Neu ino S udies wi h
Yuxiao WANG
on behal o he FASER Collabo a ion
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FASER a TI12 unnel
We a e he e!
7mlong
480 m
Fo wA d Sea ch ExpeRimen
TI12 unnel
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The FASER De ec o
10.1088/1748-0221/19/05/P05066
•10 cm adius
•7 m long
4 LHCb Ou e
ECAL modules
3 x 3 laye s o ATLAS SCT s ip modules
0.57 Tdipoles
1.5 mdecay olume
10 mm hick +dual PMT
eadou (σ=400 ps)
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FASERν Emulsion De ec o
a Xi :2504.13008
sil e b omide c ys als
•730 laye s o 1.1 mm
ungs en pla es
in e lea ed wi h
emulsion ilms
•25×30cm!,1.1 m, 1.1
•Exchange emulsions
∼3 imes ayea
50 nm in insic posi ion esolu ion
emulsion ilms om Japan
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Neu ino a FASER
2018
2019
2020
2021
2022
2023
2024
2025
Run 2
Run 3
Neu ino candida es wi h Run2 da a Fi s obse a ion o collide neu inos
Fi s 𝜈!, 𝜈"c oss sec ion measu emen s
Di e en ial 𝜈"c oss sec ion and lux
measu emen s as a unc ion o ene gy
FASERν emulsion de ec o
105 b"# da a collec ed by 2024
FASER elec onic de ec o
190 b"# da a collec ed by 2024
PhysRe D.104.L091101
PhysRe Le .133.021802
PRL edi o ’s sugges ion
Upda e wi h inc eased s a is ics
CERN-FASER-CONF-2025-002
PhysRe Le .131.031801
PRL edi o ’s sugges ion
Neu ino apidi y measu emen s
PhysRe Le .134.211801
CERN-FASER-CONF-2025-001
•Measu e neu ino c oss-sec ions a
TeV-scale;
•F om cha ged cu en (CC)
in e ac ion;
•Fla o agging: 𝜈!, 𝜈", 𝜈#
•Expec ed e en numbe o
250 b$%,Run3:
𝜈!∼1700, 𝜈"∼8500, 𝜈#∼30
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Neu ino a FASERν
Phys.Re .D 110, 012009
Pe o mance alida ion
•2024 es beam da a
•SPS (H8 beamline)
∼20% esolu ion a 200 GeV
La es esul s: CERN-FASER-CONF-2025-002
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Da a Se and Simula ions
•Da a Se s:
-9.5 b$%,LHC Run 3
-Ta ge mass: 314.7 kg in la es analysis
•MC Samples:
-Ligh had on p oduc ion (4 samples:
EPOS-LHC, QGSJET II-04, SIBYLL 2.3d, PYTHIA 8)
-Cha m had on p oduc ion (1 sample:
POWHEG+PYTHIA 8)
CERN-FASER-CONF-2025-002
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Neu ino E en Selec ion
e ex econs uc ion:
𝑁$%&'()* ≥ 5, 𝑁+&,-./.# ≥ 4
PhysRe Le .133.021802
5𝜈!,20 𝜈"
obse ed!
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𝝂𝒆
CC e en s
side iew
beam iew
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La es neu ino esul s a FASER elec onic de ec o
𝜈"c oss sec ion measu emen
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Summa y and Ou look
•FASER his o ic achie emen s:
• i s neu inos obse ed a a pa icle collide
• i s de ec ion o 𝜈$and 𝜈%a he LHC
• i s neu ino c oss-sec ion measu emen s in he TeV ange
•Cu en da a aking:
•Run3 expec a ions: ∼10,000 neu ino in e ac ions
•200 imes mo e e en s wi h ull Run3 da ase
•FASER con inues h ough LHC Run4
•Fu u e: Fo wa d Physics Facili y
•Ambi ious upg ade p og am o HL-LHC (FASER2 &FASERν2)
•Ta ge : ∼1,000,000 high-ene gy neu ino in e ac ions
A Xi 2503.19010
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Acknowledgemen
•FASER is suppo ed by:
•We also hank:
LHC o he excellen pe o mance
ATLAS Collabo a ion o p o iding luminosi y in o ma ion
ATLAS SCT Collabo a ion o spa e acke modules
ATLAS o he use o hei ATHENA so wa e amewo k
LHCb Collabo a ion o spa e ECAL modules
CERN FLUKA eam o he backg ound simula ion
CERN PBC and echnical in as uc u e g oups o he
excellen suppo
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BACKUP
FASER Physics Ta ge s
•Explo e o wa d physics
(pa icles in e y o wa d egion
no seen by ATLAS/CMS)
•Sea ch o new ligh , long-
li ed pa icles
(da k pho ons, ALPs, e c.)
•De ec and s udy collide
neu inos
( i s -e e TeV neu inos a LHC)
PRL 134.211801
JHEP 2025, 199
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Kinema ic Tools Pe o mances
•300 nm posi ion esolu ion has been achie ed -> 0.04 m ad
angula esolu ion o a 1 cm ack.
•Momen um measu emen om Mul iple Coulomb Sca e ing
(MCS): Δ𝑃/𝑃 a 200 GeV ∼0.30
•EM showe ene gy ound using segmen mul iplici y in co e o
EM showe : Δ𝐸/𝐸 a 200 GeV ∼0.21
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Da a Se and Simula ions
•Da a Se s:
-2022 second module → 9.5 b#$
-Ta ge mass: 128.6 kg
-∼1.7% o he da a collec ed o da e.
•MC Samples:
-Ligh had on p oduc ion (4 samples:
EPOS-LHC, QGSJET II-04, SIBYLL 2.3d,
PYTHIA 8)
-Cha m had on p oduc ion (1
sample: POWHEG+PYTHIA 8)
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Sys ema ic Unce ain ies
•se e al ac o s o sys ema ic unce ain ies ha e been conside ed.
• o al sys ema ics: sum in quad a u e.
•Fi s obse a ion o 𝜈!a he LHC (2023)
•Fi s neu ino c oss-sec ion
measu emen in he TeV ange (2024)
•La ge unce ain y om neu ino lux.
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Fi s X-sec ion Measu emen s
PhysRe Le .133.021802
•4𝜈!obse ed
•expec ed backg ound 0.025$'.'%'
)'.'%*
•signi icance: 5.2𝜎
•8𝜈"obse ed
•expec ed backg ound 0.22$'.'+
)'.',
•signi icance: 5.7𝜎
a ge mass 128.6 kg
•FASERν also measu es c oss-sec ion o
Neu al Cu en (NC) neu ino in e ac ions
[a Xi : 2012.10500].
•Non-S anda d In e ac ion (NSI) can be
explo ed in conjunc ion wi h
measu emen o CC c oss-sec ion.
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𝝂
NC C oss Sec ions
