new physics implications of recent data on k πνν¯ searches...new physics implications of recent...
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New physics implications of recent data on searchesK → πνν
Teppei Kitahara Nagoya University (KMI)
KMI Topics May 20, 2020, online talk
Based on PRL124, 071801 (2020) [arXiv: 1909.11111]
with T.Okui, G.Perez, Y.Soreq, K.Tobioka
Teppei Kitahara: Nagoya University, KMI Topics online seminar, May 20, 2020New physics implica=ons of recent data on searchesK → πνν
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Myself
Teppei Kitahara / 北原 鉄平
KMI, Division of theoretical studies (基礎理論研究部門), YLC Designated Assistant Professor,
term: 2018 October —2021 March (+2 years if pass examination)
2018 October—2020 March, Long term visitor at Technion pheno group in Israel
Nagoya (E-lab) → Tokyo (Ph.D) → Karlsruhe in Germany → Technion in Israel → Nagoya (KMI)
Flavor physics, CP violation, Lepton physics, Dark matter
(KEK)
KL → ππ
K0 → μ+μ− K → πνν
B physics RBC-UKQCD
FCNC and/or CPV
εK and ε′
KS → π0μ+μ−
KS → μ+μ−γKS → 4ℓKS → π+π−e+e−
Understanding of ChPT
KL → π0ℓ+ℓ−
Reduce th error
K → πX
vs unitarityVus
CORRELATION
K → πνν
KL → ππ
K0 → μ+μ− K → πνν
B physics RBC-UKQCD
FCNC and/or CPV
εK and ε′
KS → π0μ+μ−
KS → μ+μ−γKS → 4ℓKS → π+π−e+e−
Understanding of ChPT
KL → π0ℓ+ℓ−
Reduce th error
K → πX
vs unitarityVus
CORRELATION
K → πνν
Teppei Kitahara: Nagoya University, KMI Topics online seminar, May 20, 2020New physics implica=ons of recent data on searchesK → πνν
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and KL → π0νν K+ → π+ννBoth channels are theoretical clean and significantly sensitive to short-
distance contributions, especially is purely CPV decay
Sensitive to CPV in NP sector
SM predictions:
KL → π0νν
[Buras, Buttazzo,Girrbach-Noe, Knegjens ’15]
s → dνν
On-going experiments:
@CERN@J-PARC20 SM events are expected in 2016-18 runs
K+KL SM event is expected in ~2024
(almost) CP-odd CP-even in SM, see Buchalla, Isidori 9806501
c.f. (1.06± 0.09)⇥ 10�10
<latexit sha1_base64="ue8CD/H+QRhXyup38rZvP0xG4Mw=">AAACCHicbVC7TsMwFHXKq5RXgJEBiwqpDFRxQTy2ChbGItGH1ITKcZ3WquNEtoNURR1Z+BUWBhBi5RPY+BvcNgO0HOlKR+fcq3vv8WPOlHacbyu3sLi0vJJfLaytb2xu2ds7DRUlktA6iXgkWz5WlDNB65ppTluxpDj0OW36g+ux33ygUrFI3OlhTL0Q9wQLGMHaSB17v4TKzhl04xA6ZefyCLqahVRB5Nynx8gZdeyi0SeA8wRlpAgy1Dr2l9uNSBJSoQnHSrWRE2svxVIzwumo4CaKxpgMcI+2DRXYbPPSySMjeGiULgwiaUpoOFF/T6Q4VGoY+qYzxLqvZr2x+J/XTnRw4aVMxImmgkwXBQmHOoLjVGCXSUo0HxqCiWTmVkj6WGKiTXYFEwKafXmeNCpldFKu3J4Wq1dZHHmwBw5ACSBwDqrgBtRAHRDwCJ7BK3iznqwX6936mLbmrGxmF/yB9fkDHJSWPg==</latexit>
loop, GIM, and small CKM
Teppei Kitahara: Nagoya University, KMI Topics online seminar, May 20, 2020New physics implica=ons of recent data on searchesK → πνν
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KL → π0νν
K0L (sd or sd)
Special signature!
cτ ∼ 15 mInvisible
π0 (uu − dd)cτ ∼ 25 nm
νν
Invisible
Invisible
3-body decay
2-body decay
γ
γ
Detectable
Teppei Kitahara: Nagoya University, KMI Topics online seminar, May 20, 2020New physics implica=ons of recent data on searchesK → πνν
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searchKL → π0νν
In experiments, this process looks ; namely looks
“invisible beam emits two photons with missing energy”, no charged track!
We can measure only photons’ energy and positions by the elemag calorimeter;
We can not reconstruct the from two photons (!)
In an ideal experiment, the contamination (background) only comes from
( ): . This BG is totally avoided
by imposing large transverse missing energy.
K0L → π0 + missing → 2γ + missing
m2π
K0L → 2γ
K0 − π0mixing + π0 → 2γ ℬ(KL → 2γ)exp = 5.47(4) × 10−4
Teppei Kitahara: Nagoya University, KMI Topics online seminar, May 20, 2020New physics implica=ons of recent data on searchesK → πνν
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Grossman-Nir bound (theoretical relation)
Grossman-Nir bound for general NP models (including ) νiνj
B�KL ! ⇡0⌫⌫
�=
⇣ ⌧L⌧+
+�IB,EM
⌘sin2 ✓B
�K+ ! ⇡+⌫⌫
� 4.32B
�K+ ! ⇡+⌫⌫
�<latexit sha1_base64="xgbMAxhk7DkKgtpviRL9QZC9x3E=">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</latexit>
[Grossman, Nir ’97]
s → dνν s → dννu
<latexit sha1_base64="ZnBVU8ewHTObkyLI/i3dgvP1Jzs=">AAAB7nicbVBNS8NAEJ3Ur1q/qh69LBbBU0lqQY9FLx4r2A9oQ9lsJ+3SzSbsboQS+iO8eFDEq7/Hm//GbZuDtj4YeLw3w8y8IBFcG9f9dgobm1vbO8Xd0t7+weFR+fikreNUMWyxWMSqG1CNgktsGW4EdhOFNAoEdoLJ3dzvPKHSPJaPZpqgH9GR5CFn1Fip0w+oytLZoFxxq+4CZJ14OalAjuag/NUfxiyNUBomqNY9z02Mn1FlOBM4K/VTjQllEzrCnqWSRqj9bHHujFxYZUjCWNmShizU3xMZjbSeRoHtjKgZ61VvLv7n9VIT3vgZl0lqULLlojAVxMRk/jsZcoXMiKkllClubyVsTBVlxiZUsiF4qy+vk3at6l1Vaw/1SuM2j6MIZ3AOl+DBNTTgHprQAgYTeIZXeHMS58V5dz6WrQUnnzmFP3A+fwCgt4/C</latexit>
u<latexit sha1_base64="ZnBVU8ewHTObkyLI/i3dgvP1Jzs=">AAAB7nicbVBNS8NAEJ3Ur1q/qh69LBbBU0lqQY9FLx4r2A9oQ9lsJ+3SzSbsboQS+iO8eFDEq7/Hm//GbZuDtj4YeLw3w8y8IBFcG9f9dgobm1vbO8Xd0t7+weFR+fikreNUMWyxWMSqG1CNgktsGW4EdhOFNAoEdoLJ3dzvPKHSPJaPZpqgH9GR5CFn1Fip0w+oytLZoFxxq+4CZJ14OalAjuag/NUfxiyNUBomqNY9z02Mn1FlOBM4K/VTjQllEzrCnqWSRqj9bHHujFxYZUjCWNmShizU3xMZjbSeRoHtjKgZ61VvLv7n9VIT3vgZl0lqULLlojAVxMRk/jsZcoXMiKkllClubyVsTBVlxiZUsiF4qy+vk3at6l1Vaw/1SuM2j6MIZ3AOl+DBNTTgHprQAgYTeIZXeHMS58V5dz6WrQUnnzmFP3A+fwCgt4/C</latexit>K0
L<latexit sha1_base64="8nCqRQkf423YCJQvxD3h8UyT7Yc=">AAAB7HicdVBNSwMxEM3Wr1q/qh69BIvgqSRVbHsrCCLooYLbFtq1ZNNsG5rNLklWKEt/gxcPinj1B3nz35htK6jog4HHezPMzPNjwbVB6MPJLS2vrK7l1wsbm1vbO8XdvZaOEkWZSyMRqY5PNBNcMtdwI1gnVoyEvmBtf3ye+e17pjSP5K2ZxMwLyVDygFNirORe9a/vUL9YQmWEEMYYZgRXz5Al9XqtgmsQZ5ZFCSzQ7Bffe4OIJiGThgqidRej2HgpUYZTwaaFXqJZTOiYDFnXUklCpr10duwUHlllAINI2ZIGztTvEykJtZ6Evu0MiRnp314m/uV1ExPUvJTLODFM0vmiIBHQRDD7HA64YtSIiSWEKm5vhXREFKHG5lOwIXx9Cv8nrUoZn5QrN6elxsUijjw4AIfgGGBQBQ1wCZrABRRw8ACewLMjnUfnxXmdt+acxcw++AHn7RNi6Y5u</latexit>
K�<latexit sha1_base64="AN6XFLUvNAYWerDVYV36Jia26ug=">AAAB6nicdVBNS0JBFL3Pvsy+rJZthiRok8xYpO6EIII2RmmCvmTeOOrgvA9m5gXy8Ce0aVFE235Ru/5N89Sgog5cOJxzL/fe40VSaIPxh5NZWFxaXsmu5tbWNza38ts7TR3GivEGC2WoWh7VXIqAN4wwkrcixanvSX7rjc5S//aeKy3C4MaMI+76dBCIvmDUWOn68u6omy/gIsaYEIJSQsqn2JJqtVIiFURSy6IAc9S7+fdOL2SxzwPDJNW6TXBk3IQqI5jkk1wn1jyibEQHvG1pQH2u3WR66gQdWKWH+qGyFRg0Vb9PJNTXeux7ttOnZqh/e6n4l9eOTb/iJiKIYsMDNlvUjyUyIUr/Rj2hODNybAllSthbERtSRZmx6eRsCF+fov9Js1Qkx8XS1Umhdj6PIwt7sA+HQKAMNbiAOjSAwQAe4AmeHek8Oi/O66w148xnduEHnLdPDwWNrA==</latexit>
⇡�<latexit sha1_base64="jpN8MSVcGZN1yotLy/oNj4i70Ew=">AAAB7HicdVBNS8NAEJ3Ur1q/qh69LBbBiyVJQ1tvBUE8VjCt0May2W7bpZtN2N0IpfQ3ePGgiFd/kDf/jZu2goo+GHi8N8PMvDDhTGnb/rByK6tr6xv5zcLW9s7uXnH/oKXiVBLqk5jH8jbEinImqK+Z5vQ2kRRHIaftcHyR+e17KhWLxY2eJDSI8FCwASNYG8nvJuzurFcs2eXzetX1qsgu23bNcZ2MuDWv4iHHKBlKsESzV3zv9mOSRlRowrFSHcdOdDDFUjPC6azQTRVNMBnjIe0YKnBEVTCdHztDJ0bpo0EsTQmN5ur3iSmOlJpEoemMsB6p314m/uV1Uj2oB1MmklRTQRaLBilHOkbZ56jPJCWaTwzBRDJzKyIjLDHRJp+CCeHrU/Q/abllp1J2r71S43IZRx6O4BhOwYEaNOAKmuADAQYP8ATPlrAerRfrddGas5Yzh/AD1tsn0aOOtg==</latexit>
⇡0<latexit sha1_base64="w1SNhTGYSBehceNGr3xcic7yQ9M=">AAAB7HicdVBNS8NAEN3Ur1q/qh69LBbBU9ikoa23giAeK5i20May2W7apZtN2N0IpfQ3ePGgiFd/kDf/jZu2goo+GHi8N8PMvDDlTGmEPqzC2vrG5lZxu7Szu7d/UD48aqskk4T6JOGJ7IZYUc4E9TXTnHZTSXEcctoJJ5e537mnUrFE3OppSoMYjwSLGMHaSH4/ZXdoUK4g+6JRc70aRDZCdcd1cuLWvaoHHaPkqIAVWoPye3+YkCymQhOOleo5KNXBDEvNCKfzUj9TNMVkgke0Z6jAMVXBbHHsHJ4ZZQijRJoSGi7U7xMzHCs1jUPTGWM9Vr+9XPzL62U6agQzJtJMU0GWi6KMQ53A/HM4ZJISzaeGYCKZuRWSMZaYaJNPyYTw9Sn8n7Rd26na7o1XaV6t4iiCE3AKzoED6qAJrkEL+IAABh7AE3i2hPVovVivy9aCtZo5Bj9gvX0C1i+OuQ==</latexit>
Same diagram in quark level
��KL ! ⇡0⌫⌫
�
� (K+ ! ⇡+⌫⌫)=
��pA⇡0⌫⌫ � qA⇡0⌫⌫
��2��p2A⇡0⌫⌫
��2=
1
4|1� �⇡⌫⌫ |2
=1
4(1 + |�⇡⌫⌫ |2 � 2Re�⇡⌫⌫) '
1
2(1� Re�⇡⌫⌫) = sin2
Arg (�⇡⌫⌫)
2
�
<latexit sha1_base64="ffVh7GvAnyxiVoBjRiYs69mIwLw=">AAAENnicjVNLb9NAEHZtHsW8UjhyWREhJYoS2W5I4BCpERIg0UNBpK2UTaL1Zp2s6ld310C0MX+KC7+DWy8cQIgrP4G1nUJc2oqRLI9n5vu+mfGuG/uUC8s62dCNK1evXd+8Yd68dfvO3crWvX0eJQyTAY78iB26iBOfhmQgqPDJYcwIClyfHLhHz7L8wTvCOI3Ct2IRk1GAZiH1KEZChSZb+i70GMISvkBBgKBPPFF7NZG7KYCMzuYCMRa9BzCmY2mpWJgA6CImlZMWBfW0jB03/kE2zseZPXOlnSGXMehP5JpQVp+90+Zxge2npXwe/Mu3HEsnTVdckB8zob4BuIhUZdZxf3qxU9lWlTkLsEET+mqXU5STlMdY1/1YMgjN3jpbTRE1lpcwLcdOEzgACvJBsEC+IeklxXUTchoQtZRTCaeQaP4vAegBRRFmjeeDDle/IYoJQyJiIQqI7LNZka2dpSrvvZ7pF+7InFSqVsvqOp2ODaxW2+5uP3WU021bncddYLes3KrayvYmlS9wGuEkIKHAPuJ8aFuxGEnEBMU+SU2YcBIjfIRmZKjcrDM+kvmxT8EjFZkCL2LqCQXIo+sIiQLOF4GrKgMk5vxsLguelxsmwnsykjSME0FCXAh5iQ9EBLI7BKaUESz8hXIQZlT1CvAcqR0KddOyJZxOCi529p2Wvd1yXrerO89X69jUHmgPtZpma11tR3up7WkDDeuf9BP9m/7d+Gx8NX4YP4tSfWOFua+VzPj1Gy3zbBU=</latexit>
Teppei Kitahara: Nagoya University, KMI Topics online seminar, May 20, 2020New physics implica=ons of recent data on searchesK → πνν
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New preliminary result@NA62
[NA62, KAON2019; 2016+17 data]
# of events 3Single event sensitivity (0.346±0.017)×10-10
Expected BG 1.65±0.31Expected SM 2.4±0.3
B�K+ ! ⇡+⌫⌫
�< 11(14)⇥ 10�10 at 90(95)%CL
<latexit sha1_base64="Vw2Us2xXhi47Fj3BlomUYTpCIHM=">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</latexit>
B�K+ ! ⇡+⌫⌫
�< 1.85(2.44)⇥ 10�10 at 90(95)%CL
<latexit sha1_base64="ESA8bRs2O9BkBBCU/JsQD2krTuA=">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</latexit>
Factor 6 improved
B�K+ ! ⇡+⌫⌫
�= 0.47+0.72
�0.47 ⇥ 10�10<latexit sha1_base64="7zzEyJZt7p2ZUvJiHdeb4nrCdy4=">AAACUnicbVJNSysxFE3rx9P6VX1LN8EiKOKQqULdPBDfRnCjYFXo1JJJM21oJhmSO+9RwvzGBw83/hA3LtRM24VfFwLnnntubnKSOJPCAiGPlerc/MLij6Xl2srq2vpGfXPrxurcMN5mWmpzF1PLpVC8DQIkv8sMp2ks+W08+l3Wb/9wY4VW1zDOeDelAyUSwSh4qlcXUUphyKh0Z0UkeQJ7F/fuoMCREYMhUGP0XxxlYsqpHEfa71YOcz4rpqr9XyQ4bnkJCVrNoucOy9TLQaTc4pDcu8OQFL16gwRkEvgrCGeggWZx2av/j/qa5SlXwCS1thOSDLqOGhBM8qIW5ZZnlI3ogHc8VNRP67qJJQXe9UwfJ9r4pQBP2PcdjqbWjtPYK0sD7OdaSX5X6+SQnHSdUFkOXLHpoCSXGDQu/cV9YTgDOfaAMiP8WTEbUkMZ+FeoeRPCz1f+Cm6aQXgUNK+OG6dnMzuW0DbaQXsoRC10is7RJWojhv6hJ/SCXisPleeq/yVTabUy6/mJPkR19Q0q8bKJ</latexit>
[NA62, FPCP2018; 2016 data]
B�K+ ! ⇡+⌫⌫
�< 3.35⇥ 10�10 at 90%CL
<latexit sha1_base64="KgiW2h9daUA7TYvZzIFkso3w0ik=">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</latexit>
[BNL-E949, ‘09]
9
Teppei Kitahara: Nagoya University, KMI Topics online seminar, May 20, 2020New physics implica=ons of recent data on searchesK → πνν
/ 2310
New data@KOTO[KOTO, KAON2019; 2016-18 data]
# of events 4 (3) Single event sensitivity ~7×10-10
Expected BG 0.05±0.02Expected SM 0.05±0.01
B�KL ! ⇡0⌫⌫
�< 3.0⇥ 10�9 at 90%CL
<latexit sha1_base64="eRHjG+8cYOcEeYkYxMLupHFqIgc=">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</latexit>
[KOTO, PRL ‘19; 2015 data]
1 event in 4 events is suspected as a BG from an upstream activity
KOTO is planning to re-evaluate other BG sources, especially /planning a special run for BG in Feb.—Mar.
K+
Teppei Kitahara: Nagoya University, KMI Topics online seminar, May 20, 2020New physics implica=ons of recent data on searchesK → πνν
/ 2311
Preliminary improved back ground estimation 0.05 → 0.34
Slide by T. Nomura (January 17, 2020)
The data still could not explain the BG
2 events in 4 events are suspected as a BG
Teppei Kitahara: Nagoya University, KMI Topics online seminar, May 20, 2020New physics implica=ons of recent data on searchesK → πνν
/ 2312
[TK, Okui, Perez, Soreq, Tobioka ‘20]Assuming signal = 3 events in KOTO eventsStatistics:
Only KL data (1d.o.f)
Best fit vs. SM ●
p-value ~ 10-4 ~ 3.8σ
KL—K+ plane (2d.o.f)
~ 3.4σBest fit vs. SM ●
NP on the GN bound (1d.o.f)
Best fit vs. Best NP ●
~ 2.1σ
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SM+NP w/o interference
Teppei Kitahara: Nagoya University, KMI Topics online seminar, May 20, 2020New physics implica=ons of recent data on searchesK → πνν
/ 2313
What do we learn from data?
NA62 is almost probing the SM signals. Great but no surprises.
KOTO events are about two orders of magnitude larger than
the SM [~3.8 (3.4) σ discrepancy]
If we consider general new physics that interacts with
neutrinos or stable and invisible new particles, the discrepancy
can be reduced to 2.1σ (red circle)
If the events are true, the Grossman-Nir bound has to be
broken or has to be bypassed
@CERN@J-PARC20 SM events are expected in 2016-18 runs
K+KL SM event is expected in ~2024
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Teppei Kitahara: Nagoya University, KMI Topics online seminar, May 20, 2020New physics implica=ons of recent data on searchesK → πνν
/ 23
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14
Heavy new physics
Heavy new physics can not violate the Grossman-Nir bound
Current data should be just statistical fluctuation
O⌫⌫S,A =
⇥Q2
�12,�
i�Q1
⇤V�A
⇥L�12,�
i�L⇤V�A
<latexit sha1_base64="jEOyAgnRQOFZMrGgnmIw9txwFm0=">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</latexit>
O⌫⌫D =
�d2d1
�V+A
(LL)V�A<latexit sha1_base64="So8+7q0E0ANq+cUPsgH/Rm790C4=">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</latexit>
C⌫⌫S,D � C⌫⌫
A ⇡ e�i 34⇡/(150TeV)2<latexit sha1_base64="xmsUbByh+/iee98hshWxnTef+ic=">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</latexit>
Currently no constraint.
Correlation with (or bound from) the other CPV rare decays:
BR(KL → π0ee) < 2.8 × 10−10 BR(KL → π0μμ) < 3.8 × 10−10BR(KS → μμ) < 2.4 × 10−10
[KTEV ‘04] [KTEV ’00][LHCb ’19]
[TK, Okui, Perez, Soreq, Tobioka ’20] [Li, Ma, Schmidt, ’20]
Teppei Kitahara: Nagoya University, KMI Topics online seminar, May 20, 2020New physics implica=ons of recent data on searchesK → πνν
/ 2315
Pion mass new physics: Z′
Consider and with , the constraint from is
significantly loosened by the background of
KL → π0Z′ Z′ → νν mZ′ ∼ mπ K+ → π+νν
K+ → π+π0
[Fuyuto, Hou, Kohda ’15]
B�K+ ! ⇡+X
�< 5.6⇥ 10�8 at 90%CL, (mX = m⇡0)
<latexit sha1_base64="czT+9N8yC/WAG73pRZIfUVNliVg=">AAACY3icbVFBTxQxFO6MiLCoDMiNkDRuSDDKZgZRMZGEwIUED5i4sMl22XS6nd2GdmbSvlHXpvsjvXnz4v+wOzsHBV/S5sv33vve69e0lMJAHP8MwgdLD5cfray21h4/eboebWxemaLSjHdZIQvdS6nhUuS8CwIk75WaU5VKfp3ens3z11+4NqLIP8O05ANFx7nIBKPgqWH0nSgKE0alPXVE8gz2Lm7sS4eJFuMJUK2Lr5iUouZ6C/LFhzedt5iAUNzgJL6x+0eOAP8GWtkZhZl7H5NdfPbx1WwhqIa25479XevEzjUyw6gdd+I68H2QNKCNmrgcRj/IqGCV4jkwSY3pJ3EJA0s1CCa5a5HK8JKyWzrmfQ9z6hcc2Nojh3c9M8JZof3JAdfs3x2WKmOmKvWVc0fM3dyc/F+uX0F2NLAiLyvgOVsMyiqJocBzw/FIaM5ATj2gTAu/K2YTqikD/y0tb0Jy98n3wdVBJ3ndOfh02D45bexYQdvoOdpDCXqHTtA5ukRdxNCvYDlYD6Lgd7gWboZbi9IwaHqeoX8i3PkDeiu3AA==</latexit>
[BNL-E949, ‘09]
“ blind spot” (NA62); π0 116 < mmiss < 152 MeV
BR (t ! cZ 0)<latexit sha1_base64="o8OyofD4UAhwa27eHjzQ/6MzxNA=">AAACG3icbVDLSgNBEJz1bXytevQyGIR4CbtR0GPQi0cVo2I2htlJbzJkZneZ6VXDkv/w4q948aCIJ8GDf+PkcfBV0FBUddPdFaZSGPS8T2dicmp6ZnZuvrCwuLS84q6unZsk0xxqPJGJvgyZASliqKFACZepBqZCCRdh93DgX9yANiKJz7CXQkOxdiwiwRlaqelWAoQ71Co/OO0HEiIsIQ20aHeQaZ3cUk6vrvMg1UJBf6RvN92iV/aGoH+JPyZFMsZx030PWgnPFMTIJTOm7nspNnKmUXAJ/UKQGUgZ77I21C2NmQLTyIe/9emWVVo0SrStGOlQ/T6RM2VMT4W2UzHsmN/eQPzPq2cY7TdyEacZQsxHi6JMUkzoICjaEho4yp4ljGthb6W8wzTjaOMs2BD83y//JeeVsr9TrpzsFqsH4zjmyAbZJCXikz1SJUfkmNQIJ/fkkTyTF+fBeXJenbdR64QznlknP+B8fAEKFqIG</latexit>
Large was already predicted in 2015
ℬ(KL → π0νν)BR
�B+ ! K+⌫⌫
�=
�0.35+0.6
�0.15
�⇥ 10�5
<latexit sha1_base64="GttSkDBvZT4tddvhdVzhSJC4v14=">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</latexit>
[BaBar 1303.7465]
15
Teppei Kitahara: Nagoya University, KMI Topics online seminar, May 20, 2020New physics implica=ons of recent data on searchesK → πνν
/ 2316
Pion mass new physics: Minimal Higgs portal
SM + light CP-even singlet scalar, which mixes with the SM Higgs by sin θ[Egana-Ugrinovic, Homiller, Meade 1911.10203], [Bhupal Dev, Mohapatra, Zhang 1911.12334]
yt × sin θ
2σ statistical fluctuation
Dashed-gray contour:
is practically stable
cτφ
φBR(φ → ee) ∼ 100 %
“ blind spot”π0
Teppei Kitahara: Nagoya University, KMI Topics online seminar, May 20, 2020New physics implica=ons of recent data on searchesK → πνν
/ 2317
Unstable light new physics: KL → π0X, X → γγ
is rejected in the NA62 detectorK+ → π+X, X → γγ is long-lived in the KOTO detectorX
L = 150 m, E = 37 GeV
X (~CP even scalar) has finite lifetime and decays into diphoton
is CP-conserving process; CPV is not required in NP sectorKL → π0X
K+π+
γγ
KL
π0 → 2γ
XX
L = 3 m, E ~ 1.5 GeV
NA62 detetor KOTO detetor
[TK, Okui, Perez, Soreq, Tobioka ’20]
CP-odd CP-odd[Leutwyler, Shifman ’90]
Teppei Kitahara: Nagoya University, KMI Topics online seminar, May 20, 2020New physics implica=ons of recent data on searchesK → πνν
/ 2318
Probability that X does not decay in the detector volume (= efficiency factor that X looks
missing neutrinos)
Unstable light new physics: KL → π0X, X → γγ
B(K ! ⇡X)e�Lp
mXc⌧X
<latexit sha1_base64="9ezT7QJ16Rg2ppIdwXvdpUDvcOA=">AAACM3icbZDJSgNBEIZ7XGPcoh69NAZBD4YZFfQoehH1EMFoIBNDTacnaexZ6K5RQjPv5MUX8SCIB0W8+g52loPbDw0ff1VRXX+QSqHRdZ+dsfGJyanpwkxxdm5+YbG0tHypk0wxXmOJTFQ9AM2liHkNBUpeTxWHKJD8Krg56tevbrnSIokvsJfyZgSdWISCAVqrVTrxI8AuA2kO841T6ivR6SIoldxRPxW0vkn5tdnyQwXMnOUmzemQo5ap57lh1EfIBpy3SmW34g5E/4I3gjIZqdoqPfrthGURj5FJ0LrhuSk2DSgUTPK86Geap8BuoMMbFmOIuG6awc05XbdOm4aJsi9GOnC/TxiItO5Fge3sX6h/1/rmf7VGhuF+04g4zZDHbLgozCTFhPYDpG2hOEPZswBMCftXyrpgM0Ebc9GG4P0++S9cble8ncr2+W754HAUR4GskjWyQTyyRw7IMamSGmHknjyRV/LmPDgvzrvzMWwdc0YzK+SHnM8vEvKr2Q==</latexit>
efficiency factor
0.01 0.050.10 0.50 1 5 10
10-8
10-5
0.01
�X [nsec]
suppressionfactor
KOTO
NA62
mX = 100 MeV
mX = 10 MeV
P = exp(−L
γβτX) = exp(−
L(EX /mX)βτX
) ≃ exp(−LmX
pXτX)
(Energy scale)2 ≫ m2X
L = 150 m, pX = 37 GeV L = 3 m, pX~ 1.5 GeV
NA62 detetor KOTO detetor
effic
ienc
y fa
ctor
This efficiency factor can bypass GN relation
Teppei Kitahara: Nagoya University, KMI Topics online seminar, May 20, 2020New physics implica=ons of recent data on searchesK → πνν
/ 2319
Unstable light new physics: KL → π0X, X → γγ
O(10)MeV is preferred in current datamX =
� � � � � � � � � � � � � � � � �� � �
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��
�
�
�
�������� ���� �� �� �� ��� �(��� ���)
�(��� ����)
� �� ��� ��� ��� ��� ����
�
�
�
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�
�
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Required ℬ(KL → π0X)
As increases, X and its pT tend to softmX
[TK, Okui, Perez, Soreq, Tobioka ’20]
(X is assumed to be stable in this plot)
Teppei Kitahara: Nagoya University, KMI Topics online seminar, May 20, 2020New physics implica=ons of recent data on searchesK → πνν
/ 2320
Light new physics: KL → π0X, X → γγ
Specific models are investigated in Egana-Ugrinovic, Homiller, Meade 1911.10203; Liu, McGinnis, Wagner, Wang, 2001.06522
�������� ����
��-�
��-�
��-�
�(��� ���)=����(�+� �+�)
���� ���
���
�(��� ���)> %
� �� ��� ��� ��� �����-��
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� �[���]
[TK, Okui, Perez, Soreq, Tobioka ’20]
KOTO 3 events can be
explain in white region
bound KL → π0γγ
Colored regions are excluded
GN bound can indeed be effectively weakened
bound (NA62@CERN)K+ → π+νν
bound (E949@BNL)K+ → π+νν
Teppei Kitahara: Nagoya University, KMI Topics online seminar, May 20, 2020New physics implica=ons of recent data on searchesK → πνν
/ 2321
Specific model: KOTO + g-2 anomalies
type-X 2HDM plus singlet ϕ[Liu, McGinnis, Wagner, Wang, 2001.06522]
(type-X: only Yℓ is tanβ enhanced)
with n sec lifetimeℬ(ϕ → ee) ≃ 1
muon g-2 anomaly can be solved
KOTO 3 events can be explain in white region
Electron beam dump: eN → eNϕ( → ee)Charm beam dump: pp → K → πϕ( → ee)
Electron beam dump: ee → ϕ( → ee)
Teppei Kitahara: Nagoya University, KMI Topics online seminar, May 20, 2020New physics implica=ons of recent data on searchesK → πνν
/ 2322
Conclusions 1/2
Interesting preliminary events were announced by KOTO experiment. If it is true, it should
be a signal of new physics
Although the Grossman-Nir bound sets the upper bound on , several
new physics can bypass it practically
100 TeV new physics with statistical fluctuation
“ blind spot”
Unstable new light scalar using “lifetime gap”
Connection to other anomaly?
BR(KL → π0 inv.)
π0
Teppei Kitahara: Nagoya University, KMI Topics online seminar, May 20, 2020New physics implica=ons of recent data on searchesK → πνν
/ 2323
Conclusions 2/2
Very recently, several NP models that can violate the Grossman-Nir bound are proposed:
Pair production of dark particles in meson decays, Hostert, Kaneta, Pospelov, 2005.07102;
in Higgs/Z’ portal
KOTO vs. NA62 Dark Scalar Searches, Gori, Perez, Tobioka, 2005.05170;
in strange flavor symmetry with ChPT
Evading the Grossman-Nir bound with ΔI=3/2 new physics, He, Ma, Tandean, Valencia,
2005.02942, 2002.05467 ; by dim-7 or -8 SMEFT operators
Three Exceptions to the Grossman-Nir Bound, Ziegler, Zupan, Zwicky, 2005.00451;
, in explicit isospin violating ChPT
KL → X1X2, X2 → π0X1,
KL → σχ, χ → γγ,
KL → π0ϕ, π0ϕϕ
Backup
Teppei Kitahara: Nagoya University, KMI Topics online seminar, May 20, 2020New physics implica=ons of recent data on searchesK → πνν
/ 2325
Novel new physics interpretations
Heavy NP e.g.,
Light NP: KL → π0X, X → γγ
Pion mass NP:
Can explain 3 signals
still 2.1σ tension (on the GN bound)
[TK, Okui, Perez, Soreq, Tobioka ’20]
O⌫⌫S = (Q2Q1)V�A(LL)V�A
<latexit sha1_base64="QpA7HvG/QHzQ6fEMRxDtZerVRuU=">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</latexit>
KL → π0Z′ , Z′ → νν, mZ′ ∼ mπ0
B�K+ ! ⇡+X
�< 5.6⇥ 10�8 at 90%CL, (mX = m⇡0)
<latexit sha1_base64="czT+9N8yC/WAG73pRZIfUVNliVg=">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</latexit>
[BNL-E949, ‘09]
“ blind spot” (NA62); π0 116 < mmiss < 152 MeV
Can explain 3 signals
New idea
Effectively go beyond the GN bound. Key: finite lifetime, detector difference → “lifetime gap” appears
consider CPV in s → dνν
The Grossman-Nir bound holds
Light NP: pAu: fixed target → a → γγ
Could explain 3 signals
New idea
ALP is produced at fixed target. Key: KOTO does not distinguish ,
mimics with missing pTmγγ
a → γγ π0 → γγ
Teppei Kitahara: Nagoya University, KMI Topics online seminar, May 20, 2020New physics implica=ons of recent data on searchesK → πνν
/ 2326
A simple idea, but does not work
Very simple idea of breaking the Grossman-Nir bound is just kinematics:
mK± = 493.6 MeV
mKL= 497.6 MeV
mπ± = 139.5 MeV
mπ0 = 134.9 MeV
(Mass difference comes from the radiative corrections within the SM)
Δm = 354.1 MeV
Δm = 362.7 MeV
has a larger phase space than
Can new 360 MeV particle explain signals? → Impossible
Emitted is too soft, the missing pT can not become large
KL → π0 K+ → π+
π0
Predicted signal region [Fabbrichesi, Gabrielli, 1911.03755]
26
Teppei Kitahara: Nagoya University, KMI Topics online seminar, May 20, 2020New physics implica=ons of recent data on searchesK → πνν
/ 2327
Validations
Distribution of signal π0ννWe simulated efficiencies difference between
and signal (assuming stable X)
π0νν
π0X
[KOTO, Phys. Rev. Lett. 122, 021802 (2019)]
Our MCKOTO signal region
z[mm]
pπ0
T[M
eV]
[TK, Okui, Perez, Soreq, Tobioka ’20]
27
consistent
consistent
Teppei Kitahara: Nagoya University, KMI Topics online seminar, May 20, 2020New physics implica=ons of recent data on searchesK → πνν
/ 2328
Strategy of KOTO experiment[Figures from Yamanaka-san@FPW2019]
All particles are invisible. One can observe only photon energy
Assuming pion mass, one can reconstruct the decay point and missing pT
Initial state is neutral long-lived particle = KL + neutron (+ ALP see later)
KOTO can not measure diphoton invariant mass
Require large missing pT
Teppei Kitahara: Nagoya University, KMI Topics online seminar, May 20, 2020New physics implica=ons of recent data on searchesK → πνν
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ALP interpretation: pAu → a → γγALP (a) is produced at the fixed target and decays into in the KOTO detector
KOTO does not distinguish
γγ
mγγ
p30 GeV
Fixed terget = Gold (Au) γ
γ
a a
Lint =↵s
8⇡fgaGa
µ⌫Gaµ⌫ +↵EM
8⇡f�aFµ⌫ F
µ⌫
<latexit sha1_base64="QoHKPLDPQTY9ff1zVObp0Gh/+BA=">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</latexit>
Following parameter regions can explain KOTO O(1) events
ma ⇠ O(100)MeV < 3m⇡<latexit sha1_base64="5Y7OlCtlcsAuWyLQEKTxvy8ltrQ=">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</latexit>
fg ⇠ f� ⇠ O(1)TeV<latexit sha1_base64="AJWLvcGaxw14WXeyX69PQeA8c6g=">AAACHHicbVDLSitBEO3xbXxFXbppDIKChBkVdCm6uTsVTBQyYajp1MTG7pmhu+Zyw5APceOvuHFxRdy4EPwbO4+FrwMNp8+poqpOnCtpyfffvYnJqemZ2bn5ysLi0vJKdXWtabPCCGyITGXmOgaLSqbYIEkKr3ODoGOFV/Ht6cC/+ovGyiy9pF6ObQ3dVCZSADkpqu4nUZeHVmqeRGEXtIbRL9RANwJUedbfDnbC3ZDwHxldXmKzH1Vrft0fgv8kwZjU2BjnUfU17GSi0JiSUGBtK/BzapdgSAqF/UpYWMxB3EIXW46moNG2y+Fxfb7llA5PMuNeSnyofu4oQVvb07GrHOxsv3sD8TevVVBy1C5lmheEqRgNSgrFKeODpHhHGhSkeo6AMNLtysUNGBDk8qy4EILvJ/8kzb16sF/fuzioHZ+M45hjG2yTbbOAHbJj9oedswYT7I49sP/sybv3Hr1n72VUOuGNe9bZF3hvH/4RoVU=</latexit>
sin2 ✓a⇡ ⇠ 10�9<latexit sha1_base64="ActVtlMEkdKfptpfFpM0u1uJumo=">AAACC3icbVA9SwNBEN2LXzF+nVraLAmCjeEuCmoXtLGMYD4gdwl7m02yZG/v2J0TwpHexr9iY6GIrX/Azn/jJrlCEx8MPN6bYWZeEAuuwXG+rdzK6tr6Rn6zsLW9s7tn7x80dJQoyuo0EpFqBUQzwSWrAwfBWrFiJAwEawajm6nffGBK80jewzhmfkgGkvc5JWCkrl30NJedCvZgyIB0U4K9mE+wUUPsOp309GrStUtO2ZkBLxM3IyWUoda1v7xeRJOQSaCCaN12nRj8lCjgVLBJwUs0iwkdkQFrGypJyLSfzn6Z4GOj9HA/UqYk4Jn6eyIlodbjMDCdIYGhXvSm4n9eO4H+pZ9yGSfAJJ0v6icCQ4SnweAeV4yCGBtCqOLmVkyHRBEKJr6CCcFdfHmZNCpl96xcuTsvVa+zOPLoCBXRCXLRBaqiW1RDdUTRI3pGr+jNerJerHfrY96as7KZQ/QH1ucPLpWZ2g==</latexit>
KOTO setup
d = 27 m
⌧a ⇠ O(1) nsec<latexit sha1_base64="GY6us1XoUOt+6u8YJVxMkDMR/9A=">AAACEnicbVA9SwNBEN3z2/gVtbRZDIKChLsoaCna2KlgVMiFMLeZ6OLu3rE7J4Yjv8HGv2JjoYitlZ3/xk1M4deDgcd7M8zMSzIlHYXhRzAyOjY+MTk1XZqZnZtfKC8unbk0twLrIlWpvUjAoZIG6yRJ4UVmEXSi8Dy5Puj75zdonUzNKXUzbGq4NLIjBZCXWuWNmCBvAY+d1DzWQFcCVHHUW4+8g7dkdRFvGoei1ypXwmo4AP9LoiGpsCGOW+X3uJ2KXKMhocC5RhRm1CzAkhQKe6U4d5iBuIZLbHhqQKNrFoOXenzNK23eSa0vQ3ygfp8oQDvX1Ynv7B/tfnt98T+vkVNnt1lIk+WERnwt6uSKU8r7+fC2tChIdT0BYaW/lYsrsCDIp1jyIUS/X/5LzmrVaKtaO9mu7O0P45hiK2yVrbOI7bA9dsiOWZ0Jdsce2BN7Du6Dx+AleP1qHQmGM8vsB4K3TxJBnbw=</latexit>
production π→a decay a→γγ
[TK, Okui, Perez, Soreq, Tobioka ’20]