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Robert Harlander:
Research Interests
/ Home
/ TTP Karlsruhe
/ CERN Theory
/ HET
Brookhaven
Higgs production at hadron colliders
 Gluon fusion
 QCD corrections
 Pseudoscalar Higgs
 Supersymmetry
 Beyond the Heavy Top Limit
 HiggsStrahlung
 Weak
Boson Fusion
 Bottom Quark
Annihilation
 Bibliography
Gluon fusion
is the dominant production channel for ↳Higgs
bosons both at the ↳Tevatron and the ↳LHC. This is true not only in the ↳Standard Model, but also in more exotic
scenarios like the ↳Minimal Supersymmetric
Standard Model. The coupling of the ↳gluons to the Higgs boson is mediated by a top triangle, so that the ↳Feynman diagram to lowest order is given
by the left diagram in the following figure:
Lowest order contribution to gg>H in full ↳QCD (left) and in the effective
theory (right).
On July 4, 2012, a particle consistent with a Higgs boson of mass 125 GeV
was observed
at the LHC (see also here and here). For this mass, the Higgsgluon interaction is
well represented by an effective Lagrangian for the limit m_{t}
→ infinity (m_{t} is the top quark mass). Using
this effective interaction, the lowest order contribution is the tree level
diagram on the right hand side of the above figure. First order QCD corrections to
the total rate gg>H have been calculated 1991 by A. Djouadi et
al. [Phys.Lett.B264 (1991) 440] and by S. Dawson
[Nucl.Phys.B359 (1991) 283]. They turned out to be very large, namely
about 70100%, depending on the Higgs boson mass. This largeness of the
first order terms was the main motivation to evaluate the second order
corrections.
The first step towards the full NNLO terms was the evaluation of the
virtual twoloop corrections [1],
for which a sample of diagrams is shown here:
Twoloop diagrams contributing to the process gg>H.
In order to arrive at the full NNLO prediction, one needs to evaluate
the real radiation processes as well, i.e., emission of one gluon or quark
at oneloop level, and double emission of gluons or quarks at tree level.
Diagrams for single and double real emission. The main
obstacle in performing the full NNLO calculation turns out to be the phase
space integration of the double real emission contribution. A similar
calculation had been performed only once up to now, namely the classic NNLO
DrellYan calculation by R. Hamberg, W.L. van Neerven, T. Matsuura
[Nucl.Phys.B359 (1991) 343].
After a number of preliminary
results [1][2][CFG],
the full calculation has been performed by W. Kilgore and myself
[3], and independently by two
other groups [AM][RSN].
Comparison of this result with the first measurement of
the new particle at the LHC provided the first quantitative hint that
this particle is indeed the Higgs boson.
Extended models of particle physics predict a
larger variety of Higgs
bosons. They differ from one another not only by their mass, but also
charge
or parity. In the minimal supersymmetric extension of the Standard
Model (↳MSSM),
for example, there are five Higgs bosons: h and H
are electrically neutral and CPeven, A is CPodd (often
called
the pseudoscalar Higgs boson), and H^{+/}
are
charged. While the production rate for a light neutral Higgs boson h
can be easily estimated from the production cross section of a Standard
Model Higgs boson (at least in a certain range of the MSSM parameter
space),
the couplings of a pseudoscalar Higgs differ significantly from the
case
of a CPeven Higgs. The production rate for a pseudoscalar Higgs boson
can nevertheless be computed using the same methods as in the scalar
case.
This was done independently by two groups: again by W. Kilgore and
myself
[4],
and by
Anastasiou
and Melnikov [AM].
Another confirmation of these results (including the scalar
Higgs production)
was obtained by Ravindran et al. [RSN].
With M.
Steinhauser and F. Hofmann, we have evaluated an effective Lagrangian
for Higgs production in minimal ↳Supersymmetry
[7],
[9],
[10].
Once established, the
calculation of the gluon fusion process is exactly the same as in the
Standard Model, and the results can be taken over from the papers discussed
above. With F. Hofmann and H. Mantler, we have presented the first prediction for the
Higgs production cross section in the MSSM, taking into account quark and
squark effects both from the top and the bottom sector
[17].
These results, and others from
[DSV]
have recently been implemented in our general code
SusHi
[23].
It had
been a longstanding issue whether the effective theory approach mentioned
above is really valid also at NNLO. With K. Ozeren
[13],
[14],
we calculated terms that are
formally suppressed by 1/m_{t}, where m_{t} is the top quark
mass. For the gluongluon subchannel, this expansion was matched to the
highenergy limit obtained from [MBDFV]. (Similar results were
obtained in [PRS][PRS]). With K. Ozeren, H. Mantler
and S. Marzani
[15],
we extended
the analyses of
[14]
to all subchannels and found that the heavytop limit is indeed an excellent
approximation (better than 1% accuracy) also at NNLO.
While the above results were all obtained for the fully inclusive cross section,
we also studied differential distributions
[20] and found similar results.
These results give confidence in the heavy top limit for higher order
calculations.
The radiation of a
Higgs boson off an electroweak gauge boson, or "HiggsStrahlung", was the
dominant production process at the Tevatron in the low Higgs mass range; it
is also a central process at the LHC though. We provided the first
nexttonexttoleading order prediction which reduces the perturbative
uncertainty significantly with respect to lower orders
[6].
At higher orders, HiggsStrahlung receives contributions where the Higgs is
radiated off a closed top quark loop. We calculated these terms in
Ref. [18].
The gluoninduced terms, though numerically subdominant, introduce a large
theoretical uncertainty. By calculation higher orders for this process
[22], we managed to gain better
theoretical control over this process.
Text under construction. See Ref.
[12].
Text under construction. See Refs.
[5] and
[16], as well as the program
bbh@nnlo.
For other results, please see the following list of publications.
Journal articles:
[30] 
E. Bagnaschi, R.V. Harlander, H. Mantler, A. Vicini, M. Wiesemann, 
 Resummation ambiguities in the Higgs transversemomentum spectrum in the Standard Model and beyond


WUB/1506 [arXiv:1510.08850] 

JHEP 01 (2016) 090 

[29] 
R.V. Harlander, A. Kulesza, V. Theeuwes, T. Zirke 
 Soft gluon resummation for gluoninduced Higgs Strahlung


WUB/1410 [arXiv:1410.0217] 

JHEP 11 (2014) 082 

[28] 
R.V. Harlander, H. Mantler, M. Wiesemann 
 Transverse momentum resummation for Higgs production via gluon fusion in the MSSM


WUB/1407 [arXiv:1409.0531] 

JHEP 11 (2014) 116 

[27] 
R.V. Harlander, A. Tripathi, M. Wiesemann 
 Higgs production in bottom quark annihilation: Transverse momentum distribution at NNLO+NNLO


WUB/1402 [arXiv:1403.7196] 

Phys. Rev. D 90 (2014) 015017 

[26] 
E. Bagnaschi, R.V. Harlander, S. Liebler, H. Mantler,
P. Slavich, A. Vicini 
 Towards precise predictions for Higgsboson production in the MSSM


WUB/1401 [arXiv:1404.0327] 

JHEP 06 (2014) 167 

[25] 
R.V. Harlander, T. Neumann 
 Probing the nature of the Higgsgluon coupling


WUB/1308 [arXiv:1308.2225] 

Phys. Rev. D 88 (2013) 074015 

[24] 
R.V. Harlander, S. Liebler, T. Zirke 
 Higgs Strahlung at the Large Hadron Collider in the 2HiggsDoublet Model


WUB/1312 [arXiv:1307.8122] 

JHEP 02 (2014) 023 

[23] 
R.V. Harlander, S. Liebler, H. Mantler 
 SusHi: A program for the calculation of Higgs production in gluon fusion and bottomquark annihilation in the Standard Model and the MSSM


WUB/1228 [arXiv:1212.3249] 

Comp. Phys. Commun. 184 (2013) 16051617 

[22] 
L. Altenkamp, S. Dittmaier, R.V. Harlander, H. Rzehak,
T.J.E. Zirke 
 Gluoninduced Higgsstrahlung at nexttoleading order QCD


WUB/1221 [arXiv:1211.5015] 

JHEP 02 (2013) 078 

[21] 
O. Brein, R.V. Harlander, T.J.E. Zirke 
 vh@nnlo — Higgs Strahlung at hadron colliders


WUB/1220 [arXiv:1210.5347] 

Comp. Phys. Commun. 184 (2013) 9981003 

[20] 
R.V. Harlander, T. Neumann, K.J. Ozeren, M. Wiesemann 
 Topmass effects in differential Higgs production through gluon fusion at order alpha_s^4


JHEP 08 (2012) 139 [arXiv:1206.0157] 



[19] 
R. Harlander, M. Wiesemann 
 Jetveto in bottomquark induced Higgs production at
nexttonexttoleading order


JHEP 04 (2012) 066 [arXiv:1111.2182] 



[18] 
O. Brein, R. Harlander, M. Wiesemann, T. Zirke 
 Topquark mediated effects in hadronic HiggsStrahlung


Eur. Phys. J. C 72 (2012) 1868 [arXiv:1111.0761] 



[17] 
R.V. Harlander, F. Hofmann, H. Mantler 
 Supersymmetric Higgs production in gluon fusion


JHEP 02 (2011) 055 [arXiv:1012.3361] 

additional material available at this URL 

[16] 
R.V. Harlander, K.J. Ozeren, M. Wiesemann 
 Higgs plus jet production in bottom quark annihilation at
nexttoleading order


Phys. Lett. B 693 (2010) 269 [arXiv:1007.5411] 



[15] 
R.V. Harlander, H. Mantler, S. Marzani, K.J. Ozeren 
 Higgs production in gluon fusion at nexttonexttoleading order QCD for finite top mass


Eur. Phys. J. C 66 (2010) 359 [arXiv:0912.2104] 



[14] 
R.V. Harlander and K.J. Ozeren 
 Finite top mass effects in Higgs production at nexttonexttoleading order


JHEP 11 (2009) 088 [arXiv:0909.3420] 



[13] 
R.V. Harlander and K.J. Ozeren 
 Top mass effects in Higgs production at nexttonexttoleading order QCD: virtual corrections


Phys. Lett. B 679 (2009) 467472 [arXiv:0907.2997] 



[12] 
R. Harlander, J. Vollinga, M. Weber 
 GluonInduced Weak Boson Fusion


Phys. Rev. C 77 (2008) 053010 [arXiv:0801.3355] 



[11] 
R. Harlander and P. Kant 
 Higgs production and decay: Analytic results at nexttoleading order QCD 

JHEP 0512 (2005) 015 [hepph/0509189]




[10] 
R.V. Harlander and F. Hofmann 
 Pseudoscalar Higgs production at nexttoleading order SUSYQCD 

JHEP 0603 (2006) 050 [hepph/0507041]




[9] 
R.V. Harlander and M. Steinhauser 
 Supersymmetric Higgs production in gluon fusion at nexttoleading order 

JHEP 0409 (2004) 066 [hepph/0409010]




[8] 
R.V. Harlander and M. Steinhauser 
 Effects of SUSYQCD in hadronic Higgs production at
nexttonexttoleading order 

Phys. Rev. D 68 (2003) 111701 [hepph/0308210]




[7] 
R.V. Harlander and M. Steinhauser 
 Hadronic Higgs Production and Decay in Supersymmetry at NexttoLeading
Order 

Phys. Lett. B 574 (2003) 258268 [hepph/0307346]




[6] 
O. Brein, A. Djouadi, R. Harlander 
 NNLO QCD corrections to the Higgsstrahlung processes at hadron
colliders 

Phys. Lett. B 579 (2004) 149 [hepph/0307206]




[5] 
R.V. Harlander and W.B. Kilgore 
 Higgs boson production in bottom quark fusion at
nexttonexttoleading order 

Phys. Rev. D 68 (2003) 013001 [hepph/0304035]




[4] 
R.V. Harlander and W.B. Kilgore 
 Production of a pseudoscalar Higgs boson
at hadron colliders at nexttonextto leading order 

JHEP 0210 (2002) 017 [hepph/0208096]




[3] 
R.V. Harlander and W.B. Kilgore 
 Nexttonexttoleading order Higgs production at
hadron colliders 

Phys. Rev. Lett. 88 (2002) 201801 [hepph/0201206]




[2] 
R.V. Harlander and W.B. Kilgore 
 Soft and virtual corrections to pp→H+X at NNLO 

Phys. Rev. D 64 (2001) 01301 [hepph/0102241]




[1] 
R.V. Harlander 
 Virtual corrections to gg→H
to two loops in the heavy top limit 

Phys. Lett. B 492 (2000) 74 [hepph/0007289]




Proceedings contributions and other publications:
[P16] 
R.V. Harlander, A. Tripathi, M. Wiesemann 
 Resummed Higgs pT distribution at NNLO+NNLL in bottomquark annihilation


WUB/1406 [arXiv:1407.3184] 



[P15] 
R. Harlander, M. Mühlleitner, J. Rathsman, M. Spira, O. Stål 
 Recommendations for the evaluation of Higgs production cross sections and branching ratios at the LHC in the TwoHiggsDoublet Model


WUB/1319 [arXiv:1312.5571] 

(part of LHCHXSWG – not submitted for publication) 

[P14] 
R.V. Harlander 
 Higgs production in bottom quark annihilation and gluon fusion


WUB/1224; contributed to Loops&Legs 2012 

PoS (LL2012) 040 

[P13] 
R. Harlander, M. Krämer, M. Schumacher 
 Bottomquark associated Higgsboson production:
reconciling the four and fiveflavour scheme approach


available from this URL [arXiv:1112.3478] 

CERNPHTH/2011134, FRPHENO2011009, TTK1117, WUB/1104 

[P12] 
R. Harlander, H. Mantler, S. Marzani, K.J. Ozeren 
 Higgs production in gluon fusion at NNLO for finite top quark mass


PoS (RADCOR2009) 049 [arXiv:1001.2971] 



[P11] 
R.V. Harlander, 
 Higgs production at the Large Hadron Collider: theoretical status


J. Phys. G 35 (2008) 033001 



[P10] 
R. Harlander 
 Standard and SUSY Higgs production at the LHC 

Pramana 67 (2006) 875884 [hepph/0606095]


Proceedings of
WHEPP9,
Bhubaneswar, India,
Jan 314, 2006 

[P9] 
R. Harlander 
 Precise predictions for Higgs cross sections at the Large Hadron Collider


Loops
and Legs in Quantum Field Theory, Zinnowitz, Germany, April 2530, 2004,
Nucl. Phys. B 135C (2004) 3034 



[P8] 
O. Brein, M. Ciccolini, S. Dittmaier, A. Djouadi, R. Harlander, M. Krämer 
 Precision calculations for associated WH and ZH production at hadron
colliders 

Physics at TeV Colliders, Les Houches, France, May 26Jun 6, 2003 [hepph/0402003]




[P7] 
R. Harlander 
 Supersymmetric Higgs production at the Large Hadron
Collider 

HEP2003 Europhysics Conference (EPS 2003), Aachen,
Germany, July 1723, 2003
Eur. Phys. J. C 33 (2004) S454 [hepph/0311005]




[P6] 
R.V. Harlander and W.B. Kilgore 
 Techniques for NNLO Higgs production in the standard
model and the MSSM 

XXXVIIIth Rencontres de Moriond, Les Arcs, France,
2229 March 2003 [hepph/0305204]




[P5] 
R. Harlander 
 Recent Theoretical
Progress on Higgs Production at Hadron Colliders,


HCP2002, Karlsruhe, Germany, 29 Sep4 Oct 2002 



[P4] 
R.Harlander and W.Kilgore 
 Scalar and pseudoscalar Higgs production at hadron colliders 

RADCOR / Loops and Legs 2002,
Kloster Banz, Germany, 813 Sep 2002 [hepph/0211380]




[P3] 
W.B. Kilgore and R.V. Harlander 
 Inclusive Higgs boson production at hadron colliders at nexttonexttoleading order 

37th Rencontres de Moriond on QCD and Hadronic
Interactions, Les Arcs, France, 1623 Mar 2002 [hepph/0205152]




[P2] 
R.V. Harlander and W.B. Kilgore 
 Inclusive Higgs production at nexttonexttoleading order 

Snowmass 2001, Colorado, 30 Jun21 Jul 2001 [hepph/0110200]




[P1] 
R. Harlander and W. Kilgore 
 Higgs production in gluon fusion to O(alpha_s^4) 

DPF 2000, Columbus, Ohio, 912 Aug 2000
Int. J. Mod. Phys. A 16S1A (2001) 305 [hepph/0012176]




Robert Harlander: Research / Home / TTP
Karlsruhe / CERN
Theory / HET
Brookhaven
last
updated on 1 Aug 2013 by RH
