Date

Evidence for Higgs boson decays to a low-mass dilepton system and a photon in pp collisions at $\sqrt{s} =$ 13 TeV with the ATLAS detector

The ATLAS collaboration Aad, Georges ; Abbott, Braden Keim ; Abbott, Dale Charles ; et al.
Phys.Lett.B 819 (2021) 136412, 2021.
Inspire Record 1852325 DOI 10.17182/hepdata.102955

A search for the Higgs boson decaying into a photon and a pair of electrons or muons with an invariant mass $m_{\ell\ell} < 30$ GeV is presented. The analysis is performed using 139 fb$^{-1}$ of proton-proton collision data, produced by the LHC at a centre-of-mass energy of 13 TeV and collected by the ATLAS experiment. Evidence for the $H \rightarrow \ell \ell \gamma$ process is found with a significance of 3.2$\sigma$ over the background-only hypothesis, compared to an expected significance of 2.1$\sigma$. The best-fit value of the signal strength parameter, defined as the ratio of the observed signal yield to the one expected in the Standard Model, is $\mu = 1.5 \pm 0.5$. The Higgs boson production cross-section times the $H \rightarrow\ell\ell\gamma$ branching ratio for $m_{\ell\ell} <$ 30 GeV is determined to be 8.7 $^{+2.8}_{-2.7}$ fb.

2 data tables match query

The best fit value for the signal yield normalised to the Standard Model prediction (signal strength) for $pp \to H \to Z+\gamma$

Measured $\sigma( p p \rightarrow H) \cdot B(H\rightarrow \ell\ell\gamma)$ for $m_{\ell\ell} < 30$ GeV


Version 3
Search for new phenomena in events with an energetic jet and missing transverse momentum in $pp$ collisions at $\sqrt{s} = 13$ TeV with the ATLAS detector

The ATLAS collaboration Aad, Georges ; Abbott, Braden ; Abbott, Dale Charles ; et al.
Phys.Rev.D 103 (2021) 112006, 2021.
Inspire Record 1847779 DOI 10.17182/hepdata.102093

Results of a search for new physics in final states with an energetic jet and large missing transverse momentum are reported. The search uses proton-proton collision data corresponding to an integrated luminosity of 139 fb$^{-1}$ at a center-of-mass energy of 13 TeV collected in the period 2015-2018 with the ATLAS detector at the Large Hadron Collider. Compared to previous publications, in addition to an increase of almost a factor of four in the data size, the analysis implements a number of improvements in the signal selection and the background determination leading to enhanced sensitivity. Events are required to have at least one jet with transverse momentum above 150 GeV and no reconstructed leptons ($e$, $\mu$ or $\tau$) or photons. Several signal regions are considered with increasing requirements on the missing transverse momentum starting at 200 GeV. Overall agreement is observed between the number of events in data and the Standard Model predictions. Model-independent $95%$ confidence-level limits on visible cross sections for new processes are obtained in the range between 736 fb and 0.3 fb. Results are also translated into improved exclusion limits in models with pair-produced weakly interacting dark-matter candidates, large extra spatial dimensions, supersymmetric particles in several compressed scenarios, axion-like particles, and new scalar particles in dark-energy-inspired models. In addition, the data are translated into bounds on the invisible branching ratio of the Higgs boson.

6 data tables match query

The measured $p_{\mathrm{T}}^{\mathrm{recoil}}$ distributions in the $W \rightarrow \mu \nu $ control region, compared with the background predictions as estimated after the simultaneous, binned background-only fit to the data in the control regions. The last bin of the distribution contains overflows.

The measured $p_{\mathrm{T}}^{\mathrm{recoil}}$ distributions in the $W \rightarrow e \nu$ control region, compared with the background predictions as estimated after the simultaneous, binned background-only fit to the data in the control regions. The last bin of the distribution contains overflows.

The measured $p_{\mathrm{T}}^{\mathrm{recoil}}$ distributions in the top control region, compared with the background predictions as estimated after the simultaneous, binned background-only fit to the data in the control regions. The last bin of the distribution contains overflows.

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Total Cross Sections for Interaction of 4.75 and 3.7 Bev/c K+ and π+ Mesons with Protons and Nuclei

Likhachev, M.F. ; Stavinskii, V.S. ; Y\"un-ch'ang, Hs\"u ; et al.
Sov.Phys.JETP 14 (1961) 29-31, 1962.
Inspire Record 1387792 DOI 10.17182/hepdata.70227

The total cross sections for interactions of K+ and 1r+ mesons with protons were measured. The following values were obtained: 21.3 ± 4.6 mb and 21 ± 4.3 mb for 4.75 ± 0.15 Bev/c and 3.7 ± 0.1 Bev/c K+ mesons, respectively; the corresponding values for 1r+ mesons of the same momenta were 33.3 ± 1.3mb and 30 ± 1.2mb. Data on the cross sections for inelastic collisions of K+ and 1r+ mesons with various nuclei have also been obtained.

2 data tables match query

No description provided.

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$\Lambda$(c)+ Production and Semileptonic Decay in 29-{GeV} $e^+ e^-$ Annihilation

Klein, S. ; Himel, T. ; Abrams, G.S. ; et al.
Phys.Rev.Lett. 62 (1989) 2444, 1989.
Inspire Record 277034 DOI 10.17182/hepdata.20042

We present results on Λc+ production in 29-GeV e+e− annihilation. The Λc+ are observed via their semileptonic decays to Λe+X and Λμ+X. With radiative corrections, we find σ(e+e−→Λc+X)〉BΛc+→eΛX)= 1.5±0.6±0.5 pb or 0.0038±0.0015±0.0012 Λc+→Λe+X decay per hadronic event, and σ(e+e−Λc+X)B(Λc+→μΛX)= 1.4±1.4±0.4 pb or 0.0035±0.0035±0.0011 Λc+→Λμ+X decay per hadronic event. These results can be used to place constraints on the predictions of various production models.

2 data tables match query

Cross sections * branching ratio for LAMBDA/C+ production in LAMBDA E+ decay channel.

Cross sections * branching ratio for LAMBDA/C+ production in LAMBDA MU+ decay channel.


General characteristics of the annihilation reaction p p ---> 3pi+ 3pi- (pi0) at 3.6 gev/c

Atherton, H.W. ; Blair, W.M.R. ; Celnikier, L.M. ; et al.
Nucl.Phys.B 18 (1970) 221-245, 1970.
Inspire Record 62649 DOI 10.17182/hepdata.34415

In the reaction p p → 3π + 3π − 2227 events, and in the reaction p p → 3π + 3π − π 0 6578 events have been analyzed. The general characteristics of the reactions, such as total cross sections, angular and momentum distributions, the production of ϱ, f, ω and η mesons, and angular correlations are presented.

4 data tables match query

No description provided.

THETA being the angle between PI+ and P (or PI- and PBAR) in CMS.

THETA being the angle between PI+ and P (or PI- and PBAR) in CMS.

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eta meson production in p d and p p collisions

Chiavassa, E. ; Dellacasa, G. ; De Marco, N. ; et al.
Phys.Lett.B 337 (1994) 192-195, 1994.
Inspire Record 384615 DOI 10.17182/hepdata.28780

The doubly-differential cross sections for the pp → ppη and pd → ηX reactions have been measured at incident proton energies of 1.3 and 1.5 GeV. The ratio of the pd to pp -induced cross sections varies from about 8–10 at 1.3 GeV to 4.5–6 at 1.5 GeV in the η kinetic energy interval 100 MeV ⩽ T η ⩽220 MeV. Information on the pn → ηX reaction has been extracted from these measurements within the framework of a simple folding model.

8 data tables match query

No description provided.

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180-degrees Compton scattering by the proton below the pion threshold

Zieger, A. ; Van de Vyver, R. ; Christmann, D. ; et al.
Phys.Lett.B 278 (1992) 34-38, 1992.
Inspire Record 338241 DOI 10.17182/hepdata.29251

Absolute cross sections for Compton scattering from protons have been determined at 180° for the backscattered photon at incident laboratory photon energies of 98 and 132 MeV. For the difference between the electric and the magnetic polarizability of the proton a value of (7.03 − 2.37 +2.49 − 2.05 +2.14 ) × 10 −4 fm 3 has been derived using the predictions from calculations based on relativistic dispersion relations.

1 data table match query

No description provided.


Measurement of the p p ---> p p eta total cross-section between 1.265-GeV and 1.5-GeV

Chiavassa, E. ; Dellacasa, G. ; De Marco, N. ; et al.
Phys.Lett.B 322 (1994) 270-274, 1994.
Inspire Record 376677 DOI 10.17182/hepdata.28768

The total cross section of the pp→ pp η reaction has been measured at incident proton energies of 1.265, 1.3, 1.4 and 1.5 GeV by detecting the two photons from the η decay in the PINOT spectrometer. The data are compared with other near-threshold measurements and with the predictions of existing theoretical calculations.

1 data table match query

Value given at 1263 MeV assumes energy 2 MeV lower than nominal value. This uncertainty only affects this lowest energy point.


Test of lepton universality in beauty-quark decays

The LHCb collaboration Aaij, Roel ; Abellán Beteta, Carlos ; Ackernley, Thomas ; et al.
Nature Phys. 18 (2022) 277-282, 2022.
Inspire Record 1852846 DOI 10.17182/hepdata.106855

The Standard Model of particle physics currently provides our best description of fundamental particles and their interactions. The theory predicts that the different charged leptons, the electron, muon and tau, have identical electroweak interaction strengths. Previous measurements have shown a wide range of particle decays are consistent with this principle of lepton universality. This article presents evidence for the breaking of lepton universality in beauty-quark decays, with a significance of 3.1 standard deviations, based on proton-proton collision data collected with the LHCb detector at CERN's Large Hadron Collider. The measurements are of processes in which a beauty meson transforms into a strange meson with the emission of either an electron and a positron, or a muon and an antimuon. If confirmed by future measurements, this violation of lepton universality would imply physics beyond the Standard Model, such as a new fundamental interaction between quarks and leptons.

1 data table match query

Likelihood function from the fit to the nonresonant $B^+$ --> $K^+\ell^+ \ell^−$ candidates profiled as a function of $R_K$.


Measurement of differential $b\bar{b}$- and $c\bar{c}$-dijet cross-sections in the forward region of $pp$ collisions at $\sqrt{s}=13 ~ \mathrm{TeV}$

The LHCb collaboration Aaij, Roel ; Abellán Beteta, Carlos ; Ackernley, Thomas ; et al.
JHEP 02 (2021) 023, 2021.
Inspire Record 1823739 DOI 10.17182/hepdata.110430

The inclusive $b \bar{b}$- and $c \bar{c}$-dijet production cross-sections in the forward region of $pp$ collisions are measured using a data sample collected with the LHCb detector at a centre-of-mass energy of 13 TeV in 2016. The data sample corresponds to an integrated luminosity of 1.6 fb$^{-1}$. Differential cross-sections are measured as a function of the transverse momentum and of the pseudorapidity of the leading jet, of the rapidity difference between the jets, and of the dijet invariant mass. A fiducial region for the measurement is defined by requiring that the two jets originating from the two $b$ or $c$ quarks are emitted with transverse momentum greater than 20 GeV$/c$, pseudorapidity in the range $2.2 < \eta < 4.2$, and with a difference in the azimuthal angle between the two jets greater than 1.5. The integrated $b \bar{b}$-dijet cross-section is measured to be $53.0 \pm 9.7$ nb, and the total $c \bar{c}$-dijet cross-section is measured to be $73 \pm 16$ nb. The ratio between $c \bar{c}$- and $b \bar{b}$-dijet cross-sections is also measured and found to be $1.37 \pm 0.27$. The results are in agreement with theoretical predictions at next-to-leading order.

17 data tables match query

The total $b \bar{b}$-dijet and $c \bar{c}$-dijet cross-sections and their ratio in the fiducial region, compared with the NLO predictions. The first uncertainty is the combined statistical and systematic uncertainty and the second is the uncertainty from the luminosity. For the predictions, the first uncertainty corresponds to the scale uncertainty, the second to the PDF uncertainty.

Numerical results of $b \bar{b}$- and $c \bar{c}$-dijet cross-sections, $c \bar{c}$/$b \bar{b}$ dijet cross-section ratios and their total uncertainties as a function of the leading jet $\eta$ (pseudorapidity).

Numerical results of $b \bar{b}$- and $c \bar{c}$-dijet cross-sections, $c \bar{c}$/$b \bar{b}$ dijet cross-section ratios and their total uncertainties as a function of $\Delta y^*$.

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