Top Quark Research Papers - Academia.edu (original) (raw)

2025, Journal of Instrumentation

During autumn 2008, the Silicon Strip Tracker was operated with the full CMS experiment in a comprehensive test, in the presence of the 3.8 T magnetic field produced by the CMS superconducting solenoid. Cosmic ray muons were detected in the muon chambers and used to trigger the readout of all CMS sub-detectors. About 15 million events with a muon in the tracker were collected. The efficiency of hit and track reconstruction were measured to be higher than 99% and consistent with expectations from Monte Carlo simulation. This article details the commissioning and performance of the Silicon Strip Tracker with cosmic ray muons.

2025, Journal of Physics G: Nuclear and Particle Physics

2025, Physical Review Letters

We have measured the W -boson mass MW using data corresponding to 2.2 fb -1 of integrated luminosity collected in pp collisions at √ s = 1.96 TeV with the CDF II detector at the Fermilab Tevatron collider. Samples consisting of 470 126 W → eν candidates and 624 708 W → µν candidates yield the measurement MW = 80 387 ± 12stat ± 15syst = 80 387 ± 19 MeV/c 2 . This is the most precise measurement of the W -boson mass to date and significantly exceeds the precision of all previous measurements combined.

2025, Physical Review D

We report the combination of recent measurements of the helicity of the W boson from top quark decay by the CDF and D0 collaborations, based on data samples corresponding to integrated luminosities of 2.7 -5.4 fb -1 of pp collisions collected during Run II of the Fermilab Tevatron Collider. Combining measurements that simultaneously determine the fractions of W bosons with longitudinal (f0) and right-handed (f+) helicities, we find f0 = 0.722 ± 0.081 [± 0.062 (stat.) ± 0.052 (syst.)] and f+ = -0.033 ± 0.046 [± 0.034 (stat.) ± 0.031 (syst.)]. Combining measurements where one of the helicity fractions is fixed to the value expected in the standard model, we find f0 = 0.682±0.057 [± 0.035 (stat.)±0.046 (syst.)] and f+ = -0.015±0.035 [± 0.018 (stat.)±0.030 (syst.)]. The results are consistent with standard model expectations.

2025, Physics Letters B

We present a search for the pair production of scalar top quarks ( t1), the lightest supersymmetric partners of the top quarks, in pp collisions at a center-of-mass energy of 1.96 TeV, using data corresponding to an integrated luminosity of 7.3 fb -1 collected with the D0 experiment at the Fermilab Tevatron Collider. Each scalar top quark is assumed to decay into a b quark, a charged lepton, and a scalar neutrino (ν). We investigate final states arising from t1 t1→ b bµτ ν ν and t1 t1→ b bτ τ ν ν. With no significant excess of events observed above the background expected from the standard model, we set exclusion limits on this production process in the (mt 1 ,mν ) plane.

2025, Physical Review Letters

We present a measurement of the ratio of top quark branching fractions R = B(t → W b)/B(t → W q), where q can be a d, s or b quark, in the lepton+jets and dilepton t t final states. The measurement uses data from 5.4 fb -1 of pp collisions collected with the D0 detector at the Fermilab Tevatron Collider. We measure R = 0.90 ± 0.04, and we extract the CKM matrix element |V tb | as |V tb | = 0.95 ± 0.02, assuming unitarity of the 3 × 3 CKM matrix.

2025, Physical Review Letters

We present a search for pair production of a fourth generation t quark and its antiparticle, followed by their decays to a W boson and a jet, based on an integrated luminosity of 5.3 fb -1 of proton-antiproton collisions at √ s = 1.96 TeV collected by the D0 Collaboration at the Fermilab Tevatron Collider. We set upper limits on the t t production cross section that exclude at the 95% C.L. a t quark that decays exclusively to W +jet with a mass below 285 GeV. We observe a small excess in the µ+jets channel which reduces the mass range excluded compared to the expected limit of 320 GeV in the absence of a signal.

2025, Physical Review D

We present a search for the standard model Higgs boson using events with two oppositely charged leptons and large missing transverse energy as expected in H → W W decays. The events are selected from data corresponding to 8.6 fb -1 of integrated luminosity in pp collisions at √ s = 1.96 TeV collected with the D0 detector at the Fermilab Tevatron Collider. No significant excess above the standard model background expectation in the Higgs boson mass range this search is sensitive to is observed, and upper limits on the Higgs boson production cross section are derived.

2025, Physical Review D

This report describes a search for associated production of W and Higgs bosons based on data corresponding to an integrated luminosity of L ≈ 5.3 fb -1 collected with the D0 detector at the Fermilab Tevatron pp Collider. Events containing a W → ℓν candidate (with ℓ corresponding to e or µ) are selected in association with two or three reconstructed jets. One or two of the jets are required to be consistent with having evolved from a b quark. A multivariate discriminant technique is used to improve the separation of signal and backgrounds. Expected and observed upper limits are obtained for the product of the W H production cross section and branching ratios and reported in terms of ratios relative to the prediction of the standard model as a function of the mass of the Higgs boson (MH ). The observed and expected 95% C.L. upper limits obtained for an assumed MH = 115 GeV are, respectively, factors of 4.5 and 4.8 larger than the value predicted by the standard model.

2025, Physical Review D

The top quark is the heaviest known elementary particle, with a mass about 40 times larger than the mass of its isospin partner, the bottom quark. It decays almost 100% of the time to a W boson and a bottom quark. Using top-antitop pairs at the Tevatron proton-antiproton collider, the CDF and D0 collaborations have measured the top quark's mass in different final states for integrated luminosities of up to 5.8 fb -1 . This paper reports on a combination of these measurements that results in a more precise value of the mass than any individual decay channel can provide. It describes the treatment of the systematic uncertainties and their correlations. The mass value determined is 173.18 ± 0.56 (stat) ± 0.75 (syst) GeV or 173.18 ± 0.94 GeV, which has a precision of ±0.54%, making this the most precise determination of the top quark mass.

2025, International Journal of Modern Physics A

As the heaviest known fundamental particle, the top quark has taken a central role in the study of fundamental interactions. Production of top quarks in pairs provides an important probe of strong interactions. The top quark mass is a key fundamental parameter which places a valuable constraint on the Higgs boson mass and electroweak symmetry breaking. Observations of the relative rates and kinematics of top quark final states constrain potential new physics. In many cases, the tests available with study of the top quark are both critical and unique. Large increases in data samples from the Fermilab Tevatron have been coupled with major improvements in experimental techniques to produce many new precision measurements of the top quark. The first direct evidence for electroweak production of top quarks has been obtained, with a resulting direct determination of Vtb. Several of the properties of the top quark have been measured. Progress has also been made in obtaining improved limits...

2025, Physical Review Letters

We have searched for heavy neutral gauge bosons ͑Z 0 ͒ in dielectron and dimuon decay modes using 110 pb 21 of pp collisions at p s 1.8 TeV collected with the Collider Detector at Fermilab. We present a limit on the production cross section times branching ratio of a Z 0 boson decaying into dileptons as a function of Z 0 mass. For mass M Z 0 . 600 GeV͞c 2 , the upper limit is 40 fb at 95% confidence level. We set the lower mass limits of 690, 590, 620, 595, 565, 630, and 600 GeV͞c 2 for Z 0 SM , Z c , Z h , Z x , Z I , Z LR , and Z ALRM , respectively. [S0031-9007(97)04021-0]

2025, Journal of High Energy Physics

Single top quark events produced in the t channel are used to set limits on anomalous Wtb couplings and to search for top quark flavour-changing neutral current (FCNC) interactions. The data taken with the CMS detector at the LHC in proton-proton collisions at √ s = 7 and 8 TeV correspond to integrated luminosities of 5.0 and 19.7 fb -1 , respectively. The analysis is performed using events with one muon and two or three jets. A Bayesian neural network technique is used to discriminate between the signal and backgrounds, which are observed to be consistent with the standard model prediction. The 95% confidence level (CL) exclusion limits on anomalous right-handed vector, and left-and righthanded tensor Wtb couplings are measured to be |f R V | < 0.16, |f L T | < 0.057, and -0.049 < f R T < 0.048, respectively. For the FCNC couplings κ tug and κ tcg , the 95% CL upper limits on coupling strengths are |κ tug |/Λ < 4.1 × 10 -3 TeV -1 and |κ tcg |/Λ < 1.8 × 10 -2 TeV -1 , where Λ is the scale for new physics, and correspond to upper limits on the branching fractions of 2.0 × 10 -5 and 4.1 × 10 -4 for the decays t → ug and t → cg, respectively.

2025, Journal of High Energy Physics

A comparison of the differential cross sections for the processes Z/γ * +jets and photon (γ)+jets is presented. The measurements are based on data collected with the CMS detector at √ s = 8 TeV corresponding to an integrated luminosity of 19.7 fb -1 . The differential cross sections and their ratios are presented as functions of p T . The measurements are also shown as functions of the jet multiplicity. Differential cross sections are obtained as functions of the ratio of the Z/γ * p T to the sum of all jet transverse momenta and of the ratio of the Z/γ * p T to the leading jet transverse momentum. The data are corrected for detector effects and are compared to simulations based on several QCD calculations.

2025, Journal of High Energy Physics

A search for neutral Higgs bosons decaying into a b b quark pair and produced in association with at least one additional b quark is presented. This signature is sensitive to the Higgs sector of the minimal supersymmetric standard model (MSSM) with large values of the parameter tan β. The analysis is based on data from proton-proton collisions at a center-of-mass energy of 8 TeV collected with the CMS detector at the LHC, corresponding to an integrated luminosity of 19.7 fb -1 . The results are combined with a previous analysis based on 7 TeV data. No signal is observed. Stringent upper limits on the cross section times branching fraction are derived for Higgs bosons with masses up to 900 GeV, and the results are interpreted within different MSSM benchmark scenarios, m max h , m mod+ h , m mod- h , light-stau and light-stop. Observed 95% confidence level upper limits on tan β, ranging from 14 to 50, are obtained in the m mod+ h benchmark scenario.

2025, Journal of High Energy Physics

A measurement of the W boson helicity is presented, where the W boson originates from the decay of a top quark produced in pp collisions. The event selection, optimized for reconstructing a single top quark in the final state, requires exactly one isolated lepton (muon or electron) and exactly two jets, one of which is likely to originate from the hadronization of a bottom quark. The analysis is performed using data recorded at a center-of-mass energy of 8 TeV with the CMS detector at the CERN LHC in 2012. The data sample corresponds to an integrated luminosity of 19.7 fb -1 . The measured helicity fractions are F L = 0.298 ± 0.028 (stat) ± 0.032(syst), F 0 = 0.720 ± 0.039 (stat) ± 0.037(syst), and F R = -0.018 ± 0.019 (stat) ± 0.011(syst). These results are used to set limits on the real part of the tWb anomalous couplings, g L and g R .

2025, Journal of High Energy Physics

Measurements of jet production rates in association with W and Z bosons for jet transverse momenta above 30 GeV are reported, using a sample of proton-proton collision events recorded by CMS at √ s = 7 TeV, corresponding to an integrated luminosity of 36 pb -1 . The study includes the measurement of the normalized inclusive rates of jets σ(V+ ≥ n jets)/σ(V), where V represents either a W or a Z. In addition, the ratio of W to Z cross sections and the W charge asymmetry as a function of the number of associated jets are measured. A test of scaling at √ s = 7 TeV is also presented. The measurements provide a stringent test of perturbative-QCD calculations and are sensitive to the possible presence of new physics. The results are in agreement with the predictions of a simulation that uses explicit matrix element calculations for final states with jets.

2025, Physical Review D

We present a measurement of the fraction f+ of right-handed W bosons produced in top quark decays, based on a candidate sample of t t events in the ℓ+jets and dilepton decay channels corresponding to an integrated luminosity of 370 pb -1 collected by the DØ detector at the Fermilab Tevatron pp Collider at √ s = 1.96 TeV. We reconstruct the decay angle θ * for each lepton. By comparing the cos θ * distribution from the data with those for the expected background and signal for various values of f+, we find f+ = 0.056±0.080 (stat)±0.057 (syst). (f+ < 0.23 at 95% C.L.), consistent with the standard model prediction of f+ = 3.6 × 10 -4 .

2025, Nuclear Physics B

We calculate the Drell-Yan cross section, resolving the full kinematics of the lepton pair, at high transverse momentum for hadron nucleus collisions. We use the general framework of Luo, Qiu and Sterman to calculate double scattering contributions that are of twist-4 and demonstrate their nuclear enhancement. By comparing single and double scattering at RHIC energies we find that double scattering gives contributions of comparable size. We also show that the angular dependence of the Drell-Yan pair discriminates between the various double scattering contributions.

2025, European Physical Journal C

We study the prospects of searches for exotic long-lived particles with the MoEDAL detector at the LHC, assuming the integrated luminosity of 30 fb -1 that is expected at the end of Run 3. MoEDAL incorporates nuclear track detectors deployed a few metres away from the interaction point, which are sensitive to any highly-ionizing particles. Hence MoEDAL is able to detect singly-or doublycharged particles with low velocities β < 0.15 or < 0.3, respectively, and lifetimes larger than O(1) m/c. We examine the MoEDAL sensitivity to various singly-charged supersymmetric particles with long lifetimes and to several types of doubly-charged long-lived particles with different spins and SU(2) charges. We compare the prospective MoEDAL mass reaches to current limits from ATLAS and CMS, which involve auxiliary analysis assumptions. MoEDAL searches for doubly-charged fermions are particularly competitive.

2025, Journal of High Energy Physics

We investigate the phenomenological aspects of non-perturbative baryon- and lepton-number-violating processes at hadron colliders. Such processes, induced by instan- ton/sphaleron configurations of the electroweak gauge fields, are believed to play a crucial role in the generation of baryon asymmetry in the early Universe at finite temperature. On the other hand, at colliders (that represent the zero-temperature high-energy regime) the rate and observability of such processes are still under debate. Motivated by current the- oretical considerations, we construct a modern event generator within the general-purpose Herwig Monte Carlo framework, that aims to capture the most relevant features of the dominant processes. We perform a detailed phenomenological analysis focussing on the Large Hadron Collider, at 13 TeV proton-proton centre-of-mass energy, a potential high- energy upgrade at 27 TeV and the proposed Future Circular Collider (FCC-hh) at 100 TeV. We derive constraints on the e...

2025, Journal of physics

We explore the flavor-changing parameters mediated by a Higgs boson within the THDM-III context. In particular, the h → t * c processes, and check the high suppression for the FC in the THDM-III context for the low t β parameters. Our exploration in the χ u ij -χ d ij -parameter space shows the allowed regions for different t β values. We explored different modes for Higgs decays, considered the experimental constraints to get scattering plots for the FC parameters and some relevant decay modes. We expect future results to figure out the FC and its implications in the scalar sector.

2025, Physical review

A recent determination of the mass of the b quark, based exclusively on quantum chromodynamics ͑by avoiding strictly to introduce any phenomenological interaction potential of nonperturbative origin͒, may be improved by allowing for a... more

2025, Journal of High Energy Physics

We compute the real and imaginary parts of the one-loop electroweak contributions to the left and right tensorial anomalous couplings of the tbW vertex in the Standard Model (SM). For both tensorial couplings we find that the real part of the electroweak SM correction is close to 10% of the leading contribution given by the QCD gluon exchange. We also find that the electroweak real and imaginary parts for the anomalous right coupling are almost of the same order of magnitude. The one loop SM prediction for the real part of the left coupling is close to the 3σ discovery limit derived from b → sγ. Besides, taking into account that the predictions of new physics interactions are also at the level of a few percents when compared with the one loop QCD gluon exchange, these electroweak corrections should be taken into account in order to disentangle new physics effects from the standard ones. These anomalous tensorial couplings of the top quark will be investigated at the LHC in the near future where sensitivity to these contributions may be achieved.

2025, arXiv (Cornell University)

We re-examine our former predictions of the top and Higgs masses via dynamical symmetry breaking in a 4-fermion theory which produces the Higgs as a bound state, and relates the top and Higgs masses to m W . The use of dynamical symmetry breaking was stongly motivated by the apparent equality, within a factor of two, of the known and expected masses of the W , Z, top and Higgs. In later work we evaluated the masses self-consistently at the mass-poles, which resulted in predictions of m t ∼ 175 GeV, and m H ∼ 125 GeV as central values within ranges produced by varying the measured strong coupling. Figures (1) and (2) result from evolution down to m W while the number quoted for the top quark mass, i.e. 175 GeV includes an evolution back up to the top and use of the determination of α s at LEP at that time. m H is less dependent on the value of the strong coupling. The variation of the predicted masses for a range of the strong and electro-weak couplings α s , α W at m W are exhibited in Figure (3) and Figure (4) reproduced from the last work , which was submitted to PRD well before the first FNAL publications suggesting evidence for the top.

2025, Physical Review D

A model for composite electroweak bosons is re-examined to establish approximate ranges for the initial predictions of the top and Higgs masses. Higher order corrections to this 4-fermion theory at a high mass scale where the theory is matched to the Standard Model have little effect, as do wide variations in this scale. However, including all one loop evolution and defining the masses self-consistently, at their respective poles, moves the top mass upward by some 10 GeV to near 175 GeV and the Higgs mass down by a similar amount to near 125 GeV.

2025, Physics Letters B

An updated fit to the precision electroweak data and to the direct measurement of the top quark mass m t provides significant constraints on m t and on the Higgs boson mass M H : m t /GeV = 172 ± 6 and log 10 (M H /GeV) = 2.16±0.33, with an error correlation ρ = 0.5. We integrate the (M H , m t ) probability distribution found in this analysis over various zones of the (M H , m t ) plane defined by one-sided experimental and theoretical bounds on the Higgs boson mass, both in the Standard Model and in its minimal supersymmetric extension. The comparison of the cumulative probabilities gives interesting information on the likelihood that the true value of M H is compatible with different theoretical scenarios.

2025, Journal of High Energy Physics

We present the calculation of the finite part of the heavy quark impact factor at next-to-leading logarithmic accuracy in a form suitable for phenomenological studies such as the calculation of the cross-section for single bottom quark... more

2025, Journal of High Energy Physics

We compute the one loop right and left anomalous tensor couplings (gR and gL, respectively) for the top quark, in the aligned two-Higgsdoublet model. They are the magnetic-like couplings in the most general parameterization of the tbW vertex. We find that the aligned two-Higgs doublet model, that includes as particular cases some of the most studied extensions of the Higgs sector, introduces new electroweak contributions and provides theoretical predictions that are very sensitive to both new scalar masses and the neutral scalar mixing angle. For a large area in the parameters space we obtain significant deviations in both the real and the imaginary parts of the couplings gR and gL, compared to the predictions given by the electroweak sector of the Standard Model. The most important ones are those involving the imaginary part of the left coupling gL and the real part of the right coupling gR. The real part of gL and the imaginary part of gR also show an important sensitivity to new physics scenarios. The model can also account for new CP violation e ects via the introduction of complex alignment parameters that have important consequences on the values for the imaginary parts of the couplings. The top anomalous tensor couplings will be measured at the LHC and at future colliders providing a complementary insight on new physics, independent from the bounds in top decays coming from B physics and b → sγ.

2025, Physical Review D

We study the effects of the one-loop matching conditions on Higgs boson and top quark masses on the triviality bounds on the Higgs boson mass using β λ with corrected twoloop coefficients. We obtain quite higher results than previous ones and observe that the triviality bounds are not nearly influenced by varying top quark mass over the range measured at CDF and D0. The effects of typo errors in β (2) λ and the one-loop matching condition on the top quark mass are negligible. We estimate the size of effects on the triviality bounds from the one-loop matching condition on the Higgs boson mass.

2025, Journal of High Energy Physics

Measurements of four-lepton differential and integrated fiducial cross-sections in events with two same-flavour, opposite-charge electron or muon pairs are presented. The data correspond to 139 fb−1 of sqrts\sqrt{s}sqrts s = 13 TeV proton-proton collisions, collected by the ATLAS detector during Run 2 of the Large Hadron Collider (2015–2018). The final state has contributions from a number of interesting Standard Model processes that dominate in different four-lepton invariant mass regions, including single Z boson production, Higgs boson production and on-shell ZZ production, with a complex mix of interference terms, and possible contributions from physics beyond the Standard Model. The differential cross-sections include the four-lepton invariant mass inclusively, in slices of other kinematic variables, and in different lepton flavour categories. Also measured are dilepton invariant masses, transverse momenta, and angular correlation variables, in four regions of four-lepton invariant...

2025, Journal of High Energy Physics

A search for new phenomena with top quark pairs in final states with one isolated electron or muon, multiple jets, and large missing transverse momentum is performed. Signal regions are designed to search for two-, three-, and four-body decays of the directly pair-produced supersymmetric partner of the top quark (stop). Additional signal regions are designed specifically to search for spin-0 mediators that are produced in association with a pair of top quarks and decay into a pair of dark-matter particles. The search is performed using the Large Hadron Collider proton-proton collision dataset at a centre-of-mass energy of sqrts\sqrt{s}sqrts s = 13 TeV recorded by the ATLAS detector from 2015 to 2018, corresponding to an integrated luminosity of 139 fb−1. No significant excess above the Standard Model background is observed, and limits at 95% confidence level are set in the stop-neutralino mass plane and as a function of the mediator mass or the dark-matter particle mass. Stops are exclu...

2025, The European Physical Journal C

The inclusive and fiducial t t production crosssections are measured in the lepton+jets channel using 20.2 fb -1 of proton-proton collision data at a centre-ofmass energy of 8 TeV recorded with the ATLAS detector at the LHC. Major systematic uncertainties due to the modelling of the jet energy scale and b-tagging efficiency are constrained by separating selected events into three disjoint regions. In order to reduce systematic uncertainties in the most important background, the W + jets process is modelled using Z + jets events in a data-driven approach. The inclusive t t cross-section is measured with a precision of 5.7% to be σ inc (t t) = 248.3 ± 0.7 (stat.) ± 13.4 (syst.) ± 4.7 (lumi.) pb, assuming a top-quark mass of 172.5 GeV. The result is in agreement with the Standard Model prediction. The crosssection is also measured in a phase space close to that of the selected data. The fiducial cross-section is σ fid (t t) = 48.8 ± 0.1 (stat.) ± 2.0 (syst.) ± 0.9 (lumi.) pb with a precision of 4.5%. ation of the LHC, as well as the support staff from our institutions without whom ATLAS could not be operated efficiently. We acknowledge the support of ANPCyT, Argentina; YerPhI, Armenia; ARC,

2025

This is a technical document that provides supporting information and details of the publicly available code used for the preparation of the analysis for preprint "{\it A search for heavy Kaluza-Klein electroweak gauge bosons at the LHC}" (submitted to JHEP). The {\sc Moses} C++ framework is a project written for probing and developing new models for High Energy Physics processes which allows complete events to be simulated by interface with the standard simulation program Pythia8. This paper demonstrates the usage of {\sc Moses} in a study of the nature of Kaluza-Klein (KK) excitations in a specific model where the SU(2) \times U(1) gauge fields can exist in a single Extra Dimension (ED) compactified on a S1/Z_2S^1/Z_2S1/Z_2 orbifold, while the matter fermions and SU(3) gauge fields are localized in the 3d-brane. Using this framework, the events have been fully simulated at hadron level including initial and final state radiation. The study of particle decays was used to develop a ...

2025, Physics Reports

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2025, Physical Review Letters

2025, The European Physical Journal C

This final analysis of hadronic and leptonic cross-sections and of leptonic forward-backward asymmetries in e + e -collisions with the OPAL detector makes use of the full LEP 1 data sample comprising 161 pb -1 of integrated luminosity and 4.5 × 10 6 selected Z decays. An interpretation of the data in terms of contributions from pure Z exchange and from γ/Z interference allows the parameters of the Z resonance to be determined in a model-independent way. Our results are in good agreement with lepton universality and consistent with the vector and axial-vector couplings predicted in the Standard Model. A fit to the complete dataset yields the fundamental Z resonance parameters: m Z = (91.1852 ± 0.0030) GeV, Γ Z = (2.4948 ± 0.0041) GeV, σ 0 h = (41.501 ± 0.055) nb, R = 20.823 ± 0.044, and A 0, FB = 0.0145 ± 0.0017. Transforming these parameters gives a measurement of the ratio between the decay width into invisible particles and the width to a single species of charged lepton, Γ inv /Γ = 5.942 ± 0.027. Attributing the entire invisible width to neutrino decays and assuming the Standard Model couplings for neutrinos, this translates into a measurement of the effective number of light neutrino species, N ν = 2.984 ± 0.013. Interpreting the data within the context of the Standard Model allows the mass of the top quark, m t = (162 +29 -16 ) GeV, to be determined through its influence on radiative corrections. Alternatively, utilising the direct external measurement of m t as an additional constraint leads to a measurement of the strong coupling constant and the mass of the Higgs boson: α s (m Z ) = 0.127 ± 0.005 and m H = (390 +750 -280 ) GeV.

2025, arXiv (Cornell University)

Many domains of high energy physics analysis are starting to explore machine learning techniques. Powerful methods can be used to identify and measure rare processes from previously insurmountable backgrounds. One of the most profound Standard Model signatures still to be discovered at the LHC is the pair production of Higgs bosons through the Higgs self-coupling. The small cross section of this process makes detection very difficult even for the decay channel with the largest branching fraction (hh → b bb b). This paper benchmarks a variety of approaches (boosted decision trees, various neural network architectures, semi-supervised algorithms) against one another to catalog a few of the various techniques available to high energy physicists as the era of the HL-LHC approaches.

2025, Physical Review Letters