We analyze the one loop corrections to W and Z decays in an R-parity violating extension to the Minimal Supersymmetric Standard Model (MSSM). We find strong constraints on the size of the R-parity violating couplings lambda' and lambda'' coming from the b-quark asymmetry parameters A_b and A_FB(b). The Bayesian confidence limits for the couplings, with the a priori assumption that the MSSM with R-parity violation is the correct underlying theory, are weaker.
Authors:Tatsu Takeuchi, Oleg Lebedev, Will Loinaz
Proposed speaker: Tatsu Takeuchi
Contact person:Tatsu Takeuchi
(Virginia Tech),
takeuchi@vt.edu
Sessions: PA-10 Beyond the Standard Model ( Theory ) / PL-09 Beyond the Standard Model
Supporting papers: hep-ph/9910435, hep-ph/9911479 (Both to appear in Phys.Rev.D)
Notes:
The simplest unified extension of the Minimal Supersymmetric Standard Model with bi-linear R--Parity violation naturally predicts a hierarchical neutrino mass spectrum, in which one neutrino acquires mass by mixing with neutralinos, while the other two get mass radiatively. We have performed a full one-loop calculation of the neutralino-neutrino mass matrix in the bi-linear RPV MSSM, taking special care to achieve a manifestly gauge invariant calculation. We determine the range of model parameters for which the atmospheric and solar neutrino problems are solved. The main advantage of our solution to neutrino anomalies is that it can be tested also at high energy collider experiments.
Authors:M. Hirsch, M.A. Diaz, W. Porod, J. C. Romao and J.W.F. Valle
Proposed speaker: M. Hirsch
Contact person:Martin Hirsch
(Universidad de Valencia),
mahirsch@ific.uv.es
Sessions: PA-10 Beyond the Standard Model ( Theory ) /
Supporting papers: M. Hirsch et al., hep-ph/0004115 J.C.Romao et al., Phys.ReV. DD61 (2000) 071703(R)
Notes:Fits also in PA-08
In the framework of the MSSM the non-universal boundary conditions of soft SUSY breaking parameters are considered. Taking as input the top, bottom and Z-boson masses, the values of the gauge couplings at the EW scale and the infrared quasi-fixed points for Yukawa couplings and the soft parameters the mass of the lightest CP-even Higgs boson is found to be m_h=92.7 + 10 - 4.9 +- 5 +- 0.4 GeV/c^2 for the low tan\beta case and m_h = 125.7 + 6.4 - 9.0 +- 5+- 0.4 GeV/c^2 (\mu > 0) or m_h = 125.4 + 6.6 - 9.0 +- 5 +-0.4 GeV/c^2 (\mu < 0) in the case of large tan\beta.
Authors:S. Codoban, M.Jurcisin and D.Kazakov
Proposed speaker: D.Kazakov
Contact person:Dmitri Kazakov
(JINR),
kazakovd@thsun1.jinr.ru
Sessions: PA-10 Beyond the Standard Model ( Theory ) / PL-09 Beyond the Standard Model
Supporting papers:
Notes:
Previously the high tanbeta scenario of the CMSSM) was strongly constrained by a simultaneous fit of b->sgamma and the masses of the bottom quark and tau lepton assuming unification of the Yukawa couplings. New NLO b->sgamma calculations have become available. We observe that at large tanbeta the dominant NLO term of the chargino amplitude, which is proportional to \mu\tan^2\beta, changes the sign of this amplitude in a large region of the CMSSM parameter space, so that the preferred sign of the Higgs mixing parameter \mu now agrees with the preferred sign of b-\tau unification. Although the NLO calculations are incomplete, the present ones indicate that the NLO effects are large. We find that the b->sgamma rate does not constrain the CMSSM anymore, if the higher order contributions and its uncertainties are taken into account. Therefore the high tanbeta scenario has in our global analysis a good chisquare again, which is fortunate, since the low tanbeta CMSSM scenario with tanbeta<3.2 is excluded by the Higgs mass limit above 107.9 GeV from LEP. The Higgs mass in the high tanbeta scenario of the CMSSM is found to be between 105 and 125 GeV. The mean value and its dominant errors are: $$m_h=115\pm3~ (stop mass)~\pm2.5~(top mass)~\pm2~(stop mixing)~\pm2~(theory).$$ This Higgs boson mass prediction is valid for all tanbeta values above 20 and decreases slightly for lower tanbeta. If the presently claimed evidence for dark matter by the DAMA Collaboration is interpreted as the Lightest Supersymmetric Particle (LSP) of the CMSSM, then it is at the edge of the parameter space allowed by the present Higgs limit of 107.9 GeV from LEP.
Authors:
Proposed speaker: W. de Boer
Contact person:Wim de Boer
(Univ. Karlsruhe),
wim.de.boer@cern.ch
Sessions: PA-10 Beyond the Standard Model ( Theory ) / PL-09 Beyond the Standard Model
Supporting papers:
Notes:The results will be updated, if new Higgs mass limits from LEP become available.
The phenomenology of the Randall-Sundrum model of localized gravity is analyzed in detail for the two scenarios where the Standard Model (SM) gauge and matter fields are either confined to a TeV scale 3-brane or may propagate in a slice of AdS$_5$ bulk. The Kaluza-Klein (KK) towers of gravitons which emerge in this model have strikingly different properties than in the factorizable case of large extra dimensions. The interactions of the graviton and gauge KK states are derived and we find that they are substantially different when the SM fields are allowed to reside in the bulk versus being confined to the TeV brane. The specific phenomenological signatures for the model are shown to be highly dependent on the value of the bulk mass parameter for fermions. We examine the collider signatures for direct production of the graviton and gauge KK towers as well as their induced contributions to precision electroweak observables. These direct and indirect signatures are found to play a complimentary role in the exploration of the full model parameter space. In addition, we argue that spontaneous symmetry breaking of the SM must take place on the TeV brane.
Authors:H. Davoudiasl, J. Hewett, T. Rizzo
Proposed speaker: JoAnne Hewett
Contact person:JoAnne L Hewett
(SLAC),
hewett@slac.stanford.edu
Sessions: PA-10 Beyond the Standard Model ( Theory ) / PL-09 Beyond the Standard Model
Supporting papers: Phys. Rev. Lett. 84, 2080 (2000); Phys. Lett. B473, 43 (2000); hep-ph/0004xxx (SLAC-PUB-8436).
Notes:
Any pair of u- and d-quark mass matrices can be brought into the triangular form. Further,the resulting matrix elements are simple products of masses and the CKM mixing parameters. When hermitian mass matrices are thus analyzed, it is found that any pattern of texture zeros imply simple, analytical and testable predictions for the quark mixing parameters. Applications to hermitian matrices with four or five texture zeros are given.
Authors:T.K.KUO, S. Mansour, G.H. Wu
Proposed speaker: T.K.KUO
Contact person:T.K. KUO
(Purdue Univ),
tkkuo@physics.purdue.edu
Sessions: PA-10 Beyond the Standard Model ( Theory ) / PL-09 Beyond the Standard Model
Supporting papers: PLB 467 (1999) p.116 hep-ph/0003224
Notes:
A unified description of spacetime and matter is proposed by using a single irreducible representation of N=10 extended Super-Poincare algebra. All observed elementary particles except the graviton are the supersymmetric composites of more fundamental Nambu-Goldstone fermions with spin 1/2, "superons" asociating the spontaneou breakdown of supertranslation of spacetime. The standard model and SU(5)(SO(10)) grand unified model are investigated systematically by using the superon diagrams. The stability of the proton, the suppression of the flavour changing neutral currents, $K^{0}- \overline K^{0}$, $D^{0}- \overline D^{0}$ and $B^{0}- \overline B^{0}$ mixings, CP-violation, the atmospheric $\nu_{\mu}$ deficit, and the absence of the electroweak lepton-flavor-mixing are understood qualitatively and simply in the superon pictures of GUTs. The fundamental action of the superon-graviton model(SGM) for spacetime and matter is proposed.
Authors:Kazunari Shima
Proposed speaker: Kazunari Shima
Contact person:Kazunari Shima
(Saitama Institute of Technology),
shima@sit.ac.jp
Sessions: PA-10 Beyond the Standard Model ( Theory ) / PL-09 Beyond the Standard Model
Supporting papers: K. Shima, Eur. Phys. J.,C7,341(1999). Plenary Talk give at 3rd Int.Conf. on Symmetry in Nonl. Math. Physics, Kiev, 99. hep-th
Notes:
I will review an efficient formulation of the complete theory of SUSY without R-parity, where all the admissible R-parity violating terms incorporated. Some interesting recent results will be discussed, including newly identified 1-loop contributions to neutrino masses and electric dipole moments of neutron and electron.
Authors:Otto C.W. Kong
Proposed speaker: Otto C.W. Kong
Contact person:Otto C.W. Kong
(Institute of Physics, Academia Sinica),
kongcw@phys.sinica.edu.tw
Sessions: PA-10 Beyond the Standard Model ( Theory ) / PL-09 Beyond the Standard Model
Supporting papers: M. Bisset, O.C.W. Kong, C. Macesanu, and L.H. Orr, Phys. Lett. B430, 274 (1998); Phys. Rev. D (2000) {\it to be published}, hep-ph/9811498. O.C.W. Kong, Mod. Phys. Lett. A. {\bf 14} (1999) 903; K. Cheung and O.C.W. Kong, hep-ph/9912238, Phys. Rev. {\bf D} (2000) {\it to be published}. O.C.W. Kong, hep-ph/0004107. Y.-Y. Keum and O.C.W. Kong, hep-ph/0004110; mansucript in preparation.
Notes:
We discuss the constraint to the mass density of LSP from LHC and LC. Mass determination and coupling determination are important part of the issue. We discuss the mass determination at LHC, and its implication to Omega. Regarding to LSP couplings, we study that LHC can tell when LSP is a mixture of gaugino and higgsino. It turns out that LHC has a good chance to reveal the details of MSSM for the case.
Authors:M. Drees, K. Hasuko, Y. G. Kim, T. Kobayashi, M. Nojiri, D. Toya
Proposed speaker: M. M. Nojiri
Contact person:Mihoko M Nojiri
(Kyoto University),
nojiri@yukawa.kyoto-u.ac.jp
Sessions: PA-10 Beyond the Standard Model ( Theory ) / PL-17 Particle Physics and Cosmology
Supporting papers: hep-ph/0001267
Notes:
In the minimal supersymmetric standard model (MSSM), the $\mu-$parameter and the trilinear coupling $A_t$ may be generically complex and can affect various observables at B factories. Working in the effective SUSY models and imposing the edm constraints from Chang-Keung-Pilaftsis (CKP) mechanism, we find that (i) there is no new large phase shift in the $B^0 - \bar{B^0}$ mixing from the $A_t$ and $\mu$ phases, (ii) CP violating dilepton asymmetry is smaller than 0.1%, (iii) the direct CP violation in $B\to X_s \gamma$ can be as large as $\sim \pm 16 %$, (iv) the ${\rm Br} (B\to X_s l^+ l^-)$ can be enhanced by upto $\sim 85 %$ compared to the standard model (SM) prediction, and its correlation with ${\rm Br} (B \to X_s \gamma)$ is distinctly different from the minimal supergravity scenario. Also, we find $1 \leq \epsilon_K / \epsilon_K^{SM} \leq 1.4$, and $\epsilon_K$ cannot be saturated by the $A_t$ and $\mu$ phases alone : namely, $|\epsilon_K^{\rm SUSY}| \leq O(10^{-5})$ if the phases of $\mu$ and A_t are the sole origin of CP violation.
Authors:Seungwon Baek and Pyungwon Ko
Proposed speaker: Pyungwon Ko
Contact person:Pyungwon Ko
(KAIST),
pko@muon.kaist.ac.kr
Sessions: PA-10 Beyond the Standard Model ( Theory ) / PL-09 Beyond the Standard Model
Supporting papers: (1) PROBING SUSY INDUCED CP VIOLATIONS AT B FACTORIES, By Seungwon Baek, Pyungwon Ko, Phys.Rev.Lett.83:488-491 (1999) (2) EFFECTS OF SUPERSYMMETRIC CP VIOLATING PHASES ON B ---> X(S) LEPTON+ LEPTON- AND EPSILON(K), By Seungwon Baek, Pyungwon Ko, Phys.Lett.B462:95-102 (1999)
Notes:
We show that, on the contrary to the usual claims, fully supersymmetric CP violations in the kaon system are possible through the gluino mediated flavor changing interactions. Both $\epsilon_K$ and ${\rm Re} (\epsilon' / \epsilon_K)$ can be accommodated for relatively large $\tan\beta$ without any fine tunings or contradictions to the FCNC and EDM constraints.
Authors:Seungwon Baek, Ji-Ho Jang, Pyungwon Ko and Jae Hyun Park
Proposed speaker: Pyungwon Ko
Contact person:Pyungwon Ko
(KAIST),
pko@muon.kaist.ac.kr
Sessions: PA-10 Beyond the Standard Model ( Theory ) / PL-09 Beyond the Standard Model
Supporting papers: (1) Preprint by S. Baek, J.H. Jang, P. Ko, J.H. Park. KAIST-99-04, Aug 1999. e-Print Archive: hep-ph/9907572 . Submitted to Phys. Rev. Lett.
Notes:
A realistic supersymmetric grand unified $SO(10)$ model with $U(2)_{F}$ family symmetry has been constructed. A distinct feature of our model is the use of $126$ dimensional Higgses in generating fermion mass matrices. The quark-lepton symmetry is manifest via $SO(10)$. The inter-family hierarchy is explained by the two $U(2)_{F}$ breaking scales, while the intrafamily hierarchy is explained by $\tan \beta$ and the Higgs doublet mixing parameter. We use mass textures resulting from the proposed Yukawa superpotential giving rise to realistic mass relations including Georgi-Jarlskog relations at the GUT scale. We obtain a large mixing and a large mass splitting in the $\nu_{\mu}-\nu_{\tau}$ sector using an appropriate RH neutrino texture, thus getting the large lepton mixing from the small quark mixing . A good fit to the experimental data is obtained; 15 fermion masses and 6 mixing angles are governed by only 10 input parameters at the GUT scale. Our model favors the solar vacuum oscillation solutions.
Authors:Mu-Chun Chen and K.T. Mahanthappa
Proposed speaker: K.T. Mahanthappa
Contact person:K.T. Mahanthappa
(University of Colorado at Boulder),
ktm@verb.colorado.edu
Sessions: PA-10 Beyond the Standard Model ( Theory ) / PL-09 Beyond the Standard Model
Supporting papers:
Notes:A paper containing above results is under preparation.
There are many models with significant deviations from universality (the hallmark of the mSUGRA framework) of soft SUSY breaking parameters. We outline the physics behind these models and mention recent improvements to the event generator ISAJET that facilitate their simulation. We also discuss how D-term contributions, which are generically present when an SO(10) GUT is broken to the Standard Model, facilitate electroweak symmetry breaking and lead to calculable models where Yukawa couplings also unify at M_GUT. We show that a phenomenologically desirable hierarchy between the masses of the third generation and the first two generations of sfermions may be dynamically generated in these models. Time permitting, we will discuss the phenomenology of these models, and also some recent results on the reach of the LHC within the gauge-mediated SUSY breaking framework.
Authors:Xerxes Tata
Proposed speaker: Xerxes Tata
Contact person:Xerxes R Tata
(University of Hawaii),
tata@phys.hawaii.edu
Sessions: PA-10 Beyond the Standard Model ( Theory ) / PL-09 Beyond the Standard Model
Supporting papers: Mass Spectra from SO(10) Grand Unified Models with Yukawa Coupling Unification, hep-ph/9907211 (Phys. Rev. D, in press) Calculable Sparticle Masses with Radiatively Driven Inverted Mass Hierarchy, hep-ph/9912494 (Phys. Lett. B in press) Impact of Physical Principles at Very High Energy scales on the Superparticle Mass spectrum, hep-ph/0002245 (JHEP, in press) The Reach of the CERN Large Hadron Collider for Gauge-Mediated Supersymmetry Breaking Models, hep-ph/0004001
Notes:
We study various regularization schemes in order to analyze concretely the regularization scheme dependence of the Kaluza-Klein threshold effects, which cause the power law behavior of the running couplings. We also present a method to control the scheme dependence and rexamine the gauge coupling unifucation. We are going to discuss also the ruunning couplings in the case that our four dimensional world is on a brane, whose fluctuation supresses some Kaluza-Klein mode couplings.
Authors:Jisuke Kubo, Haruhiko Terao, George Zoupanos
Proposed speaker: Haruhiko Terao
Contact person:Haruhiko Terao
(Kanazawa Univ.),
terao@hep.s.kanazawa-u.ac.jp
Sessions: PA-10 Beyond the Standard Model ( Theory ) /
Supporting papers: hep-ph/9910277 to appear in Nucl. Phys. B
Notes:
Recently, Randall and Sundrum proposed a static solution to Einstein's equations in five spacetime dimensions with two 3-branes located at the fixed points of $S^1/Z_2$ to solve the hierarchy problem. We extend the solution and construct static and also inflationary solutions to Einstein's equations in five spacetime dimensions, one of which is compactified on $S^1$, with any number of 3-branes whose locations are taken to be arbitrary. We discuss how the hierarchy problem can be explained in our model.
Authors:Hisaki Hatanaka, Makoto Sakamoto, Motoi Tachibana and Kazunori Takenaga
Proposed speaker: Hisaki Hatanaka
Contact person:Hisaki Hatanaka
(Tokyo Univ.),
hatanaka@icrr.u-tokyo.ac.jp
Sessions: PA-10 Beyond the Standard Model ( Theory ) /
Supporting papers:
Notes:
Recently, Randall and Sundrum proposed a static solution to Einstein's equations in five spacetime dimensions with two 3-branes located at the fixed points of $S^1/Z_2$ to solve the hierarchy problem. We extend the solution and construct static and also inflationary solutions to Einstein's equations in five spacetime dimensions, one of which is compactified on $S^1$, with any number of 3-branes whose locations are taken to be arbitrary. We discuss how the hierarchy problem can be explained in our model.
Authors:Hisaki Hatanaka, Makoto Sakamoto, Motoi Tachibana and Kazunori Takenaga
Proposed speaker: Hisaki Hatanaka
Contact person:Hisaki Hatanaka
(Tokyo Univ.),
hatanaka@icrr.u-tokyo.ac.jp
Sessions: PA-10 Beyond the Standard Model ( Theory ) / PL-09 Beyond the Standard Model
Supporting papers:
Notes:
Effects of supersymmetric particles on flavor changing neutral current and lepton flavor violating processes are studied in the supersymmetric SU(5) grand unified theory with right-handed neutrino supermultiplets. Using input parameters motivated by neutrino oscillation, it is shown that the time-dependent CP asymmetry of radiative $B$ decay can be as large as 30\% when the $\tau \to \mu \gamma$ branching ratio becomes close to the present experimental upper bound. We also show that the $B_s$--$\bar{B}_s$ mixing can be significantly different from the presently allowed range in the standard model.
Authors:Seungwon Baek, Toru Goto, Yasuhiro Okada and Ken-ichi Okumura
Proposed speaker: Toru Goto
Contact person:Toru Goto
(KEK),
toru.goto@kek.jp
Sessions: PA-10 Beyond the Standard Model ( Theory ) /
Supporting papers: hep-ph/0002141 (KEK Preprint 99-176, KEK-TH-677)
Notes:
We discuss one-loop effects of the super-partner particles on the $W$-pair production process at future linear colliders in the Minimal Supersymmetric Standard Model. The helicity amplitudes calculated in the $\overline{MS}$ scheme are thoroughly tested by using the BRS sum-sules among the form factors, the decoupling property of the super-partner particles in the large-mass limit, and the equivalence theorem in the high-energy limit. By taking into account the constraint on the parameters from the available experimental data, the one-loop contributions to the helicity amplitudes are evaluated.
Authors:Sher Alam, Kaoru Hagiwara, Shinya Kanemura, Michael Klasen, Robert Szalapski and Yoshiaki Umeda
Proposed speaker: Shinya Kanemura
Contact person:Shinya Kanemura
(Universitaet Karlsruhe),
kanemu@particle.uni-karlsruhe.de
Sessions: PA-10 Beyond the Standard Model ( Theory ) / PL-09 Beyond the Standard Model
Supporting papers: S.Alam, K.Hagiwara, S.Kanemura, R.Szalapski and Y.Umeda, Published in Nuclear Physics B541 (1999) 50. S.Alam, K.Hagiwara, S.Kanemura, R.Szalapski and Y.Umeda, Submitted to Physical Review D (hep-ph/0002066). K.Hagiwara, S.Kanemura, M.Klasen and Y.Umeda, in preparation.
Notes:
In terms of an effective Lagrangian we investigate the possibilities of probing anomalous top quark couplings, $t \bar{t} H$, $\gamma t \bar{t}$, $Z t \bar{t}$ and $tWb$ at NLC. It is found that at a linear collider with a c.~m.~energy $\sqrt s \sim 0.5-1.5$ TeV and a high luminosity of $10-1000$ fb$^{-1}$, $e^+e^-\to t \bar{t} H$ is an ideal process in probing anomalous $t \bar t H$couplings. We study in detail the effects of anomalous couplings on $t \bar{t}$ spin correlations in the top pair production as well as the top quark decay processes with three spin bases. Our results show that with a c.~m.~energy $\sqrt s \sim 0.5-1$ TeV and a high luminocity of $100-1000$ fb$^{-1}$, the anomalous couplings $\gamma t \bar{t}$, $Z t \bar{t}$ and $tWb$ may be sensitively probed.
Authors:A.Datta, T.Han, T.Huang, Z.-H.Lin, J.-X.Wang and X.Zhang
Proposed speaker: Tao Huang
Contact person:Tao Huang
(Institute of High Energy Physics),
Huangt@hptc5.ihep.ac.cn
Sessions: PA-10 Beyond the Standard Model ( Theory ) / PL-09 Beyond the Standard Model
Supporting papers: hep-ph/9908236 and other(in preparation)
Notes:
We study constraints on the supersymmetric standard model from the electroweak precision measurements. We find that the light sfermions always make the fit worse than the Standard Model (SM), while the light charginos and neutralinos generally make the fit slightly better. The contributions from the Higgs sector are found to be small. The best overall fit to the precision measurements are found when the mass of lighter chargino with a dominant wino-component is about 100 GeV and the SU(2) doublet sfermions are all much heavier. We find the slight improvement of the fit over the SM, where the total chi-square of the fit to the 22 data points decreases by about one unit.
Authors:Gi-Chol Cho and Kaoru Hagiwara
Proposed speaker: Gi-Chol Cho
Contact person:Gi-Chol Cho
(Ochanomizu University),
cho@phys.ocha.ac.jp
Sessions: PA-10 Beyond the Standard Model ( Theory ) / PL-09 Beyond the Standard Model
Supporting papers: hep-ph/9912260 (Nuclear Physics B, in press)
Notes:
We discuss models of neutrino masses that, in the context of the see-saw mechanism, could lead to a large mixing angle for the atmospheric neutrino oscillations without requiring too much fine--tuning between the Dirac and the Majorana sectors. These models are compatible with Abelian flavour symmetries and with the picture of flavour expected in grand unified theories.
Authors:G. Altarelli, F. Feruglio, I. Masina
Proposed speaker: F. Feruglio
Contact person:ferruccio feruglio
(Padova University),
feruglio@pd.infn.it
Sessions: PA-10 Beyond the Standard Model ( Theory ) / PL-09 Beyond the Standard Model
Supporting papers: G.~Altarelli and F.~Feruglio, Neutrino masses and mixings: A theoretical perspective,'' Phys.\ Rept.\ {\bf 320}, 295 (1999). G.~Altarelli, F.~Feruglio and I.~Masina, Large neutrino mixing from small quark and lepton mixings, Phys.\ Lett.\ {\bf B472}, 382 (2000) [hep-ph/9907532].
Notes:Additional aspects of the interplay between the flavor sector of grand unified theories and the proton decay rates are currently under investication and could be included in a talk.
First, by constructing a nonabelian loop-space generalization of the Hodge *, one shows that a dual (magnetic) symmetry exists also in Yang-Mills theory. Secondly, from a result of 't~Hooft's, one finds that for confined colour $SU(3)$, the dual symmetry $\widetilde{SU}(3)$ is spontaneously broken and can be assigned the role of ``horizontal symmetry'' for generations. Thereby, one obtains not only an explanation for exactly three fermion generations with the distinctive mass and mixing patterns seen experimentally, but even a means for calculating the relevant parameters giving very sensible results. Other testable predictions follow ranging from hadron decays to cosmic rays.
Authors:CHAN Hong-Mo, TSOU Sheung Tsun, Jose BORDES
Proposed speaker: Chan Hong-Mo
Contact person:Hong-Mo Chan
(Rutherford Appleton Loboratory),
chanhm@v2.rl.ac.uk
Sessions: PA-10 Beyond the Standard Model ( Theory ) / PL-09 Beyond the Standard Model
Supporting papers: Phys. Rev. D53 (1996) 7293; D56 (1997) 3646; D57 (1998) 2507 Astroparticle 8 (1998) 135 Phys Rev D58 (1998) 013004; D58 (1998) 053003; D58 (1998) 053006; D60 (1999) 013005; Europ Phy J C10 (1999) 63.
Notes:
It is shown that by making use of the fact that U(1) is a mulipli-connected group, all the results in the domain of standard model can be explained without assigning peculiar hypercharges to left handed and right handed leptons and without changing the parameterization of the group U(1) while considering its couplings to singlets and doublets. By a simple extension of the model, it can be used to explain the physics beyond the standard model.
Authors:Mohammad Saleem, Haris Rashid and Faisal Akram
Proposed speaker: Mohammad Saleem
Contact person:Mohammad Saleem
(Punjab Univeristy),
saleem@time.lhr.sdnpk.org
Sessions: PA-10 Beyond the Standard Model ( Theory ) / PL-09 Beyond the Standard Model
Supporting papers:
Notes:6/10/00 TY-Fixed missing last name. Deleted duplicate and incomplete abstract #679,678.
We discuss the breaking of gauge symmetries by the higgs mechanism in the bulk of the Randall Sundrum background. With the higgs mechanism confined on the "TeV" brane, the W and Z boson masses can naturally be an order of magnitude smaller than the masses of their Kaluza- Klein excitations. Current electroweak precision data requires the lowest lying excitations to lie above about 10 TeV.
Authors:Stephan J. Huber and Qaisar Shafi
Proposed speaker: Qaisar Shafi
Contact person:Qaisar Shafi
(University of Delaware),
shafi@bartol.udel.edu
Sessions: PA-10 Beyond the Standard Model ( Theory ) / PL-09 Beyond the Standard Model
Supporting papers:
Notes:
As an attempt to give a unified description of quark and lepton mass matrices M_f, the following mass matrix from is proposed: the from of the matrices are invariant under a cyclic permutation among the fermions (f_1->f_2, f_2->f_3, f_3->f_1). The model naturally leads to the maximal mixing between nu_mu and nu_tau, and with an additional anzatz, it leads to the well-satisfied relations |V_{us}| \simeq \sqrt{m_d/m_s} and |V_{cb}| \simeq \sqrt{m_d/m_b}.
Authors:Yoshio Koide
Proposed speaker: Yoshio Koide
Contact person:Morimitsu Tanimoto
(Niigata University),
tanimoto@muse.hep.sc.niigata-u.ac.jp
Sessions: PA-10 Beyond the Standard Model ( Theory ) / PL-09 Beyond the Standard Model
Supporting papers:
Notes:
We analyze and summarize the most up-to-date constraints on the $R$ symmetry breaking parameters in supersymmetric theories. In particular, we include the new constraints from two loop level contributions to electric dipole moments of neutron and electron, the new constraints due to two loop contributions to muon anomalous magnetic moment, $g-2$, the new constraint due to $K_L-K_S$ mass difference as well as the new constraint due to the new contribution to the neutrionoless double decays are all included.
Authors:Darwin Chang, We-Fu Chang, Chung-Shian Chou, Wai-Yee Keung
Proposed speaker: Darwin Chang
Contact person:Darwin Chang
(National Tsing-Hua University),
chang@phys.nthu.edu.tw
Sessions: PA-10 Beyond the Standard Model ( Theory ) / PL-09 Beyond the Standard Model
Supporting papers:
Notes:
We analyze and summarize the most up-to-date constraints on the $R$ symmetry breaking parameters in supersymmetric theories. In particular, we include the new constraints from two loop level contributions to electric dipole moments of neutron and electron, the new constraints due to two loop contributions to muon anomalous magnetic moment, $g-2$, the new constraint due to $K_L-K_S$ mass difference as well as the new constraint due to the new contribution to the neutrionoless double decays are all included.
Authors:Darwin Chang, We-Fu Chang, Chung-Shian Chou and Wai-Yee Keung
Proposed speaker: Darwin Chang
Contact person:Darwin Chang
(National Tsing-Hua University),
chang@phys.nthu.edu.tw
Sessions: PA-10 Beyond the Standard Model ( Theory ) / PL-02 CP Violation and Rare Decays ( Kaon, Muon )
Supporting papers:
Notes:
If the underlying flavor symmetry is Abelian, mixings in $d_R$ sector are most prominent. Their effects can show through $\tilde d_R$ squarks under supersymmetry. Alignment is necessary to deal with $\Delta m_K$ and $\varepsilon_K$ constraints, but interestingly, with $m_{\tilde q}$, $m_{\tilde g} \sim$ TeV, the effects are comparable to Standard Model for $B_d$ and $B_s$ mixings, while $D^0$ mixing is tantalizing close to a hint from data. $CP$ phases in these mixings would be deviant, and $\vert V_{td}\vert$ and $\arg V_{ub}^*$ may be larger than allowed by CKM constraints. With non-standard soft breaking terms, an extra $\tan\beta$ enhancement could generate sizable mixing induced $CP$ violation in $b\to s\gamma$ and $d\gamma$ transitions.
Authors:C.K. Chua and W.S. Hou
Proposed speaker: W.S. Hou
Contact person:George W.S. Hou
(National Taiwan University),
wshou@phys.ntu.edu.tw
Sessions: PA-10 Beyond the Standard Model ( Theory ) / PL-09 Beyond the Standard Model
Supporting papers:
Notes:
The method to derive relations between the parameters of the effective Lagrangian describing deviations from the Standard Nodel is developed. The obtained relations can be implimented in a series of medel independent observables specific for signals of various various heavy virtual particles. New observables convenient in searching for signals of heavy Z` boson in e+ e- -> \bar{f} f processes are introduced. They give possibility to uniqually distinguish Z` gauge boson.
Authors:A.V. Gulov and V.V. Skalozub
Proposed speaker: Vladimir Skalozub
Contact person:Vladimir Vasil`evich Skalozub
(Dniepropetrovsk State University),
skalozub@ff.dsu.dp.ua
Sessions: PA-10 Beyond the Standard Model ( Theory ) /
Supporting papers: A.V. Gulov and V.V. Skalozub, hep-ph/0004038; A.V. Gulov and V.V. Skalozub, hep-ph/9906213 (Phys. Rev. D 2000 (murch))
Notes:
Yukawa textures are conventionally characterized by a parameter of smallness lambda=0.2 and require entries as small as (lambda)^6 to account for the hierarchies seen in quark masses and the CKM matrix. Advances in Horava-Witten M-theory [1] based on non-standard embeddings has recently allowed the construction of three generation models with Standard Model gauge symmetry [2]. Central to these constructions is the existance of additional 5-branes in the bulk. Such models allow for a possible alternate description of quark/lepton properties where Yukawa matrices are diagonal and O(1), and the matter Kahler metric is non-diagonal with a parameter of smallness d=0.1 (related to the position of the 5-branes) arising naturally. Phenomenological models are presented in agreement with all data with predictions V_us=0.21, V_cb=0.333, V_ub=0.0015, and m_s=115 MeV.
Authors:R. Arnowitt and B. Dutta
Proposed speaker: R. Arnowitt
Contact person:Richard L. Arnowitt
(Texas A&M University),
arnowitt@physics.tamu.edu
Sessions: PA-10 Beyond the Standard Model ( Theory ) / PL-09 Beyond the Standard Model
Supporting papers: [1] P. Horava and E. Witten, Nucl. Phys. B460, 506 (1966); B475, 94 (1996). [2] R. Donagi, B. Ovrut, T. Pantev, and D. Waldrum, hep-ph/9912208. [3] R. Arnowitt and B. Dutta, in preparation.
Notes:May also be relevant for sessions PA-16 Superstring Theory and PL-13 Superstring Theory
We present complete results of a next-to-leading order calculation of the production of gaugino-like charginos and neutralinos in association with gluinos ($\gluino$) at hadron colliders, including the strong corrections from the exchange of colored particles and sparticles. Adopting typical models for supersymmetry breaking, with different possibilities for the sparticle mass spectra, we provide predictions for total and differential cross sections at the energies of the Fermilab Tevatron and CERN Large Hadron Collider (LHC)
Authors:Edmond L. Berger, Michael Klasen, and Tim M. P. Tait
Proposed speaker: Edmond L. Berger
Contact person:Edmond L. Berger
(Argonne National Laboratory ),
berger@anl.gov
Sessions: PA-10 Beyond the Standard Model ( Theory ) / PL-07b Search for New Particles and New Phenomena (Results from Hadron Colliders)
Supporting papers:
Notes:
Single-top-squark production via the s-channel subprocess q q' to top squark ($\overline{\widetilde{t}}_1$) probes R-parity-violating extensions of the minimal supersymmetric standard model through the $\lambda^{\prime\prime}_{3ij}$ couplings. For masses in the range 180--325 GeV, and $\lambda^{\prime\prime}_{3ij} >$ 0.02--0.06, we show that discovery of the top squark is possible with 2 fb$^{-1}$ of integrated luminosity at run II of the Fermilab Tevatron. The bound on $\lambda^{\prime\prime}_{3ij}$ can be reduced by up to an order of magnitude with existing data from run I, and by two orders of magnitude at run II if the top squark is not found.
Authors:Edmond L. Berger, B. W. Harris, and Z. Sullivan
Proposed speaker: Edmond L. Berger
Contact person:Edmond L. Berger
(Argonne National Laboratory ),
berger@anl.gov
Sessions: PA-10 Beyond the Standard Model ( Theory ) / PL-07b Search for New Particles and New Phenomena (Results from Hadron Colliders)
Supporting papers: Phys.Rev.Lett.83:4472-4475,1999, hep-ph/9903549
Notes:
We will discuss the implications of neutrino masses, as suggested by the SuperKamiokande data, on the stability of the nucleon within the framework of unified gauge models. Interactions responsible for neutrino masses can also provide mechanisms for nucleon decay. This will be analyzed within the context of a predictive SO(10) based framework that describes the masses and mixings of all quarks and leptons. We find that the current limit on nucleon stability puts significant stress on the framework. Improved searches in the \mu+ K^0 channel and the \bar{\nu} K^+ channel for proton decay will either turn up events, or force us outside this circle of ideas.
Authors:K.S. Babu, J.C. Pati and F. Wilczek
Proposed speaker: K.S. Babu
Contact person:K.S. Babu
(Oklahoma State University),
babu@osuunx.ucc.okstate.edu
Sessions: PA-10 Beyond the Standard Model ( Theory ) / PL-09 Beyond the Standard Model
Supporting papers: Nulcear Physics B 566 (2000) 33-91
Notes:
We study the impact of various radiative effects on the kinematic reconstruction of squark pair events at future $e^+e^-$ colliders. We focus on the simplest case where both squarks decay directly into a stable neutralino, but include both photon radiation off the initial state and gluon radiation during the production and/or decay of the squarks. These effects change the shapes of the distributions used to determine the squark mass; they can therefore also introduce additional systematic uncertainties.
Authors:M. DREES, O.J.P. \'EBOLI, R.M. GODBOLE and S. KRAML
Proposed speaker: O.J.P. \'EBOLI
Contact person:Oscar JP Eboli
(Instituto de Fisica Teorica da UNESP),
eboli@ift.unesp.br
Sessions: PA-10 Beyond the Standard Model ( Theory ) / PL-09 Beyond the Standard Model
Supporting papers: In preparation
Notes:
It has been pointed out that the current bounds on electron and neutron electric dipole moments (EDMs) can be accomodated in SUSY models with relatively large CP violating phases and a light (< 1TeV) mass spectrum at the electroweak scale in SUSY models due to cancellations at the electroweak scale [1]. This is investigated within the framework of supergravity models with R-parity for (1) universal soft breaking (mSUGRA), (2) non-universal soft breaking and (3) a D-brane model [2] (based on type 2B orientifolds[3]). A new fine tuning problem is seen to develop, however, at the GUT scale.Thus the combined contraints of the experimental EDM bounds and the requirement of radiative breaking force the B (or mu) phase at M_G to be both large and highly fine tuned unless tanbeta is ~< 3. Possible models where all phases are naturally small at M_G is given.
Authors:E. Accomando, R. Arnowitt and B. Dutta
Proposed speaker: R. Arnowitt
Contact person:Richard L. Arnowitt
(Texas A&M University),
arnowitt@physics.tamu.edu
Sessions: PA-10 Beyond the Standard Model ( Theory ) / PL-09 Beyond the Standard Model
Supporting papers: [1] T. Ibrahim and P. Nath, Phys. Rev D58, 111301 (1998) [2] E. Accomando, R. Arnowitt and B. Dutta, hep-ph/9907446; 9909333(Phys. Rev. D61, 075010 (2000)). [3] M. Brhlik, L. Everett, G. Kane and J. Lykken, hep-ph/9905215(Phys. Rev.Lett. 83, 2124 (1999); 9908326.
Notes:
This work describes a detailed study of the unification of the three gauge couplings in MSSM in presence of large extra dimensions. In addition to the usual case, we consider several new scenarios not previously studied such as the compactification scale lower than the supersymmetry breaking scale, gauge bosons and fermions with different gauge quantum numbers belong to different D-branes associated with different compactification scales. We find cases where the compactification and the unification scale can be in the few TeV range to be probed at the LHC. We will also review the unification with extra matter fields, and extended gauge groups.
Authors:D. Dumitru and S. Nandi
Proposed speaker: S. Nandi
Contact person:Satyanarayan Nandi
(Oklahoma State University),
shaown@okstate.edu
Sessions: PA-10 Beyond the Standard Model ( Theory ) / PL-09 Beyond the Standard Model
Supporting papers: Gauge coupling unification with large extra dimensions, D. Dumitru and S. Nandi, hep-ph/9906514 ( to appear in Phys. Rev. D, in press)
Notes:I will also briefly review the other relevant works for this topic.
A new supersymmetric standard model based on N=1 supergravity is constructed, aiming at natural explanation for the proton stability without invoking a discrete symmetry through R parity. The proton is protected from decay by an extra U(1) gauge symmetry. We also take into account the problems of the neutrino masses and the Higgs linear coupling. The gauge symmetry breaking is induced by radiative corrections. Certain ranges of the parameter values compatible with phenomena at the electroweak energy scale can be derived from universal values of masses-squared and trilinear coupling constants for scalar fields at a very high energy scale.
Authors:Mayumi Aoki and Noriyuki Oshimo
Proposed speaker: Mayumi Aoki
Contact person:Mayumi Aoki
(KEK),
mayumi.aoki@kek.jp
Sessions: PA-10 Beyond the Standard Model ( Theory ) / PL-09 Beyond the Standard Model
Supporting papers: M.Aoki and N. Oshimo OCHA-PP-137(hep-ph/9907481)(1999)(to appear in Phys.Rev.Lett.) OCHA-PP-149(hep-ph/0003286)(1999)
Notes:
I would like to talk about that 'no-scale' model makes hierarchy between scalar top mass and Z boson mass naturally. FCNC constrains supersymmetry breaking parameters in minimal supersymmetric standard model. One of the solution of the problem is that gaugino mass is the only source of the supersymmetry breaking parameters at Planck scale. However, in such secnario, we need a weird cancelation between Higgs mass parameters in minimization condition of the Higgs potential. We insist that there is no such cancelation in no-scale model, and that the no-scale model gives us the prediction of scalar top mass and lightest Higgs mass.
Authors:Y.Chikira and Y.Mimura
Proposed speaker: Y.Mimura
Contact person:Yukihiro Mimura
(KEK),
mimura@ccthmail.kek.jp
Sessions: PA-10 Beyond the Standard Model ( Theory ) / PL-09 Beyond the Standard Model
Supporting papers:
Notes:
We propose a supersymmetric standard model with right-handed neutrinos and a singlet Higgs field. The Majorana masses for right-handed neutrinos are generated around the supersymmetry breaking scale through the vacuum expectation value of the singlet Higgs field. This model induces spontaneous R-parity violation via the vacuum expectation value of right-handed sneutrino, where the effective theory is similar to the bilinear R-parity violating model. Combining biliear and ordinary seesaw effect, hierarchical neutrino mass pattern arises naturally, even when the neutrino Yukawa matrices are not hierarchical. We acquire appropriate masses and mixings to explain both the solar and atmospheric neutrino oscillations.
Authors:Ryuichiro Kitano and Kin-ya Oda
Proposed speaker: Kin-ya Oda
Contact person:Kin-ya Oda
(KEK),
kin-ya.oda@kek.jp
Sessions: PA-10 Beyond the Standard Model ( Theory ) / PL-09 Beyond the Standard Model
Supporting papers: Phys.Rev.D61:113001,2000
Notes:e-print: hep-ph/9911327
There have been some claims that the Weinberg Model of spontaneous CP violation is ruled out from considerations of electric dipole moment of the neutron and the branching ratio of b to s gamma. We carry out a detailed analysis and show that there is still parameter space where the Weinberg model is consistent with experimental data. We also comment on how this model can be further tested in B decays.
Authors:Darwin Chang, Xiao-Gang He and Bruce H.J. McKellar
Proposed speaker: Bruce H.J. McKellar
Contact person:Bruce H J McKellar
(University of Melbourne),
mckellar@physics.unimelb.edu.au
Sessions: PA-10 Beyond the Standard Model ( Theory ) / PL-02 CP Violation and Rare Decays ( Kaon, Muon )
Supporting papers:
Notes:
We show how the gravity, gauge, and matter fields are induced on dynamically localized brane world (domain wall, vortex etc.). Solitonic solutions localized on a curved brane in certain field theories in higher dimensions are given in terms of gravity, gauge and extrinsic curvature fields of the brane. Then we deduce the effective field theory on the brane in terms of those fields and the quantum fluctuations of the solitonic solution. The gravity, gauge and the extrinsic curvature fields should obey the Gauss-Codazzi-Ricci equation in addition to their own equations of motion.
Authors:Keiichi Akama
Proposed speaker: Keiichi Akama
Contact person:Keiichi Akama
(Saitama Medical College),
akama@saitama-med.ac.jp
Sessions: PA-10 Beyond the Standard Model ( Theory ) / PL-09 Beyond the Standard Model
Supporting papers: K. Akama, in Lecture Notes in Physics, 176, Gauge Theory and Gravitation, Proceedings, Nara, 1982, edited by K. Kikkawa, N. Nakanishi and H. Nariai, (Springer-Verlag), 267(available in e-print hep-th/0001113 "An Early Proposal of 'Brane World'" K. Akama, Prog. Theor. Phys. 78 (1987) 184; 79 (1988) 1299; 80 (1988) 935. K. Akama, Submitted to the Proceedings of the workshop on extra dimensions held at Kyoto, March, 1-3, 2000.
Notes:Note that the first of the reference above is an early proposal of the brane world picture which attracts much attention recently. It already contained an idea how the gravity on the brane is incorporated. Here we develop the idea to include the fully unified field theory on the brane.
SUSY Flavor Problem is solved elegantly in effective supersymmetry, where sfermions in the first-two generations have masses of order multi-TeV, and those in the third generation have of order 100 GeV for "naturalness". However, this large mass splitting among the superpartners causes large negative renormalization-group corrections for the third-generation sfermions, so that masses for the third-generation sfermions must be of order TeV at the GUT scale. It requires an "unnatural" fine tuning of electroweak symmetry breaking. In this talk we propose "natural effective supersymmetry" which solves this problem by introducing extra vector-like matters around multi-TeV, and discuss its phenomenology.
Authors:Junji Hisano, Yasunori Nomura, Kiichi Kurosawa
Proposed speaker: Kiichi Kurosawa
Contact person:Kiichi Kurosawa
(University of Tokyo),
kurosawa@hep-th.phys.s.u-tokyo.ac.jp
Sessions: PA-10 Beyond the Standard Model ( Theory ) / PL-09 Beyond the Standard Model
Supporting papers: [1] "Large squark and slepton masses for the first-two generations in the anomalous U(1) SUSY breaking models J.Hisano, Kiichi Kurosawa and Yasunori Nomura Phys.Lett. B445(1999)316, hep-ph/9810411 [2] "Natural effective supersymmetry" Junji Hisano, Kiichi Kurosawa and Yasunori Nomura hep-ph/0002286
Notes:
We study gravity localization in the context of a six-dimensional gravity model coupled with complex scalar fields. With a supergravity-motivated scalar potential, the domain wall junction solutions localize a four-dimensional massless graviton. We show that unlike the global supersymmetric model, contributions to the junction tension cancel locally with gravitational contributions. The wall tension vanishes due to the metric suppression.
Authors:Takeshi Nihei
Proposed speaker: Takeshi Nihei
Contact person:Takeshi Nihei
(Lancaster University),
t.nihei@lancaster.ac.uk
Sessions: PA-10 Beyond the Standard Model ( Theory ) / PL-09 Beyond the Standard Model
Supporting papers:
Notes:
We have studied to what extent the reconstruction of supersymmetric theories at high energy scales is possible by elvoing the fundamental parameters from the electroweak scale upwards. Universal minimal supergravity and gauge mediated supersymmetry breaking have been taken as representative alternatives. Pseudo-fixed point structures require the low-energy boundary values to be measured with high precision.
Authors:G.A. Blair, W. Porod, P. Zerwas
Proposed speaker: W. Porod
Contact person:Werner Porod
(University of Valencia),
porod@ific.uv.es
Sessions: PA-10 Beyond the Standard Model ( Theory ) /
Supporting papers:
Notes:DESY 99-181
I report on recent predictive models of fermion masses and mixing angles based on the exceptional group E6.
Authors:Gregory Anderson, Tomas Blazek
Proposed speaker:
Contact person:Gregory w Anderson
(Northwestern University),
ganderson@nwu.edu
Sessions: PA-10 Beyond the Standard Model ( Theory ) / PL-09 Beyond the Standard Model
Supporting papers:
Notes:
Authors:I.Ots, R.Saar, and R.-K.Loide
Proposed speaker: I.Ots Abstract: We consider the field-dependent invariant representation (the "dynamical" representation) of the Poincare algebra as a dynamical principle for generating the F {\mu\nu} interaction term needed for the g=2 value of an elementary spin >= 1 charged particle. In the "dynamical" representation the Poincare generators depend on the (special) electromagnetic field obeying nevertheless the commutation relations of the free Poincare algebra. The wave equations corresponding to this representation are the equations with the "dynamical" interaction. For s=0,1/2 the "dynamical" interaction coincides with the minimal one. In the higher-spin cases the "dynamical" interaction is inevitably nonminimal with the desired F {\mu\nu} term.
Contact person:Ilmar - Ots
(Institute of Physics, University of Tartu Street: Riia 142),
ots@fi.tartu.ee
Sessions: PA-10 Beyond the Standard Model ( Theory ) /
Supporting papers:
Notes:- (031)
We perform a detailed study of the decay of the lighter stop and sbottom quarks (stop 1 and sbottom 1) in the Minimal Supersymmetric Standard Model (MSSM). We show that the decays into Higgs or gauge bosons (such as stop 1 -> sbottom 1 H^+ and stop 1 -> sbottom 1 W^+) can be dominant in a wide range of the model parameters due to the large Yukawa couplings and mixings of stop and sbottom. Compared to the conventional decays into fermions these bosonic decay modes can have significantly different decay distributions. This could have a very important impact on the search for stop 1 and sbottom 1 and the determination of the MSSM parameters at future colliders such as LHC, LC, and muon-collider.
Authors:K. Hidaka (Tokyo Gakugei U.)
Proposed speaker: K. Hidaka
Contact person:Keisho Hidaka
(Tokyo Gakugei Univ.),
hidaka@u-gakugei.ac.jp
Sessions: PA-10 Beyond the Standard Model ( Theory ) / PL-09 Beyond the Standard Model
Supporting papers:
Notes: (035)
We perform a detailed study of the decays of the heavier tau slepton (stau 2) and tau-sneutrino (snu tau) in the Minimal Supersymmetric Standard Model (MSSM). We show that the decays into Higgs or gauge bosons, i.e. stau 2 -> stau 1 + (h^0, H^0, A^0 or Z^0), stau 2 -> snu tau + (H^- or W^-), and snu tau -> stau 1 + (H^+ or W^+), can be very important due to the sizable tau Yukawa coupling and large mixing parameters of stau. Compared to the decays into fermions, such as stau 2 -> tau + neutralino i and stau 2 -> nu tau + chargino j^-, these bosonic decay modes can have significantly different decay distributions. This could have an important influence on the search for stau 2 and snu tau and the determination of the MSSM parameters at future colliders.
Authors:A. Bartl (Vienna U.), H. Eberl (Vienna, OAW), K. Hidaka (Tokyo Gakugei U.), S. Kraml (Vienna, OAW), T. Kon (Seikei U.), W. Majerotto (Vienna, OAW), W. Porod (Vienna U.), Y. Yamada (Tohoku U.)
Proposed speaker: K. Hidaka
Contact person:Keisho Hidaka
(Tokyo Gakugei Univ.),
hidaka@u-gakugei.ac.jp
Sessions: PA-10 Beyond the Standard Model ( Theory ) / PL-09 Beyond the Standard Model
Supporting papers:
Notes:Published in Phys.Lett. B460 (1999) 157-163 (hep-ph/9904417). (036)
We improve the calculation of the supersymmetric $O(\alpha s)$ QCD corrections to the decays of Higgs bosons into quarks and squarks in the Minimal Supersymmetric Standard Model. In the on-shell renormalization scheme these corrections can be very large, which makes the perturbative expansion unreliable. This is especially serious for decays into bottom quarks and squarks for large $\tan\beta$. Their corrected widths can even become negative. We show that this problem can be solved by a careful choice of the tree-level Higgs boson couplings to quarks and squarks, in terms of the QCD and SUSY QCD running quark masses, running trilinear couplings $A q$, and on-shell left-right mixing angles of squarks. We also present numerical results for the corrected partial decay widths for the large $\tan\beta$ case.
Authors:H. Eberl (Vienna, OAW), K. Hidaka (Tokyo Gakugei U.), S. Kraml (Vienna, OAW), W. Majerotto (Vienna, OAW), Y. Yamada (Tohoku U.)
Proposed speaker: Y. Yamada (Tohoku U.)
Contact person:Keisho Hidaka
(Tokyo Gakugei Univ.),
hidaka@u-gakugei.ac.jp
Sessions: PA-10 Beyond the Standard Model ( Theory ) / PL-09 Beyond the Standard Model
Supporting papers:
Notes:hep-ph/9912463. (037)
We calculate the order(\alpha s) SUSY-QCD corrections to the widths of stop and sbottom decays into Higgs bosons within the Minimal Supersymmetric Standard Model. We give the complete analytical formulae paying particular attention to the on-shell renormalization of the soft SUSY-breaking parameters. We also perform a detailed numerical analysis of both stop and sbottom decays into all Higgs bosons h^0, H^0, A^0, and H^\pm. We find that the SUSY-QCD corrections are significant, mostly negative and of the order of a few ten percent.
Authors:: A. Bartl (Vienna U.), H. Eberl (Vienna, OAW), K. Hidaka (Tokyo Gakugei U.), S. Kraml (Vienna, OAW), W. Majerotto (Vienna, OAW), W. Porod (Vienna U.), Y. Yamada (Tohoku U.)
Proposed speaker: Y. Yamada (Tohoku U.)
Contact person:Keisho Hidaka
(Tokyo Gakugei Univ.),
hidaka@u-gakugei.ac.jp
Sessions: PA-10 Beyond the Standard Model ( Theory ) / PL-09 Beyond the Standard Model
Supporting papers:
Notes:Published in Phys.Rev.D59(1999)115007 (hep-ph/9806299). (038)
Some aspects of moduli in string theory are considered, including both questions of vacuum selection, and cosmology, as well as the possibility of making generic string predictions.
Authors:Michael Dine
Proposed speaker: Michael Dine
Contact person:Michael Dine
(University of California, Santa Cruz),
dine@scipp.ucsc.edu
Sessions: PA-10 Beyond the Standard Model ( Theory ) / PL-09 Beyond the Standard Model
Supporting papers:
Notes:
Using the resolution of the gauge hierarchy problem recently proposed by Randall and Sundrum, we find a natural explanation for the obsesrved fermion masses and mixings of the three Standard Model (SM) generations. Localizing massless SM matter generations on neighboring 3-branes in an extra-dimensional world leads to effective four dimensional masses and mixings from the coupling of the fermions with the background metric. We find that the position of the 3-branes required to solve the gauge hierarchy problem simultaneously reproduces phenomenologically acceptable fermion masses and mixings.
Authors:David Dooling and Kyungsik Kang
Proposed speaker: Kyungsik Kang
Contact person:Kyungsik Kang
(Brown Univeristy),
kang@het.brown.edu
Sessions: PA-10 Beyond the Standard Model ( Theory ) / PL-09 Beyond the Standard Model
Supporting papers: 1. D. Dooling and K. Kang, "Gravitional origin of fermion masses and mixings in an extra-dimensional brane-world" (in preparation). 2. L. Randall and R. Sundrum, Phys. Rev. Lett. 83 (1999) [hep-ph/9905221]. 3. J. Lykken and L. Randall, "The Shape of Gravity" [hep-th/9908076]. 4. Y. Grossman and M. Neubert, "Neutrino masses and mixings in non-factorizable geometry" [hep-ph/9912408]. 5. G. Dvali and M. Shifman, "Families as Neighbors in Extra Dimension" [hep-ph/0001072].
Notes:
End of abstracts for PA-10 Beyond the Standard Model ( Theory )