar{B^0}\rightarrow B_-$($-$…

High Energy Physics - Phenomenology · Physics 2015-06-23 Takuya Morozumi , Hideaki Okane , Hiroyuki Umeeda

The general production {\it and} decay mechanism of $\ttbar$ in future high-energy $\epem$ colliders has been investigated in a model-independent way, focusing on an observation of possible CP violation. Angular asymmetries sensitive to CP…

High Energy Physics - Phenomenology · Physics 2010-11-01 Bohdan Grzcadkowski