Directed, elliptic and higher order flow harmonics of protons, deuterons and tritons in Au+Au collisions at $\sqrt{s_{NN}} = 2.4$ GeV

The HADES collaboration Adamczewski-Musch, J. ; Arnold, O. ; Behnke, C. ; et al.
Phys.Rev.Lett. 125 (2020) 262301, 2020.
Inspire Record 1797626 DOI 10.17182/hepdata.102468

Flow coefficients $v_{n}$ of the orders $n = 1 - 6$ are measured with the High-Acceptance DiElectron Spectrometer (HADES) at GSI for protons, deuterons and tritons as a function of centrality, transverse momentum and rapidity in Au+Au collisions at $\sqrt{s_{NN}} = 2.4$ GeV. Combining the information from the flow coefficients of all orders allows to construct for the first time, at collision energies of a few GeV, a multi-differential picture of the angular emission pattern of these particles. It reflects the complicated interplay between the effect of the central fireball pressure on the emission of particles and their subsequent interaction with spectator matter. The high precision information on higher order flow coefficients is a major step forward in constraining the equation-of-state of dense baryonic matter.

18 data tables

The $p_{t}$ dependence of $v_{1}$ for protons, deuterons and tritons in the rapidity interval $-0.25 < y_{cm} < -0.15$ in semi-central ($20 - 30$ %) $\mathrm{Au}+\mathrm{Au}$ collisions at $\sqrt{{s}_{NN}}=2.4$ GeV.

The $p_{t}$ dependence of $v_{3}$ for protons, deuterons and tritons in the rapidity interval $-0.25 < y_{cm} < -0.15$ in semi-central ($20 - 30$ %) $\mathrm{Au}+\mathrm{Au}$ collisions at $\sqrt{{s}_{NN}}=2.4$ GeV.

The $p_{t}$ dependence of $v_{5}$ for protons, deuterons and tritons in the rapidity interval $-0.25 < y_{cm} < -0.15$ in semi-central ($20 - 30$ %) $\mathrm{Au}+\mathrm{Au}$ collisions at $\sqrt{{s}_{NN}}=2.4$ GeV.

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Charged pion production in $\mathbf{Au+Au}$ collisions at $\mathbf{\sqrt{s_{NN}}}$ = 2.4$\mathbf{GeV}$

The HADES collaboration Adamczewski-Musch, J. ; Arnold, O. ; Behnke, C. ; et al.
Eur.Phys.J.A 56 (2020) 259, 2020.
Inspire Record 1796710 DOI 10.17182/hepdata.97368

We present high-statistic data on charged pion emission from Au+Au collisions at $\sqrt{s_{\rm{NN}}}$ = 2.4 GeV (corresponding to $E_{beam}$ = 1.23 A GeV) in four centrality classes in the range 0 - 40$\%$ of the most central collisions. The data are analyzed as a function of transverse momentum, transverse mass, rapidity, and polar angle. Pion multiplicity per participating nucleon decreases moderately with increasing centrality. The polar angular distributions are found to be non-isotropic even for the most central event class. Our results on pion multiplicity fit well into the general trend of the world data, but undershoot by $2.5 \sigma$ data from the FOPI experiment measured at slightly lower beam energy. We compare our data to state-of-the-art transport model calculations (PHSD, IQMD, PHQMD, GiBUU and SMASH) and find substantial differences between the measurement and the results of these calculations.

11 data tables

Mid-rapidity and forward rapidity transverse momentum distributions ($p_{t}$) for charged pion for the 10$\%$most central events.

Reduced transverse mass distribution for negatively charged pions in rapidity bins of $\Delta y_{cm}$ = 0.1width between -0.65 and 0.75 for 0-10$\%$ most central events. The most backward rapidity is shown unscaledwhile for following rapidity slices are scaled up by succesive factors of 10.

Reduced transverse mass distribution for positively charged pions in rapidity bins of $\Delta y_{cm}$ = 0.1width between -0.65 and 0.75 for 0-10$\%$ most central events. The most backward rapidity is shown unscaledwhile for following rapidity slices are scaled up by succesive factors of 10.

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Version 2
Probing dense baryon-rich matter with virtual photons

The HADES collaboration Adamczewski-Musch, J. ; Arnold, O. ; Behnke, C. ; et al.
Nature Phys. 15 (2019) 1040-1045, 2019.
Inspire Record 1758156 DOI 10.17182/hepdata.90846

About 10 μs after the Big Bang, the universe was filled—in addition to photons and leptons—with strong-interaction matter consisting of quarks and gluons, which transitioned to hadrons at temperatures close to kT = 150 MeV and densities several times higher than those found in nuclei. This quantum chromodynamics (QCD) matter can be created in the laboratory as a transient state by colliding heavy ions at relativistic energies. The different phases in which QCD matter may exist depend for example on temperature, pressure or baryochemical potential, and can be probed by studying the emission of electromagnetic radiation. Electron–positron pairs emerge from the decay of virtual photons, which immediately decouple from the strong interaction, and thus provide information about the properties of QCD matter at various stages. Here, we report the observation of virtual photon emission from baryon-rich QCD matter. The spectral distribution of the electron–positron pairs is nearly exponential, providing evidence for a source of temperature in excess of 70 MeV with constituents whose properties have been modified, thus reflecting peculiarities of strong-interaction QCD matter. Its bulk properties are similar to the dense matter formed in the final state of a neutron star merger, as apparent from recent multimessenger observation.

10 data tables

Reconstructed $e^{+} e^{-}$ mass distribution from Au+Au collisions.

Reconstructed $e^{+} e^{-}$ mass distribution from Au+Au collisions.

Reconstructed $e^{+} e^{-}$ mass distribution from Au+Au collisions.

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Version 2
Sub-threshold production of K$^{0}_{s}$ mesons and ${\Lambda}$ hyperons in Au(1.23A GeV)$+$Au

The HADES collaboration Adamczewski-Musch, J. ; Arnold, O. ; Behnke, C. ; et al.
Phys.Lett.B 793 (2019) 457-463, 2019.
Inspire Record 1709767 DOI 10.17182/hepdata.90954

We present first data on sub-threshold production of K0 s mesons and {\Lambda} hyperons in Au+Au collisions at $\sqrt{s_{NN}}$ = 2.4 GeV. We observe an universal <Apart> scaling of hadrons containing strangeness, independent of their corresponding production thresholds. Comparing the yields, their <Apart> scaling, and the shapes of the rapidity and the pt spectra to state-of-the-art transport model (UrQMD, HSD, IQMD) predictions, we find that none of the latter can simultaneously describe all observables with reasonable \c{hi}2 values.

36 data tables

Example of $K^{0}_{S}$ signal for 0-40% most central events, over mixed-event background for the bin $-0.05 < y_{cm} < 0.05$ and reduced transverse masses between $80-120 MeV/c^{2}$.

Example of $K^{0}_{S}$ signal for 0-40% most central events, over mixed-event background for the bin $-0.05 < y_{cm} < 0.05$ and reduced transverse masses between $80-120 MeV/c^{2}$.

Example of $\Lambda$ signal for 0-40% most central events, over mixed-event background for the bin $-0.05 < y_{cm} < 0.05$ and reduced transverse masses between $100-150 MeV/c^{2}$.

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Version 3
Deep sub-threshold {\phi} production and implications for the K+/K- freeze-out in Au+Au collisions

The HADES collaboration Adamczewski-Musch, J. ; Arnold, O. ; Behnke, C. ; et al.
Phys.Lett.B 778 (2018) 403-407, 2018.
Inspire Record 1519164 DOI 10.17182/hepdata.92099

We present data on charged kaons (K+-) and {\phi} mesons in Au(1.23A GeV)+Au collisions. It is the first simultaneous measurement of K and {\phi} mesons in central heavy-ion collisions below a kinetic beam energy of 10A GeV. The {\phi}/K- multiplicity ratio is found to be surprisingly high with a value of 0.52 +- 0.16 and shows no dependence on the centrality of the collision. Consequently, the different slopes of the K+ and K- transverse-mass spectra can be explained solely by feed- down, which substantially softens the spectra of K- mesons. Hence, in contrast to the commonly adapted argumentation in literature, the different slopes do not necessarily imply diverging freeze- out temperatures of K+ and K- mesons caused by different couplings to baryons.

37 data tables

Acceptance and efficiency corrected transverse-mass spectra around mid-rapidity.

Acceptance and efficiency corrected transverse-mass spectra around mid-rapidity.

Acceptance and efficiency corrected transverse-mass spectra around mid-rapidity.

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Neutron-nucleon interactions in the GeV energy region

Palevsky, H. ; Friedes, J.L. ; Sutter, R.J. ; et al.
Conference Paper, 1964.
Inspire Record 1498651 DOI 10.17182/hepdata.75445

None

1 data table

'1'. '2'.


Summary data on elastic $pp$ and $pd$ scattering at small angles and the real part of the $pn$-scattering amplitude in the energy interval 1-10 BeV

Dalkhazhav, N. ; Devinski, P.A. ; Zayachki, V.I. ; et al.
Sov.J.Nucl.Phys. 8 (1969) 196-202, 1969.
Inspire Record 1392874 DOI 10.17182/hepdata.69719

None

32 data tables

RE/IM MEASUREMENTS TAKEN FROM TABLE 1 OF KIRILLOVA 65.

TABLE 1 (REF. 1 ).

RE/IM MEASUREMENTS TAKEN FROM TABLE 1 OF KIRILLOVA 65.

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Antiproton-proton elastic scattering from 1.51–2.90 GeV/ c

Parker, D.L. ; Oh, B.Y. ; Smith, G.A. ; et al.
Nucl.Phys.B 32 (1971) 29-44, 1971.
Inspire Record 1392679 DOI 10.17182/hepdata.814

In a bubble chamber experiment, we have measured p p elastic scattering at nine momenta in the range 1.51–2.90 GeV/ c . The extrapolation of the small angle region to t = 0 is discussed and compared with results of other experiments. The differential cross sections are fitted to an adaptation of the Frahn-Venter optical model and also compared to Regge-pole model predictions.

19 data tables

'1'. '2'. '3'.

'1'. '3'.

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The transverse and longitudinal cross sections for electroproduction of pions near the Δ(1236)-isobar

Bartel, W. ; Dudelzak, B. ; Krehbiel, H. ; et al.
Phys.Lett.B 27 (1968) 660-662, 1968.
Inspire Record 1389642 DOI 10.17182/hepdata.29204

The reaction e + p → e ′+ N ∗ was studied for four momentum transfers up to 2.34 (GeV/ c ) 2 in the region of the 1236 MeV isobar. An analysis of the data in terms of the cross sections σ T and σ L for the absorption of transverse and longitudinal photons is given for invariant masses of the final pion nucleon system W =1.220 GeV and W =1.350 GeV.

3 data tables

Total errors are presented.

Total errors are presented.

Total errors are presented.


Analysing power for quasi-elastic pp scattering in carbon and for elastic pp scattering on free protons

Bystricky, J. ; Deregel, J. ; Lehar, F. ; et al.
Lett.Nuovo Cim. 40 (1984) 466-470, 1984.
Inspire Record 1388775 DOI 10.17182/hepdata.37297

The ratio of the analysing powers for quasi-elastic pp scattering in carbon and for elastic scattering on free protons was measured fromT = 0.52 to 2.8 GeV by scattering of the SATURNE II polarized proton beam on carbon and CH2. It was found to have a maximum at about 0.8 GeV. The energy dependence for quasielastic scattering on carbon had not been measured before above 1 GeV. The observed effect was not expected from simple models.

1 data table

No description provided.