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Related papers: Heterotic string backgrounds and CP violation

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The observed light neutrinos may be related to the existence of new heavy neutrinos in the spectrum of the SM. If a pair of heavy neutrinos has nearly degenerate masses, then CP violation from the interference between tree-level and…

High Energy Physics - Phenomenology · Physics 2008-11-26 Simon Bray , Jae Sik Lee , Apostolos Pilaftsis

Because 4-dimensional CP is a good symmetry of many higher-dimensional theories, this suggests the possible existence of a universal CP-violating phase originating from the process of compactification. Such a phase, if it existed, would not…

High Energy Physics - Phenomenology · Physics 2011-04-22 R. D. Peccei

CP violation in the SM is naturally implemented as a small imaginary perturbation to real Yukawa couplings. For example, a large CP asymmetry in B_d decays can arise if the imaginary parts of quark mass matrices are of order 10^(-3)m_t,b or…

High Energy Physics - Phenomenology · Physics 2010-04-05 Thomas Dent , Joaquim Silva-Marcos

If massive neutrinos are Majorana particles, then the lepton number should be violated and neutrino-antineutrino oscillations will take place. In this talk, we present the properties of CP violation in neutrino-antineutrino oscillations…

High Energy Physics - Phenomenology · Physics 2022-09-12 Yilin Wang , Shun Zhou

String geometry theory is one of the candidates of the non-perturbative formulation of superstring theory. In this paper, in string geometry theory, we identify perturbative heterotic vacua, which include general heterotic backgrounds. From…

High Energy Physics - Theory · Physics 2025-11-06 Koichi Nagasaki , Matsuo Sato

We consider spontaneous CP violation in the Next to Minimal Supersymmetric Standard Model (NMSSM), without the usual $Z_3$ discrete symmetry. CP violation can occur at tree level, raising a potential conflict with the experimental bounds on…

High Energy Physics - Phenomenology · Physics 2007-05-23 A. T. Davies , C. D. Froggatt , A. Usai

We study Higgs boson decays in the minimal supersymmetric standard model where the tree-level CP invariance of the Higgs potential is explicitly broken by loop effects of soft CP-violating Yukawa interactions related to scalar quarks of the…

High Energy Physics - Phenomenology · Physics 2008-11-26 S. Y. Choi , Jae Sik Lee

The effects of CP violating anomalous ZZZ and gammaZZ vertices in ZZ production are determined. We present the differential cross-section for e+e- -> ZZ with dependence on the spins of the Z bosons. It is shown that from the different spin…

High Energy Physics - Phenomenology · Physics 2009-10-31 Jochen Biebel

Spontaneous breaking of global symmetries can produce ``Alice'' strings: line defects which make unbroken symmetries multivalued, induce apparent charge violation via Aharonov-Bohm interactions, and form point defects when twisted into…

High Energy Physics - Theory · Physics 2009-11-07 Katherine M. Benson

From the string partition function, we discuss the mass-shell and GSO projection conditions valid for Kaluza-Klein (KK) as well as massless states in the heterotic string theory compactified on a nonprime orbifold. Based on the obtained…

High Energy Physics - Phenomenology · Physics 2009-02-02 Bumseok Kyae

It is shown that effects of CP violation arise in neutrino-photon scattering. Several CP-violating $\nu\gamma$ reactions are considered within the Standard Model and predictions for some observables are made. It is emphasized that…

High Energy Physics - Phenomenology · Physics 2014-01-21 I. Alikhanov

The manifestation of CP, T violation in the leptonic sector is studied for flavour neutrino oscillations, both in vacuum and in matter. Different conditions of short-base-line versus long-base-line experiments are discussed.

High Energy Physics - Phenomenology · Physics 2007-05-23 J. Bernabeu

We analyse the CP problem in the context of a supersymmetric extension of the standard model with universal strength of Yukawa couplings. In these models we find a small amount of CP violation from the usual CKM mechanism and therefore a…

High Energy Physics - Phenomenology · Physics 2007-05-23 A. M. Teixeira , G. C. Branco , M. E. Gomez , S. Khalil

We review the present status of CP violating problem in supersymmetric extensions of the standard model. We analyze the constraints imposed by the experimental limits of the electron, neutron, and mercury electric dipole moments on the…

High Energy Physics - Phenomenology · Physics 2014-11-17 Shaaban Khalil

We demonstrate that in effective theories arising from a class of N=1 fluxless compactifications of M-theory on a G2 manifold with low energy supersymmetry, CP-violating phases do not appear in the soft-breaking Lagrangian except via the…

High Energy Physics - Phenomenology · Physics 2011-01-26 Gordon Kane , Piyush Kumar , Jing Shao

We consider the stabilization of string moduli and resulting soft supersymmetry-breaking terms in heterotic string orbifolds. Among the results obtained are: formulae for the scalar interaction soft terms without integrating out the hidden…

High Energy Physics - Theory · Physics 2014-11-18 Thomas Dent

I discuss some theoretical aspects of how to observe leptonic CP violation. It is divided into two parts, one for CP violation due to Majorana, and the other more conventional leptonic Kobayashi-Maskawa (KM) phases. In the first part, I…

High Energy Physics - Phenomenology · Physics 2008-11-26 Hisakazu Minakata

We study the impacts of matter field K\"ahler metric on physical Yukawa couplings in string compactifications. Since the K\"ahler metric is non-trivial in general, the kinetic mixing of matter fields opens a new avenue for realizing a…

High Energy Physics - Theory · Physics 2021-07-20 Keiya Ishiguro , Tatsuo Kobayashi , Hajime Otsuka

We analyze possible CP-violating effects induced in the $Z$ decay with hard photon radiation by $\gamma ZZ$ and $\gamma\gamma Z$ anomalous vertices. We estimate the sensibility of future linear collider experiments on these couplings coming…

High Energy Physics - Phenomenology · Physics 2010-04-05 M. A. Perez , F. Ramirez-Zavaleta

We review basic aspects of the phenomenology of CP violation in the decays of $K$ and $B$ mesons. In particular we discuss the commonly used classification of CP violation -- CP violation in the mass matrix, in the interference of mixing…

High Energy Physics - Phenomenology · Physics 2009-10-30 Gerhard Buchalla
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