scholarly journals A special Higgs challenge: measuring the mass and production cross section with ultimate precision at FCC-ee

2021 ◽  
Vol 137 (1) ◽  
Author(s):  
Paolo Azzurri ◽  
Gregorio Bernardi ◽  
Sylvie Braibant ◽  
David d’Enterria ◽  
Jan Eysermans ◽  
...  
Keyword(s):  
Higgs Boson ◽  
Cross Section ◽  
Production Cross Section ◽  
Production Cross ◽  
Boson Mass ◽  
Higgs Boson Mass ◽  
Centre Of Mass ◽  
Reconstruction Performance ◽  
Statistical Limit

AbstractThe FCC-ee offers powerful opportunities to determine the Higgs boson parameters, exploiting over $$10^6$$ 10 6 $${ \hbox {e}^+\hbox {e}^- \rightarrow \hbox {ZH}}$$ e + e - → ZH events and almost $$10^5$$ 10 5 $${ \hbox {WW} \rightarrow \hbox {H}}$$ WW → H events at centre-of-mass energies around 240 and 365 GeV. This essay spotlights the important measurements of the ZH production cross section and of the Higgs boson mass. The measurement of the total ZH cross section is an essential input to the absolute determination of the HZZ coupling—a “standard candle” that can be used by all other measurements, including those made at hadron colliders—at the per-mil level. A combination of the measured cross sections at the two different centre-of-mass energies further provides the first evidence for the trilinear Higgs self-coupling, and possibly its first observation if the cross section measurement can be made accurate enough. The determination of the Higgs boson mass with a precision significantly better than the Higgs boson width (4.1 MeV in the standard model) is a prerequisite to either constrain or measure the electron Yukawa coupling via direct $${ \hbox {e}^+\hbox {e}^- \rightarrow \hbox {H}}$$ e + e - → H production at $$\sqrt{s} = 125$$ s = 125  GeV. Approaching the statistical limit of 0.1% and $${\mathcal {O}}(1)$$ O ( 1 )  MeV on the ZH cross section and the Higgs boson mass, respectively, sets highly demanding requirements on accelerator operation (ZH threshold scan, centre-of-mass energy measurement), detector design (lepton momentum resolution, hadronic final state reconstruction performance), theoretical calculations, and analysis techniques (efficiency and purity optimization with modern tools, constrained kinematic fits, control of systematic uncertainties). These challenges are examined in turn in this essay

scholarly journals DECAY WIDTH MODELING OF HIGGS BOSON WITHIN THDM MODEL

2021 ◽  
pp. 11-13
Author(s):  
T.V. Obikhod ◽  
E.A. Petrenko
Keyword(s):  
Higgs Boson ◽  
Decay Width ◽  
Cross Section ◽  
Production Cross Section ◽  
Production Cross ◽  
New Physics ◽  
Higgs Bosons ◽  
Beyond The Standard Model ◽  
The Standard Model

As part of the search for new physics beyond the Standard Model, we chose the determination of the Higgs boson decay width as one of the least experimentally determined values. The decay widths into the four fermions of the lightest and heaviest CP-even Higgs bosons of the THDM model were calculated, taking into account QCD and electroweak corrections in the NLO approximation. To achieve this goal, the program Monte Carlo Prophecy 4f with special scenarios of parameters, 7B1 and 5B1 were used. It was found that the decay width of the heavier CPeven Higgs boson H differs from HSM by 1227.93 times and changes to a negative value when deviating from the standard scenarios. Scale factors kZ2 and kW2 showed the predominance of the associated with Z boson production cross section of CP-even Higgs boson over the associated with W production cross section.

scholarly journals Search for a heavy Higgs boson decaying into two lighter Higgs bosons in the ττbb final state at 13 TeV

2021 ◽  
Vol 2021 (11) ◽  
Author(s):  
◽  
A. Tumasyan ◽  
W. Adam ◽  
J. W. Andrejkovic ◽  
T. Bergauer ◽  
...  
Keyword(s):  
Higgs Boson ◽  
Cross Section ◽  
Production Cross Section ◽  
Production Cross ◽  
Branching Fractions ◽  
Center Of Mass ◽  
Final State ◽  
Signal Process ◽  
Center Of Mass Energy ◽  
Heavy Higgs Boson

Abstract A search for a heavy Higgs boson H decaying into the observed Higgs boson h with a mass of 125 GeV and another Higgs boson hS is presented. The h and hS bosons are required to decay into a pair of tau leptons and a pair of b quarks, respectively. The search uses a sample of proton-proton collisions collected with the CMS detector at a center-of-mass energy of 13 TeV, corresponding to an integrated luminosity of 137 fb−1. Mass ranges of 240–3000 GeV for mH and 60–2800 GeV for $$ {m}_{{\mathrm{h}}_{\mathrm{S}}} $$ m h S are explored in the search. No signal has been observed. Model independent 95% confidence level upper limits on the product of the production cross section and the branching fractions of the signal process are set with a sensitivity ranging from 125 fb (for mH = 240 GeV) to 2.7 fb (for mH = 1000 GeV). These limits are compared to maximally allowed products of the production cross section and the branching fractions of the signal process in the next-to-minimal supersymmetric extension of the standard model.

scholarly journals Measurement of the Higgs boson mass and e+e−→ZH cross section using Z→μ+μ− and Z→e+e− at the ILC

2016 ◽  
Vol 94 (11) ◽  
Author(s):  
J. Yan ◽  
S. Watanuki ◽  
K. Fujii ◽  
A. Ishikawa ◽  
D. Jeans ◽  
...  
Keyword(s):  
Higgs Boson ◽  
Cross Section ◽  
Boson Mass ◽  
Higgs Boson Mass

scholarly journals Measurement of the inclusivett¯production cross section inpp¯collisions ats=1.96  TeVand determination of the top quark pole mass

2016 ◽  
Vol 94 (9) ◽  
Author(s):  
V. M. Abazov ◽  
B. Abbott ◽  
B. S. Acharya ◽  
M. Adams ◽  
T. Adams ◽  
...  
Keyword(s):  
Cross Section ◽  
Top Quark ◽  
Production Cross Section ◽  
Production Cross ◽  
Pole Mass

PRODUCTION OF CHARGED HIGGS BOSON ASSOCIATED WITH A W GAUGE BOSON AT THE LHC

2011 ◽  
Vol 26 (32) ◽  
pp. 2391-2402
Author(s):  
CHONG-XING YUE ◽  
XIAO-JIAO GUO ◽  
NA LI
Keyword(s):  
Higgs Boson ◽  
Cross Section ◽  
Gauge Boson ◽  
Production Cross Section ◽  
Production Cross ◽  
Charged Higgs Boson ◽  
Tree Level ◽  
Charged Higgs ◽  
Triplet Model ◽  
The One

Production of charged Higgs boson associated with a W gauge boson at the LHC is mainly induced by the tree-level [Formula: see text] annihilation and the one-loop gg fusion. In the context of the Higgs triplet model (HTM) and the left–right twin Higgs (LRTH) model, we calculate the production cross-section σ of the process pp→H±W∓ and compare our results with those given by supersymmetry (SUSY). We find that, in most of the parameter space of the HTM, the production cross-section σ is smaller than that predicted by the LRTH model or SUSY. The value of σ within the LRTH model is larger or smaller than the SUSY case, which depends on the relevant free parameters.

SEARCH FOR CHARGINOS AND NEUTRALINOS WITH THE DELPHI DETECTOR AT LEP

2001 ◽  
Vol 16 (supp01b) ◽  
pp. 775-777
Author(s):  
◽  
THOMAS ALDERWEIRELD
Keyword(s):  
Cross Section ◽  
Production Cross Section ◽  
Production Cross ◽  
Branching Fraction ◽  
Centre Of Mass ◽  
Mass Energy ◽  
Delphi Detector ◽  
Upper Limit

Search for charginos and neutralinos are presented, based on the data samples recorded in 1999 and 2000 by the DELPHI detector at centre-of-mass energies from 192 to 209 GeV. No evidence for a signal was found. The lower chargino mass limits are 5-6 GeV /c2 higher than those obtained at a centre-of-mass energy of 189 GeV. The (μ, M 2) MSSM domain excluded by combining the chargino searches with neutralino searches at the Z resonance implies a limit on the mass of the lightest neutralino which, for a heavy sneutrino, is constrained to be above 37.6 GeV /c2 for tan β≥1. Upper limit at 95% CL on the neutralino production cross-section times branching fraction are derived.

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