View source for Scattering and Neutrino Detector

{{LHC}}

The '''Scattering and Neutrino Detector (SND)''' at the [[Large Hadron Collider]] (LHC), [[CERN]], is an experiment built for the detection of the [[collider]] [[Neutrino|neutrinos]]. The primary goal of SND is to measure the p+p --> <math>\mathrm{\nu}</math>+X  process and search for the [[Feebly Interacting Particles|feebly interacting particles]]. It will be operational from 2022, during the LHC-Run 3 (2022-2024). SND will be installed in an empty tunnel- TI18 that links the LHC and [[Super Proton Synchrotron]], 480m away from the [[ATLAS experiment]] interaction point in the fast forward region and along the beam collision axis.<ref name=":0">{{Cite web|title=CERN approves new LHC experiment|url=https://home.cern/news/news/experiments/cern-approves-new-lhc-experiment|access-date=2021-07-28|website=CERN|language=en}}</ref><ref name="CERNcourier2021">{{Cite web|date=2021-06-02|title=Collider neutrinos on the horizon|url=https://cerncourier.com/a/collider-neutrinos-on-the-horizon/|access-date=2021-08-19|website=CERN Courier|language=en-GB}}</ref><ref name="detectordesign">{{Cite web|title=Designing the SND@LHC experiment|url=https://ep-news.web.cern.ch/content/designing-sndlhc-experiment|access-date=2021-08-19|website=EP News|language=en}}</ref><ref>{{Cite web|title=INSPIRE|url=https://inspirehep.net/literature/1859300|access-date=2021-08-19|website=inspirehep.net}}</ref><ref name="SHiP2020">{{Cite journal|last=Pastore|first=A|date=December 2020|title=Neutrino physics with the SHiP experiment at CERN|journal=Journal of Physics: Conference Series|volume=1690|pages=012171|doi=10.1088/1742-6596/1690/1/012171|s2cid=221931137|issn=1742-6588|doi-access=free}}</ref>

In February 2020, the Search for Hidden Particle (SHiP) collaboration expressed its interest in [[neutrino]]-measurement to the LHC Council (LHCC). The letter of intent for SND was presented in August 2020.<ref name="LOI">{{Cite book|last=Collaboration|first=S. N. D.|url=https://cds.cern.ch/record/2729015?ln=en|title=Scattering and Neutrino Detector at the LHC|date=2020|others=CERN. Geneva. The LHC experiments Committee, LHCC|series=Letter of Intent}}</ref> Based on LHCC’s recommendation, the Letter of intent was followed by the Technical Design report presented in February 2021. The experiment was later approved in March 2021 by the CERN Research Board to be the ninth experiment at LHC.<ref name=":0" /><ref>{{Cite web|title=Greybook|url=https://greybook.cern.ch/experiment/detail?id=SND@LHC|access-date=2021-08-19|website=greybook.cern.ch}}</ref> In 2023, SND@LHC and [[FASER experiment|FASER]] reported the first observation of collider neutrinos.<ref>{{Cite journal |last1=SND@LHC Collaboration |last2=Albanese |first2=R. |last3=Alexandrov |first3=A. |last4=Alicante |first4=F. |last5=Anokhina |first5=A. |last6=Asada |first6=T. |last7=Battilana |first7=C. |last8=Bay |first8=A. |last9=Betancourt |first9=C. |last10=Biswas |first10=R. |last11=Blanco Castro |first11=A. |last12=Bogomilov |first12=M. |last13=Bonacorsi |first13=D. |last14=Bonivento |first14=W. M. |last15=Bordalo |first15=P. |date=2023-07-19 |title=Observation of Collider Muon Neutrinos with the SND@LHC Experiment |journal=Physical Review Letters |volume=131 |issue=3 |pages=031802 |doi=10.1103/PhysRevLett.131.031802|doi-access=free |pmid=37540851 |arxiv=2305.09383 |bibcode=2023PhRvL.131c1802A }}</ref><ref>{{Cite journal |last1=FASER Collaboration |last2=Abreu |first2=Henso |last3=Anders |first3=John |last4=Antel |first4=Claire |last5=Ariga |first5=Akitaka |last6=Ariga |first6=Tomoko |last7=Atkinson |first7=Jeremy |last8=Bernlochner |first8=Florian U. |last9=Blesgen |first9=Tobias |last10=Boeckh |first10=Tobias |last11=Boyd |first11=Jamie |last12=Brenner |first12=Lydia |last13=Cadoux |first13=Franck |last14=Casper |first14=David W. |last15=Cavanagh |first15=Charlotte |date=2023-07-19 |title=First Direct Observation of Collider Neutrinos with FASER at the LHC |journal=Physical Review Letters |volume=131 |issue=3 |pages=031801 |doi=10.1103/PhysRevLett.131.031801|doi-access=free |pmid=37540863 |arxiv=2303.14185 |bibcode=2023PhRvL.131c1801A }}</ref><ref name="colliderneutrino">{{cite journal |last1=Worcester |first1=Elizabeth |date=July 19, 2023 |title=The Dawn of Collider Neutrino Physics |url=https://physics.aps.org/articles/v16/113 |journal=Physics |volume=16 |page=113 |doi=10.1103/Physics.16.113 |bibcode=2023PhyOJ..16..113W |access-date=July 23, 2023}}</ref>

== Physics potential and goals ==
The SND will cover a wide range of physics, such as detecting all three neutrino flavors in the [[pseudorapidity]]  (angular) range that has never been explored before.<ref name="detectordesign" /> Along with the [[FASER experiment|FASERnu detector]] at LHC, it will be the first experiment to observe and study the [[collider]] neutrinos.<ref name="SHiP2020" /> It will also search for [[Physics beyond the Standard Model|Beyond Standard Model]] particles such as [[Feebly Interacting Particles]] and particles that could make up the [[dark matter]].<ref name="LOI" />

=== Physics with neutrinos ===
SND will primarily observe neutrinos in the pseudorapidity range of 7.2 to 8.6. It will detect the [[Scattering parameters|scattering properties]] of the neutrinos in this yet unexplored range and complement the observation range of FASERnu.<ref name="CERNcourier2021" /><ref name="detectordesign" /><ref name="technical proposal">{{Cite book|last1=Ahdida|first1=C.|url=https://cds.cern.ch/record/2750060?ln=en|title=SND@LHC - Scattering and Neutrino Detector at the LHC|last2=Albanese|first2=R.|last3=Alexandrov|first3=A.|last4=Andreini|first4=M.|last5=Anokhina|first5=A.|last6=Bay|first6=A.|last7=Bestmann|first7=P.|last8=Betancourt|first8=C.|last9=Bezshyiko|first9=I.|date=2021|others=CERN. Geneva. The LHC experiments Committee, LHCC|series=Technical proposal}}</ref> The neutrinos in this range come from the decay of heavy quarks such as [[Charm quark|charm decays]] (c → s + <math display="inline">\mathrm{W^{\pm}}</math> : charm quark decaying into a [[strange quark]] and a [[W and Z bosons|W boson]]), and hence SND aims to give valuable insights into the physics of heavy quark production. The charmed-[[hadron]] production studies will also provide data to constrain the [[gluon]] [[Parton (particle physics)|parton distribution function]] in the low Bjorken-x region.<ref name="SHiP2020" /><ref name="LOI" /> In its first operational run, i.e. the LHC's Run-3 between 2022 and 2025, SND is expected to detect and study about 2000 high-energy neutrinos.<ref name="SHiP2020" /><ref name="technical proposal" />

=== Physics with feebly interacting particles ===
The [[Feebly Interacting Particles]] (FIPs) are theorized to be produced in the proton-proton collisions. SND has the potential to detect two types of FIPs; stable FIPs by observing their scattering from the atoms (mostly protons) in the detector target section, and unstable FIPs which could decay inside the detector itself.<ref name="LOI" /> The [[Light dark matter|light-dark matter]] particles hypothesized with scattering properties similar to the neutrinos, and which interact with the Standard Model particles through ‘portal mediators’, could also be possibly detected as FIPs,<ref>{{Cite journal|last1=The SHiP collaboration|last2=Ahdida|first2=C.|last3=Akmete|first3=A.|last4=Albanese|first4=R.|last5=Alexandrov|first5=A.|last6=Anokhina|first6=A.|last7=Aoki|first7=S.|last8=Arduini|first8=G.|last9=Atkin|first9=E.|last10=Azorskiy|first10=N.|last11=Back|first11=J. J.|date=April 2021|title=Sensitivity of the SHiP experiment to light dark matter|journal=Journal of High Energy Physics|language=en|volume=2021|issue=4|pages=199|doi=10.1007/JHEP04(2021)199|bibcode=2021JHEP...04..199S|s2cid=228980760|issn=1029-8479|doi-access=free|hdl=10400.26/40350|hdl-access=free}}</ref> although they will have to be separated from the neutrino scattering background. One basic criterion for such a separation would be to observe the number of [[Inelastic collision|inelastic]] and [[elastic collision]] events. Neutrinos usually scatter inelastically due to the high mass of their mediators ([[W and Z bosons]]). Thus more than the predicted number of elastic collisions will hint at light dark matter scattering events.<ref name="LOI" /><ref name="technical proposal" /> 

== See also ==

* [[FASER experiment|FASERnu experiment at LHC]]
* [[List of Large Hadron Collider experiments|List of LHC experiments]]

== References ==
<!--- See http://en.wikipedia.org/wiki/Wikipedia:Footnotes on how to create references using <ref></ref> tags, these references will then appear here automatically -->
{{Reflist}}

== External links ==

* [https://greybook.cern.ch/experiment/detail?id=SND@LHC SND in CERN Greybook]
* [https://inspirehep.net/experiments/1109026 SND experiment] record on [[INSPIRE-HEP]]

[[Category:Particle experiments]]
[[Category:CERN experiments]]
[[Category:CERN]]
[[Category:Neutrino experiments]]