Jan Olav Eeg

• Eeg, Jan Olav (2020). Electric dipole moment of the neutron in two-Higgs-doublet models with flavor changing couplings. Physical Review D. ISSN 2470-0010. 102(9). doi: 10.1103/PhysRevD.102.095009. Full text in Research Archive Show summary

  I consider contributions to the neutron electric dipole moment within two-Higgs-doublet models which allow for small flavor changing neutral Higgs couplings. In a previous paper, I considered flavor changing interactions for the Standard Model Higgs boson to first order in the flavor changing coupling. In that paper I found that the obtained value of the neutron electric dipole moment was below the present experimental limit, given previous restrictions on such couplings. Because this was an effective theory, the result depended on an ultraviolet cut off Λ, parametrized as ln(Λ2). In the present paper I demonstrate that, when going to two-Higgs-doublet models, the result stays the same as in the previous paper, up to M2SM/M2H corrections, where MSM is the mass of the top quark or the W boson. MH is the mass of the heavy neutral scalar Higgs boson H which is much heavier than the light neutral Higgs boson h with mass Mh. In the limit M2H≫M2h, the ln(Λ2) behavior in the previous paper is replaced by ln(˜MH2), where ˜MH is of order MH. I also explain how some divergences due to exchange of the pseudoscalar Higgs A are canceled by similar contributions from the scalar heavy Higgs H, and that these contributions, and finite contributions from A exchange, are suppressed.

• Eeg, Jan Olav (2018). Electric dipole moment of the neutron from a flavor changing Higgs-boson. European Physical Journal C. ISSN 1434-6044. 78(12), p. 1–11. doi: 10.1140/epjc/s10052-018-6477-6. Full text in Research Archive Show summary

  I consider neutron electric dipole moment contributions induced by flavor changing Standard Model Higgs boson couplings to quarks. Such couplings might stem from non-renormalizable SU(2)L×U(1)Y invariant Lagrange terms of dimension six, containing a product of three Higgs doublets. We extend previous one loop analysis to two loops. The divergent loops, due to non-renormalisabillity, are parametrized in terms of an ultraviolet cut-off Λ . I also consider QCD corrections. Using the current experimental bound on the neutron electric dipole moment, then for cut offs from one to seven TeV, I find a constraint of order 10−3 for the imaginary part of the product of the Higgs flavor changing coupling for (d→b) -transition and the CKM element Vtd . Assuming that the previous bound of the absolute value of the Higgs flavor changing coupling for (d→b) -transition obtained from Bd−Bd¯ -mixing is saturated, the experimental bound on the neutron electric dipole moment would be reached for the bare result, if the cut off were extended up to about ca 20 TeV. However, QCD corrections suppress this result by a factor of order ten, and keep the nEDM below the experimental bound.

• Fajfer, Svjetlana & Eeg, Jan Olav (2014). Neutron Electric Dipole Moment from colored scalars. In Bruno, G.E.; Chiodini, G.; Colangelo, P; Corianò, C.; Creanza, D; Fazio, F De & Nappi, E. (Ed.), 7th International Workshop on Quantum Chromodynamics Theory and Experiment (QCD@Work 2014). EPJ Web of Conferences. ISSN 9782759816859. doi: 10.1051/epjconf/20148000050. Full text in Research Archive
• Palmer, Teresa & Eeg, Jan Olav (2014). Form factors for semileptonic D decays. Physical Review D. ISSN 1550-7998. 89(3). doi: 10.1103/PhysRevD.89.034013. Full text in Research Archive
• Fajfer, Svjetlana & Eeg, Jan Olav (2014). Colored scalars and the neutron electric dipole moment. Physical Review D. ISSN 1550-7998. 89(9). doi: 10.1103/PhysRevD.89.095030. Full text in Research Archive
• Eeg, Jan Olav (2012). Non-leptonic decays in an extended chiral quark model. AIP Conference Proceedings. ISSN 0094-243X. 1492, p. 88–94. doi: 10.1063/1.4763498. Full text in Research Archive
• Bertolini, Stefano; Eeg, Jan Olav; Maiezza, A & Nesti, F (2012). New physics in epsilon ' from chromomagnetic contributions and limits on left-right symmetry. Physical Review D. Particles and fields. ISSN 0556-2821. 86(9). doi: 10.1103/PhysRevD.86.095013. Full text in Research Archive
• Eeg, Jan Olav & Palmer, Teresa (2011). Color suppressed contribution to (B)over-bar(d)(0) -> pi(0)pi(0). Physical Review D. Particles and fields. ISSN 0556-2821. 83(5). doi: 10.1103/PhysRevD.83.054016. Full text in Research Archive
• Eeg, Jan Olav & Kumericki, Kresimir (2010). Isgur-Wise function within a modified heavy-light chiral quark model. Physical Review D. Particles and fields. ISSN 0556-2821. 81(7). doi: 10.1103/PhysRevD.81.074015. Full text in Research Archive
• Leganger, Lars Erlend & Eeg, Jan Olav (2010). Nonfactorizable contribution to B-d(0) -> pi D-0(0). Physical Review D. Particles and fields. ISSN 0556-2821. 82(7). doi: 10.1103/PhysRevD.82.074007. Full text in Research Archive Show summary

  The decay modes of the type B→πD are dynamically different. For the case Bd0̅ →π-D+ there is a substantial factorized contribution which dominates. In contrast, the decay mode Bd0̅ →π0D0 has a small factorized contribution, being proportional to a very small Wilson coefficient combination. In this paper we calculate the relevant Wilson coefficients at one loop level in the heavy quark limits, both for the b quark and the c quark. We also emphasize that for the decay mode Bd0̅ →π0D0 there is a sizeable nonfactorizable contribution due to long-distance interactions, which dominate the amplitude. We estimate the branching ratio for this decay mode within our framework, which uses the heavy quark limits, both for the b and the c quarks. In addition, we treat energetic light (u,d,s) quarks within a variant of large energy effective theory and combine this with a new extension of chiral quark models in order to estimate the effect of soft-gluon emission. For reasonable values of the model-dependent parameters of our model, we can account for at least 3/4 of the amplitude needed to explain the experimental branching ratio ≃2.6×10-4.

• Eeg, Jan Olav; Fajfer, S & Kamenik, JF (2008). Chiral corrections to the scalar form factor in B-q -> D-q transitions. Physical Review D. Particles and fields. ISSN 0556-2821. 78(7). doi: 10.1103/PhysRevD.78.074008. Full text in Research Archive
• Eeg, Jan Olav; Kumericki, K & Picek, I (2008). New dipole penguin contribution to K -> pi pi decays. Physics Letters B. ISSN 0370-2693. 669(2), p. 150–155. doi: 10.1016/j.physletb.2008.09.039. Full text in Research Archive
• Sørensen, John Atle Macdonald & Eeg, Jan Olav (2007). Decay modes (B)over-bar(d,s)(0) -> gamma D-*0. Physical Review D. Particles and fields. ISSN 0556-2821. 75. doi: 10.1103/PhysRevD.75.034015. Full text in Research Archive Show summary

  The various decay modes of the type $B \rightarrow \gamma \, D^* $ are dynamically different. In general there are factorized contributions of pole and non-pole type, and pseudoscalar exchange contributions at meson level. The purpose of this paper is to point out that the decay modes $\overline{B_{d,s}^0} \rightarrow \, \gamma D^{*0} $ have small contributions from such mechanisms, in contrast to the decay modes $\overline{B_{d,s}^0} \rightarrow \, \gamma \overline{D^{*0}} $ and $B^- \rightarrow \, \gamma D_{s,d}^{*-} $. On the other hand, for the decay modes $\overline{B_{d,s}^0} \rightarrow \, \gamma D^{*0}$ there are non-factorizable contributions due to emision of soft gluons, which dominate the amplitudes for these latter decay modes. We estimate the branching ratio for these modes in the heavy quark limits, both for the $b$- and the $c$- quarks, and obtain a value $ \simeq \, 1 \times 10^{-5}$ for $\overline{B_{d}^0} \rightarrow \, \gamma D^{*0}$, and $ \simeq \, 6 \times 10^{-7}$ for $\overline{B_{s}^0} \rightarrow \, \gamma D^{*0}$. We expect large corrections to these numbers because the energy gap between the $b$- and $c$- quark masses are significantly bigger than 1 GeV. However, we expect that our estimates of the {\em amplitudes} for $\overline{B_{d,s}^0} \rightarrow \, \gamma D^{*0}$ give the right order of magnitude because other mechanisms are numerically suppressed in this special case.

• Eeg, Jan Olav (2007). Low energy aspects of heavy meson decays. Acta Physica Polonica B. ISSN 0587-4254. 38(9), p. 2869–2878. Full text in Research Archive Show summary

  I discuss low energy aspects of heavy meson decays, where there is at least one heavy meson in the final state. Examples are B -\overline{B} mixing, B --> D \overline{D}, B --> D \eta', and B --> D \gamma. The analysis is performed in the heavy quark limit within heavy-light chiral perturbation theory. Coefficients of 1/N_c suppressed chiral Lagrangian terms (beyond factorization) have been estimated by means of a heavy-light chiral quark model.

• Eeg, Jan Olav; Fajfer, S & Kamenik, J (2007). Chiral loop corrections to weak decays of B mesons to positive and negative parity charmed mesons. Journal of High Energy Physics (JHEP). ISSN 1126-6708. Full text in Research Archive
• Eeg, Jan Olav; Fajfer, Svjetlana & Brdnik, Anita Prapotnik (2006). Non-factorizable contributions to $\overline{B^0_d} \rightarrow D_s^{(*)} \overline{D_s^{(*)}}$ from chiral loops and tree level $1/N_c$ terms. AIP Conference Proceedings. ISSN 0094-243X. 806, p. 183–189. Full text in Research Archive
• Eeg, Jan Olav; Kumericki, Kresimir & Picek, Ivica (2006). Soft gluon contributions to the B -> K eta ' amplitude in a low energy bosonization model. Journal of Physics G: Nuclear and Particle Physics. ISSN 0954-3899. 32, p. 2081–2087. doi: 10.1088/0954-3899/32/11/003. Full text in Research Archive
• Eeg, Jan Olav & Hiorth, Aksel (2005). Chiral quark models and their applications. Fizika B. ISSN 1330-0016. B 14(1), p. 41–74. Full text in Research Archive Show summary

  We give an overview of chiral quark models, both for the pure light sector and the heavy-light sector. We describe how such models can be bosonized to obtain well known chiral Lagrangians which can be inferred from the symmetries of QCD alone. In addition, the coefficients of the various pieces of the chiral Lagrangians can be calculated within these models. We discuss a few applications of the models, in particular, $\bbar$ mixing and processes of the type $B \rightarrow D \bar{D}$, where $D$ might be both pseudoscalar and vector. We suggest how the formalism might be extended to include light vectors ($\rho,\omega,K^*$), and heavy to light transitions like $B \to \pi$.

• Eeg, Jan Olav; Fajer, S; Hiroth, A & Prapotnik, A (2005). Non-factorizable contributions to B-d(0) & (DsDs(*))-D-(*). Nuclear physics B, Proceedings supplements. ISSN 0920-5632. 142, p. 188–191. Full text in Research Archive
• Eeg, Jan Olav; Fajfer, S & Prapotnik, A (2005). Color suppressed contributions to the decay modes B-d,B-s -> Ds,dDs,d, B-d,B-s -> Ds,dD*(s,d,) and B-d,B-s -> D*(s,d) D*(s,d). European Physical Journal C. ISSN 1434-6044. 42, p. 29–36. Full text in Research Archive
• Eeg, Jan Olav & Hiorth, Aksel (2004). The beta-term for D* --> D gamma within a heavy light chiral quark model. European Physical Journal C. ISSN 1434-6044. doi: 10.1140/epjcd/s2004-01-003-1. Full text in Research Archive
• Eeg, Jan Olav; Fajfer, Svjetlana & Hiorth, Aksel (2003). On the colour suppressed decay modes B --> Ds anti-Ds. Physics Letters B. ISSN 0370-2693. 570, p. 46–52. Full text in Research Archive
• Hiorth, Aksel & Eeg, Jan Olav (2003). "Non-factorizable effects in B - anti-B mixing'';. European Physical Journal C. ISSN 1434-6044. 30, p. 006–006. Full text in Research Archive
• Eeg, Jan Olav; Kumericki, Kresimir & Picek, Ivica (2003). "On the short distance part of the QCD anomaly contribution to the b -> s eta-prim amplitude''. Physics Letters B. ISSN 0370-2693. 563, p. 87–92. Full text in Research Archive
• Eeg, Jan Olav (2003). B-decays and B - anti-B mixing within a heavy light chiral quark model. In Colangelo, Pietro; Fazio, Fulvia De; Fini, Rosa Anna; Nappi, Eugenio & Nardulli, Guiseppe (Ed.), QCD at work. International workshop on Quantum Chromodynamics, Conversano, Bari, Italy, june 2003. Editrice Proto. ISSN 9788888823065. p. 171–178. Full text in Research Archive
• Eeg, Jan Olav; Kumericki, Kresimir & Picek, Ivica (2002). The double radiative annihilation of the heavy-light fermion bound states. Fizika B. ISSN 1330-0016. 10, p. 285–306. Full text in Research Archive Show summary

  We consider the doubly radiative decays of heavy-light QED and QCD atoms e^- mu^- -> 2 gamma and B -> 2 gamma. Especially, we take under scrutiny effects of operators which vanish on the mass-shell.

• Eeg, Jan Olav; Hiorth, Aksel & Polosa, Antonio (2002). Gluonic mechanism for B -> D eta'. Physical Review D. Particles and fields. ISSN 0556-2821. 65(054030). Full text in Research Archive Show summary

  We present a calculation of the process B -> D eta' within a heavy-light chiral quark model, assuming that eta' has a gluonic component described via an effective glue-glue-eta' vertex. The main contribution comes from non-factorizable contributions.

• Eeg, Jan Olav & Hiorth, Aksel (2002). Heavy-light chiral quark model. Physical Review D. Particles and fields. ISSN 0556-2821. 66(074001). Full text in Research Archive Show summary

  We present a new chiral quark model for mesons involving a heavy and a light (anti) quark. The model relates various combinations of quark-meson couplings to physical quantities. Soft gluon effects in terms of gluon condensates are included.

• Eeg, Jan Olav; Fajfer, Svjetlana & Zupan, Jure (2001). Nonfactorizable contributions to the decay mode D^0 -> K^0 + anti-K^0. Physical Review D. Particles and fields. ISSN 0556-2821. 64(034010), p. 1–13. Full text in Research Archive Show summary

  We point out that the decay mode D^0 -> K^0 + anti-K^0 has no factorizable contribution. In the chiral perturbation language, treating D^0 as heavy, the O(p) contribution is zero. We calculate the nonfactorizable chiral loop contributions of order O(p^3). Then, we use a heavy-light type chiral quark model to calculate nonfactorizable tree level terms, also of order O(p^3), proportional to the gluon condensate.

• Bertolini, Stefano; Eeg, Jan Olav & Fabbrichesi, Marco (2001). An updated analysis of epsilon'/epsilon in the Standard Model with hadronic matrix elements from the Chiral Quark Model. Physical Review D. Particles and fields. ISSN 0556-2821. 63(056009), p. 1–12. Full text in Research Archive Show summary

  We discuss the theoretical and experimental status of the CP violating quantity epsilon'/epsilon. ......

• Bertolini, Stefano; Eeg, Jan Olav & Fabbrichesi, Marco (2000). Theory of the CP-violating quantity epsilon'/epsilon. Reviews of Modern Physics. ISSN 0034-6861. 72(1), p. 65–93. Full text in Research Archive Show summary

  We have given a review of estimeates of the real part of CP-violating parameter epsilon'/epsilon, which measures direct CP-violation in the decays of a neutral K-meson in two pi-mesons. Special emphasisis is put on the long-distance part of the calculations. Because of the intrinsic uncertainties of the long-distance computations, values ranging from 10^{-4} to a few times 10^{-3} may be accounted for in the standard model. Since this range covers most of the present experimental uncertainty, it is unlikely that new physics effects can be disentangled from the standard model prediction.

• Eeg, Jan Olav; Kumericki, Kresimir & Picek, Ivica (2000). Bound-state effects in _m<SUP>+</SUP> e<SUP>-</SUP> -> _g_g and B<SUP>0</SUP> -> _g_g decays. European Physical Journal C. ISSN 1434-6044. 17, p. 163–168. Full text in Research Archive Show summary

  We demonstrate that in the double-radiative decays of heavy-light QED and QCD atoms, mu^{+} e^{-} --> gamma gamma and {B}^{0} --> gamma gamma, there is a contribution coming from operators that vanish on the free-quark mass shell. This off-shell effect is suppressed with respect to the effect of the well known flavour-changing magnetic-moment operator by the bound-state binding factor. Accordingly, the negligible off-shellness of the weakly bound QED atoms becomes important for strongly bound QCD atoms. We present this effect in two different model-approaches to QCD, one of them enabling us to keep close contact to the related effect in QED.

• Eeg, Jan Olav; Kumericki, Kresimir & Picek, Ivica (1999). Long vs. short distance dispersive two photon K(L) -> _m<SUP>+</SUP>_m<SUP>-</SUP> amplitude. Fizika B. ISSN 1330-0016. p. 395–400. Full text in Research Archive Show summary

  We report on the calculation of the two-loop electroweak, two-photon mediated short-distance dispersive K_L \to \mu^+\mu^- decay amplitude. QCD corrections change the sign of this contribution and reduce it by an order of magnitude. The resulting amplitude enables us to provide a constraint on the otherwise uncertain long-distance dispersive amplitude.

• Eeg, Jan Olav; Kumericki, Kresimir & Picek, Ivica (1998). On The Short-Distance Dispersive Two-Photon K<SUB>L</SUB>->_m<SUP>+</SUP>_m<SUP>-</SUP> Amplitude. European Physical Journal C. ISSN 1434-6044. 1, p. 531–537. Full text in Research Archive

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• Bugge, Lars & Eeg, Jan Olav (1999). Diverse oversikter i tabell-form. Kunnskapsforlaget. ISBN 9788257306922. -1 p. Full text in Research Archive

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• Eeg, Jan Olav (2020). Building the Standard Model. Historial and Qualitative Aspects (3 lectures). Full text in Research Archive
• Eeg, Jan Olav (2018). Building the Standard Model. Qualitative and historical aspects. (3 double lessons). Full text in Research Archive
• Eeg, Jan Olav (2017). Frå Atom til Kvark og Higgs. Frå 1963 til 2017. Full text in Research Archive
• Eeg, Jan Olav (2016). Electric dipole meoments from flavor changing Higgs interactions. Full text in Research Archive
• Eeg, Jan Olav (2015). Status for partikkelfysikken. Klassekampen. ISSN 0805-3839. p. 25–25. Full text in Research Archive
• Eeg, Jan Olav (2015). Neutron Electric Dipole Moment from flavor changing scalar couplings ? Full text in Research Archive
• Eeg, Jan Olav (2015). Electric dipole moments generated from flavor changing scalars. Full text in Research Archive
• Eeg, Jan Olav (2014). Oppdaging av nye baryoner Xi_b. [Internet]. Interviu i Forskning.no. Full text in Research Archive
• Eeg, Jan Olav & Fajfer, Svjetlana (2014). Neutron Electric Dipole Moment from Colored Scalars. Full text in Research Archive
• Eeg, Jan Olav (2014). From charm and beauty to charm and colored scalars. Full text in Research Archive
• Eeg, Jan Olav (2013). Non-leptonic decays within chiral quark models. Full text in Research Archive
• Eeg, Jan Olav (2012). Symmetriar som brytast- Om kva Higgs gjer og ikkje gjer. Fra Fysikkens Verden. ISSN 0015-9247. Årg 74(4), p. 97–103. Full text in Research Archive
• Eeg, Jan Olav (2011). Jan O. Eeg: ``A model for the color suppressed decay mode B^0 --> 2 \pi^0''. Full text in Research Archive
• Eeg, Jan Olav (2009). Lambshift-like Dipole Contributions for K -> 2 pi decays - http://indico.cern.ch/getFile.py/access?contribId=36&resId=0&materialId=slides&confId=55990. Full text in Research Archive
• Eeg, Jan Olav (2009). Lamb-Shift-Like Effects in K - decays. Full text in Research Archive
• Eeg, Jan Olav (2009). Lamb-Shift-Like Dipole Contribution to K -> 2 \pi Decays. Full text in Research Archive Show summary

  Hele foredraget (slides) er tilgjengelig på nettsidene http://hippo.irb.hr//primosten09

• Eeg, Jan Olav (2008). Short and long distance effects in B --> D \pi decays. Full text in Research Archive
• Eeg, Jan Olav (2007). Low energy aspects of heavy meson decays (talk II). Full text in Research Archive
• Eeg, Jan Olav (2006). Low energy aspect of heavy meson decays (talk). Full text in Research Archive
• Eeg, Jan Olav; Fajfer, Svjetlana & Brdnik, Anita Prapotnik (2006). Non-factorizable contributions to $\overline{B^0_d} \rightarrow D_s^{(*)} \overline{D_s^{(*)}}$ from chiral loops and tree level $1/N_c$ terms. Full text in Research Archive
• Eeg, Jan Olav; Fajfer, Svjetlana & Prapotnik, Anita (2005). Non-factorizable contributions to anti-B0(D) ---> D(*)(S) anti-D(*)(S) from chiral loops and tree level 1/N(C) terms. Full text in Research Archive
• Eeg, Jan Olav (2004). Chiral Lagrangians obtained from Chiral Quark Models. Full text in Research Archive
• Eeg, Jan Olav (2004). `Colour suppressed contributions to B^0 --> Ds^(*) anti-Ds^(*) from chiral loops and gluon condensates". Full text in Research Archive
• Eeg, Jan Olav (2004). ``Non-factorizable contributions to B --> D anti-D from chiral loops and gluon condensates''. Full text in Research Archive
• Eeg, Jan Olav (2003). Bosonization of qurk operators within a heavy light chiral quark model. Full text in Research Archive
• Eeg, Jan Olav (2003). B - anti-B mixing and B-decays within a heavy light chiral quark model and chiral perturbation theory. Full text in Research Archive
• Eeg, Jan Olav; Fajfer, Svjetlana & Hiorth, Aksel (2003). On the Colour Suppressed Decay Modes B^0 -> D_s^+ D_s^- and B_s^0 -> D^+ D^- (presentert av s: Fajfer). Full text in Research Archive
• Eeg, Jan Olav (2002). A heavy-light chiral quark model and its relevance for B- anti-B mixing. Full text in Research Archive Show summary

  I present a heavy-light chiral quark model, and show how it describes B- anti-B mixing in terms of gluon condensates and chiral loops.

• Eeg, Jan Olav (2002). A heavy-light chiral quark model and its relevance for B -> D eta' and B - anti-B mixing. Full text in Research Archive Show summary

  I present a heavy-light chiral quark model and show how it can descaribe B-> D eta' and B - anti-B mixing.

• Eeg, Jan Olav; Fajfer, Svjetlana & Zupan, Jure (2001). The D -> K anti-K beyond factorization. Full text in Research Archive Show summary

  We consoder nonfactorizable contributions to the process D -> K anti-K, in terms of gluon condensates and chiral loops.

• Bugge, Lars & Eeg, Jan Olav (2000). Verdt å vite spesial om antimaterie. [Radio]. NRK P2 : NRK P2. Full text in Research Archive
• Eeg, Jan Olav (2000). Theoretical estimates of the CP-violating quantity epsilon'/epsilon in K -> 2 pi decays. Full text in Research Archive Show summary

  I give a short presentation of the theoretical prediction of epsilon'/epsilon. Short distance and especially long distance aspects of the computation is discussed. I consentrate on the general framework and the chiral quark model approach, while other approaches are also shortly presented. Because of the intrinsic uncertainties of the long-distance computations, it is unlikely that new physics effects can be disentangled from the standard model prediction.

• Eeg, Jan Olav (2000). Direct CP-violation in the K --> 2_p decay modes. Full text in Research Archive Show summary

  I gave a short review on the CP-violating quantity epsilon'/epsilon in the K --> 2 pi decay process. A special emphsis on the chiral quark model estimate was given.

• Eeg, Jan Olav (2000). Estimates of direct CP-violation in K --> 2_p decays. Full text in Research Archive Show summary

  I gave a review on estimates on the CP-violating parameter epsilon'/epsilon within the Standard Model. Special emphasis on the chiral quark model estimate was given.

• Eeg, Jan Olav (1999). Hvorfor er det langt mer materie enn antimeaterie i universet? Full text in Research Archive Show summary

  Like etter "ursmellet" (Big Bang) besto universet bare av elementærpartikler ved svært høg temperatur. Foredraget vil ta for seg hvordan universet kan ha utvikla seg fra denne tilstanden til dagens univers, som ser ut til å inneholde nesten bare materie. Vi regner med at dette kommer av at kreftene mellom elementærpartiklene virker litt forskjellig på en partikkel og en antipartikkel. At det fins slike krefter blei eksperimentelt påvist i 1964.

• Eeg, Jan Olav (1999). Div. mindre artikler om elementærpartikkelfysikk, Store Norske Leksikon. Kunnskapsforlaget. Full text in Research Archive Show summary

  Jeg har skrivi og/eller oppdatert artikler om elemntærpartikler, dvs. om deres egenskaper (feks. hvor tunge de er, hva slags ladningstyper de har) og hvordan de vekselvirker med hverandre.

• Eeg, Jan Olav; Fajfer, Svjetlana; Prapotnik, Anita & Hiorth, Aksel (2004). ``Non-factorizable contributions to B^0 --> Ds^(*) anti-Ds^(*)'', (hep-ph/0408298). Based on talk given by J.O. Eeg at BEACH2004, 6thinternational conference on Hyperons, Charm and Beauty Hadrons, Illinois Institute of Technology, june 27.-july 3., Chicago, 2004. Illinois Inst of technology, Chicago. Full text in Research Archive
• Eeg, Jan Olav; Kumericki, Kresimir & Picek, Ivica (2004). "On the singlet penguin in B -> K eta-prim decay"Proceedings of 9th Adriatic Meeting, Dubrovnik, Croatia, 4-14 Sep 2003; hep-ph/0407279. Springer. ISSN 9783540228035. Full text in Research Archive
• Eeg, Jan Olav (2004). Chiral quark models and their applications (Dedicated to the memory of Prof. Dubravko Tadi\'c}, submitted to Fizika B, Zagreb ) hep-ph/0411393. hep-ph@arXiv.org. Full text in Research Archive
• Eeg, Jan Olav; Fajfer, Svjetlana & Hiorth, Aksel (2003). "Non.factorizable contributions in B -> Ds^+ Ds^-'' ; Contributed to 21st International Symposium on Lepton and Photon Interactions at High Energies (LP 03), Batavia,Illinois, 11-16 Aug 2003; (hep-ph/0307042). (Fermilab). Full text in Research Archive
• Eeg, Jan Olav; Kumericki, Kresimir & Picek, Ivica (2001). Double radiative annihilation of the heavy-light fermion bound states. UiO, Fys. inst., teoretisk fysikk. Full text in Research Archive Show summary

  We consider the double-radiative decays of heavy-light QED and QCD atoms, mu^+ e^- 2 gamma B_s -> 2 gamma. Especially, we take under scrutiny contributions coming from operators that vanish on the free-quark mass shell. We show that by the field redefinitions these operators are converted into contact terms attached to the bound state dynamics. As a result a net off-shell effect is suppressed with respect to the effect of the well known flavour-changing magnetic-moment operator by the bound-state binding factor. The negligible off-shellness of the weakly bound QED atoms becomes more relevant for strongly bound QCD atoms. We present this effect in model-approaches to QCD, one of them enabling us to keep close contact to the related effect in QED. We also comment on the off-shell effect in the related process B_d -> K^* + gamma

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