LIMITS ON NEUTRAL PARTICLE PRODUCTION

ATLS

${{\mathit p}}$ ${{\mathit p}}$ $\rightarrow$ ${{\mathit e}}{{\mathit \mu}}$ $/$ ${{\mathit e}}{{\mathit \tau}}$ $/$ ${{\mathit \mu}}{{\mathit \tau}}$

⁶

LHCB

${{\mathit p}}$ ${{\mathit p}}$ $\rightarrow$ ${{\mathit A}^{\,'}}$ $\rightarrow$ ${{\mathit \mu}^{+}}{{\mathit \mu}^{-}}$ ; dark photon

⁷

NA64

${{\mathit e}}$ ${{\mathit Z}}$ $\rightarrow$ ${{\mathit e}}{{\mathit Z}}{{\mathit X}}$( ${{\mathit A}^{\,'}}$)

⁸

NA64

${{\mathit e}}$ ${{\mathit Z}}$ $\rightarrow$ ${{\mathit e}}{{\mathit Z}}{{\mathit A}^{\,'}}$ , ${{\mathit A}^{\,'}}$ $\rightarrow$ ${{\mathit \chi}}{{\mathit \chi}}$

⁹

MARSICANO

E137

${{\mathit e}^{+}}$ ${{\mathit e}^{-}}$ $\rightarrow$ ${{\mathit A}^{\,'}}$( ${{\mathit \gamma}}$) visible decay

¹⁰

CMS

${{\mathit p}}$ ${{\mathit p}}$ $\rightarrow$ ${{\mathit Z}^{\,'}}$ $\rightarrow$ ${{\mathit \ell}^{+}}{{\mathit \ell}^{-}}$ at 13 TeV

¹¹

CMS

${{\mathit p}}$ ${{\mathit p}}$ $\rightarrow$ Black Hole, string ball, sphaleron

¹²

CMS

${{\mathit p}}$ ${{\mathit p}}$ $\rightarrow$ ${{\mathit j}}{{\mathit j}}$

¹³

CMS

${{\mathit p}}$ ${{\mathit p}}$ $\rightarrow$ ${{\mathit b}}{{\mathit \mu}}{{\overline{\mathit \mu}}}$

¹⁴

CMS

${{\mathit p}}$ ${{\mathit p}}$ $\rightarrow$ ${{\mathit \gamma}}{{\mathit \gamma}}$

¹⁵

CMS

${{\mathit p}}$ ${{\mathit p}}$ $\rightarrow$ ${{\mathit V}}$ $\rightarrow$ ${{\mathit W}}{{\mathit h}}$ ; ${{\mathit h}}$ $\rightarrow$ ${{\mathit b}}{{\overline{\mathit b}}}$ ; ${{\mathit W}}$ $\rightarrow$ ${{\mathit \ell}}{{\mathit \nu}}$

¹⁶

2017

ATLS

${{\mathit W}}{{\mathit H}}$ , ${{\mathit Z}}{{\mathit H}}$ resonance

¹⁷

2017

LHCB

${{\mathit p}}$ ${{\mathit p}}$ $\rightarrow$ ${{\mathit \pi}_{{v}}}{{\mathit \pi}_{{v}}}$ , ${{\mathit \pi}_{{v}}}$ $\rightarrow$ ${{\mathit j}}{{\mathit j}}$

¹⁸

ATLS

${{\mathit \ell}}$ + (${{\mathit \ell}}$s or jets)

¹⁹

ATLS

${{\mathit W}}{{\mathit W}}$ , ${{\mathit W}}{{\mathit Z}}$ , ${{\mathit Z}}{{\mathit Z}}$ resonance

²⁰

KRASZNAHORKAY

${{\mathit p}}$ ${}^{7}\mathrm {Li}$ $\rightarrow$ ${}^{8}\mathrm {Be}$ $\rightarrow$ ${{\mathit X}{(17)}}{{\mathit N}}$ , ${{\mathit X}{(17)}}$ $\rightarrow$ ${{\mathit e}^{+}}{{\mathit e}^{-}}$

²¹

LEES

2015

BABR

${{\mathit e}^{+}}{{\mathit e}^{-}}$ collisions

²²

ADAMS

1997

KTEV

$\mathit m$= $1.2 - 5$ GeV

$<10^{-36} - 10^{-33}$

²³

GALLAS

1995

TOF

$\mathit m$= $0.5 - 20$ GeV

$<(4 - 0.3){\times }\text{ 10^}{-31}$

²⁴

AKESSON

1991

CNTR

$\mathit m$ = $0 - 5$ GeV

$<2 \times 10^{-36}$

²⁵

BADIER

1986

BDMP

$\tau $ = (0.05$-1.){\times }10^{-8}$s

$<2.5 \times 10^{-35}$

²⁶

GUSTAFSON

1976

CNTR

$\tau $ $>10^{-7}$ s

¹ AABOUD 2019H searches for di-photon-jet resonance at 13 TeV and 36.7 fb${}^{-1}$ of data; no signal found and limits placed on ${{\mathit \sigma}}\cdot{}$BR vs. mass plane for various simplified models.

² AABOUD 2019V review ATLAS searches for mediator-based DM at 7, 8, and 13 TeV with up to 37 fb${}^{-1}$ of data; no signal found and limits set for wide variety of simplified models of dark matter.

³ SIRUNYAN 2019O search for ${{\mathit p}}$ ${{\mathit p}}$ $\rightarrow$ ${{\mathit \gamma}}$ $\not E_T$ at 13 TeV with 36.1 fb${}^{-1}$; no signal found and limits set for various simplified models.

⁴ AABOUD 2018CJ make multichannel search for ${{\mathit p}}$ ${{\mathit p}}$ $\rightarrow$ ${{\mathit V}}{{\mathit V}}$ $/$ ${{\mathit \ell}}{{\mathit \ell}}$ $/$ ${{\mathit \ell}}{{\mathit \nu}}$ , ${{\mathit V}}$ = ${{\mathit W}},{{\mathit Z}},{{\mathit h}}$ at 13 TeV, 36.1 fb${}^{-1}$; no signal found; limits placed for several BSM models.

⁵ AABOUD 2018CM search for lepton-flavor violating resonance in ${{\mathit p}}$ ${{\mathit p}}$ $\rightarrow$ ${{\mathit e}}{{\mathit \mu}}$ $/$ ${{\mathit e}}{{\mathit \tau}}$ $/$ ${{\mathit \mu}}{{\mathit \tau}}$ at 13 TeV, 36.1 fb${}^{-1}$; no signal is found and limits placed for various BSM models.

⁶ AAIJ 2018AJ search for prompt and delayed dark photon decay ${{\mathit A}^{\,'}}$ $\rightarrow$ ${{\mathit \mu}^{+}}{{\mathit \mu}^{-}}$ at LHCb detector using 1.6 fb${}^{-1}$ of ${{\mathit p}}{{\mathit p}}$ collisions at 13 TeV; limits on m(${{\mathit A}^{\,'}}$) vs. kinetic mixing are set.

⁷ BANERJEE 2018 search for dark photon ${{\mathit A}^{\,'}}$/16.7 MeV boson ${{\mathit X}}$ at NA64 via ${{\mathit e}}$ ${{\mathit Z}}$ $\rightarrow$ ${{\mathit e}}{{\mathit Z}}{{\mathit X}}$( ${{\mathit A}^{\,'}}$); no signal found and limits set on the ${{\mathit X}}-{{\mathit e}^{-}}$ coupling ${{\mathit \epsilon}_{{e}}}$ in the range $1.3 \times 10^{-4}{}\leq{}{{\mathit \epsilon}_{{e}}}{}\leq{}4.2 \times 10^{-4}$ excluding part of the allowed parameter space.

⁸ BANERJEE 2018A search for invisibly decaying dark photons in ${{\mathit e}}$ ${{\mathit Z}}$ $\rightarrow$ ${{\mathit e}}{{\mathit Z}}{{\mathit A}^{\,'}}$ , ${{\mathit A}^{\,'}}$ $\rightarrow$ invisible; no signal found and limits set on mixing for m(${{\mathit A}^{\,'}}$) $<$ 1 GeV.

⁹ MARSICANO 2018 search for dark photon ${{\mathit e}^{+}}$ ${{\mathit e}^{-}}$ $\rightarrow$ ${{\mathit A}^{\,'}}$( ${{\mathit \gamma}}$) visible decay in SLAC E137 ${{\mathit e}}$ beam dump data. No signal observed and limits set in ${{\mathit \epsilon}}$ coupling vs m(${{\mathit A}^{\,'}}$) plane, see their figure 7.

¹⁰ SIRUNYAN 2018BB search for high mass dilepton resonance; no signal found and exclude portions of p-space of ${{\mathit Z}^{\,'}}$, KK graviton models.

¹¹ SIRUNYAN 2018DA search for ${{\mathit p}}$ ${{\mathit p}}$ $\rightarrow$ Black Hole, string ball, sphaleron via high multiplicity events at 13 TeV, 35.9 fb${}^{-1}$; no signal, require e.g. m(BH) $>$ 10.1 TeV.

¹² SIRUNYAN 2018DD search for ${{\mathit p}}$ ${{\mathit p}}$ $\rightarrow$ ${{\mathit j}}{{\mathit j}}$ deviations in dijet angular distribution. No signal observed. Set limits on large extra dimensions, black holes and DM mediators e.g. m(BH) $>$ $5.9 - 8.2$ TeV.

¹³ SIRUNYAN 2018DR search for dimuon resonance in ${{\mathit p}}$ ${{\mathit p}}$ $\rightarrow$ ${{\mathit b}}{{\mathit \mu}}{{\overline{\mathit \mu}}}$ at 8 and 13 TeV. Slight excess seen at m( ${{\mathit \mu}}{{\overline{\mathit \mu}}}$ ) $\sim{}$ 28 GeV in some channels.

¹⁴ SIRUNYAN 2018DU search for high mass diphoton resonance in ${{\mathit p}}$ ${{\mathit p}}$ $\rightarrow$ ${{\mathit \gamma}}{{\mathit \gamma}}$ at 13 TeV using 35.9 fb${}^{-1}$; no signal; limits placed on RS Graviton, LED, and clockwork.

¹⁵ SIRUNYAN 2018ED search for ${{\mathit p}}$ ${{\mathit p}}$ $\rightarrow$ ${{\mathit V}}$ $\rightarrow$ ${{\mathit W}}{{\mathit h}}$ ; ${{\mathit h}}$ $\rightarrow$ ${{\mathit b}}{{\overline{\mathit b}}}$ ; ${{\mathit W}}$ $\rightarrow$ ${{\mathit \ell}}{{\mathit \nu}}$ at 13 TeV with 35.9 fb${}^{-1}$; no signal; limits set on m(${{\mathit W}^{\,'}}$) $>$ 2.9 TeV.

¹⁶ AABOUD 2017B exclude m(${{\mathit W}^{\,'}}$, ${{\mathit Z}^{\,'}}$) $<1.49 - 2.31$ TeV depending on the couplings and ${{\mathit W}^{\,'}}/{{\mathit Z}^{\,'}}$ degeneracy assumptions via ${{\mathit W}}{{\mathit H}}$ , ${{\mathit Z}}{{\mathit H}}$ search in ${{\mathit p}}{{\mathit p}}$ collisions at 13 TeV with 3.2$~$fb${}^{-1}$ of data.

¹⁷ AAIJ 2017BR search for long-lived hidden valley pions from Higgs decay. Limits are set on the signal strength as a function of the mass and lifetime of the long-lived particle in their Fig. 4 and Tab. 4.

¹⁸ AAD 2016O search for high $\mathit E_{T}{{\mathit \ell}}$ + (${{\mathit \ell}}$s or jets) with 3.2 fb${}^{-1}$ at 13 TeV; exclude micro black holes mass $<$ 8 TeV (Fig. 3) for models with two extra dimensions.

¹⁹ AAD 2016R search for ${{\mathit W}}{{\mathit W}}$ , ${{\mathit W}}{{\mathit Z}}$ , resonance in 20.3 fb${}^{-1}$ at 8 TeV data; limits placed on massive RS graviton (Fig. 4).

²⁰ KRASZNAHORKAY 2016 report ${{\mathit p}}$ ${}^{7}{}^{}\mathrm {Li}$ $\rightarrow$ ${}^{8}{}^{}\mathrm {Be}$ $\rightarrow$ ${{\mathit e}}$ ${{\overline{\mathit e}}}$ ${{\mathit N}}$ 5${{\mathit \sigma}}$ resonance at 16.7 MeV-- possible evidence for nuclear interference or new light boson . However, such nuclear interference was ruled out already by ZANG 2017 .

²¹ LEES 2015E search for long-lived neutral particles produced in ${{\mathit e}^{+}}{{\mathit e}^{-}}$ collisions in the Upsilon region, which decays into ${{\mathit e}^{+}}{{\mathit e}^{-}}$ , ${{\mathit \mu}^{+}}{{\mathit \mu}^{-}}$ , ${{\mathit e}^{\pm}}{{\mathit \mu}^{\mp}}$ , ${{\mathit \pi}^{+}}{{\mathit \pi}^{-}}$ , ${{\mathit K}^{+}}{{\mathit K}^{-}}$ , or ${{\mathit \pi}^{\pm}}{{\mathit K}^{\mp}}$ . See their Fig. 2 for cross section limits.

²² ADAMS 1997B search for a hadron-like neutral particle produced in ${{\mathit p}}{{\mathit N}}$ interactions, which decays into a ${{\mathit \rho}^{0}}$ and a weakly interacting massive particle. Upper limits are given for the ratio to ${{\mathit K}_{{L}}}~$production for the mass range $1.2 - 5$ GeV and lifetime $10^{-9} - 10^{-4}~$s. See also our Light Gluino Section.

²³ GALLAS 1995 limit is for a weakly interacting neutral particle produced in 800 GeV/$\mathit c$ ${{\mathit p}}{{\mathit N}}$ interactions decaying with a lifetime of $10^{-4} - 10^{-8}~$s. See their Figs.$~$8 and 9. Similar limits are obtained for a stable particle with interaction cross section $10^{-29} - 10^{-33}$ cm${}^{2}$. See Fig.$~$10.

²⁴ AKESSON 1991 limit is from weakly interacting neutral long-lived particles produced in ${{\mathit p}}{{\mathit N}}$ reaction at 450 GeV/$\mathit c$ performed at CERN$~$SPS. Bourquin-Gaillard formula is used as the production model. The above limit is for $\tau ~>~10^{-7}~$s. For $\tau ~>~10^{-9}~$s, $\sigma ~<~10^{-30}~$cm${}^{−2}$/nucleon is obtained.

²⁵ BADIER 1986 looked for long-lived particles at 300 GeV ${{\mathit \pi}^{-}}$ beam dump. The limit applies for nonstrongly interacting neutral or charged particles with mass $>$2 GeV. The limit applies for particle modes, ${{\mathit \mu}^{+}}{{\mathit \pi}^{-}}$ , ${{\mathit \mu}^{+}}{{\mathit \mu}^{-}}$ , ${{\mathit \pi}^{+}}{{\mathit \pi}^{-}}$ X, ${{\mathit \pi}^{+}}{{\mathit \pi}^{-}}{{\mathit \pi}^{\pm}}$ etc. See their figure 5 for the contours of limits in the mass-$\tau $ plane for each mode.

²⁶ GUSTAFSON 1976 is a 300 GeV FNAL experiment looking for heavy ($\mathit m$ $>$2 GeV) long-lived neutral hadrons in the M4 neutral beam. The above typical value is for $\mathit m$ = 3 GeV and assumes an interaction cross section of 1 mb. Values as a function of mass and interaction cross section are given in figure 2.

References:

2019V

JHEP 1905 142

Constraints on mediator-based dark matter and scalar dark energy models using $\sqrt s = 13$ TeV $pp$ collision data collected by the ATLAS detector

2019H

PR D99 012008

A search for pairs of highly collimated photon-jets in $pp$ collisions at $\sqrt{s}$ = 13 TeV with the ATLAS detector

2019O

JHEP 1902 074

Search for new physics in final states with a single photon and missing transverse momentum in proton-proton collisions at $\sqrt{s} =$ 13 TeV

2018CJ

PR D98 052008

Combination of searches for heavy resonances decaying into bosonic and leptonic final states using 36??fb$^{-1}$ of proton-proton collision data at $\sqrt{s} = 13$ TeV with the ATLAS detector

2018CM

PR D98 092008

Search for lepton-flavor violation in different-flavor, high-mass final states in $pp$ collisions at $\sqrt s=13?$?TeV with the ATLAS detector

2018AJ

PRL 120 061801

Search for Dark Photons Produced in 13�TeV $pp$ Collisions

2018A

PR D97 072002

Search for vector mediator of Dark Matter production in invisible decay mode

PRL 120 231802

Search for a Hypothetical 16.7�MeV Gauge Boson and Dark Photons in the NA64 Experiment at CERN

MARSICANO

PR D98 015031

Dark photon production through positron annihilation in beam-dump experiments

2018BB

JHEP 1806 120

Search for high-mass resonances in dilepton final states in proton-proton collisions at $\sqrt{s}=$ 13 TeV

2018DA

JHEP 1811 042

Search for black holes and sphalerons in high-multiplicity final states in proton-proton collisions at $ \sqrt{s}=13 $ TeV

2018DD

EPJ C78 789

Search for new physics in dijet angular distributions using proton?proton collisions at $\sqrt{s}=$ 13 TeV and constraints on dark matter and other models

2018DR

JHEP 1811 161

Search for resonances in the mass spectrum of muon pairs produced in association with b quark jets in proton-proton collisions at $\sqrt{s} =$ 8 and 13 TeV

2018DU

PR D98 092001

Search for physics beyond the standard model in high-mass diphoton events from proton-proton collisions at $\sqrt{s} =$ 13 TeV

2018ED

JHEP 1811 172

Search for heavy resonances decaying into a vector boson and a Higgs boson in final states with charged leptons, neutrinos and b quarks at $ \sqrt{s}=13 $ TeV

2017B

PL B765 32

Search for New Resonances Decaying to a ${{\mathit W}}$ or ${{\mathit Z}}$ Boson and a Higgs Boson in the ${{\mathit \ell}^{+}}{{\mathit \ell}^{-}}{\mathit {\mathit b}}{\mathit {\overline{\mathit b}}}$, ${{\mathit \ell}}{{\mathit \nu}}{\mathit {\mathit b}}{\mathit {\overline{\mathit b}}}$, and ${{\mathit \nu}}{{\overline{\mathit \nu}}}{\mathit {\mathit b}}{\mathit {\overline{\mathit b}}}$ Channels with ${{\mathit p}}{{\mathit p}}$ Collisions at $\sqrt {s }$ = 13 TeV with the ATLAS Detector

2017BR

EPJ C77 812

Updated Search for Long-Lived Particles Decaying to Jet Pairs

2016O

PL B760 520

Search for TeV-Scale Gravity Signatures in High-Mass Final States with Leptons and Jets with the ATLAS Detector at $\sqrt {s }$ = 13 TeV

2016R

PL B755 285

Combination of Searches for ${{\mathit W}}{{\mathit W}}$, ${{\mathit W}}{{\mathit Z}}$, and ${{\mathit Z}}{{\mathit Z}}$ Resonances in ${{\mathit p}}{{\mathit p}}$ Collisions at $\sqrt {s }$ = 8 TeV with the ATLAS Detector

KRASZNAHORKAY