cometadata/datacite-titles-descriptions-related-identifiers huggingface dataset:
DOI: 10.17182/hepdata.145132.v1/t8
title: "Fig5 This Analysis Au+Au, U+U, Zr+Zr, Ru+Ru" of "Observation of the Antimatter Hypernucleus $^4_{\bar{\Lambda}}\overline{\hbox{H}}$"

description: Production yield ratios of various particles with the same baryon number. Results combining all collision systems in this work are shown by filled stars. Open stars show results with only U+U and Au+Au collisions, while quadrangular stars show results with only Zr+Zr and Ru+Ru collisions. Statistical uncertainties and systematic uncertainties are shown by vertical bars and boxes, respectively. Previous measurement results and thermal model predictions are also shown for comparison. Ratio Typle Index, 0:$\frac{{}^{3}\bar{He}}{{}^{3}He}$ 1:$\frac{{}^{3}\bar{He}}{{}^{3}He}\times\frac{\bar{p}}{p}$ 2:$\frac{{}^{4}\bar{He}}{{}^{4}He}$ 3:$\frac{{}^{3}_{\bar{\Lambda}}\bar{H}}{{}^{3}_{\Lambda}H}$ 4:$\frac{{}^{3}_{\bar{\Lambda}}\bar{H}}{{}^{3}_{\Lambda}H}\times\frac{\bar{p}}{p}$ 5:$\frac{{}^{4}_{\bar{\Lambda}}\bar{H}}{{}^{4}_{\Lambda}H}$ 6:$\frac{{}^{3}_{\Lambda}H}{{}^{3}He}$ 7:$\frac{{}^{4}_{\Lambda}H}{{}^{4}He}$ 8:$\frac{{}^{3}_{\bar{\Lambda}}\bar{H}}{^{3}\bar{He}}$ 9:$\frac{{}^{4}_{\bar{\Lambda}}\bar{H}}{^{4}\bar{He}}$
description: Matter-antimatter asymmetry is a research topic of fundamental interest, as it is the basis for the existence of the matter world, which survived annihilation with antimatter in the early Universe. High energy nuclear collisions create conditions similar to the Universe microseconds after the Big Bang, with comparable amounts of matter and antimatter. Much of the antimatter created escapes the rapidly expanding fireball without annihilation, making such collisions an effective experimental tool to create heavy antimatter nuclear objects and study their properties. In this paper, we report the first observation of the antimatter hypernucleus \hbox{$^4_{\bar{\Lambda}}\overline{\hbox{H}}$}, composed of an $\bar{\Lambda}$, an antiproton and two antineutrons. The discovery was made through its two-body decay after production in ultrarelativistic heavy ion collisions by the STAR experiment at the Relativistic Heavy Ion Collider. In total, 15.6 candidate \hbox{$^4_{\bar{\Lambda}}\overline{\hbox{H}}$} \ antimatter hypernuclei are obtained with an estimated background count of 6.4. Lifetimes of the antihypernuclei \hbox{$^3_{\bar{\Lambda}}\overline{\hbox{H}}$} \ and \hbox{$^4_{\bar{\Lambda}}\overline{\hbox{H}}$} \ are measured and compared with lifetimes of their corresponding hypernuclei, testing the symmetry between matter and antimatter. Various production yield ratios among (anti)hypernuclei and (anti)nuclei are also measured and compared with theoretical model predictions, shedding light on their production mechanism.
DOI: 10.17182/hepdata.145132.v1/t9
title: "Fig5 This Analysis Au+Au, U+U" of "Observation of the Antimatter Hypernucleus $^4_{\bar{\Lambda}}\overline{\hbox{H}}$"

description: Production yield ratios of various particles with the same baryon number. Results combining all collision systems in this work are shown by filled stars. Open stars show results with only U+U and Au+Au collisions, while quadrangular stars show results with only Zr+Zr and Ru+Ru collisions. Statistical uncertainties and systematic uncertainties are shown by vertical bars and boxes, respectively. Previous measurement results and thermal model predictions are also shown for comparison. Ratio Typle Index, 0:$\frac{{}^{3}\bar{He}}{{}^{3}He}$ 1:$\frac{{}^{3}\bar{He}}{{}^{3}He}\times\frac{\bar{p}}{p}$ 2:$\frac{{}^{4}\bar{He}}{{}^{4}He}$ 3:$\frac{{}^{3}_{\bar{\Lambda}}\bar{H}}{{}^{3}_{\Lambda}H}$ 4:$\frac{{}^{3}_{\bar{\Lambda}}\bar{H}}{{}^{3}_{\Lambda}H}\times\frac{\bar{p}}{p}$ 5:$\frac{{}^{4}_{\bar{\Lambda}}\bar{H}}{{}^{4}_{\Lambda}H}$ 6:$\frac{{}^{3}_{\Lambda}H}{{}^{3}He}$ 7:$\frac{{}^{4}_{\Lambda}H}{{}^{4}He}$ 8:$\frac{{}^{3}_{\bar{\Lambda}}\bar{H}}{^{3}\bar{He}}$ 9:$\frac{{}^{4}_{\bar{\Lambda}}\bar{H}}{^{4}\bar{He}}$
description: Matter-antimatter asymmetry is a research topic of fundamental interest, as it is the basis for the existence of the matter world, which survived annihilation with antimatter in the early Universe. High energy nuclear collisions create conditions similar to the Universe microseconds after the Big Bang, with comparable amounts of matter and antimatter. Much of the antimatter created escapes the rapidly expanding fireball without annihilation, making such collisions an effective experimental tool to create heavy antimatter nuclear objects and study their properties. In this paper, we report the first observation of the antimatter hypernucleus \hbox{$^4_{\bar{\Lambda}}\overline{\hbox{H}}$}, composed of an $\bar{\Lambda}$, an antiproton and two antineutrons. The discovery was made through its two-body decay after production in ultrarelativistic heavy ion collisions by the STAR experiment at the Relativistic Heavy Ion Collider. In total, 15.6 candidate \hbox{$^4_{\bar{\Lambda}}\overline{\hbox{H}}$} \ antimatter hypernuclei are obtained with an estimated background count of 6.4. Lifetimes of the antihypernuclei \hbox{$^3_{\bar{\Lambda}}\overline{\hbox{H}}$} \ and \hbox{$^4_{\bar{\Lambda}}\overline{\hbox{H}}$} \ are measured and compared with lifetimes of their corresponding hypernuclei, testing the symmetry between matter and antimatter. Various production yield ratios among (anti)hypernuclei and (anti)nuclei are also measured and compared with theoretical model predictions, shedding light on their production mechanism.
DOI: 10.17182/hepdata.133217.v1/t1
title: "Figure 2.1" of "Observation of sequential $\Upsilon$ suppression in Au+Au collisions at $\sqrt{s_{_\mathrm{NN}}}$ = 200 GeV with the STAR experiment"

description: Inclusive Y(1S) $R_{AA}$ as a function of centrality in Au+Au collisions at 200 GeV. The bin corresponding to $N_{part}$ = 162 is for 0-60% centrality. Global uncertainty of 20.0% not shown.
description: We report on measurements of sequential $\Upsilon$ suppression in Au+Au collisions at $\sqrt{s_{_\mathrm{NN}}}$ = 200 GeV with the STAR detector at the Relativistic Heavy Ion Collider (RHIC) through both the dielectron and dimuon decay channels. In the 0-60\% centrality class, the nuclear modification factors ($R_{\mathrm{AA}}$), which quantify the level of yield suppression in heavy-ion collisions compared to p+p collisions, for $\Upsilon$(1S) and $\Upsilon$(2S) are $0.40 \pm 0.03~\textrm{(stat.)} \pm 0.03~\textrm{(sys.)} \pm 0.09~\textrm{(norm.)}$ and $0.26 \pm 0.08~\textrm{(stat.)} \pm 0.02~\textrm{(sys.)} \pm 0.06~\textrm{(norm.)}$, respectively, while the upper limit of the $\Upsilon$(3S) $R_{\mathrm{AA}}$ is 0.17 at a 95\% confidence level. This provides experimental evidence that the $\Upsilon$(3S) is significantly more suppressed than the $\Upsilon$(1S) at RHIC. The level of suppression for $\Upsilon$(1S) is comparable to that observed at the much higher collision energy at the Large Hadron Collider. These results point to the creation of a medium at RHIC whose temperature is sufficiently high to strongly suppress excited $\Upsilon$ states.
DOI: 10.17182/hepdata.133217.v1/t2
title: "Figure 2.2" of "Observation of sequential $\Upsilon$ suppression in Au+Au collisions at $\sqrt{s_{_\mathrm{NN}}}$ = 200 GeV with the STAR experiment"

description: Inclusive Y(2S) $R_{AA}$ as a function of centrality in Au+Au collisions at 200 GeV. The bin corresponding to $N_{part}$ = 162 is for 0-60% centrality. Global uncertainty of 20.5% not shown.
description: We report on measurements of sequential $\Upsilon$ suppression in Au+Au collisions at $\sqrt{s_{_\mathrm{NN}}}$ = 200 GeV with the STAR detector at the Relativistic Heavy Ion Collider (RHIC) through both the dielectron and dimuon decay channels. In the 0-60\% centrality class, the nuclear modification factors ($R_{\mathrm{AA}}$), which quantify the level of yield suppression in heavy-ion collisions compared to p+p collisions, for $\Upsilon$(1S) and $\Upsilon$(2S) are $0.40 \pm 0.03~\textrm{(stat.)} \pm 0.03~\textrm{(sys.)} \pm 0.09~\textrm{(norm.)}$ and $0.26 \pm 0.08~\textrm{(stat.)} \pm 0.02~\textrm{(sys.)} \pm 0.06~\textrm{(norm.)}$, respectively, while the upper limit of the $\Upsilon$(3S) $R_{\mathrm{AA}}$ is 0.17 at a 95\% confidence level. This provides experimental evidence that the $\Upsilon$(3S) is significantly more suppressed than the $\Upsilon$(1S) at RHIC. The level of suppression for $\Upsilon$(1S) is comparable to that observed at the much higher collision energy at the Large Hadron Collider. These results point to the creation of a medium at RHIC whose temperature is sufficiently high to strongly suppress excited $\Upsilon$ states.
DOI: 10.17182/hepdata.145132.v1/t11
title: "Fig5 Thermal Model" of "Observation of the Antimatter Hypernucleus $^4_{\bar{\Lambda}}\overline{\hbox{H}}$"

description: Production yield ratios of various particles with the same baryon number. Results combining all collision systems in this work are shown by filled stars. Open stars show results with only U+U and Au+Au collisions, while quadrangular stars show results with only Zr+Zr and Ru+Ru collisions. Statistical uncertainties and systematic uncertainties are shown by vertical bars and boxes, respectively. Previous measurement results and thermal model predictions are also shown for comparison. Ratio Typle Index, 0:$\frac{{}^{3}\bar{He}}{{}^{3}He}$ 1:$\frac{{}^{3}\bar{He}}{{}^{3}He}\times\frac{\bar{p}}{p}$ 2:$\frac{{}^{4}\bar{He}}{{}^{4}He}$ 3:$\frac{{}^{3}_{\bar{\Lambda}}\bar{H}}{{}^{3}_{\Lambda}H}$ 4:$\frac{{}^{3}_{\bar{\Lambda}}\bar{H}}{{}^{3}_{\Lambda}H}\times\frac{\bar{p}}{p}$ 5:$\frac{{}^{4}_{\bar{\Lambda}}\bar{H}}{{}^{4}_{\Lambda}H}$ 6:$\frac{{}^{3}_{\Lambda}H}{{}^{3}He}$ 7:$\frac{{}^{4}_{\Lambda}H}{{}^{4}He}$ 8:$\frac{{}^{3}_{\bar{\Lambda}}\bar{H}}{^{3}\bar{He}}$ 9:$\frac{{}^{4}_{\bar{\Lambda}}\bar{H}}{^{4}\bar{He}}$
description: Matter-antimatter asymmetry is a research topic of fundamental interest, as it is the basis for the existence of the matter world, which survived annihilation with antimatter in the early Universe. High energy nuclear collisions create conditions similar to the Universe microseconds after the Big Bang, with comparable amounts of matter and antimatter. Much of the antimatter created escapes the rapidly expanding fireball without annihilation, making such collisions an effective experimental tool to create heavy antimatter nuclear objects and study their properties. In this paper, we report the first observation of the antimatter hypernucleus \hbox{$^4_{\bar{\Lambda}}\overline{\hbox{H}}$}, composed of an $\bar{\Lambda}$, an antiproton and two antineutrons. The discovery was made through its two-body decay after production in ultrarelativistic heavy ion collisions by the STAR experiment at the Relativistic Heavy Ion Collider. In total, 15.6 candidate \hbox{$^4_{\bar{\Lambda}}\overline{\hbox{H}}$} \ antimatter hypernuclei are obtained with an estimated background count of 6.4. Lifetimes of the antihypernuclei \hbox{$^3_{\bar{\Lambda}}\overline{\hbox{H}}$} \ and \hbox{$^4_{\bar{\Lambda}}\overline{\hbox{H}}$} \ are measured and compared with lifetimes of their corresponding hypernuclei, testing the symmetry between matter and antimatter. Various production yield ratios among (anti)hypernuclei and (anti)nuclei are also measured and compared with theoretical model predictions, shedding light on their production mechanism.
DOI: 10.17182/hepdata.145132.v1/t12
title: "Fig2 Tau Bin Efficiency for A=3 Particle" of "Observation of the Antimatter Hypernucleus $^4_{\bar{\Lambda}}\overline{\hbox{H}}$"

description: Reconstruction efficiency as a function of $L/(\beta\gamma)$ obtained from the embedding Monte Carlo technique. Hypernuclei have stricter topological cuts than antihypernuclei to suppress knock-out $^3\hbox{He}$ and $^4\hbox{He}$, resulting in lower efficiencies.
description: Matter-antimatter asymmetry is a research topic of fundamental interest, as it is the basis for the existence of the matter world, which survived annihilation with antimatter in the early Universe. High energy nuclear collisions create conditions similar to the Universe microseconds after the Big Bang, with comparable amounts of matter and antimatter. Much of the antimatter created escapes the rapidly expanding fireball without annihilation, making such collisions an effective experimental tool to create heavy antimatter nuclear objects and study their properties. In this paper, we report the first observation of the antimatter hypernucleus \hbox{$^4_{\bar{\Lambda}}\overline{\hbox{H}}$}, composed of an $\bar{\Lambda}$, an antiproton and two antineutrons. The discovery was made through its two-body decay after production in ultrarelativistic heavy ion collisions by the STAR experiment at the Relativistic Heavy Ion Collider. In total, 15.6 candidate \hbox{$^4_{\bar{\Lambda}}\overline{\hbox{H}}$} \ antimatter hypernuclei are obtained with an estimated background count of 6.4. Lifetimes of the antihypernuclei \hbox{$^3_{\bar{\Lambda}}\overline{\hbox{H}}$} \ and \hbox{$^4_{\bar{\Lambda}}\overline{\hbox{H}}$} \ are measured and compared with lifetimes of their corresponding hypernuclei, testing the symmetry between matter and antimatter. Various production yield ratios among (anti)hypernuclei and (anti)nuclei are also measured and compared with theoretical model predictions, shedding light on their production mechanism.
DOI: 10.17182/hepdata.145132.v1/t16
title: "Fig3, invariant-mass distributions for each tau bin of H4L" of "Observation of the Antimatter Hypernucleus $^4_{\bar{\Lambda}}\overline{\hbox{H}}$"

description: H3L, antiH3L, H4L and antiH4L candidate invariant-mass distributions in different $L/\beta\gamma$ intervals.
description: Matter-antimatter asymmetry is a research topic of fundamental interest, as it is the basis for the existence of the matter world, which survived annihilation with antimatter in the early Universe. High energy nuclear collisions create conditions similar to the Universe microseconds after the Big Bang, with comparable amounts of matter and antimatter. Much of the antimatter created escapes the rapidly expanding fireball without annihilation, making such collisions an effective experimental tool to create heavy antimatter nuclear objects and study their properties. In this paper, we report the first observation of the antimatter hypernucleus \hbox{$^4_{\bar{\Lambda}}\overline{\hbox{H}}$}, composed of an $\bar{\Lambda}$, an antiproton and two antineutrons. The discovery was made through its two-body decay after production in ultrarelativistic heavy ion collisions by the STAR experiment at the Relativistic Heavy Ion Collider. In total, 15.6 candidate \hbox{$^4_{\bar{\Lambda}}\overline{\hbox{H}}$} \ antimatter hypernuclei are obtained with an estimated background count of 6.4. Lifetimes of the antihypernuclei \hbox{$^3_{\bar{\Lambda}}\overline{\hbox{H}}$} \ and \hbox{$^4_{\bar{\Lambda}}\overline{\hbox{H}}$} \ are measured and compared with lifetimes of their corresponding hypernuclei, testing the symmetry between matter and antimatter. Various production yield ratios among (anti)hypernuclei and (anti)nuclei are also measured and compared with theoretical model predictions, shedding light on their production mechanism.
DOI: 10.17182/hepdata.145132.v1/t17
title: "Fig3, invariant-mass distributions for each tau bin of antiH4L" of "Observation of the Antimatter Hypernucleus $^4_{\bar{\Lambda}}\overline{\hbox{H}}$"

description: H3L, antiH3L, H4L and antiH4L candidate invariant-mass distributions in different $L/\beta\gamma$ intervals.
description: Matter-antimatter asymmetry is a research topic of fundamental interest, as it is the basis for the existence of the matter world, which survived annihilation with antimatter in the early Universe. High energy nuclear collisions create conditions similar to the Universe microseconds after the Big Bang, with comparable amounts of matter and antimatter. Much of the antimatter created escapes the rapidly expanding fireball without annihilation, making such collisions an effective experimental tool to create heavy antimatter nuclear objects and study their properties. In this paper, we report the first observation of the antimatter hypernucleus \hbox{$^4_{\bar{\Lambda}}\overline{\hbox{H}}$}, composed of an $\bar{\Lambda}$, an antiproton and two antineutrons. The discovery was made through its two-body decay after production in ultrarelativistic heavy ion collisions by the STAR experiment at the Relativistic Heavy Ion Collider. In total, 15.6 candidate \hbox{$^4_{\bar{\Lambda}}\overline{\hbox{H}}$} \ antimatter hypernuclei are obtained with an estimated background count of 6.4. Lifetimes of the antihypernuclei \hbox{$^3_{\bar{\Lambda}}\overline{\hbox{H}}$} \ and \hbox{$^4_{\bar{\Lambda}}\overline{\hbox{H}}$} \ are measured and compared with lifetimes of their corresponding hypernuclei, testing the symmetry between matter and antimatter. Various production yield ratios among (anti)hypernuclei and (anti)nuclei are also measured and compared with theoretical model predictions, shedding light on their production mechanism.
DOI: 10.17182/hepdata.133217.v1/t3
title: "Figure 2.3" of "Observation of sequential $\Upsilon$ suppression in Au+Au collisions at $\sqrt{s_{_\mathrm{NN}}}$ = 200 GeV with the STAR experiment"

description: Upper limit of inclusive Y(3S) $R_{AA}$ with 95% confidence level in 0-60% Au+Au collisions at 200 GeV
description: We report on measurements of sequential $\Upsilon$ suppression in Au+Au collisions at $\sqrt{s_{_\mathrm{NN}}}$ = 200 GeV with the STAR detector at the Relativistic Heavy Ion Collider (RHIC) through both the dielectron and dimuon decay channels. In the 0-60\% centrality class, the nuclear modification factors ($R_{\mathrm{AA}}$), which quantify the level of yield suppression in heavy-ion collisions compared to p+p collisions, for $\Upsilon$(1S) and $\Upsilon$(2S) are $0.40 \pm 0.03~\textrm{(stat.)} \pm 0.03~\textrm{(sys.)} \pm 0.09~\textrm{(norm.)}$ and $0.26 \pm 0.08~\textrm{(stat.)} \pm 0.02~\textrm{(sys.)} \pm 0.06~\textrm{(norm.)}$, respectively, while the upper limit of the $\Upsilon$(3S) $R_{\mathrm{AA}}$ is 0.17 at a 95\% confidence level. This provides experimental evidence that the $\Upsilon$(3S) is significantly more suppressed than the $\Upsilon$(1S) at RHIC. The level of suppression for $\Upsilon$(1S) is comparable to that observed at the much higher collision energy at the Large Hadron Collider. These results point to the creation of a medium at RHIC whose temperature is sufficiently high to strongly suppress excited $\Upsilon$ states.
DOI: 10.17182/hepdata.133217.v1/t4
title: "Figure 4.1" of "Observation of sequential $\Upsilon$ suppression in Au+Au collisions at $\sqrt{s_{_\mathrm{NN}}}$ = 200 GeV with the STAR experiment"

description: Inclusive Y(1S) $R_{AA}$ as a function of $p_{T}$ in Au+Au collisions at 200 GeV. Global uncertainty of 6.8% not shown.
description: We report on measurements of sequential $\Upsilon$ suppression in Au+Au collisions at $\sqrt{s_{_\mathrm{NN}}}$ = 200 GeV with the STAR detector at the Relativistic Heavy Ion Collider (RHIC) through both the dielectron and dimuon decay channels. In the 0-60\% centrality class, the nuclear modification factors ($R_{\mathrm{AA}}$), which quantify the level of yield suppression in heavy-ion collisions compared to p+p collisions, for $\Upsilon$(1S) and $\Upsilon$(2S) are $0.40 \pm 0.03~\textrm{(stat.)} \pm 0.03~\textrm{(sys.)} \pm 0.09~\textrm{(norm.)}$ and $0.26 \pm 0.08~\textrm{(stat.)} \pm 0.02~\textrm{(sys.)} \pm 0.06~\textrm{(norm.)}$, respectively, while the upper limit of the $\Upsilon$(3S) $R_{\mathrm{AA}}$ is 0.17 at a 95\% confidence level. This provides experimental evidence that the $\Upsilon$(3S) is significantly more suppressed than the $\Upsilon$(1S) at RHIC. The level of suppression for $\Upsilon$(1S) is comparable to that observed at the much higher collision energy at the Large Hadron Collider. These results point to the creation of a medium at RHIC whose temperature is sufficiently high to strongly suppress excited $\Upsilon$ states.
DOI: 10.17182/hepdata.145132.v1/t18
title: "Fig4 Lambda and anti-Lambda" of "Observation of the Antimatter Hypernucleus $^4_{\bar{\Lambda}}\overline{\hbox{H}}$"

description: $dN/d(L/\beta\gamma)$ as a function of $L/\beta\gamma$ for $\Lambda$ and $\bar{\Lambda}$, and exponential fits to obtain their lifetimes.
description: Matter-antimatter asymmetry is a research topic of fundamental interest, as it is the basis for the existence of the matter world, which survived annihilation with antimatter in the early Universe. High energy nuclear collisions create conditions similar to the Universe microseconds after the Big Bang, with comparable amounts of matter and antimatter. Much of the antimatter created escapes the rapidly expanding fireball without annihilation, making such collisions an effective experimental tool to create heavy antimatter nuclear objects and study their properties. In this paper, we report the first observation of the antimatter hypernucleus \hbox{$^4_{\bar{\Lambda}}\overline{\hbox{H}}$}, composed of an $\bar{\Lambda}$, an antiproton and two antineutrons. The discovery was made through its two-body decay after production in ultrarelativistic heavy ion collisions by the STAR experiment at the Relativistic Heavy Ion Collider. In total, 15.6 candidate \hbox{$^4_{\bar{\Lambda}}\overline{\hbox{H}}$} \ antimatter hypernuclei are obtained with an estimated background count of 6.4. Lifetimes of the antihypernuclei \hbox{$^3_{\bar{\Lambda}}\overline{\hbox{H}}$} \ and \hbox{$^4_{\bar{\Lambda}}\overline{\hbox{H}}$} \ are measured and compared with lifetimes of their corresponding hypernuclei, testing the symmetry between matter and antimatter. Various production yield ratios among (anti)hypernuclei and (anti)nuclei are also measured and compared with theoretical model predictions, shedding light on their production mechanism.
DOI: 10.17182/hepdata.145132.v1/t19
title: "Fig5 pT spectra of He3 and anti-He3" of "Observation of the Antimatter Hypernucleus $^4_{\bar{\Lambda}}\overline{\hbox{H}}$"

description: Efficiency corrected $p_{T}$ spectra for $^3\hbox{He}$, $^3\overline{\hbox{He}}$, \htl, and \ahtl. The spectra are in the phase space of $|y|&lt;0.7$ with only MB-triggered events. The spectra are not normalized by the number of events. The lines represent the BW-function fits.
description: Matter-antimatter asymmetry is a research topic of fundamental interest, as it is the basis for the existence of the matter world, which survived annihilation with antimatter in the early Universe. High energy nuclear collisions create conditions similar to the Universe microseconds after the Big Bang, with comparable amounts of matter and antimatter. Much of the antimatter created escapes the rapidly expanding fireball without annihilation, making such collisions an effective experimental tool to create heavy antimatter nuclear objects and study their properties. In this paper, we report the first observation of the antimatter hypernucleus \hbox{$^4_{\bar{\Lambda}}\overline{\hbox{H}}$}, composed of an $\bar{\Lambda}$, an antiproton and two antineutrons. The discovery was made through its two-body decay after production in ultrarelativistic heavy ion collisions by the STAR experiment at the Relativistic Heavy Ion Collider. In total, 15.6 candidate \hbox{$^4_{\bar{\Lambda}}\overline{\hbox{H}}$} \ antimatter hypernuclei are obtained with an estimated background count of 6.4. Lifetimes of the antihypernuclei \hbox{$^3_{\bar{\Lambda}}\overline{\hbox{H}}$} \ and \hbox{$^4_{\bar{\Lambda}}\overline{\hbox{H}}$} \ are measured and compared with lifetimes of their corresponding hypernuclei, testing the symmetry between matter and antimatter. Various production yield ratios among (anti)hypernuclei and (anti)nuclei are also measured and compared with theoretical model predictions, shedding light on their production mechanism.