Measurement of the muon flux at the SND@LHC experiment
Authors: Albanese R. , Alexandrov A. , Alicante F. , Anokhina A. , Asada T. , Battilana C. , Bay A. , Betancourt C. , Bick D. , Biswas R. , Castro A. Blanco , Boccia V. , Bogomilov M. , Bonacorsi D. , Bonivento W. M. , Bordalo P. , Boyarsky A. , Buontempo S. , Campanelli M. , Camporesi T. , Canale V. , Castro A. , Centanni D. , Cerutti F. , Chernyavskiy M. , Choi K. -Y. , Cholak S. , Cindolo F. , Climescu M. , Conaboy A. P. , Dallavalle G. M. , Davino D. , de Bryas P. T. , De Lellis G. , De Magistris M. , De Roeck A. , De Rújula A. , De Serio M. , De Simone D. , Crescenzo A. Di , Donà R. , Durhan O. , Fabbri F. , Fedotovs F. , Ferrillo M. , Ferro-Luzzi M. , Fini R. A. , Fiorillo A. , Fresa R. , Funk W. , Walls F. M. Garay , Golovatiuk A. , Golutvin A. , Graverini E. , Guler A. M. , Guliaeva V. , Haefeli G. J. , Hagner C. , Herrera J. C. Helo , van Herwijnen E. , Iengo P. , Ilieva S. , Infantino A. , Iuliano A. , Jacobsson R. , Kamiscioglu C. , Kauniskangas A. M. , Khalikov E. , Kim S. H. , Kim Y. G. , Klioutchnikov G. , Komatsu M. , Konovalova N. , Kuleshov S. , Lacker H. M. , Lantwin O. , Manghi F. Lasagni , Lauria A. , Lee K. Y. , Lee K. S. , Meo S. Lo , Loschiavo V. P. , Marcellini S. , Margiotta A. , Mascellani A. , Miano A. , Mikulenko A. , Montesi M. C. , Navarria F. L. , Ogawa S. , Okateva N. , Ovchynnikov M. , Paggi G. , Park B. D. , Pastore A. , Perrotta A. , Podgrudkov D. , Polukhina N. , Prota A. , Quercia A. , Ramos S. , Reghunath A. , Roganova T. , Ronchetti F. , Rovelli T. , Ruchayskiy O. , Ruf T. , Gilarte M. Sabate , Sadykov Z. , Samoilov M. , Scalera V. , Schmidt-Parzefall W. , Schneider O. , Sekhniaidze G. , Serra N. , Shaposhnikov M. , Shevchenko V. , Shchedrina T. , Shchutska L. , Shibuya H. , Simone S. , Siroli G. P. , Sirri G. , Soares G. , Sohn J. Y. , Sandoval O. J. Soto , Spurio M. , Starkov N. , Timiryasov I. , Tioukov V. , Tramontano F. , Trippl C. , Ursov E. , Ustyuzhanin A. , Vankova-Kirilova G. , Verguilov V. , Leonardo N. Viegas Guerreiro , Vilela C. , Visone C. , Wanke R. , Yaman E. , Yazici C. , Yoon C. S. , Zaffaroni E. , Saa J. Zamora 
Published: January 2024

The Scattering and Neutrino Detector at the LHC (SND@LHC) started taking data at the beginning of Run 3 of the LHC. The experiment is designed to perform measurements with neutrinos produced in proton-proton collisions at the LHC in an energy range between 100 GeV and 1 TeV. It covers a previously unexplored pseudo-rapidity range of $$7.2<\eta <8.4$$

7.2
<
η
<
8.4

. The detector is located 480 m downstream of the ATLAS interaction point in the TI18 tunnel. It comprises a veto system, a target consisting of tungsten plates interleaved with nuclear emulsion and scintillating fiber (SciFi) trackers, followed by a muon detector (UpStream, US and DownStream, DS). In this article we report the measurement of the muon flux in three subdetectors: the emulsion, the SciFi trackers and the DownStream Muon detector. The muon flux per integrated luminosity through an 18$$\times $$
×
18 cm$$^{2}$$

2

area in the emulsion is: $$\begin{aligned} 1.5 \pm 0.1(\text {stat}) \times 10^4\,\text {fb/cm}^{2}. \end{aligned}$$

1.5
±
0.1

(
stat
)

×

10
4

fb/cm
2

.

The muon flux per integrated luminosity through a 31$$\times $$
×
31 cm$$^{2}$$

2

area in the centre of the SciFi is: $$\begin{aligned} 2.06\pm 0.01(\text {stat})\pm 0.12(\text {sys}) \times 10^{4} \text {fb/cm}^{2} \end{aligned}$$

2.06
±
0.01

(
stat
)

±
0.12

(
sys
)

×

10
4

fb/cm
2

The muon flux per integrated luminosity through a 52$$\times $$
×
52 cm$$^{2}$$

2

area in the centre of the downstream muon system is: $$\begin{aligned} 2.35\pm 0.01(\text {stat})\pm 0.10(\text {sys}) \times 10^{4}\,\text {fb/cm}^{2} \end{aligned}$$

2.35
±
0.01

(
stat
)

±
0.10

(
sys
)

×

10
4

fb/cm
2

The total relative uncertainty of the measurements by the electronic detectors is 6$$\%$$
%
for the SciFi and 4$$\%$$
%
for the DS measurement. The Monte Carlo simulation prediction of these fluxes is 20–25$$\%$$
%
lower than the measured values.