Improved $$(g-2)_\mu $$ measurements and supersymmetry

AbstractThe electroweak (EW) sector of the Minimal Supersymmetric Standard Model (MSSM) can account for variety of experimental data. The lighest supersymmetric particle (LSP), which we take as the lightest neutralino, $${\tilde{\chi }}_{1}^0$$ χ ~ 1 0 , can account for the observed Dark Matter (DM) content of the universe via coannihilation with the next-to-LSP (NLSP), while being in agreement with negative results from Direct Detection (DD) experiments. Owing to relatively small production cross-sections a comparably light EW sector of the MSSM is also in agreement with the unsuccessful searches at the LHC. Most importantly, the EW sector of the MSSM can account for the persistent $$3-4\,\sigma $$ 3 - 4 σ discrepancy between the experimental result for the anomalous magnetic moment of the muon, $$(g-2)_\mu $$ ( g - 2 ) μ , and its Standard Model (SM) prediction. Under the assumption that the $${\tilde{\chi }}_{1}^0$$ χ ~ 1 0 provides the full DM relic abundance we first analyze which mass ranges of neutralinos, charginos and scalar leptons are in agreement with all experimental data, including relevant LHC searches. We find an upper limit of $$\sim 600 \,\, \mathrm {GeV}$$ ∼ 600 GeV for the LSP and NLSP masses. In a second step we assume that the new result of the Run 1 of the “MUON G-2” collaboration at Fermilab yields a precision comparable to the existing experimental result with the same central value. We analyze the potential impact of the combination of the Run 1 data with the existing $$(g-2)_\mu $$ ( g - 2 ) μ data on the allowed MSSM parameter space. We find that in this case the upper limits on the LSP and NLSP masses are substantially reduced by roughly $$100 \,\, \mathrm {GeV}$$ 100 GeV . This would yield improved upper limits on these masses of $$\sim 500 \,\, \mathrm {GeV}$$ ∼ 500 GeV . In this way, a clear target could be set for future LHC EW searches, as well as for future high-energy $$e^+e^-$$ e + e - colliders, such as the ILC or CLIC.

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Improved $${(g-2)_\mu }$$ measurements and wino/higgsino dark matter

The European Physical Journal C ◽

10.1140/epjc/s10052-021-09814-1 ◽

2021 ◽

Vol 81 (12) ◽

Author(s):

Manimala Chakraborti ◽

Sven Heinemeyer ◽

Ipsita Saha

Keyword(s):

Experimental Data ◽

Dark Matter ◽

Standard Model ◽

Cross Sections ◽

Direct Detection ◽

Production Cross ◽

High Energy ◽

Experimental Result ◽

Supersymmetric Particle ◽

Relic Density

AbstractThe electroweak (EW) sector of the Minimal Supersymmetric Standard Model (MSSM) can account for a variety of experimental data. In particular it can explain the persistent $$3-4\,\sigma $$ 3 - 4 σ discrepancy between the experimental result for the anomalous magnetic moment of the muon, $$(g-2)_\mu $$ ( g - 2 ) μ , and its Standard Model (SM) prediction. The lightest supersymmetric particle (LSP), which we take as the lightest neutralino, $${\tilde{\chi }}_{1}^0$$ χ ~ 1 0 , can furthermore account for the observed Dark Matter (DM) content of the universe via coannihilation with the next-to-LSP (NLSP), while being in agreement with negative results from Direct Detection (DD) experiments. Concerning the unsuccessful searches for EW particles at the LHC, owing to relatively small production cross-sections a comparably light EW sector of the MSSM is in full agreement with the experimental data. The DM relic density can fully be explained by a mixed bino/wino LSP. Here we take the relic density as an upper bound, which opens up the possibility of wino and higgsino DM. We first analyze which mass ranges of neutralinos, charginos and scalar leptons are in agreement with all experimental data, including relevant LHC searches. We find roughly an upper limit of $$\sim 600 \,\, \mathrm {GeV}$$ ∼ 600 GeV for the LSP and NLSP masses. In a second step we assume that the new result of the Run 1 of the “MUON G-2” collaboration at Fermilab yields a precision comparable to the existing experimental result with the same central value. We analyze the potential impact of the combination of the Run 1 data with the existing $$(g-2)_\mu $$ ( g - 2 ) μ data on the allowed MSSM parameter space. We find that in this case the upper limits on the LSP and NLSP masses are substantially reduced by roughly $$100 \,\, \mathrm {GeV}$$ 100 GeV . We interpret these upper bounds in view of future HL-LHC EW searches as well as future high-energy $$e^+e^-$$ e + e - colliders, such as the ILC or CLIC.

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The new “MUON G-2” result and supersymmetry

The European Physical Journal C ◽

10.1140/epjc/s10052-021-09900-4 ◽

2021 ◽

Vol 81 (12) ◽

Author(s):

Manimala Chakraborti ◽

Sven Heinemeyer ◽

Ipsita Saha

Keyword(s):

Experimental Data ◽

Dark Matter ◽

Standard Model ◽

Anomalous Magnetic Moment ◽

Direct Detection ◽

High Energy ◽

Experimental Result ◽

Susy Particle ◽

Upper Limits ◽

The Universe

AbstractThe electroweak (EW) sector of the Minimal Supersymmetric Standard Model (MSSM), with the lightest neutralino as Dark Matter (DM) candidate, can account for a variety of experimental data. This includes the DM content of the universe, DM direct detection limits, EW SUSY searches at the LHC and in particular the so far persistent $$3-4\,\sigma $$ 3 - 4 σ discrepancy between the experimental result for the anomalous magnetic moment of the muon, $$(g-2)_\mu $$ ( g - 2 ) μ , and its Standard Model (SM) prediction. The recently published “MUON G-2” result is within $${0.8}\,\sigma $$ 0.8 σ in agreement with the older BNL result on $$(g-2)_\mu $$ ( g - 2 ) μ . The combination of the two results was given as $$a_\mu ^{\mathrm{exp}} = (11 659 {206.1}\pm {4.1}) \times 10^{-10}$$ a μ exp = ( 11659 206.1 ± 4.1 ) × 10 - 10 , yielding a new deviation from the SM prediction of $$\Delta a_\mu = ({25.1}\pm {5.9}) \times 10^{-10}$$ Δ a μ = ( 25.1 ± 5.9 ) × 10 - 10 , corresponding to $${4.2}\,\sigma $$ 4.2 σ . Using this improved bound we update the results presented in Chakraborti et al. (Eur Phys J C 80(10):984, 2020) and set new upper limits on the allowed parameters space of the EW sector of the MSSM. We find that with the new $$(g-2)_\mu $$ ( g - 2 ) μ result the upper limits on the (next-to-) lightest SUSY particle are in the same ballpark as previously, yielding updated upper limits on these masses of $$\sim 750 \,\, \mathrm {GeV}$$ ∼ 750 GeV . In this way, a clear target is confirmed for future (HL-)LHC EW searches, as well as for future high-energy $$e^+e^-$$ e + e - colliders, such as the ILC or CLIC.

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Measurement of nuclide production cross section for lead and bismuth with proton in energy range from 0.4 GeV to 3.0 GeV

EPJ Web of Conferences ◽

10.1051/epjconf/202023906004 ◽

2020 ◽

Vol 239 ◽

pp. 06004

Author(s):

Hiroki Matsuda ◽

Shin-ichiro Meigo ◽

Hiroki Iwamoto ◽

Fujio Maekawa

Keyword(s):

Experimental Data ◽

Cross Section ◽

Cross Sections ◽

Production Cross Section ◽

Production Cross ◽

High Energy ◽

Production Yield ◽

Thin Foils ◽

Hpge Detectors ◽

Decay Gamma

For the Accelerator-Driven nuclear transmutation System (ADS), nuclide production yield estimation in a lead-bismuth target is important to manage the target. However, experimental data of nuclide production yield by spallation and high-energy fission reactions are scarce. In order to obtain the experimental data, an experiment in J-PARC using natPb and 209Bi samples were carried out. The samples were thin foils with about 0.1 mm thick and 25 mm × 25 mm square and were irradiated with protons at kinematic energy points of 0.4GeV, 2.2GeV, and 3.0 GeV. After the irradiation, the nuclide production cross section was determined by spectroscopic measurement of decay gamma-rays from the samples with HPGe detectors. In this paper, 14 nuclide production cross sections for lead and bismuth were obtained. They were compared with the calculated cross sections with various models and the evaluated one.

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Search for direct production of electroweakinos in final states with missing transverse momentum and a Higgs boson decaying into photons in pp collisions at $$ \sqrt{s} $$ = 13 TeV with the ATLAS detector

Journal of High Energy Physics ◽

10.1007/jhep10(2020)005 ◽

2020 ◽

Vol 2020 (10) ◽

Author(s):

G. Aad ◽

◽

B. Abbott ◽

D. C. Abbott ◽

A. Abed Abud ◽

...

Keyword(s):

Higgs Boson ◽

Cross Section ◽

Cross Sections ◽

Confidence Level ◽

Production Cross ◽

Atlas Detector ◽

Supersymmetric Particle ◽

Direct Production ◽

Missing Transverse Momentum ◽

Upper Limits

Abstract A search for a chargino-neutralino pair decaying via the 125 GeV Higgs boson into photons is presented. The study is based on the data collected between 2015 and 2018 with the ATLAS detector at the LHC, corresponding to an integrated luminosity of 139 fb−1 of pp collisions at a centre-of-mass energy of 13 TeV. No significant excess over the expected background is observed. Upper limits at 95% confidence level for a massless $$ {\tilde{\chi}}_1^0 $$ χ ˜ 1 0 are set on several electroweakino production cross-sections and the visible cross-section for beyond the Standard Model processes. In the context of simplified supersymmetric models, 95% confidence-level limits of up to 310 GeV in $$ m\left({\tilde{\chi}}_1^{\pm }/{\tilde{\chi}}_2^0\right) $$ m χ ˜ 1 ± / χ ˜ 2 0 , where $$ m\left({\tilde{\chi}}_1^0\right) $$ m χ ˜ 1 0 = 0.5 GeV, are set. Limits at 95% confidence level are also set on the $$ {\tilde{\chi}}_1^{\pm }{\tilde{\chi}}_2^0 $$ χ ˜ 1 ± χ ˜ 2 0 cross-section in the mass plane of $$ m\left({\tilde{\chi}}_1^{\pm }/{\tilde{\chi}}_2^0\right) $$ m χ ˜ 1 ± / χ ˜ 2 0 and $$ m\left({\tilde{\chi}}_1^0\right) $$ m χ ˜ 1 0 , and on scenarios with gravitino as the lightest supersymmetric particle. Upper limits at the 95% confidence-level are set on the higgsino production cross-section. Higgsino masses below 380 GeV are excluded for the case of the higgsino fully decaying into a Higgs boson and a gravitino.

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Elastic scattering and breakup reactions with light proton- and neutron-rich exotic nuclei

EPJ Web of Conferences ◽

10.1051/epjconf/201819407002 ◽

2018 ◽

Vol 194 ◽

pp. 07002

Author(s):

M.K. Gaidarov ◽

V.K. Lukyanov ◽

D.N. Kadrev ◽

E.V. Zemlyanaya ◽

A.N. Antonov ◽

...

Keyword(s):

Experimental Data ◽

Elastic Scattering ◽

Cross Sections ◽

Cluster Model ◽

Microscopic Analysis ◽

High Energy ◽

The Real ◽

Optical Potentials ◽

Generator Coordinate ◽

Energy Approximation

A microscopic analysis of the optical potentials (OPs) and cross sections of elastic scattering of 8B on 12C, 58Ni, and 208Pb targets at energies 20 < E < 170 MeV and 12,14Be on 12C at 56 MeV/nucleon is carried out. The real part of the OP is calculated by a folding procedure and the imaginary part is obtained on the base of the high-energy approximation (HEA). The density distributions of 8B evaluated within the variational Monte Carlo (VMC) model and the three-cluster model (3CM) are used to construct the potentials. The 14Be densities obtained in the framework of the the generator coordinate method (GCM) are used to calculate the optical potentials, while for the same purpose both the VMC model and GCM densities of 12Be are used. In the hybrid model developed and explored in our previous works, the only free parameters are the depths of the real and imaginary parts of OP obtained by fitting the experimental data. The use of HEA to estimate the imaginary OP at energies just above the Coulomb barrier is discussed. In addition, cluster model, in which 8B consists of a p-halo and the 7Be core, is applied to calculate the breakup cross sections of 8B nucleus on 9Be, 12C, and 197Au targets, as well as momentum distributions of 7Be fragments. A good agreement of the theoretical results with the available experimental data is obtained. It is concluded that the reaction studies performed in this work may provide supplemental information on the internal spatial structure of the proton- and neutron-halo nuclei.

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INVESTIGATION ON THE NEUTRINO INDUCED MUONS FROM ACTIVE GALACTIC NUCLEI

Modern Physics Letters A ◽

10.1142/s0217732300001742 ◽

2000 ◽

Vol 15 (25) ◽

pp. 1567-1576

Author(s):

NAYANTARA GUPTA ◽

D. P. BHATTACHARYYA

Keyword(s):

Cross Sections ◽

Neutrino Flux ◽

High Energy ◽

Energy Spectra ◽

Muon Energy ◽

Model Calculations ◽

Charge Current ◽

Upper Limits ◽

Total Interaction ◽

Interaction Cross Sections

The fluxes of neutrino induced muons at different zenith angles have been calculated using the high energy diffused neutrino spectra emitted from blazars. We have used the standard formulation developed by Gaisser based on charge-current interactions in rock and the QED-based energy loss formulation to estimate the spectra of neutrino induced muons. The energy spectra of neutrino flux generated from blazars has been taken from the model calculations of Protheroe. The latest charge-current and total interaction cross-sections at ultrahigh energies from Kwiecinski et al. have been used to find the probability of muon generation from neutrinos and the loss of neutrinos during propagation through the Earth. We find that our derived horizontal neutrino induced muon energy spectra expected from blazar model of Protheroe is comparable with the upper limits as predicted by SOUDAN 2 experiment.

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W-boson production in the high energy electron-photon collisions

Journal of the Belarusian State University. Physics ◽

10.33581/2520-2243-2019-3-41-50 ◽

2019 ◽

pp. 41-50

Author(s):

Ivan A. Shershan ◽

Tatiana V. Shishkina

Keyword(s):

Standard Model ◽

Cross Sections ◽

W Boson ◽

High Energy ◽

New Physics ◽

Coupling Constants ◽

Boson Production ◽

The Standard Model ◽

Electron Photon ◽

W Boson Production

In this paper the analysis of W-boson production process in high-energy electron-photon collisions as a tool to search for deviations from the Standard Model is considered. In particular, a set of extended gauge models, including anomalous multi-boson interactions, are discussed as a promising way for «new physics» study. A numerical analysis of the total cross sections of the processes was carried out. The lowest order radiative corrections in the soft-photon approximation within the Standard Model are taken into account. Calculations beyond the Standard Model was performed, the kinematic features of the cross sections were identified. The restrictions on the anomalous triple gauge boson coupling constants were analyzed and the kinematic areas to the search for their manifestations were obtained during the experiments at the International Linear Collider. The paper shows that the search for «new physics» effects based on electron-photon collisions around the W-boson production peak is the maximal promising. It was also shown that future experiments at high luminosity linear colliders will significantly clarify the constraints on anomalous gauge coupling constants.

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Production cross-section of heavy flavored hadrons in pp collision at s = 7 TeV

Modern Physics Letters A ◽

10.1142/s0217732319501505 ◽

2019 ◽

Vol 34 (19) ◽

pp. 1950150 ◽

Cited By ~ 6

Author(s):

Muhammad Ajaz ◽

Irfan Khan ◽

M. K. Suleymanov

Keyword(s):

Experimental Data ◽

Transverse Momentum ◽

Differential Cross Section ◽

Cross Section ◽

Momentum Distribution ◽

Cross Sections ◽

Production Cross ◽

Center Of Mass ◽

Transverse Momentum Distribution ◽

Mass Frame

The transverse momentum distribution of the differential production cross-sections of heavy flavored charm hadrons [Formula: see text], [Formula: see text] in pp collisions at 7 TeV are simulated. Predictions of DPMJETIII.17-1, HIJING1.383 and Sibyll2.3c are compared to the differential cross-section measurements of the LHCb experimental data presented in the region of [Formula: see text] and [Formula: see text], where the pp center of mass frame is used to measure the transverse momentum and rapidity. The models reproduce only some regions of [Formula: see text] and/or bins of [Formula: see text] but none of them predict completely all the [Formula: see text] bins over the entire [Formula: see text] range.

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K-shell ionization cross sections of K and Lα X-ray production cross sections of I by 10–30 keV electron impact

Canadian Journal of Physics ◽

10.1139/p11-149 ◽

2012 ◽

Vol 90 (2) ◽

pp. 125-130 ◽

Cited By ~ 7

Author(s):

Y. Wu ◽

Z. An ◽

Y.M. Duan ◽

M.T. Liu ◽

X.P. Ouyang

Keyword(s):

Experimental Data ◽

Electron Impact ◽

Cross Sections ◽

Production Cross ◽

Carbon Substrate ◽

Ionization Cross ◽

X Ray ◽

Pure Carbon ◽

Ionization Cross Sections ◽

Shell Ionization

The absolute K-shell ionization cross sections of K and Lα X-ray production cross sections of I by 10–30 keV electron impact have been measured. The target was prepared by evaporating a thin film of compound KI to a thick pure carbon substrate. The effects of multiple scattering of electrons penetrating the target films, electrons reflected from the thick pure carbon substrates and bremsstrahlung photons produced when incident electrons impacted on the targets were corrected by using the Monte Carlo method. For K K-shell and I L-shell X-ray characteristic peaks, the spectra were fitted using the spectrum-fitting program ALLFIT to extract the Kα and Kβ peak counts more accurately for element K, and Lα peak counts for element I. The experimental results were compared with some theoretical results developed recently and available experimental data from the literature. The experimental data for I L-shell X-ray production cross sections by 10–30 keV electron impact are given here for the first time.

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