New particles discovered at the LHC
New fundamental particles
| Counter | Experiment | Particle | Mass [GeV] | Date | Reference | Note |
|---|---|---|---|---|---|---|
| 1. | ATLAS | $\sf Higgs\ Boson$ | $126.0\pm0.6$ | 31 Jul 2012 | Phys. Lett. B716 (2012) 1 | |
| 1. | CMS | $\sf Higgs\ Boson$ | $125.3\pm0.7$ | 31 Jul 2012 | Phys. Lett. B716 (2012) 30 |
So far 1 fundamental particle has been discovered at the LHC.
New hadrons
| Counter | Experiment | Particle | Mass [MeV] | Quarks | Date | Reference | Note |
|---|---|---|---|---|---|---|---|
| 1. | ATLAS | $\chi_b(3P)$ | $10530\pm10$ | $b\bar{b}$ | 21 Dec 2011 | Phys. Rev. Lett. 108 (2012) 152001 | Later resolved into $\chi_{b1}(3P)$ and $\chi_{b2}(3P)$ |
| 2. | CMS | $\Xi_b^{*0}$ | $5945\pm3$ | $bsu$ | 26 Apr 2012 | Phys. Rev. Lett. 108 (2012) 252002 | |
| 3. | LHCb | $\Lambda_b(5920)^0$ | $5919.8\pm0.7$ | $bud$ | 15 May 2012 | Phys. Rev. Lett. 109 (2012) 172003 | |
| 4. | LHCb | $\Lambda_b(5912)^0$ | $5912.0\pm0.7$ | $bud$ | 15 May 2012 | Phys. Rev. Lett. 109 (2012) 172003 | |
| 5-6. | LHCb | $D_J^*(3000)^{+,0}$ | $3008\pm4$ | $c\bar{q}$ | 17 Jul 2013 | JHEP 09 (2013) 145 | Mass of $+$ state fixed in fit |
| 7. | LHCb | $D_J(3000)^0$ | $2972\pm9$ | $c\bar{u}$ | 17 Jul 2013 | JHEP 09 (2013) 145 | |
| 8. | LHCb | $D_J^*(2760)^+$ | $2772\pm4$ | $c\bar{d}$ | 17 Jul 2013 | JHEP 09 (2013) 145 | |
| 9. | LHCb | $D_J(2740)^0$ | $2737\pm12$ | $c\bar{u}$ | 17 Jul 2013 | JHEP 09 (2013) 145 | |
| 10. | LHCb | $D_J(2580)^0$ | $2580\pm6$ | $c\bar{u}$ | 17 Jul 2013 | JHEP 09 (2013) 145 | |
| 11. | CMS | $X(4140)$ | $4148\pm7$ | $c\bar{c}s\bar{s}$ | 26 Sep 2013 | Phys. Lett. B 734 (2014) 261 | |
| 12. | ATLAS | $B_c(2S)^+$ | $6842\pm6$ | $\bar{b}c$ | 03 Jul 2014 | Phys. Rev. Lett. 113 (2014) 212004 | Later resolved into two states. |
| 13. | LHCb | $D_{s1}^*(2860)^+$ | $2859\pm27$ | $c\bar{s}$ | 28 Jul 2014 | Phys. Rev. Lett. 113 (2014) 162001 | Resolves $D_{sJ}(2860)^+$. See Note c. |
| 14. | LHCb | $\Xi_b^{*-}$ | $5955.3\pm0.5$ | $bsd$ | 18 Nov 2014 | Phys. Rev. Lett. 114 (2015) 062004 | |
| 15. | LHCb | $\Xi_b^{'-}$ | $5935.0\pm0.5$ | $bsd$ | 18 Nov 2014 | Phys. Rev. Lett. 114 (2015) 062004 | |
| 16-17. | LHCb | $B_J(5970)^{+,0}$ | $5969\pm6$ | $\bar{b}q$ | 09 Feb 2015 | JHEP 1504 (2015) 024 | See Note b. |
| 18-19. | LHCb | $B_J(5840)^{+,0}$ | $5863\pm9$ | $\bar{b}q$ | 09 Feb 2015 | JHEP 1504 (2015) 024 | See Note b. |
| 20. | LHCb | $P_c(4380)^+$ | $4380\pm30$ | $c\bar{c}uud$ | 13 Jul 2015 | Phys. Rev. Lett. 115 (2015) 072001 | |
| 21. | LHCb | $P_c(4450)^+$ | $4449.8\pm3.0$ | $c\bar{c}uud$ | 13 Jul 2015 | Phys. Rev. Lett. 115 (2015) 072001 | Later resolved into $P_c(4440)^+$ and $P_c(4457)^+$. |
| 22. | LHCb | $X(4700)$ | $4704\,^{+\,17}_{-\,26}$ | $c\bar{c}s\bar{s}$ | 25 Jun 2016 | Phys. Rev. Lett. 118 (2017) 022003 | See Note d. |
| 23. | LHCb | $X(4500)$ | $4506\,^{+\,16}_{-\,19}$ | $c\bar{c}s\bar{s}$ | 25 Jun 2016 | Phys. Rev. Lett. 118 (2017) 022003 | |
| 24. | LHCb | $X(4274)$ | $4273\,^{+\,19}_{-\,9}$ | $c\bar{c}s\bar{s}$ | 25 Jun 2016 | Phys. Rev. Lett. 118 (2017) 022003 | |
| 25. | LHCb | $D_3^*(2760)^0$ | $2776\pm8$ | $c\bar{u}$ | 03 Aug 2016 | Phys. Rev. D 94 (2016) 072001 | |
| 26. | LHCb | $\Lambda_c(2860)^+$ | $2856\,^{+\,2}_{-\,6}$ | $cud$ | 26 Jan 2017 | JHEP 05 (2017) 30 | |
| 27. | LHCb | $\Omega_c(3119)^0$ | $3119.1\,^{+\,1.0}_{-\,1.1}$ | $css$ | 14 Mar 2017 | Phys. Rev. Lett. 118 (2017) 182001 | |
| 28. | LHCb | $\Omega_c(3090)^0$ | $3090.2\,^{+\,0.7}_{-\,0.8}$ | $css$ | 14 Mar 2017 | Phys. Rev. Lett. 118 (2017) 182001 | |
| 29. | LHCb | $\Omega_c(3066)^0$ | $3065.6\,^{+\,0.4}_{-\,0.6}$ | $css$ | 14 Mar 2017 | Phys. Rev. Lett. 118 (2017) 182001 | |
| 30. | LHCb | $\Omega_c(3050)^0$ | $3050.2\,^{+\,0.3}_{-\,0.5}$ | $css$ | 14 Mar 2017 | Phys. Rev. Lett. 118 (2017) 182001 | |
| 31. | LHCb | $\Omega_c(3000)^0$ | $3000.4\,^{+\,0.4}_{-\,0.5}$ | $css$ | 14 Mar 2017 | Phys. Rev. Lett. 118 (2017) 182001 | |
| 32. | LHCb | $\Xi^{++}_{cc}$ | $3621.4\pm0.8$ | $ccu$ | 06 Jul 2017 | Phys. Rev. Lett. 119 (2017) 112001 | Weakly decaying |
| 33. | LHCb | $\Xi_b(6227)^-$ | $6226.9\pm2.0$ | $bsd$ | 23 May 2018 | Phys. Rev. Lett. 121 (2018) 072002 | |
| CMS | $\chi_{b2}(3P)$ | $10524.0 \pm 0.6$ | $b\bar{b}$ | 28 May 2018 | Phys. Rev. Lett. 121 (2018) 092002 | Resolves $\chi_{b}(3P)$. | |
| 34. | CMS | $\chi_{b1}(3P)$ | $10513.4 \pm 0.4$ | $b\bar{b}$ | 28 May 2018 | Phys. Rev. Lett. 121 (2018) 092002 | Resolves $\chi_{b}(3P)$. |
| 35. | LHCb | $\Sigma_b(6097)^-$ | $6095.8\pm1.8$ | $bdd$ | 20 Sep 2018 | Phys. Rev. Lett. 122 (2019) 012001 | |
| 36. | LHCb | $\Sigma_b(6097)^+$ | $6098.0\pm1.8$ | $buu$ | 20 Sep 2018 | Phys. Rev. Lett. 122 (2019) 012001 | |
| 37. | CMS | $B_c^{*}(2S)^+$ | Undetermined | $\bar{b}c$ | 01 Feb 2019 | Phys. Rev. Lett. 122 (2019) 132001 | Resolves $B_c(2S)^+$ (ATLAS). See Note a. |
| CMS | $B_c(2S)^+$ | $6871.0\pm1.6$ | $\bar{b}c$ | 01 Feb 2019 | Phys. Rev. Lett. 122 (2019) 132001 | Resolves $B_c(2S)^+$ (ATLAS). See Note a. | |
| 38. | LHCb | $X(3842)$ | $3842.7\pm0.2$ | $c\bar{c} (q\bar{q}?)$ | 28 Mar 2019 | JHEP 1907 (2019) 035 | |
| LHCb | $P_c(4457)^+$ | $4457\,^{+\,4}_{-\,2}$ | $c\bar{c}uud$ | 08 Apr 2019 | Phys. Rev. Lett. 122 (2019) 222001 | Resolves $P_c(4450)^+$. | |
| 39. | LHCb | $P_c(4440)^+$ | $4440\,^{+\,4}_{-\,5}$ | $c\bar{c}uud$ | 08 Apr 2019 | Phys. Rev. Lett. 122 (2019) 222001 | Resolves $P_c(4450)^+$. |
| 40. | LHCb | $P_c(4312)^+$ | $4312\,^{+\,7}_{-\,1}$ | $c\bar{c}uud$ | 08 Apr 2019 | Phys. Rev. Lett. 122 (2019) 222001 | |
| 41. | LHCb | $\Lambda_b(6152)^0$ | $6152.5\pm0.4$ | $bud$ | 31 Jul 2019 | Phys. Rev. Lett. 123 (2019) 152001 | |
| 42. | LHCb | $\Lambda_b(6146)^0$ | $6146.2\pm0.4$ | $bud$ | 31 Jul 2019 | Phys. Rev. Lett. 123 (2019) 152001 | |
| 43. | LHCb | $\Omega_b(6350)^-$ | $6349.9\pm0.6$ | $bss$ | 03 Jan 2020 | Phys. Rev. Lett. 124 (2020) 082002 | |
| 44. | LHCb | $\Omega_b(6340)^-$ | $6339.7\pm0.6$ | $bss$ | 03 Jan 2020 | Phys. Rev. Lett. 124 (2020) 082002 | |
| 45. | LHCb | $\Lambda_b(6070)^0$ | $6072.3\pm3.0$ | $bud$ | 12 Feb 2020 | JHEP 06 (2020) 136 | |
| 46. | LHCb | $\Xi_c(2939)^0$ | $2938.55\pm0.30$ | $csd$ | 30 Mar 2020 | Phys. Rev. Lett. 124 (2020) 222001 | |
| 47. | LHCb | $\Xi_c(2923)^0$ | $2923.04\pm0.35$ | $csd$ | 30 Mar 2020 | Phys. Rev. Lett. 124 (2020) 222001 | |
| 48. | LHCb | $T_{c\bar{c}c\bar{c}}$ | $6905\pm13$ | $c\bar{c}c\bar{c}$ | 30 Jun 2020 | Science Bulletin 2020 65(23) 1983 | Mass for one of the fits. |
| 49. | LHCb | $X_1(2900)$ | $2904\pm5$ | $\bar{c}d\bar{s}u$ | 31 Aug 2020 | Phys. Rev. D 102 (2020) 112003 | |
| 50. | LHCb | $X_0(2900)$ | $2866\pm7$ | $\bar{c}d\bar{s}u$ | 31 Aug 2020 | Phys. Rev. D 102 (2020) 112003 | |
| 51. | LHCb | $\Xi_b(6227)^0$ | $6227.1\,^{+\,1.5}_{-\,1.6}$ | $bsu$ | 27 Oct 2020 | Phys. Rev. D103 (2021) 012004 | Isospin partner of $\Xi_b(6227)^-$ |
| 52. | LHCb | $B_s(6114)^0$ | $6114\pm6$ | $\bar{b}s$ | 29 Oct 2020 | arXiv:2010.15931 | |
| 53. | LHCb | $B_s(6063)^0$ | $6063.5\pm1.4$ | $\bar{b}s$ | 29 Oct 2020 | arXiv:2010.15931 | |
| 54. | LHCb | $D_{s0}(2590)^+$ | $2591\pm9$ | $c\bar{s}$ | 18 Nov 2020 | arXiv:2011.09112 | |
| 55. | CMS | $\Xi_b(6100)^-$ | $6100.3\pm0.6$ | $bsd$ | 08 Feb 2021 | arXiv:2102.04524 | |
| 56. | LHCb | $Z_{cs}(4000)^+$ | $4003\,^{+\,7}_{-\,15}$ | $c\bar{c}u\bar{s}$ | 02 Mar 2021 | arXiv:2103.01803 | See Note e. |
| 57. | LHCb | $Z_{cs}(4220)^+$ | $4220\,^{+\,50}_{-\,40}$ | $c\bar{c}u\bar{s}$ | 02 Mar 2021 | arXiv:2103.01803 | |
| 58. | LHCb | $X(4630)$ | $4630\,^{+\,20}_{-\,110}$ | $c\bar{c}s\bar{s}$ | 02 Mar 2021 | arXiv:2103.01803 | |
| 59. | LHCb | $X(4685)$ | $4684\,^{+\,15}_{-\,17}$ | $c\bar{c}s\bar{s}$ | 02 Mar 2021 | arXiv:2103.01803 |
So far 59 hadrons have been discovered at the LHC, of which 52 by LHCb
 Number of new hadrons per year. LHCb-only version: pdf, png |
 Number of hadrons versus time. LHCb-only version: pdf, png |
 Masses and discovery date for states observed at the LHC. Hollow markers indicate superseded states. |
 Masses and discovery date for states observed at LHCb. Hollow markers indicate superseded states. |
Only first observations of particles with $5\sigma$ significance are listed. $q$ stands for $u$ or $d$. If a peak is observed and later resolved into several components, both papers are listed but particles are not double counted.
Notes:- Two peaks are observed. One is the $B_c(2S)^+$, the other likely the partially reconstructed $B_c^*(2S)^+$. The mass of the $B_c(2S)^{*+}$ is determined to be $m(B_c^{*+}(2S))-m(B_c^{*+}) = 567.0\pm1.0$ MeV.
- Charged and neutral states seen. The masses reported here are those of the neutral state (using the "empirical fit"). The heavier state could be the $B_J(5970)$ seen by CDF.
- Previously known narrow $D_{s}(2860)^-$ resolved into a wide spin-1 and a narrow spin-3 state. We therefore consider the spin-1 state to be new.
- A state dubbed $X(4740)$ was reported by LHCb with properties that are consistent with those of the $X(4700)$ state. It is not listed here.
- The mass of the $Z_{cs}(4000)^+$ state is consistent with that of the $Z_{cs}(3985)^-$ reported by BESIII but its width is significantly larger.
Please report mistakes and omissions.
A supporting note (dated 2 March 2021, with a count at 59 resonances) is available at LHCb-FIGURE-2021-001.