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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
- Higgs-Strahlung
- 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 Higgs-gluon interaction is
well represented by an effective Lagrangian for the limit mt
→ infinity (mt 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 70-100%, 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 two-loop corrections [1],
for which a sample of diagrams is shown here:    
Two-loop 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 one-loop 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
Drell-Yan 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 CP-even, A is CP-odd (often
called
the pseudo-scalar 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 pseudo-scalar Higgs differ significantly from the
case
of a CP-even Higgs. The production rate for a pseudo-scalar 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 long-standing 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/mt, where mt is the top quark
mass. For the gluon-gluon subchannel, this expansion was matched to the
high-energy 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 heavy-top 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 electro-weak gauge boson, or "Higgs-Strahlung", 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
next-to-next-to-leading order prediction which reduces the perturbative
uncertainty significantly with respect to lower orders
[6].
At higher orders, Higgs-Strahlung receives contributions where the Higgs is
radiated off a closed top quark loop. We calculated these terms in
Ref. [18].
The gluon-induced 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 transverse-momentum spectrum in the Standard Model and beyond
|
|
WUB/15-06 [arXiv:1510.08850] |
|
JHEP 01 (2016) 090 |
|
| [29] |
R.V. Harlander, A. Kulesza, V. Theeuwes, T. Zirke |
| Soft gluon resummation for gluon-induced Higgs Strahlung
|
|
WUB/14-10 [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/14-07 [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/14-02 [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 Higgs-boson production in the MSSM
|
|
WUB/14-01 [arXiv:1404.0327] |
|
JHEP 06 (2014) 167 |
|
| [25] |
R.V. Harlander, T. Neumann |
| Probing the nature of the Higgs-gluon coupling
|
|
WUB/13-08 [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 2-Higgs-Doublet Model
|
|
WUB/13-12 [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 bottom-quark annihilation in the Standard Model and the MSSM
|
|
WUB/12-28 [arXiv:1212.3249] |
|
Comp. Phys. Commun. 184 (2013) 1605-1617 |
|
| [22] |
L. Altenkamp, S. Dittmaier, R.V. Harlander, H. Rzehak,
T.J.E. Zirke |
| Gluon-induced Higgs-strahlung at next-to-leading order QCD
|
|
WUB/12-21 [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/12-20 [arXiv:1210.5347] |
|
Comp. Phys. Commun. 184 (2013) 998-1003 |
|
| [20] |
R.V. Harlander, T. Neumann, K.J. Ozeren, M. Wiesemann |
| Top-mass 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 |
| Jet-veto in bottom-quark induced Higgs production at
next-to-next-to-leading order
|
|
JHEP 04 (2012) 066 [arXiv:1111.2182] |
|
|
|
| [18] |
O. Brein, R. Harlander, M. Wiesemann, T. Zirke |
| Top-quark mediated effects in hadronic Higgs-Strahlung
|
|
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
next-to-leading 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 next-to-next-to-leading 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 next-to-next-to-leading order
|
|
JHEP 11 (2009) 088 [arXiv:0909.3420] |
|
|
|
| [13] |
R.V. Harlander and K.J. Ozeren |
| Top mass effects in Higgs production at next-to-next-to-leading order QCD: virtual corrections
|
|
Phys. Lett. B 679 (2009) 467-472 [arXiv:0907.2997] |
|
|
|
| [12] |
R. Harlander, J. Vollinga, M. Weber |
| Gluon-Induced 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 next-to-leading order QCD |
|
JHEP 0512 (2005) 015 [hep-ph/0509189]
|
|
|
|
| [10] |
R.V. Harlander and F. Hofmann |
| Pseudo-scalar Higgs production at next-to-leading order SUSY-QCD |
|
JHEP 0603 (2006) 050 [hep-ph/0507041]
|
|
|
|
| [9] |
R.V. Harlander and M. Steinhauser |
| Supersymmetric Higgs production in gluon fusion at next-to-leading order |
|
JHEP 0409 (2004) 066 [hep-ph/0409010]
|
|
|
|
| [8] |
R.V. Harlander and M. Steinhauser |
| Effects of SUSY-QCD in hadronic Higgs production at
next-to-next-to-leading order |
|
Phys. Rev. D 68 (2003) 111701 [hep-ph/0308210]
|
|
|
|
| [7] |
R.V. Harlander and M. Steinhauser |
| Hadronic Higgs Production and Decay in Supersymmetry at Next-to-Leading
Order |
|
Phys. Lett. B 574 (2003) 258-268 [hep-ph/0307346]
|
|
|
|
| [6] |
O. Brein, A. Djouadi, R. Harlander |
| NNLO QCD corrections to the Higgs-strahlung processes at hadron
colliders |
|
Phys. Lett. B 579 (2004) 149 [hep-ph/0307206]
|
|
|
|
| [5] |
R.V. Harlander and W.B. Kilgore |
| Higgs boson production in bottom quark fusion at
next-to-next-to-leading order |
|
Phys. Rev. D 68 (2003) 013001 [hep-ph/0304035]
|
|
|
|
| [4] |
R.V. Harlander and W.B. Kilgore |
| Production of a pseudo-scalar Higgs boson
at hadron colliders at next-to-next-to leading order |
|
JHEP 0210 (2002) 017 [hep-ph/0208096]
|
|
|
|
| [3] |
R.V. Harlander and W.B. Kilgore |
| Next-to-next-to-leading order Higgs production at
hadron colliders |
|
Phys. Rev. Lett. 88 (2002) 201801 [hep-ph/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 [hep-ph/0102241]
|
|
|
|
| [1] |
R.V. Harlander |
| Virtual corrections to gg→H
to two loops in the heavy top limit |
|
Phys. Lett. B 492 (2000) 74 [hep-ph/0007289]
|
|
|
|
Proceedings contributions and other publications:
| [P16] |
R.V. Harlander, A. Tripathi, M. Wiesemann |
| Resummed Higgs pT distribution at NNLO+NNLL in bottom-quark annihilation
|
|
WUB/14-06 [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 Two-Higgs-Doublet Model
|
|
WUB/13-19 [arXiv:1312.5571] |
|
(part of LHC-HXSWG – not submitted for publication) |
|
| [P14] |
R.V. Harlander |
| Higgs production in bottom quark annihilation and gluon fusion
|
|
WUB/12-24; contributed to Loops&Legs 2012 |
|
PoS (LL2012) 040 |
|
| [P13] |
R. Harlander, M. Krämer, M. Schumacher |
| Bottom-quark associated Higgs-boson production:
reconciling the four- and five-flavour scheme approach
|
|
available from this URL [arXiv:1112.3478] |
|
CERN-PH-TH/2011-134, FR-PHENO-2011-009, TTK-11-17, WUB/11-04 |
|
| [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) 875-884 [hep-ph/0606095]
|
|
Proceedings of
WHEPP9,
Bhubaneswar, India,
Jan 3-14, 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 25-30, 2004,
Nucl. Phys. B 135C (2004) 30-34 |
|
|
|
| [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 26-Jun 6, 2003 [hep-ph/0402003]
|
|
|
|
| [P7] |
R. Harlander |
| Supersymmetric Higgs production at the Large Hadron
Collider |
|
HEP2003 Europhysics Conference (EPS 2003), Aachen,
Germany, July 17-23, 2003
Eur. Phys. J. C 33 (2004) S454 [hep-ph/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,
22-29 March 2003 [hep-ph/0305204]
|
|
|
|
| [P5] |
R. Harlander |
| Recent Theoretical
Progress on Higgs Production at Hadron Colliders,
|
|
HCP2002, Karlsruhe, Germany, 29 Sep-4 Oct 2002 |
|
|
|
| [P4] |
R.Harlander and W.Kilgore |
| Scalar and pseudo-scalar Higgs production at hadron colliders |
|
RADCOR / Loops and Legs 2002,
Kloster Banz, Germany, 8-13 Sep 2002 [hep-ph/0211380]
|
|
|
|
| [P3] |
W.B. Kilgore and R.V. Harlander |
| Inclusive Higgs boson production at hadron colliders at next-to-next-to-leading order |
|
37th Rencontres de Moriond on QCD and Hadronic
Interactions, Les Arcs, France, 16-23 Mar 2002 [hep-ph/0205152]
|
|
|
|
| [P2] |
R.V. Harlander and W.B. Kilgore |
| Inclusive Higgs production at next-to-next-to-leading order |
|
Snowmass 2001, Colorado, 30 Jun-21 Jul 2001 [hep-ph/0110200]
|
|
|
|
| [P1] |
R. Harlander and W. Kilgore |
| Higgs production in gluon fusion to O(alpha_s^4) |
|
DPF 2000, Columbus, Ohio, 9-12 Aug 2000
Int. J. Mod. Phys. A 16S1A (2001) 305 [hep-ph/0012176]
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Robert Harlander: Research -/- Home -/- TTP
Karlsruhe -/- CERN
Theory -/- HET
Brookhaven
last
updated on 1 Aug 2013 by RH
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