Townhall in Hagen/Westfalen Dr. habil. Stefan Groote

"Mathematischer Vorkurs Frühjahr 2005" (in German)
My habilitation thesis (Habilitationsschrift)
pictures from the factulty reception of Marcus Mauser after his defense are now found on his own homepage!
instead: pictures of (parts of the) ThEP group taken for a present for Dirk Kreimer in occasion of his departure.
Reference to my PhD thesis (Dissertation)
The second subject of my thesis, the anomalous dimension in the calculation of twoloop corrections to the mesonic and baryonic vertex, was result of a collaboration between Prof. Körner, Dr. Oleg I. Yakovlev and me. Using these results, we calculated first order radiative corrections to to the twopoint correlator for the baryonic current related to this the radiative corrected diagonal and nondiagonal QCD sum rules.
On February 21, 1997, I passed my PhD examination with "magna cum laude".
Since March 1996 I coattended the work of Dipl. Phys. Alfonso Leyva, PhD student at Prof. Körner, whos first subject was gluon polarization effects. For the second theme, namely the calculation of spinspin correlations in electronpositronannihilations into quarks and gluons, we were joined by Prof. Körner's PhD student Dipl. Phys. Volker Kleinschmidt since February until he left the Institute, since April by Dipl. Phys. Marcus Mauser.
In collaboration with Prof. Dr. Karl Schilcher and Prof. Dr. J. Körner I worked on the improvement for the accuracy of the QED coupling constant on the Z pole. We were joined by Dr. Alexei A. Pivovarov, who was guest at Mainz for several times. We extended the analysis to high order relations between physical observables as test for perturbative QCD and analyzed the resummation techniques in tau decays. We also searched for new calculation techniques for sunset diagrams. In this curse we were able to find some configuration space techniques to handle sunsettype diagrams, called water melons, and could reproduce the transcendental numbers obtained in the tetrahedron diagrams of threeloop bubbles within easier topologies. We shall continue the collaboration also be incorporating calculations on radiative corrections to massive baryonic correlators.
In summer 1997 and 1998, Dr. Andrei G. Grozin was guest at the ThEP working group. In cooperation with him we started a project for calculating electric and magnetic formfactors for massive quarks.
S. Groote, J.G. Körner, M.M. Tung
(MZTH / 9509):
"Longitudinal contribution to the longitudinal polarization of quarks
produced in electronpositronannihilation: an O(alpha_s) effect",
Z. Phys. C70 (1996) 281290
S. Groote, J.G. Körner
(MZTH / 9517):
"Transverse polarization of top quarks produced in
electronpositronannihilation at O(alpha_s)",
Z. Phys. C72 (1996) 255261
S. Groote, J.G. Körner, M.M. Tung
(MZTH / 9519):
"Polar angle dependence of the alignment polarization of quarks
produced in electronpositronannihilation",
Z. Phys. C74 (1997) 615629
S. Groote, J.G. Körner, O.I. Yakovlev
(MZTH / 9606):
"Twoloop anomalous dimensions of heavy baryon currents
in heavy quark effective theory",
Phys. Rev. D54 (1996) 34473456
S. Groote, J.G. Körner, O.I. Yakovlev
(MZTH / 9621):
"QCD sum rules for heavy baryons at nexttoleading order in alpha_s",
Phys. Rev. D55 (1997) 30163026
S. Groote, J.G. Körner, J.A. Leyva
(MZTH / 9634):
"Gluon polarization in electronpositron to topantitopgluon",
Phys. Rev. D56 (1997) 60316034
S. Groote, J.G. Körner, A.A. Pivovarov
(MZTH / 9703):
"Resummation analysis of the tau decay width using the fourloop
betafunction",
Mod. Phys. Lett. A13 (1998) 637650
S. Groote,
(MZTH / 9705):
"Twoloop anomalous dimensions of heavy baryon currents in heavy quark
symmetry",
Talk given on the
2nd Triangle School in Particle Physics,
Prague, Czech Republic, September 210, 1996
S. Groote, J.G. Körner, A.A. Pivovarov, K. Schilcher
(MZTH / 9709):
"New high order relations between physical observables in perturbative
QCD",
Phys. Rev. Lett. 79 (1997) 27632766
S. Groote, J.G. Körner, A.A. Pivovarov
(MZTH / 9716):
"Perturbative relations between electronpositron annihilation and tau decay
observables including resummation effects",
Phys. Lett. 407 B (1997) 6672
S. Groote, J.G. Körner, J.A. Leyva
(MZTH / 9717):
"Gluon polarization in electronpositron to electronpositron to
topantitopgluon: polar angle dependence and beam polarization effects",
Eur. Phys. J. C7 (1999) 4959
S. Groote, J.G. Körner, O.I. Yakovlev
(MZTH / 9719):
"An analysis of diagonal and nondiagonal QCD sum rules for heavy baryons at
nexttoleading order in alpha_s",
Phys. Rev. D56 (1997) 39433954
S. Groote, J.G. Körner, J.A. Leyva
(MZTH / 9727):
"O(alpha_s) corrections to longitudinal spinspin correlations in
electronpositron to quarkantiquark",
Phys. Lett. 418 B (1998) 192198
S. Groote
(MZTH / 9734):
"Analyzing QCD sum rules for heavy baryons at nexttoleading order in
alpha_s", Proceedings of the IVth International Workshop "Progress in
Heavy Quark Physics", Rostock, September 2022, 1997, pages 195198
S. Groote, J.G. Körner, J.A. Leyva
(MZTH / 9739):
"On the rigidity of backtoback top quark pairs in electronpositron
annihilation",
Nucl. Phys. B527 (1998) 320
S. Groote, J.G. Körner, K. Schilcher, N.F. Nasrallah
(MZTH / 9802):
"QCD sum rule determination of alpha(M_Z) with minimal data input",
Phys. Lett. 440 B (1998) 375385
S. Groote, J.G. Körner and A.A. Pivovarov
(MZTH / 9809):
"On the evaluation of sunsettype Feynman diagrams",
Nucl. Phys. B542 (1999) 515547
S. Groote, J.G. Körner and A.A. Pivovarov
(MZTH / 9812):
"A new technique for computing the spectral density of sunsettype
diagrams: integral transformation in configuration space",
Phys. Lett. 443 B (1998) 269275
M. Fischer, S. Groote, J.G. Körner and M.C. Mauser, B. Lampe
(MZTH / 9847):
"Polarized top decay into polarized W",
Phys. Lett. 451 B (1999) 406413
J.G. Körner and S. Groote
(MZTH / 9863):
"Heavy Baryons: Status and overview (theory)",
Invited talk given by J.G. Körner at the 8th International Conference on
the Structure of Baryons (BARYONS'98), Bonn, Germany, 2226 September 1998,
published in the Proceedings "BARYONS '98", edited by D.W. Menze and
B. Metsch (World Scientific, Singapore, 1999) pages 232245.
S. Groote, J.G. Körner and A.A. Pivovarov
(MZTH / 9907, CLNS / 991606):
"Configuration space based recurrence relations for sunsettype
diagrams",
Eur. Phys. J. C11 (1999) 279292
S. Groote, J.G. Körner and A.A. Pivovarov
(MZTH / 9913, CLNS / 991613):
"Transcendental numbers and the topology of threeloop bubbles",
Phys. Rev. D60 (1999) 061701
S. Groote
(MZTH / 9918, CLNS / 991619):
"Local and global duality and the determination of alpha(M_Z)", Proceedings
of the conference "High Energy Physics at the Millennium (MRST'99)", Ottawa,
Canada, May 1012, 1999, pages 124131
S. Groote, J.G. Körner and A.A. Pivovarov
(MZTH / 9949, CLNS / 991647):
"O(alpha_s) corrections to the correlator of finite mass baryon
currents",
Phys. Rev. D61 (2000) 071501
M. Fischer, J.G. Körner, M.C. Mauser and S. Groote
(MZTH / 9927):
"Inclusive decays of B mesons into D_s and D^* and D_s^* at O(alpha_s)
including D_s^* polarization effects",
Phys. Lett. 480 B (2000) 265272
S. Groote and J. Shigemitsu
(MZTH / 9964):
"Oneloop self energy and renormalization of the speed of light for some
anisotropic inproved quark actions",
Phys. Rev. D62 (2000) 014508
S. Groote and A.A. Pivovarov
(MZTH / 0007):
"Threshold expansion of Feynman diagrams within a configuration space
technique", Nucl. Phys. B580 (2000) 459484
J.G. Körner and S. Groote
(MZTH / 0008):
"Theory of Heavy Baryon Decay",
Invited talk given by J.G. Körner at the 3rd International Conference
on B Physics and CP Violation (BCONF99), Taipei, Taiwan, 37 Dec 1999,
published in the Proceedings, edited by H.Y. Cheng and W.S. Hou
(World Scientific, 2000).
Stefan Groote
(MZTH / 0024):
"QCD sum rules as applied to heavy baryons", Proceedings of the 5th
International Conference on "Heavy Quark Physics", Dubna, Russia, April 68,
2000, p.2630
S. Groote and O.I. Yakovlev
(MZTH / 0033, CLNS / 001686):
"Top quark mass definition and t antit production near threshold at the
NLC", Phys. Rev. D63 (2001) 074012
S. Groote and O.I. Yakovlev
(MZTH / 0036):
"A dynamic mass definition near the t antit threshold", talk given by
Stefan Groote at the Laboratory of Nuclear Studies, Cornell Univ., Ithaca,
N.Y., 23 Aug 2000
O.I. Yakovlev and S. Groote
(MZTH / 0038, CLNS / 001690):
"Top quark production near threshold at NLC", talk given by Oleg Yakovlev at
PHENO 2000: Symposium on Phenomenology for the Nu Century, Madison,
Wisconsin, 1719 Apr 2000
S. Groote, J.G. Körner and A.A. Pivovarov
(MZTH / 0041, CLNS / 001693):
"Analytical calculation of heavy baryon correlators in NLO of perturbative
QCD", contribution to the "VII International Workshop on Advanced Computing
and Analysis Techniques in Physics Research (ACAT2000)", Fermi National
Laboratory, Batavia, Illinois, USA, 1620 Oct 2000, to appear in the
Proceedings
S. Groote, J.G. Körner and J.A. Leyva
(MZTH / 0041, CLNS / 001693):
"O(alpha_s) corrections to the polar angle dependence of the longitudinal
spinspin correlation asymmetry in electron + positron > quark + antiquark"
M. Fischer, S. Groote, J.G. Körner and M.C. Mauser
(MZTH / 0050):
"Longitudinal, transverse plus and transverse minus W bosons in unpolarized
top quark decays at O(alpha_s)", Phys. Rev. D63 (2001) 031501
O.I. Yakovlev and S. Groote
(MZTH / 0057, MCTP0010):
"On top antitop threshold and top quark mass definition", talk given by
Oleg Yakovlev on the Linear Collider Workshop 2000, Fermilab, October 2000,
to appear in the Proceedings
M. Fischer, S. Groote, J.G. Körner and M.C. Mauser
(MZTH / 9910):
"Complete angular analysis of polarized top decay at O(alpha_s)",
Phys. Rev. D65 (2002) 054036
S. Groote and A.A. Pivovarov
(MZTH / 0106):
"Lowenergy gluon contributions to the vacuum polarization of heavy quarks",
JETP Lett. 75 (2002) 221 [Pisma Zh. Eksp. Teor. Fiz. 75 (2002) 267]
S. Groote and A.A. Pivovarov
(MZTH / 0110):
"Heavy quark induced effective action for gauge fields in the
SU(N_c) x U(1) model and the lowenergy structure of heavy quark
current correlators", Eur. Phys. J. C21 (2001) 133143
S. Groote, J.G. Körner and A.A. Pivovarov
(MZTH / 0115):
"Spectral moments of twopoint correlators in perturbation theory and
beyond", Phys. Rev. D65 (2002) 036001
M. Fischler et al. (FERMILABCONF01237T):
Summaries of recent computerassisted Feynman diagram calculations",
prepared for the 7th International Workshop on Advanced Computing and
Analysis Techniques in Physics Research (ACAT 2000), Batavia, Illinois,
1620 Oct 2000
S. Groote, J.G. Körner and A.A. Pivovarov
(MZTH / 0131):
"An interpolation of the vacuum polarization function for the evaluation of
hadronic contributions to the muon anomalous magnetic moment",
Eur. Phys. J. C24 (2002) 393405
M. Fischer, S. Groote, J.G. Körner and M.C. Mauser
(MZTH / 0203):
"Leptonic mu and tau decays: mass effects, polarization effects and O(alpha)
radiative corrections",
Phys. Rev. D67 (2003) 067311
H.S. Do, S. Groote, J.G. Körner and M.C. Mauser
(MZTH / 0103):
"Electroweak and finite width corrections to top quark decays into
transverse and longitudinal Wbosons", Phys. Rev. D67 (2003) 091501
S. Groote
(MZTH / 0229):
"Polarization effects in e+ e annihilation processes"
S. Groote
(MZTH / 0230):
"The electronpositron annihilation cross section used for high precision
tests of the Standard Model"
S. Groote
(MZTH / 0310):
"Lectures on configuration space methods for sunrisetype diagrams",
invited lecture series given at the International Research Workshop
"Calculations for Modern and Future Colliders
(Calc2003)", June 1321, 2003, Dubna, Russia
M. Fischer, S. Groote, J.G. Körner and M.C. Mauser
(MZTH / 0306):
"Semiinclusive decays Lambda_b > X_c + D_s^* at O(alpha_s) including
Lambda_b and D_s^* polarization effects",
Phys. Rev. D70 (2004) 094026
S. Groote, J.G. Körner and J. Maul
(MZTH / 0314):
"QCD improved determination of the hadronic contribution to the anomalous
magnetic moment of the muon"
S. Groote, J.G. Körner and A.A. Pivovarov
(MZTH / 0403):
"Laurent series expansion of sunrisetype diagrams using configuration space
techniques", Eur. Phys. J. C36 (2004) 471482
S. Groote, J.G. Körner and A.A. Pivovarov
(MZTH / 0508):
"On the evaluation of a certain class of Feynman diagrams in xspace:
Sunrisetype topologies at any loop order",
Annals of Physics (2007)
S. Groote, W.S. Huo, A. Kadeer and J.G. Körner
(MZTH / 0513):
"Azimuthal correlation between the (p_l,p_Xb) and (p_l,P_t) planes in the
semileptonic rest frame decay of a polarized top quark: An O(alpha_s)
effect"
S. Groote, M. Knodel
(MZTH / 0517):
"Evaluating massive planar twoloop tensor vertex integrals",
Eur. Phys. J. C46 (2006) 157178
S. Groote, J.G. Körner and A.A. Pivovarov
(MZTH / 0606):
"Large nexttoleading order QCD corrections to pentaquark sum rules",
Phys. Rev. D74 (2006) 017503
S. Groote and C. Beck
(MZTH / 0607):
"Scaling behavior of nonhyperbolic coupled map lattices",
Phys. Rev. E74 (2006) 046216
S. Groote and C. Beck
(MZTH / 0609):
"Scaling properties of invariant densities of coupled Chebyshev maps",
Dyn. Sys. 22(2) (2007) 219248
S. Groote, J.G. Körner and A.A. Pivovarov
(MZTH / 0720):
"NexttoLeading Order perturbative QCD corrections to baryon correlators in
matter", Phys. Rev. D78(3) (2008) 034039
S. Groote, J.G. Körner and A.A. Pivovarov
(MZTH / 0721):
"Heavy baryon properties with NLO accuracy in perturbative QCD",
Eur. Phys. J. C58(3) (2008) 355382
S. Groote and H. Veermäe
(MZTH / 0811):
"Short chaotic strings and their behaviour in the scaling region",
Chaos, Solitons and Fractals 41(5) (2005) 23542359
S. Groote and J.G. Körner
(MZTH / 9823, superseded by MZTH / 0839):
"Analytical results for O(alpha_s) radiative corrections to
electronpositron annihilation into antitop and polarized top up to a given
energy cut", Phys. Rev. D80(3) (2009) 034001
S. Groote, J.G. Körner and J.A. Leyva
(MZTH / 0049, superseded by MZTH / 0918):
"O(alpha_s) corrections to the polar angle dependence of the longitudinal
spinspin correlation asymmetry in e^+ e^ > q qbar",
Eur. Phys. J. C63(3) (2009) 391406
S. Groote, H. Liivat, I. Ots and T. Sepp
(MZTH / 0929):
"Probing scalar particle and unparticle couplings in e+ e > t tbar with
transversely polarized beams", Eur. Phys. J. C66(1) (2010) 271281
S. Groote, J.G. Körner
(MZTH / 0942):
"O(alpha(s)) spin effects in e+ e > q antiq (g)",
Proceedings of 13th Workshop on High Energy Spin Physics (DSPIN09),
Dubna, Moscow Region, Russia, 15 Sep 2009
R. Saar, S. Groote, H. Liivat and I. Ots
(MZTH / 1020):
"Gauge and Lorentz transformation placed on the same foundation",
Adv. Math. Phys. 2011 (2011) 652126
S. Groote, H. Liivat and I. Ots
(MZTH / 1029):
"Symmetries and similarities for spin orientation parameters in
e^+ e^ > ZH, Z\gamma, ZZ at SM thresholds",
Nucl. Phys. B843 (2011) 213222
S. Groote, J.G. Körner, B. Melić and S. Prelovsek
(MZTH / 1047):
"A survey of top quark polarization at a polarized linear e^+ e^ collider",
Phys. Rev. D83 (2011) 054018
R. Saar, S. Groote, H. Liivat and I. Ots
(MZTH / 0930):
"`Dynamical' interactions and gauge invariance",
Phys. Rev. D84(6) (2011) 065022
S. Groote, J.G. Körner and A.A. Pivovarov
(MZTH / 1117):
"Calculation loops without loop calculations: NLO computation of pentaquark
correlators",
Phys. Rev. D86(3) (2012) 034023
S. Groote and J.G. Körner
(MZTH / 1145):
"Quark polarization at a polarized linear e^+ e^ collider",
Proceedings of the conference DSPIN11, Dubna, Russia,
Sept 2024, 2011
S. Groote, J.G. Körner and A.A. Pivovarov
(MZTH / 1215):
"A numerical test of differential equations for one and twoloop sunrise
diagrams using configuration space techniques",
Eur. Phys. J. C72(7) (2012) 2085
S. Groote, J.G. Körner and P. Tuvike
(MZTH / 1216):
"O(alpha_s) corrections to the decays of polarized W^+ and Z bosons into
massive quark pairs",
Eur. Phys. J. C72(10) (2012) 2177
S. Groote, H. Veermäe and C. Beck
(MZTH / 1235):
"Renormalization group approach to chaotic strings",
Chaos, Solitons & Fractals 53 (2013) 1833
S. Groote, J.G. Körner, B. Melić and S. Prelovsek
(MZTH / 1241):
"Single top quark polarization at O(alpha_s) in t tbar production at a
polarized linear e^+ e^ collider", extended version of a talk given at the
LC Forum Munich 2011, to be published as a DESY123 LC review report
S. Groote, J.G. Körner and A.A. Pivovarov
(MZTH / 1253):
"Understanding perturbative results for decays of tau leptons into hadrons",
contribution to the Festschrift published on the occasion of the 60th
birthday of Dmitri Kazakov, Phys. Part. Nucl. 44 (2013) 285298
S. Groote, J.G. Körner and P. Tuvike
(MZTH / 1255):
"Fully analytical O(alpha_s) results for onshell and offshell polarized
Wboson decays into massive quark pairs",
Eur. Phys. J. C73 (2013) 2454
S. Groote, J.G. Körner and P. Tuvike
(MITP / 13009):
"The decays of onshell and offshell polarized gauge bosons into massive
quark pairs at NLO QCD", invited talk given by J.G. Körner at the 20th
International Symposium on Spin Physics, September 1722, 2012, Dubna Russia.
Published in the Proceedings, Phys. Part. Nucl. 45 (2014) 214216
S. Groote, J.G. Körner and D. Niinepuu
(MITP / 14003):
"Perturbative O(alpha_s) corrections to the correlation functions of light
tetraquark currents",
Phys. Rev. D90 (2014) 054028
L. Kaldamäe and S. Groote
(MITP / 14032):
"Virtual and real processes, the Källén function, and the
relation to dilogarithms",
J. Phys. G42 (2015) 085003
S. Groote, H. Veermäe and C. Beck:
"Renormalization aspects of chaotic strings", talk given at the conference
"QQQ12  3Quantum: Algebra Geometry Information", Tallinn, Estonia,
July 1014, 2012, J. Phys. Conf. Ser. 532 (2014) 012008
S. Groote and R. Saar:
"Group theory aspects of chaotic strings", talk given at the conference
"QQQ12  3Quantum: Algebra Geometry Information", Tallinn, Estonia,
July 1014, 2012, J. Phys. Conf. Ser. 532 (2014) 012006
S. Groote, R. Saar and H. Liivat:
"Lorentz invariance and gauge equivariance", talk given at the conference
"QQQ12  3Quantum: Algebra Geometry Information", Tallinn, Estonia,
July 1014, 2012, J. Phys. Conf. Ser. 532 (2014) 012007
S. Berge, S. Groote, J.G. Körner and Lauri Kaldamäe
(MITP / 15034):
"Leptonmass effects in the decays H > ZZ* > l+ l tau+ tau and
H > WW* > l nu tau nu_tau",
Phys. Rev. D92 (2015) 033001
R. Saar and S. Groote
(MITP / 16055):
"Mass, zero mass and ... nophysics",
Adv. Appl. Clifford Algebras 27 (2017) 2739
L. Kaldamäe, S. Groote and J.G. Körner
(MITP / 16057):
"Analytical O(alpha_s) corrections to the beam frame doublespin density
matrix elements of e+ e > t tbar",
Phys. Rev. D94 (2016) 114003
Sergey Koshkarev and Stefan Groote
(arXiv:1611.08149):
"Double quarkonium production at high Feynmanx",
Nucl. Phys. B915 (2017) 384391
Stefan Groote and Sergey Koshkarev
(arXiv:1704.02850):
"Production of doubly charmed baryons nearly at rest",
Eur. Phys. J. C77 (2017) 509
Stanley J. Brodsky, Stefan Groote and Sergey Koshkarev
(arXiv:1709.09903):
"Resolving the SELEXLHCb DoubleCharm Baryon Conflict: The Impact of
Intrinsic HeavyQuark Hadroproduction and Supersymmetric LightFront
Holographic QCD", submitted to Physics Letters B
Stefan Groote and Jürgen G. Körner
(MITP17 / 072):
"Bread and butter physics: NLO electroweak corrections to polarized top
quark decays",
Contribution to the proceedings of the XVII Workshop on High Energy Spin
Physics DSPIN17, September 1115, Dubna (Russia): Journal of Physics,
Conference Series 938 (2018) 012053
Stefan Groote and Jürgen G. Körner
(MITP17 / 084):
"Positivity bound on the imaginary part of the rightchiral tensor coupling
g_R in polarized top quark decay",
Phys. Rev. D96 (2017) 111301
Sergey Koshkarev and Stefan Groote
(arXiv:1711:07252):
"Signals of the double intrinsic heavy quark at the current experiments",
Contribution to the proceedings of the XVII Workshop on High Energy Spin
Physics DSPIN17, September 1115, Dubna (Russia): Journal of Physics,
Conference Series 938 (2018) 012054
I love Hagen, the town I am born in 1963, although visitors told me that it is ugly and not as representative as other towns in the Ruhrgebiet like e.g. Dortmund, my former place of studies. To give you a small insight in my town, I display a picture of our townhall, only twenty years old. I have painted it for the "Kirchentag im Ruhrgebiet" in 1991, when tenthousands of children came to Hagen to see the Musical "Zack" there. Because of this favour for my town I frequently use the Deutsche Bahn to get from here to there. But on holidays, my favorite country is Sweden or Sverige. After my engagement with Edith Vohu from Tartu on August 12th, 2001, or registration on August 13th, 2003, the birth of our daughter LindaReet on January 24th, 2004 and Ediths and my marriage on August 28th, 2004 you will find us more or less in Estonia. On January 1st, 2006 our second daughter EloMaarja was born. So be aware to meet me in Tartu (earlier name: Dorpat) at Tartu Ülikoolil!
My hobbies are the following:
© by Stefan Groote, 21.12.2017