Search for dark matter produced in association with a Higgs boson decaying to tau leptons at $\sqrt{s}=13$ TeV with the ATLAS detector

The ATLAS collaboration Aad, Georges ; Aakvaag, Erlend ; Abbott, Braden Keim ; et al.
JHEP 09 (2023) 189, 2023.
Inspire Record 2661503 DOI 10.17182/hepdata.140433

A search for dark matter produced in association with a Higgs boson in final states with two hadronically decaying $\tau$-leptons and missing transverse momentum is presented. The analysis uses $139$ fb$^{-1}$ of proton-proton collision data at $\sqrt{s}=13$ TeV collected by the ATLAS experiment at the Large Hadron Collider between 2015 and 2018. No evidence for physics beyond the Standard Model is found. The results are interpreted in terms of a 2HDM+$a$ model. Exclusion limits at 95% confidence level are derived. Model-independent limits are also set on the visible cross section for processes beyond the Standard Model producing missing transverse momentum in association with a Higgs boson decaying to $\tau$-leptons.

70 data tables

<b>- - - - - - - - Overview of HEPData Record - - - - - - - -</b> <br><br> <b>CLs and CLs+b values</b> <ul> <li><a href=?table=CLs_tanb_mA_grid_Expected>Expected CLs values in mA vs tanB grid, Low mA SR</a> <li><a href=?table=CLs_tanb_mA_grid_Observed>Observed CLs values in mA vs tanB grid, Low mA SR</a> <li><a href=?table=CLs_ma_mA_grid_HighmA_SR_Expected>Expected CLs values in mA vs ma grid, High mA SR</a> <li><a href=?table=CLs_ma_mA_grid_HighmA_SR_Observed>Observed CLs values in mA vs ma grid, High mA SR</a> <li><a href=?table=CLs_ma_mA_grid_LowmA_SR_Expected>Expected CLs values in mA vs ma grid, Low mA SR</a> <li><a href=?table=CLs_ma_mA_grid_LowmA_SR_Observed>Observed CLs values in mA vs ma grid, Low mA SR</a> <li><a href=?table=CLsplusb_tanb_mA_grid>CLs+b values in mA vs tanB grid, Low mA SR</a> <li><a href=?table=CLsplusb_ma_mA_grid_HighmA_SR>CLs+b values in mA vs ma grid, High mA SR</a> <li><a href=?table=CLsplusb_ma_mA_grid_LowmA_SR>CLs+b values in mA vs ma grid, Low mA SR</a> </ul> <b>Cutflow tables</b> <ul> <li><a href=?table=Cutflows_ggf_LowmA_SR>Low mA SR, ggF production</a> <li><a href=?table=Cutflows_ggf_HighmA_SR>High mA SR, ggF production</a> <li><a href=?table=Cutflows_bb_LowmA_SR>Low mA SR, bb production</a> <li><a href=?table=Cutflows_bb_HighmA_SR>High mA SR, bb production</a> </ul> <b>Kinematic Distributions</b> <ul> <li><a href=?table=KinDist_LowmA_SR>Low mA SR mTtau1+mTtau2 distribution</a> <li><a href=?table=KinDist_HighmA_SR>High mA SR mTtau1+mTtau2 distribution</a> </ul> <b>Limits</b> <ul> <li><a href=?table=Expected_95%_CL_exclusion_limit_mAma_grid>Expected 95% CL exclusion limit in mA vs ma grid</a> <li><a href=?table=Observed_95%_CL_exclusion_limit_mAma_grid>Observed 95% CL exclusion limit in mA vs ma grid</a> <li><a href=?table=Expected_pm1sigma_95%_CL_exclusion_limit_mAma_grid>Expected +-1 sigma 95% CL exclusion limit in mA vs ma grid</a> <li><a href=?table=Expected_95%_CL_exclusion_limit_mAtanB_grid>Expected 95% CL exclusion limit in mA vs tanB grid</a> <li><a href=?table=Observed_95%_CL_exclusion_limit_mAtanB_grid>Observed 95% CL exclusion limit in mA vs tanB grid</a> <li><a href=?table=Expected_pm1sigma_95%_CL_exclusion_limit_mAtanB_grid>Expected +-1 sigma 95% CL exclusion limit in tanB grid</a> </ul> <b>Acceptance and efficiency</b> <ul> <li><a href=?table=table1>Acceptance, High mA SR, mA vs tanB grid, 400-750 GeV, bb prod</a> <li><a href=?table=table2>Acceptance, High mA SR, mA vs tanB grid, >750 GeV, bb prod</a> <li><a href=?table=table3>Acceptance, Low mA SR, mA vs tanB grid, 100-250 GeV, bb prod</a> <li><a href=?table=table4>Acceptance, Low mA SR, mA vs tanB grid, 250-400 GeV, bb prod</a> <li><a href=?table=table5>Acceptance, Low mA SR, mA vs tanB grid, 400-550 GeV, bb prod</a> <li><a href=?table=table6>Acceptance, Low mA SR, mA vs tanB grid, >550 GeV, bb prod</a> <li><a href=?table=table7>Acceptance, High mA SR, mA vs ma grid, 400-750 GeV, bb prod</a> <li><a href=?table=table8>Acceptance, High mA SR, mA vs ma grid, >750 GeV, bb prod</a> <li><a href=?table=table9>Acceptance, Low mA SR, mA vs ma grid, 100-250 GeV, bb prod</a> <li><a href=?table=table10>Acceptance, Low mA SR, mA vs ma grid, 250-400 GeV, bb prod</a> <li><a href=?table=table11>Acceptance, Low mA SR, mA vs ma grid, 400-550 GeV, bb prod</a> <li><a href=?table=table12>Acceptance, Low mA SR, mA vs ma grid, >550 GeV, bb prod</a> <li><a href=?table=table13>Acceptance, High mA SR, mA vs tanB grid, 400-750 GeV, ggF prod</a> <li><a href=?table=table14>Acceptance, High mA SR, mA vs tanB grid, >750 GeV, ggF prod</a> <li><a href=?table=table15>Acceptance, Low mA SR, mA vs tanB grid, 100-250 GeV, ggF prod</a> <li><a href=?table=table16>Acceptance, Low mA SR, mA vs tanB grid, 250-400 GeV, ggF prod</a> <li><a href=?table=table17>Acceptance, Low mA SR, mA vs tanB grid, 400-550 GeV, ggF prod</a> <li><a href=?table=table18>Acceptance, Low mA SR, mA vs tanB grid, >550 GeV, ggF prod</a> <li><a href=?table=table19>Acceptance, High mA SR, mA vs ma grid, 400-750 GeV, ggF prod</a> <li><a href=?table=table20>Acceptance, High mA SR, mA vs ma grid, >750 GeV, ggF prod</a> <li><a href=?table=table21>Acceptance, Low mA SR, mA vs ma grid, 100-250 GeV, ggF prod</a> <li><a href=?table=table22>Acceptance, Low mA SR, mA vs ma grid, 250-400 GeV, ggF prod</a> <li><a href=?table=table23>Acceptance, Low mA SR, mA vs ma grid, 400-550 GeV, ggF prod</a> <li><a href=?table=table24>Acceptance, Low mA SR, mA vs ma grid, >550 GeV, ggF prod</a> <li><a href=?table=table25>Efficiency, High mA SR, mA vs tanB grid, 400-750 GeV, bb prod</a> <li><a href=?table=table26>Efficiency, High mA SR, mA vs tanB grid, >750 GeV, bb prod</a> <li><a href=?table=table27>Efficiency, Low mA SR, mA vs tanB grid, 100-250 GeV, bb prod</a> <li><a href=?table=table28>Efficiency, Low mA SR, mA vs tanB grid, 250-400 GeV, bb prod</a> <li><a href=?table=table29>Efficiency, Low mA SR, mA vs tanB grid, 400-550 GeV, bb prod</a> <li><a href=?table=table30>Efficiency, Low mA SR, mA vs tanB grid, >550 GeV, bb prod</a> <li><a href=?table=table31>Efficiency, High mA SR, mA vs ma grid, 400-750 GeV, bb prod</a> <li><a href=?table=table32>Efficiency, High mA SR, mA vs ma grid, >750 GeV, bb prod</a> <li><a href=?table=table33>Efficiency, Low mA SR, mA vs ma grid, 100-250 GeV, bb prod</a> <li><a href=?table=table34>Efficiency, Low mA SR, mA vs ma grid, 250-400 GeV, bb prod</a> <li><a href=?table=table35>Efficiency, Low mA SR, mA vs ma grid, 400-550 GeV, bb prod</a> <li><a href=?table=table36>Efficiency, Low mA SR, mA vs ma grid, >550 GeV, bb prod</a> <li><a href=?table=table37>Efficiency, High mA SR, mA vs tanB grid, 400-750 GeV, ggF prod</a> <li><a href=?table=table38>Efficiency, High mA SR, mA vs tanB grid, >750 GeV, ggF prod</a> <li><a href=?table=table39>Efficiency, Low mA SR, mA vs tanB grid, 100-250 GeV, ggF prod</a> <li><a href=?table=table40>Efficiency, Low mA SR, mA vs tanB grid, 250-400 GeV, ggF prod</a> <li><a href=?table=table41>Efficiency, Low mA SR, mA vs tanB grid, 400-550 GeV, ggF prod</a> <li><a href=?table=table42>Efficiency, Low mA SR, mA vs tanB grid, >550 GeV, ggF prod</a> <li><a href=?table=table43>Efficiency, High mA SR, mA vs ma grid, 400-750 GeV, ggF prod</a> <li><a href=?table=table44>Efficiency, High mA SR, mA vs ma grid, >750 GeV, ggF prod</a> <li><a href=?table=table45>Efficiency, Low mA SR, mA vs ma grid, 100-250 GeV, ggF prod</a> <li><a href=?table=table46>Efficiency, Low mA SR, mA vs ma grid, 250-400 GeV, ggF prod</a> <li><a href=?table=table47>Efficiency, Low mA SR, mA vs ma grid, 400-550 GeV, ggF prod</a> <li><a href=?table=table48>Efficiency, Low mA SR, mA vs ma grid, >550 GeV, ggF prod</a> </ul>

Expected CLs values in the Low mA SR, mA vs tanB signal grid.

Observed CLs values in the Low mA SR, mA vs tanB signal grid.

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Search for jet quenching effects in high-multiplicity pp collisions at $\sqrt{s}$ = 13 TeV via di-jet acoplanarity

The ALICE collaboration Acharya, Shreyasi ; Adamova, Dagmar ; Aglieri Rinella, Gianluca ; et al.
JHEP 05 (2024) 229, 2024.
Inspire Record 2694579 DOI 10.17182/hepdata.151783

The ALICE Collaboration reports a search for jet quenching effects in high-multiplicity (HM) proton$-$proton collisions at $\sqrt{s}$ = 13 TeV, using the semi-inclusive azimuthal-difference distribution $\Delta\varphi$ of charged-particle jets recoiling from a high transverse momentum (high-$p_{\mathrm{T,trig}}$) trigger hadron. Jet quenching may broaden the $\Delta\varphi$ distribution measured in HM events compared to that in minimum bias (MB) events. The measurement employs a $p_{\mathrm{T,trig}}$-differential observable for data-driven suppression of the contribution of multiple partonic interactions, which is the dominant background. While azimuthal broadening is indeed observed in HM compared to MB events, similar broadening for HM events is observed for simulations based on the PYTHIA 8 Monte Carlo generator, which does not incorporate jet quenching. Detailed analysis of these data and simulations show that the azimuthal broadening is due to bias of the HM selection towards events with multiple jets in the final state. The identification of this bias has implications for all jet quenching searches where selection is made on the event activity.

8 data tables

Probability distribution of $\mathrm{V0M}/\langle \mathrm{V0M} \rangle$ in MB pp collisions measured at $\sqrt{s}=13$ TeV.

Fully-corrected $\Delta_{\mathrm{recoil}} (p_{\mathrm{T, jet}}^{\mathrm{ch}})$ distributions measured in MB and HM-selected events in pp collisions at $\sqrt{s}= 13$ TeV.

Fully-corrected $\Delta_{\mathrm{recoil}} (\Delta\phi)$ distributions for $p_{\mathrm{T, jet}}^{\mathrm{ch}} \in (20, 40)$ GeV/$c$ measured in MB and HM-selected events in pp collisions at $\sqrt{s}= 13$ TeV.

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Multiplicity and event-scale dependent flow and jet fragmentation in pp collisions at $\sqrt{s}$ = 13 TeV and in p$-$Pb collisions at $\sqrt{s_\mathrm{NN}}$ = 5.02 TeV

The ALICE collaboration Acharya, Shreyasi ; Adamova, Dagmar ; Aglieri Rinella, Gianluca ; et al.
JHEP 03 (2024) 092, 2024.
Inspire Record 2692432 DOI 10.17182/hepdata.151802

Long- and short-range correlations for pairs of charged particles are studied via two-particle angular correlations in pp collisions at $\sqrt{s}=13$ TeV and p$-$Pb collisions at $\sqrt{s_\mathrm{NN}} = 5.02$ TeV. The correlation functions are measured as a function of relative azimuthal angle $\Delta\varphi$ and pseudorapidity separation $\Delta\eta$ for pairs of primary charged particles within the pseudorapidity interval $|\eta| < 0.9$ and the transverse-momentum interval $1 < p_{\rm T} < 4$ GeV/$c$. Flow coefficients are extracted for the long-range correlations ($1.6 < |\Delta\eta| <1.8$) in various high-multiplicity event classes using the low-multiplicity template fit method. The method is used to subtract the enhanced yield of away-side jet fragments in high-multiplicity events. These results show decreasing flow signals toward lower multiplicity events. Furthermore, the flow coefficients for events with hard probes, such as jets or leading particles, do not exhibit any significant changes compared to those obtained from high-multiplicity events without any specific event selection criteria. The results are compared with hydrodynamic-model calculations, and it is found that a better understanding of the initial conditions is necessary to describe the results, particularly for low-multiplicity events.

10 data tables

High and low multiplicity long-range delta phi correlations

Jet fragmentation yields of near and away side as a function of multiplicity class and and the ratio of them, please see the definition of x-axis

The second and third harmonic coefficients as a function of transverse momentum in pp and p--Pb collisions.

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Charged-particle production as a function of the relative transverse activity classifier in pp, p$-$Pb, and Pb$-$Pb collisions at the LHC

The ALICE collaboration Acharya, Shreyasi ; Adamova, Dagmar ; Aglieri Rinella, Gianluca ; et al.
JHEP 01 (2024) 056, 2024.
Inspire Record 2709103 DOI 10.17182/hepdata.146104

Measurements of charged-particle production in pp, p$-$Pb, and Pb$-$Pb collisions in the toward, away, and transverse regions with the ALICE detector are discussed. These regions are defined event-by-event relative to the azimuthal direction of the charged trigger particle, which is the reconstructed particle with the largest transverse momentum ($p_{\mathrm{T}}^{\rm trig}$) in the range $8<p_{\mathrm{T}}^{\rm trig}<15$ GeV$/c$. The toward and away regions contain the primary and recoil jets, respectively; both regions are accompanied by the underlying event (UE). In contrast, the transverse region perpendicular to the direction of the trigger particle is dominated by the so-called UE dynamics, and includes also contributions from initial- and final-state radiation. The relative transverse activity classifier, $R_{\mathrm{T}}=N_{\mathrm{ch}}^{\mathrm{T}}/\langle N_{\mathrm{ch}}^{\mathrm{T}}\rangle$, is used to group events according to their UE activity, where $N_{\mathrm{ch}}^{\mathrm{T}}$ is the charged-particle multiplicity per event in the transverse region and $\langle N_{\mathrm{ch}}^{\mathrm{T}}\rangle$ is the mean value over the whole analysed sample. The energy dependence of the $R_{\mathrm{T}}$ distributions in pp collisions at $\sqrt{s}=2.76$, 5.02, 7, and 13 TeV is reported, exploring the Koba-Nielsen-Olesen (KNO) scaling properties of the multiplicity distributions. The first measurements of charged-particle $p_{\rm T}$ spectra as a function of $R_{\mathrm{T}}$ in the three azimuthal regions in pp, p$-$Pb, and Pb$-$Pb collisions at $\sqrt{s_{\rm NN}}=5.02$ TeV are also reported. Data are compared with predictions obtained from the event generators PYTHIA 8 and EPOS LHC. This set of measurements is expected to contribute to the understanding of the origin of collective-like effects in small collision systems (pp and p$-$Pb).

28 data tables

$R_\mathrm{T}$ distribution using events with trigger particles $5<p_\mathrm{T}^\mathrm{trig}<40~\mathrm{GeV}/c$ in the pseudorapidity range of $|\eta|<0.8$ and with $p_\mathrm{T}>0.5~\mathrm{GeV}/c$ in pp collisions at $\sqrt{s}=2.76~\mathrm{TeV}$

$R_\mathrm{T}$ distribution using events with trigger particles $5<p_\mathrm{T}^\mathrm{trig}<40~\mathrm{GeV}/c$ in the pseudorapidity range of $|\eta|<0.8$ and with $p_\mathrm{T}>0.5~\mathrm{GeV}/c$ in pp collisions at $\sqrt{s}=5.02~\mathrm{TeV}$

$R_\mathrm{T}$ distribution using events with trigger particles $5<p_\mathrm{T}^\mathrm{trig}<40~\mathrm{GeV}/c$ in the pseudorapidity range of $|\eta|<0.8$ and with $p_\mathrm{T}>0.5~\mathrm{GeV}/c$ in pp collisions at $\sqrt{s}=7~\mathrm{TeV}$

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Multiplicity dependence of charged-particle intra-jet properties in pp collisions at $\sqrt{s}$ = 13 TeV

The ALICE collaboration Acharya, Shreyasi ; Adamova, Dagmar ; Aglieri Rinella, Gianluca ; et al.
Eur.Phys.J.C 84 (2024) 1079, 2024.
Inspire Record 2725603 DOI 10.17182/hepdata.153919

The first measurement of the multiplicity dependence of intra-jet properties of leading charged-particle jets in proton-proton (pp) collisions is reported. The mean charged-particle multiplicity and jet fragmentation distributions are measured in minimum-bias and high-multiplicity pp collisions at $\sqrt{s}$ = 13 TeV using the ALICE detector. Jets are reconstructed from charged particles produced in the midrapidity region ($|\eta|<0.9$) using the sequential recombination anti-$k_{\rm T}$ algorithm with jet resolution parameters $R=0.2$, 0.3, and 0.4 for the transverse momentum ($p_{\rm T}$) interval 5-110 GeV/$c$. High-multiplicity events are selected by the forward V0 scintillator detectors. The mean charged-particle multiplicity inside the leading jet cone rises monotonically with increasing jet $p_{\rm T}$ in qualitative agreement with previous measurements at lower energies. The distributions of jet fragmentation function variables $z^{\rm ch}$ and $\xi^{\rm ch}$ are measured for different jet-$p_{\rm T}$ intervals. Jet-$p_{\rm T}$ independent fragmentation of leading jets is observed for wider jets except at high- and low-$z^{\rm ch}$. The observed hump-backed plateau structure in the $\xi^{\rm ch}$ distribution indicates suppression of low-$p_{\rm T}$ particles. In high-multiplicity events, an enhancement of the fragmentation probability of low-$z^{\rm ch}$ particles accompanied by a suppression of high-$z^{\rm ch}$ particles is observed compared to minimum-bias events. This behavior becomes more prominent for low-$p_{\rm T}$ jets with larger jet radius. The results are compared with predictions of QCD-inspired event generators, PYTHIA 8 with Monash 2013 tune and EPOS LHC. It is found that PYTHIA 8 qualitatively reproduces the jet modification in high-multiplicity events except at high jet $p_{\rm T}$. These measurements provide important constraints to models of jet fragmentation.

21 data tables

Mean number of charged particles ($\langle N_{\mathrm{ch}} \rangle$) within leading charged-particle jets as a function of $p_{T}^{\mathrm{jet, ch}}$ for minimum-bias (MB) pp collisions.

Mean number of charged particles ($\langle N_{\mathrm{ch}} \rangle$) within leading charged-particle jets as a function of $p_{T}^{\mathrm{jet, ch}}$ for high-multiplicity (HM) pp collisions.

The ratio of $\langle N_{\mathrm{ch}} \rangle$ between high-multiplicity (HM) and minimum-bias (MB) events as a function of $p_{T}^{\mathrm{jet, ch}}$ for pp collisions.

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Emergence of long-range angular correlations in low-multiplicity proton-proton collisions

The ALICE collaboration Acharya, Shreyasi ; Adamova, Dagmar ; Aglieri Rinella, Gianluca ; et al.
Phys.Rev.Lett. 132 (2024) 172302, 2024.
Inspire Record 2725922 DOI 10.17182/hepdata.150695

This Letter presents the measurement of near-side associated per-trigger yields, denoted ridge yields, from the analysis of angular correlations of charged hadrons in proton-proton collisions at $\sqrt{s}$ = 13 TeV. Long-range ridge yields are extracted for pairs of charged particles with a pseudorapidity difference of $1.4 < |\Delta\eta| < 1.8$ and a transverse momentum of $1 < p_{\rm T} < 2$ GeV/$c$, as a function of the charged-particle multiplicity measured at midrapidity. This study extends the measurements of the ridge yield to the low multiplicity region, where in hadronic collisions it is typically conjectured that a strongly-interacting medium is unlikely to be formed. The precision of the new low multiplicity results allows for the first direct quantitative comparison with the results obtained in $\mathrm {e^{+}e^{-}}$ collisions at $\sqrt{s}$ = 91 GeV and $\sqrt{s}$ = 183$-$209 GeV, where initial-state effects such as pre-equilibrium dynamics and collision geometry are not expected to play a role. In the multiplicity range $8\lesssim\langle N_\mathrm{ch}\rangle\lesssim 24$ where the $\mathrm {e^{+}e^{-}}$ results have good precision, the measured ridge yields in pp collisions are substantially larger than the limits set in $\mathrm {e^{+}e^{-}}$ annihilations. Consequently, the findings presented in this Letter suggest that the processes involved in $\mathrm {e^{+}e^{-}}$ annihilations do not contribute significantly to the emergence of long-range correlations in pp collisions.

1 data table

Ridge yield $Y_\mathrm{ridge}$ extracted at $1.4<|\Delta\eta|<1.8$ with $1.0<p_\mathrm{T,trig}<2.0\,\mathrm{GeV}/c$, $1.0<p_\mathrm{T,assoc}<2.0\,\mathrm{GeV}/c$ as a function of charged particle multiplicity counted at midrapidity $|\eta|<1.0$. The first three points at $N_\mathrm{ch}<8$ represent a 95% upper confidence limit where the statistical and systematic uncertainty have been combined.


Common femtoscopic hadron-emission source in pp collisions at the LHC

The ALICE collaboration Acharya, Shreyasi ; Adamova, Dagmar ; Aglieri Rinella, Gianluca ; et al.
Eur.Phys.J.C 85 (2025) 198, 2025.
Inspire Record 2725934 DOI 10.17182/hepdata.152623

The femtoscopic study of pairs of identical pions is particularly suited to investigate the effective source function of particle emission, due to the resulting Bose-Einstein correlation signal. In small collision systems at the LHC, pp in particular, the majority of the pions are produced in resonance decays, which significantly affect the profile and size of the source. In this work, we explicitly model this effect in order to extract the primordial source in pp collisions at $\sqrt{s} = 13$ TeV from charged $\pi$-$\pi$ correlations measured by ALICE. We demonstrate that the assumption of a Gaussian primordial source is compatible with the data and that the effective source, resulting from modifications due to resonances, is approximately exponential, as found in previous measurements at the LHC. The universality of hadron emission in pp collisions is further investigated by applying the same methodology to characterize the primordial source of K-p pairs. The size of the primordial source is evaluated as a function of the transverse mass ($m_{\rm T}$) of the pairs, leading to the observation of a common scaling for both $\pi$-$\pi$ and K-p, suggesting a collective effect. Further, the present results are compatible with the $m_{\rm T}$ scaling of the p-p and p$-\Lambda$ primordial source measured by ALICE in high multiplicity pp collisions, providing compelling evidence for the presence of a common emission source for all hadrons in small collision systems at the LHC. This will allow the determination of the source function for any hadron--hadron pairs with high precision, granting access to the properties of the possible final-state interaction among pairs of less abundantly produced hadrons, such as strange or charmed particles.

29 data tables

K$^+$p (K$^+$p $\oplus$ K$^-\overline{\mathrm p}$) correlation function in HM pp collisions at $\sqrt{s_{\mathrm {NN}}}=13 $ TeV (1.2<$m_T$<1.4 GeV/$c^{2}$).

K$^+$p (K$^+$p $\oplus$ K$^-\overline{\mathrm p}$) correlation function in HM pp collisions at $\sqrt{s_{\mathrm {NN}}}=13 $ TeV (1.4<$m_T$<1.5 GeV/$c^{2}$).

K$^+$p (K$^+$p $\oplus$ K$^-\overline{\mathrm p}$) correlation function in HM pp collisions at $\sqrt{s_{\mathrm {NN}}}=13 $ TeV (1.5<$m_T$<1.8 GeV/$c^{2}$).

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Combination of searches for resonant Higgs boson pair production using $pp$ collisions at $\sqrt{s}=13$ TeV with the ATLAS detector

The ATLAS collaboration Aad, Georges ; Aakvaag, Erlend ; Abbott, Braden Keim ; et al.
Phys.Rev.Lett. 132 (2024) 231801, 2024.
Inspire Record 2726938 DOI 10.17182/hepdata.145876

A combination of searches for a new resonance decaying into a Higgs boson pair is presented, using up to 139 fb$^{-1}$ of $pp$ collision data at $\sqrt{s}=13$ TeV recorded with the ATLAS detector at the LHC. The combination includes searches performed in three decay channels: $b\bar{b}b\bar{b}$, $b\bar{b}\tau^+\tau^-$ and $b\bar{b}\gamma\gamma$. No excess above the expected Standard Model background is observed and upper limits are set at the 95% confidence level on the production cross section of Higgs boson pairs originating from the decay of a narrow scalar resonance with mass in the range 251 GeV-5 TeV. The observed (expected) limits are in the range 0.96-600 fb (1.2-390 fb). The limits are interpreted in the Type-I Two-Higgs-Doublet Model and the Minimimal Supersymmetric Standard Model, and constrain parameter space not previously excluded by other searches.

3 data tables

Local p-value as a function of the resonance mass $m_{X}$. Some table entries are empty because resonance masses from 251 GeV to 5 TeV are considered, whereas some channels only use masses in a certain, more restricted, range.

Observed significance as a function of the resonance $m_{X}$. Some table entries are empty because resonance masses from 251 GeV to 5 TeV are considered, whereas some channels only use masses in a certain, more restricted, range.

Observed and expected upper limits at the 95% CL on the resonant Higgs boson pair production cross section as a function of the resonance mass $m_{X}$. Some table entries are empty because resonance masses from 251 GeV to 5 TeV are considered, whereas some channels only use masses in a certain, more restricted, range.


Evidence for the $VH, H\rightarrow \tau\tau$ process with the ATLAS detector in Run 2

The ATLAS collaboration Aad, Georges ; Aakvaag, Erlend ; Abbott, Braden Keim ; et al.
Phys.Lett.B 855 (2024) 138817, 2024.
Inspire Record 2730582 DOI 10.17182/hepdata.151813

A measurement of the Standard Model Higgs boson produced in association with a $W$ or $Z$ boson and decaying into a pair of $\tau$-leptons is presented. This search is based on proton-proton collision data collected at $\sqrt{s}=13$ TeV by the ATLAS experiment at the LHC corresponding to an integrated luminosity of 140 fb$^{-1}$. For the Higgs boson candidate, only final states with at least one $\tau$-lepton decaying hadronically ($\tau\rightarrow \mathrm{hadrons} + \nu_\tau$) are considered. For the vector bosons, only leptonic decay channels are considered: $Z \rightarrow \ell\ell$ and $W\rightarrow \ell\nu_\ell$, with $\ell=e,\mu$. An excess of events over the expected background is found with an observed (expected) significance of 4.2 (3.6) standard deviations, providing evidence of the Higgs boson produced in association with a vector boson and decaying into a pair of $\tau$-leptons. The ratio of the measured cross-section to the Standard Model prediction is $\mu_{\text{VH}}^{\tau\tau} = 1.28\ ^{+0.30}_{-0.29}\ (\mathrm{stat.})\ ^{+0.25}_{-0.21}\ (\mathrm{syst.})$. This result represents the most accurate measurement of the \vh process achieved to date.

35 data tables

Distributions of representative kinematic variables in the misidentified background-enriched same-sign region: (a) the Higgs boson transverse momentum (${p_\text{T}}^H$) in the $WH(\tau_{\mathrm{had}}\tau_{\mathrm{had}})$ category, (b) the missing transverse momentum (${E_{\mathrm{T}}^{\mathrm{miss}}}$) in the $WH(\tau_{\mathrm{lep}}\tau_{\mathrm{had}})$ category, (c) the radial distance (dR$(\ell,\ell)$) between the two light leptons associated to the $Z\to\ell{}\ell$ decay process in the $ZH(\tau_{\mathrm{had}}\tau_{\mathrm{had}})$ category, and (d) the invariant mass ($m_{\ell\ell}$) of the two light leptons associated to the $Z\to\ell{}\ell$ decay in the $ZH(\tau_{\mathrm{lep}}\tau_{\mathrm{had}})$ category. The hatched band represents the pre-fit statistical, experimental and theoretical uncertainties. The signal contributions are considered as part of the predictions and are normalized as predicted by the Standard Model.

Distributions of representative kinematic variables in the misidentified background-enriched same-sign region: (a) the Higgs boson transverse momentum (${p_\text{T}}^H$) in the $WH(\tau_{\mathrm{had}}\tau_{\mathrm{had}})$ category, (b) the missing transverse momentum (${E_{\mathrm{T}}^{\mathrm{miss}}}$) in the $WH(\tau_{\mathrm{lep}}\tau_{\mathrm{had}})$ category, (c) the radial distance (dR$(\ell,\ell)$) between the two light leptons associated to the $Z\to\ell{}\ell$ decay process in the $ZH(\tau_{\mathrm{had}}\tau_{\mathrm{had}})$ category, and (d) the invariant mass ($m_{\ell\ell}$) of the two light leptons associated to the $Z\to\ell{}\ell$ decay in the $ZH(\tau_{\mathrm{lep}}\tau_{\mathrm{had}})$ category. The hatched band represents the pre-fit statistical, experimental and theoretical uncertainties. The signal contributions are considered as part of the predictions and are normalized as predicted by the Standard Model.

Distributions of representative kinematic variables in the misidentified background-enriched same-sign region: (a) the Higgs boson transverse momentum (${p_\text{T}}^H$) in the $WH(\tau_{\mathrm{had}}\tau_{\mathrm{had}})$ category, (b) the missing transverse momentum (${E_{\mathrm{T}}^{\mathrm{miss}}}$) in the $WH(\tau_{\mathrm{lep}}\tau_{\mathrm{had}})$ category, (c) the radial distance (dR$(\ell,\ell)$) between the two light leptons associated to the $Z\to\ell{}\ell$ decay process in the $ZH(\tau_{\mathrm{had}}\tau_{\mathrm{had}})$ category, and (d) the invariant mass ($m_{\ell\ell}$) of the two light leptons associated to the {Z\to\ell{}\ell}\xspace{} decay in the $ZH(\tau_{\mathrm{lep}}\tau_{\mathrm{had}})$ category. The hatched band represents the pre-fit statistical, experimental and theoretical uncertainties. The signal contributions are considered as part of the predictions and are normalized as predicted by the Standard Model.

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Investigating the nature of the K$^*_0(700)$ state with $\pi^\pm$K$^0_{\rm S}$ correlations at the LHC

The ALICE collaboration Acharya, Shreyasi ; Adamova, Dagmar ; Aglieri Rinella, Gianluca ; et al.
Phys.Lett.B 856 (2024) 138915, 2024.
Inspire Record 2739149 DOI 10.17182/hepdata.153749

The first measurements of femtoscopic correlations with the particle pair combinations $\pi^\pm$K$^0_{\rm S}$ in pp collisions at $\sqrt{s}=13$ TeV at the Large Hadron Collider (LHC) are reported by the ALICE experiment. Using the femtoscopic approach, it is shown that it is possible to study the elusive K$^*_0(700)$ particle that has been considered a tetraquark candidate for over forty years. Source and final-state interaction parameters are extracted by fitting a model assuming a Gaussian source to the experimentally measured two-particle correlation functions. The final-state interaction in the $\pi^\pm$K$^0_{\rm S}$ system is modeled through a resonant scattering amplitude, defined in terms of a mass and a coupling parameter. The extracted mass and Breit-Wigner width, derived from the coupling parameter, of the final-state interaction are found to be consistent with previous measurements of the K$^*_0(700)$. The small value and increase of the correlation strength with increasing source size support the hypothesis that the K$^*_0(700)$ is a four-quark state, i.e. a tetraquark state of the form $({\rm q_1},\overline{\rm q_2}, {\rm q_3}, \overline{\rm q_3})$ in which ${\rm q_1}$, ${\rm q_2}$, and ${\rm q_3}$ indicate the flavor of the valence quarks of the $\pi$ and K$^0_{\rm S}$. This latter trend is also confirmed via a simple geometric model that assumes a tetraquark structure of the K$^*_0(700)$ resonance.

12 data tables

Experimental $C(k^*)$, 0-100% mult. class, $k_{\rm T}>0$.

PYTHIA $C(k^*)$, 0-100% mult. class, $k_{\rm T}>0$.

Experimental $C(k^*)$, 0-100% mult. class, $k_{\rm T}<0.5$ GeV/$c$.

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