Search

VBFNLO is a flexible parton level Monte Carlo program for the simulation of vector boson fusion (VBF), QCD-induced single and double vector boson production plus two jets, and double and triple vector boson production (plus jet) in hadronic collisions at next-to-leading order (NLO) in the strong coupling constant, as well as Higgs boson plus two and three jet production via gluon fusion at the one-loop level. For the new version -- Version 3.0 -- several major enhancements have been included. An interface according to the Binoth Les Houches Accord (BLHA) has been added for all VBF and di/tri-boson processes including fully leptonic decays. For all dimension-8 operators affecting vector boson scattering (VBS) processes, a modified T-matrix unitarization procedure has been implemented. Several new production processes have been added, namely the VBS $Z\gamma jj$ and $\gamma \gamma jj$ processes at NLO, $\gamma \gamma jj $, $WWj$ and $ZZj$ production at NLO including the loop-induced gluon-fusion contributions and the gluon-fusion one-loop induced $\Phi jjj$ ($\Phi$ is a CP-even or CP-odd scalar boson) process at LO, retaining the full top-mass dependence. Finally, the code has been parallelized using OpenMPI., Comment: 16 pages, 3 figures; new code available at http://ific.uv.es/vbfnlo/. arXiv admin note: text overlap with arXiv:1107.4038

After the discovery of the Higgs boson in 2012 at the CERN Large Hadron Collider (LHC), the study of its properties still leaves room for an extended Higgs sector with more than one Higgs boson. 2-Higgs Doublet Models (2HDMs) are well-motivated extensions of the Standard Model (SM) with five physical Higgs bosons: two CP-even states $h$ and $H$, one CP-odd state $A$, and two charged states $H^\pm_{}$. In this letter, we present the calculation of the full next-to-leading order (NLO) QCD corrections to $hH$ and $AA$ production at the LHC in the 2HDM at small values of the ratio of the vacuum expectation values, $\tan\beta$, including the exact top-mass dependence everywhere in the calculation. Using techniques applied in the NLO QCD SM Higgs pair production calculation, we present results for the total cross section as well as for the invariant Higgs-pair-mass distribution at the LHC. We also provide the top-quark scale and scheme uncertainties which are found to be sizeable., Comment: 13 pages, 10 figures. V2: minor typos corrected, identical to published version

In this note we discuss the combination of the usual renormalization and factorization scale uncertainties of Higgs-pair production via gluon fusion with the novel uncertainties originating from the scheme and scale choice of the virtual top mass. Moreover, we address the uncertainties related to the top-mass definition for different values of the trilinear Higgs coupling and their combination with the other uncertainties., Comment: 8 pages, 2 figures, minor extensions of text, matches published version

Higgs-pair production via gluon fusion is the dominant production mechanism of Higgs-boson pairs at hadron colliders. In this work, we present details of our numerical determination of the full next-to-leading-order (NLO) QCD corrections to the leading top-quark loops. Since gluon fusion is a loop-induced process at leading order, the NLO calculation requires the calculation of massive two-loop diagrams with up to four different mass/energy scales involved. With the current methods, this can only be done numerically, if no approximations are used. We discuss the setup and details of our numerical integration. This will be followed by a phenomenological analysis of the NLO corrections and their impact on the total cross section and the invariant Higgs-pair mass distribution. The last part of our work will be devoted to the determination of the residual theoretical uncertainties with special emphasis on the uncertainties originating from the scheme and scale dependence of the (virtual) top mass. The impact of the trilinear Higgs-coupling variation on the total cross section will be discussed., Comment: 51 pages, 21 figures. v2: added comments clarifying some details

In this paper, we present results at next-to-leading order (NLO) QCD for photon pair production in association with two jets via vector boson scattering within the Standard Model (SM), and also in an effective field theory framework with anomalous gauge coupling effects via bosonic dimension-6 and 8 operators. We observe that, compared to other processes in the class of two electroweak (EW) vector boson production in association with two jets, more exclusive cuts are needed in order to suppress the SM QCD-induced background channel. As expected, the NLO QCD corrections reduce the scale uncertainties considerably. Using a well-motivated dynamical scale choice, we find moderate $K$-factors for the EW-induced process while the QCD-induced channel receives much larger corrections. Furthermore, we observe that applying a cut of $\Delta \phi_{j_2 \gamma_1}^{\text{cut}} < 2.5$ for the second hardest jet and the hardest photon helps to increase the signal significance and reduces the impact of higher-order QCD corrections.

This document summarises the current theoretical and experimental status of the di-Higgs boson production searches, and of the direct and indirect constraints on the Higgs boson self-coupling, with the wish to serve as a useful guide for the next years. The document discusses the theoretical status, including state-of-the-art predictions for di-Higgs cross sections, developments on the effective field theory approach, and studies on specific new physics scenarios that can show up in the di-Higgs final state. The status of di-Higgs searches and the direct and indirect constraints on the Higgs self-coupling at the LHC are presented, with an overview of the relevant experimental techniques, and covering all the variety of relevant signatures. Finally, the capabilities of future colliders in determining the Higgs self-coupling are addressed, comparing the projected precision that can be obtained in such facilities. The work has started as the proceedings of the Di-Higgs workshop at Colliders, held at Fermilab from the 4th to the 9th of September 2018, but it went beyond the topics discussed at that workshop and included further developments., Comment: 279 pages, 136 figures, document produced partially as outcome of the conference Double Higgs Production at Colliders - Fermilab - Chicago (US) 4 - 9 September 2018. Submitted to Review in Physics. The editors can be contacted at the following address: hh-2018-paper-editors@cern.ch

In this letter, we address the question of whether the almost four standard deviations difference between theory and experiment for the muon anomalous magnetic moment $a_\mu$ can be explained as a higher-order Standard Model perturbation effect in the pion form factor measurements. This question has, until now, remained open, obscuring the source of discrepancies between the measurements. We calculate the last radiative corrections for the extraction of the pion form factor, which were believed to be potentially substantial enough to explain the data within the Standard Model. We find that the corrections are too small to diminish existing discrepancies in the determination of the pion form factor for different kinematical configurations of low-energy BABAR, BESS-III and KLOE experiments. Consequently, they cannot noticeably change the previous predictions for $a_\mu$ and decrease the deviations between theory and direct measurements. To solve the above issues, new data and better understanding of low-energy experimental setups are needed, especially as new direct $a_\mu$ measurements at Fermilab and J-PARC will provide new insights and substantially shrink the experimental error.

The successful operation of the Large Hadron Collider (LHC) and the excellent performance of the ATLAS, CMS, LHCb and ALICE detectors in Run-1 and Run-2 with $pp$ collisions at center-of-mass energies of 7, 8 and 13 TeV as well as the giant leap in precision calculations and modeling of fundamental interactions at hadron colliders have allowed an extraordinary breadth of physics studies including precision measurements of a variety physics processes. The LHC results have so far confirmed the validity of the Standard Model of particle physics up to unprecedented energy scales and with great precision in the sectors of strong and electroweak interactions as well as flavour physics, for instance in top quark physics. The upgrade of the LHC to a High Luminosity phase (HL-LHC) at 14 TeV center-of-mass energy with 3 ab$^{-1}$ of integrated luminosity will probe the Standard Model with even greater precision and will extend the sensitivity to possible anomalies in the Standard Model, thanks to a ten-fold larger data set, upgraded detectors and expected improvements in the theoretical understanding. This document summarises the physics reach of the HL-LHC in the realm of strong and electroweak interactions and top quark physics, and provides a glimpse of the potential of a possible further upgrade of the LHC to a 27 TeV $pp$ collider, the High-Energy LHC (HE-LHC), assumed to accumulate an integrated luminosity of 15 ab$^{-1}$., Comment: Report from Working Group 1 on the Physics of the HL-LHC, and Perspectives at the HE-LHC

We present the calculation of the full next-to-leading order (NLO) QCD corrections to Higgs boson pair production via gluon fusion at the LHC, including the exact top-mass dependence in the two-loop virtual and one-loop real corrections. This is the first independent cross-check of the NLO QCD corrections presented in the literature before. Our calculation relies on numerical integrations of Feynman integrals, stabilised with integration-by-parts and a Richardson extrapolation to the narrow width approximation. We present results for the total cross section as well as for the invariant Higgs-pair-mass distribution at the LHC, including for the first time a study of the uncertainty due to the scheme and scale choice for the top mass in the loops., Comment: 8 pages double column, 2 figures. V2: identical to published version

We consider electro-weak Higgs plus three jets production at NLO QCD beyond strict VBF acceptance cuts. We investigate, for the first time, how accurate the VBF approximation is in these regions and within perturbative uncertainties, by a detailed comparison of full and approximate calculations. We find that a rapidity gap between the tagging jets guarantees a good approximation, while an invariant mass cut alone is not sufficient, which needs to be confronted with experimental choices. We also find that a significant part of the QCD corrections can be attributed to Higgs-Strahlungs-type topologies., Comment: 6 pages, 5 figures, add VBSCAN report number

Cross sections and differential distributions for ZA production in association with two jets via vector boson fusion are presented at next-to-leading order in QCD. The leptonic decays of the Z boson with full off-shell effects and spin correlations are taken into account. The uncertainties due to different scale choices and pdf sets are studied. Furthermore, we analyze the effect of including anomalous quartic gauge couplings at NLO QCD., Comment: 10 pages, 11 figures

We study WZ production with anomalous couplings at $\bar{n}$NLO QCD using the LoopSim method in combination with the Monte Carlo program VBFNLO. Higher order corrections to WZ production are dominated by additional hard jet radiation. Those contributions are insensitive to anomalous couplings and should thus be removed in analyses. We do this using a dynamical jet veto based on the transverse energy of the QCD and EW final state particles. This removes jet dominated events without introducing problematic logs like a fixed $p_{\text{T}}$ jet veto., Comment: Talk presented at Fourth Annual Large Hadron Collider Physics conference (LHCP2016), 13-18 June 2016, Lund, Sweden (10 pages)

This Report summarizes the results of the activities of the LHC Higgs Cross Section Working Group in the period 2014-2016. The main goal of the working group was to present the state-of-the-art of Higgs physics at the LHC, integrating all new results that have appeared in the last few years. The first part compiles the most up-to-date predictions of Higgs boson production cross sections and decay branching ratios, parton distribution functions, and off-shell Higgs boson production and interference effects. The second part discusses the recent progress in Higgs effective field theory predictions, followed by the third part on pseudo-observables, simplified template cross section and fiducial cross section measurements, which give the baseline framework for Higgs boson property measurements. The fourth part deals with the beyond the Standard Model predictions of various benchmark scenarios of Minimal Supersymmetric Standard Model, extended scalar sector, Next-to-Minimal Supersymmetric Standard Model and exotic Higgs boson decays. This report follows three previous working-group reports: Handbook of LHC Higgs Cross Sections: 1. Inclusive Observables (CERN-2011-002), Handbook of LHC Higgs Cross Sections: 2. Differential Distributions (CERN-2012-002), and Handbook of LHC Higgs Cross Sections: 3. Higgs properties (CERN-2013-004). The current report serves as the baseline reference for Higgs physics in LHC Run 2 and beyond., Comment: 869 pages, 295 figures, 248 tables and 1645 citations. Working Group web page: https://twiki.cern.ch/twiki/bin/view/LHCPhysics/LHCHXSWG

In these proceedings, we review results for several di-boson production processes beyond NLO QCD at high transverse momenta using the VBFNLO Monte-Carlo program together with the LOOPSIM method. Additionally, we show for the WZ production process how higher order QCD corrections can resemble anomalous coupling effects., Comment: Conference Proceedings:C15-05-25.1

We study the production of the four-lepton final state $l^+ l^- l^+ l^-$, predominantly produced by a pair of electroweak Z bosons, ZZ. Using the LoopSim method, we merge NLO QCD results for ZZ and ZZ+jet and obtain approximate NNLO predictions for ZZ production. The exact gluon-fusion loop-squared contribution to the ZZ process is also included. On top of that, we add to our merged sample the gluon-fusion ZZ+jet contributions from the gluon-gluon channel, which is formally of N^3LO and provides approximate results at NLO for the gluon-fusion mechanism. The predictions are obtained with the VBFNLO package and include the leptonic decays of the Z bosons with all off-shell and spin-correlation effects, as well as virtual photon contributions. We compare our predictions with existing results for the total inclusive cross section at NNLO and find a very good agreement. Then, we present results for differential distributions for two experimental setups, one used in searches for anomalous triple gauge boson couplings, the other in Higgs analyses in the four charged-lepton final state channel. We find that the approximate NNLO corrections are large, reaching up to 20% at high transverse momentum of the Z boson or the leading lepton, and are not covered by the NLO scale uncertainties. Distributions of the four-lepton invariant mass are, however, stable with respect to QCD corrections at this order., Comment: 21 pages, 2 tables, 9 figures

We study QCD radiation for the WH and WZ production processes at the LHC. We identify the regions sensitive to anomalous couplings, by considering jet observables, computed at NLO QCD with the use of the Monte Carlo program VBFNLO. Based on these observations, we propose the use of a dynamical jet veto. The dynamical jet veto avoids the problem of large logarithms depending on the veto scale, hence, providing more reliable predictions and simultaneously increasing the sensitivity to anomalous coupling searches, especially in the WZ production process., Comment: 9 pages, 6 figures

In these proceedings, we present results for Higgs production at the LHC via gluon fusion with triple real emission corrections and the validity range of the heavy-top effective theory approximation for this process. For a general CP-violating Higgs boson, we show that bottom-quark loop corrections in combination with large values of $\tan \beta $ significantly distort differential distributions., Comment: 7 pages, 7 figures. To appear in the proceedings of Conference: C14-07-02

We discuss results for di-boson plus two jets production processes at the LHC at NLO QCD. Issues related to the scale choice are reviewed. We focus on the distributions of the invariant mass and rapidity separation of the two hardest jets and show, for $W^\pm \gamma jj$ and $Z\gamma jj$ production, how the contribution from the radiative decays of the massive gauge bosons can be significantly reduced., Comment: 7 pages, 6 figures, To appear in the proceedings of conference C14-07-02

Next-to-leading order QCD corrections to the QCD-induced $pp \rightarrow l^+l^- \gamma j j +X$ and $pp \rightarrow \bar{\nu}_l \nu_l \gamma jj+X$ processes are presented. The latter is used to find an optimal cut to reduce the contribution of radiative photon emission off the charged leptons in the first channel. As expected, the scale uncertainties are significantly reduced at NLO and the QCD corrections are phase space dependent and important for precise measurements at the LHC., Comment: 7 pages, 4 figures

In this talk we discuss the implementation of the full next-to-leading order QCD corrections to electroweak Higgs boson plus three jet production at the LHC within the Matchbox framework of the Herwig++ event generator. We also present numerical results for integrated cross sections and kinematic distributions., Comment: 21 pages, 4 figures, submission prepared for the Loops and Legs conference 2014, C14-04-27, reference added

The production of multiple gauge bosons via weak boson fusion is an important process at the LHC. It is relevant as a background process appearing in many searches and measurements, but also serves as a signal process when studying new-physics contributions to triple and in particular quartic gauge boson vertices. We first review the theoretical status of multi-boson production in weak boson fusion and present the current state of the art. In the second part, the impact of anomalous gauge couplings on this class of processes is discussed., Comment: 7 pages, 4 figures; to appear in the proceedings of the 22nd International Workshop on Deep-Inelastic Scattering and Related Subjects (DIS 2014), 28 April - 2 May 2014 Warsaw (Poland)

We present the first calculation of next-to-leading order QCD corrections to QCD-induced ZZ production in association with two jets at hadron colliders. Both Z bosons decay leptonically with all off-shell effects, virtual photon contributions and spin-correlation effects fully taken into account. This process is an important background to weak boson scattering, to the measurement of quartic gauge couplings and to searches for signals of new physics beyond the Standard Model. As expected, the next-to-leading order corrections reduce significantly the scale uncertainty and show a non-trivial phase space dependence in kinematic distributions. Our code will be publicly available as part of the parton level Monte Carlo program VBFNLO., Comment: 12 pages, 4 figures, 2 tables. arXiv admin note: text overlap with arXiv:1402.0505

VBFNLO is a flexible parton level Monte Carlo program for the simulation of vector boson fusion (VBF), double and triple vector boson (plus jet) production as well as QCD-induced single and double vector boson production plus two jets in hadronic collisions at next-to-leading order (NLO) in the strong coupling constant. Furthermore, Higgs boson plus two jet production via gluon fusion at the one-loop level is included. This note briefly describes the main additional features and processes that have been added in the new release -- VBFNLO Version 2.7.0. At NLO QCD several new processes are available. These are $W^\pm\gamma$ and $HH$ production in VBF, the QCD-induced single and double vector boson plus two jets processes $W^\pm jj$, $W^\pm Zjj$, $W^\pm\gamma jj$, same-sign $W^\pm W^\pm jj$, and the Higgs-strahlung process $W^\pm H$ (plus jet) production. Anomalous couplings are now available for all VBF, diboson and triboson (plus jet) processes including the new VBF $W^\pm\gamma jj$ implementation, as well as in the Higgs-strahlung (plus jet) process. Semi-leptonic decay modes are supported for the following diboson, triboson and VBF processes: $VV$, $VVV$, $VV\gamma$ production and $VV$ production via VBF, where $V$ denotes a massive gauge boson, i.e. $W^\pm$ or $Z$. Additionally, the VBF-Higgs production process with decay into $WW$ or $ZZ$ supports semi-leptonic decays of the gauge bosons. All these semi-leptonic processes contain the possibility to include anomalous gauge boson couplings., Comment: 22 pages; new code available at http://www.itp.kit.edu/vbfnlo/

In high energy hadronic collisions, a general CP-violating Higgs boson $\Phi$ with accompanying jets can be efficiently produced via gluon fusion, which is mediated by heavy quark loops. In this letter we study the dominant sub-channel $ gg \to \Phi ggg$ of the gluon fusion production process with triple real emission corrections at order $\alpha_s^5$. We go beyond the heavy top limit approximation and include the full mass dependence of the top- and bottom-quark contributions. Furthermore, we show within a toy-model scenario that bottom-quark loop contributions in combination with large values of $\tan \beta$ can modify visibly the differential distributions sensitive to $\mathcal{CP}$-measurements of the Higgs boson particle., Comment: 7 pages, 5 figures. arXiv admin note: text overlap with arXiv:1306.1830

The QCD-induced $W^\pm \gamma$ production channels in association with two jets are computed at next-to-leading order QCD accuracy. The W bosons decay leptonicly and full off-shell and finite width effects as well as spin correlations are taken into account. These processes are important backgrounds to beyond Standard Model physics searches and also relevant to test the nature of the quartic gauge couplings of the Standard Model. The next-to-leading order corrections reduce the scale uncertainty significantly and show a non-trivial phase space dependence. Our code will be publicly available as part of the parton level Monte Carlo program VBFNLO., Comment: 9 pages, 5 figures, 6 tables. arXiv admin note: text overlap with arXiv:1311.6738

KLOE and Babar have an observed discrepancy of 2% to 5% in the invariant pion pair production cross section. These measurements are based on approximate NLO $ \mu^+ \mu^- \gamma $ cross section predictions of the Monte Carlo event generator PHOKHARA7.0. In this article, the complete NLO radiative corrections to $ \mu^+ \mu^- \gamma $ production are calculated and implemented in the Monte Carlo event generator PHOKHARA9.0. Numerical reliability is guaranteed by two independent approaches to the real and the virtual corrections. The novel features include the contribution of pentagon diagrams in the virtual corrections, which form a gauge-invariant set when combined with their box diagram partners. They may contribute to certain distributions at the percent level. Also the real emission was complemented with two-photon final state emission contributions not included in the generator PHOKHARA7.0. We demonstrate that the numerical influence reaches, for realistic charge-averaged experimental setups, not more than 0.1% at KLOE and 0.3% at BaBar energies. As a result, we exclude the approximations in earlier versions of PHOKHARA as origin of the observed experimental discrepancy., Comment: 28 pages, 8 figures

Purpose: The aim of this study is to analyze the disciplinary coverage of the Thomson Reuters' Book Citation Index database focusing on publisher presence, impact and specialization. Design/Methodology/approach: We conduct a descriptive study in which we examine coverage by discipline, publisher distribution by field and country of publication, and publisher impact. For this the Thomson Reuters' Subject Categories were aggregated into 15 disciplines. Findings: 30% of the total share of this database belongs to the fields of Humanities and Social Sciences. Most of the disciplines are covered by very few publishers mainly from the UK and USA (75.05% of the books), in fact 33 publishers concentrate 90% of the whole share. Regarding publisher impact, 80.5% of the books and chapters remained uncited. Two serious errors were found in this database. Firstly, the Book Citation Index does not retrieve all citations for books and chapters. Secondly, book citations do not include citations to their chapters. Research limitations/implications: The Book Citation Index is still underdeveloped and has serious limitations which call into caution when using it for bibliometric purposes. Practical implications: The results obtained from this study warn against the use of this database for bibliometric purposes, but opens a new window of opportunities for covering long neglected areas such as Humanities and Social Sciences. The target audience of this study is librarians, bibliometricians, researchers, scientific publishers, prospective authors and evaluation agencies. Originality/Value: There are currently no studies analyzing in depth the coverage of this novel database which covers monographs., Comment: Online Information Review, 38(1)