Teppei Kitahara

Researcher in Physics | teppeik@kmi.nagoya-u.ac.jp

北原 鉄平

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ABOUT

I'm a researcher in physics at Institute for Advanced Research, Nagoya University, Japan. I'm interested in physics beyond the standard model with particular concerns of the flavor physics, the dark matter and the Higgs boson. My primarily focus is on supersymmetric theories as a new physics beyond the standard model, but I have also worked in other many theories including the standard model.
I am from Nagano, Japan. I completed a B.Sc. in Physics at the Nagoya University in 2010 and a M.Sc. in Theoretical Physics at the University of Tokyo in 2012, and received a Ph.D. in Theoretical Physics from the University of Tokyo in March 2015.

CAREER

Designated Assistant Professor
Nagoya University, Japan

October 2018 - current

Long-term Visiting Researcher
Technion–Israel Institute of Technology, Israel

October 2018 - March 2020

Postdoctoral Fellow
Karlsruhe Institute of Technology, Germany

October 2015 - September 2018

Postdoctoral Fellow
High Energy Accelerator Research Organization (KEK), Japan

April 2015 - September 2015



EDUCATION

Ph.D. in Theoretical Physics
The University of Tokyo, Japan

April 2010 - March 2015

B.Sc. in Physics
Nagoya University, Japan

April 2006 - March 2010

Matsumoto Fukashi High school, Japan

April 2003 - March 2006


RESEARCH AREA

Primary Interests
Phenomenology of physics beyond the Standard Model:
Supersymmetric models, CP  violation,  Flavor physics,  Dark matter,
Effective field theories

Secondary Interests
Lepton physics,  Higgs physics,  Collider physics,  Radiative correction, 
Long-distance correction,  Vacuum decay,  Diquark,   Scattering amplitudes,  
Weak measurement

AWARDS

The Lady Davis Fellowship Trust [website] (declined for technical reasons)

October 2018

Young Scientist Award of the Physical Society of Japan (Theoretical Particle Physics) [website: 第12回 日本物理学会若手奨励賞 (素粒子論領域)]

March 2018


MEDIA

February 2020

February 2020


WORKS

Papers

You can check my latest publication list and a total citation from inSPIRE HEP (the most accurate) and Google Scholar.
The others are arXiv,   researchmap,   ResearchGateORCiDScopus,  and CV.
Note that the alphabetical authorship is used, which is a tradition in the high energy physics.

[38] Novel approach to neutron electric dipole moment search using weak measurement
By Daiki Ueda, Teppei Kitahara.
arXiv:2002.11731 [hep-ph]

[37] Probing   flavor-violating ALP at Belle II
By Motoi Endo, Syuhei Iguro, Teppei Kitahara.
arXiv:2002.05948 [hep-ph]

[36] Muon g-2 vs LHC Run 2 in Supersymmetric Models
By Motoi Endo, Koichi Hamaguchi, Sho Iwamoto, Teppei Kitahara.
[arXiv:2001.11025 [hep-ph]]. JHEP 2004 (2020) 165.

[35] Direct CP  Violation in K → μ+ μ- 
By Teppei Kitahara.
Springer Proc.Phys. 234 (2019) 211.
(proceedings of FPCP2018 conference)

[34] New physics implications of recent search for KL→πνν at KOTO
By Teppei Kitahara, Takemichi Okui, Gilad Perez, Yotam Soreq, Kohsaku Tobioka.
[arXiv:1909.11111 [hep-ph]]. Phys.Rev.Lett. 124 (2020) no.7, 071801.
Selected as Editors’ Suggestion and cover of this issue.
Featured in APS Physics SynopsisScience NewsParticleBitesPopular MechanicsPhys.org and so on.

[33] The electroweak effective field theory from on-shell amplitudes
By Gauthier Durieux, Teppei Kitahara, Yael Shadmi, Yaniv Weiss
[arXiv:1909.10551 [hep-ph]]. JHEP 2001 (2020) 119.

[32] Addendum to "Impact of polarization observables and Bc→τν on new physics explanations of the b→cτν anomaly"
By Monika Blanke, Andreas Crivellin, Teppei Kitahara, Marta Moscati, Ulrich Nierste, Ivan Nisandzic.
[arXiv:1905.08253 [hep-ph]]. Phys.Rev. D100 (2019) no.3, 035035.

[31] Opportunities in Flavour Physics at the HL-LHC and HE-LHC
By A. Cerri et al.
[arXiv:1812.07638 [hep-ph]]. CERN Yellow Rep. Monogr. 7 (2019) 867.
(Report from Working Group 4 on the Physics of the HL-LHC, and Perspectives at the HE-LHC)

[30] D* polarization vs. RD(*) anomalies in the leptoquark models
By Syuhei Iguro, Teppei Kitahara, Yuji Omura, Ryoutaro Watanabe, Kei Yamamoto.
[arXiv:1811.08899 [hep-ph]]. JHEP 1902 (2019) 194.

[29] Impact of polarization observables and Bc→τν on new physics explanations of the b→cτν anomaly
By Monika Blanke, Andreas Crivellin, Stefan de Boer, Teppei Kitahara, Marta Moscati, Ulrich Nierste, Ivan Nisandzic.
[arXiv:1811.09603 [hep-ph]]. Phys.Rev. D99 (2019) no.7, 075006.

[28] SMEFT top-quark effects on ΔF =2 observables
By Motoi Endo, Teppei Kitahara, Daiki Ueda.
[arXiv:1811.04961 [hep-ph]]. JHEP 1907 (2019) 182.

[27] Recent developments on direct CP  violation in the kaon system and connection to K →πνν  measurements
By Teppei Kitahara.
PoS HQL2018 (2018) 026.
(proceedings of HQL2018 conference)

[26] Prospects for Measurements with Strange Hadrons at LHCb
By A. A. Alves Junior et al.
[arXiv:1808.03477 [hep-ex]]. JHEP 1905 (2019) 048.

[25] Standard Model and New physics for ε'KK
By Teppei Kitahara.
EPJ Web Conf. 179 (2018) 01007.
(proceedings of FCCP2017 conference)

[24] Soft-Photon Corrections to B → D τ ν  Relative to B → D μ ν
By Stefan de Boer, Teppei Kitahara, Ivan Nisandzic.
[arXiv:1803.05881 [hep-ph]]. Phys.Rev.Lett. 120 (2018) no.26, 261804.

[23] Gluino-mediated electroweak penguin with flavor-violating trilinear couplings
By Motoi Endo, Toru Goto, Teppei Kitahara, Satoshi Mishima, Daiki Ueda, Kei Yamamoto.
[arXiv:1712.04959 [hep-ph]]. JHEP 1804 (2018) 019.

[22] Probing SUSY effects in KS0 → μ+ μ- 
By Veronika Chobanova, Giancarlo D'Ambrosio, Teppei Kitahara, Miriam Lucio Martinez, Diego Martinez Santos, Isabel Suarez Fernandez, Kei Yamamoto.
[arXiv:1711.11030 [hep-ph]]. JHEP 1805 (2018) 024.

[21] Direct CP  Violation in K → μ+ μ- 
By Giancarlo D'Ambrosio, Teppei Kitahara.
[arXiv:1707.06999 [hep-ph]]. Phys.Rev.Lett. 119 (2017) no.20, 201802.

[20] Correlations of ε'KK with K→πνν  in Models of New Physics
By Teppei Kitahara.
[arXiv:1705.05462 [hep-ph]]. (proceedings of 52th Rencontres de Moriond electroweak interactions and unified theories, March 2017)

[19] K→πνν  in the MSSM in Light of the ε'KK Anomaly
By Andreas Crivellin, Giancarlo D'Ambrosio, Teppei Kitahara, Ulrich Nierste.
[arXiv:1703.05786 [hep-ph]]. Phys.Rev. D96 (2017) no.1, 015023.

[18] Revisiting Kaon Physics in General Z  Scenario
By Motoi Endo, Teppei Kitahara, Satoshi Mishima, Kei Yamamoto.
[arXiv:1612.08839 [hep-ph]]. Phys.Lett. B771 (2017) 37-44

[17] Direct CP  violation in K → π π  decays and supersymmetry
By Teppei Kitahara, Ulrich Nierste, Paul Tremper.
[arXiv:1612.07967 [hep-ph]]. PoS ICHEP2016 (2016) 564.
(proceedings of ICHEP 2016 conference)

[16] Recent progress on CP  violation in K → π π  decays in the SM and a supersymmetric solution
By Teppei Kitahara, Ulrich Nierste, Paul Tremper.
[arXiv:1611.08278 [hep-ph]]. J.Phys.Conf.Ser. 800 (2017) no.1, 012019.
(proceedings of KAON 2016 conference)

[15] The Protophobic Light Vector Boson as a Mediator to the Dark Sector
By Teppei Kitahara, Yasuhiro Yamamoto.
[arXiv:1609.01605 [hep-ph]]. Phys.Rev. D95 (2017) no.1, 015008.

[14] Singularity-free Next-to-leading Order Δ S= 1 Renormalization Group Evolution and ε'KK in the Standard Model and Beyond
By Teppei Kitahara, Ulrich Nierste, Paul Tremper.
[arXiv:1607.06727 [hep-ph]]. JHEP 1612 (2016) 078.

[13] Supersymmetric Explanation of CP  Violation in K → π π  Decays
By Teppei Kitahara, Ulrich Nierste, Paul Tremper.
[arXiv:1604.07400 [hep-ph]]. Phys.Rev.Lett. 117 (2016) no.9, 091802.

[12] ATLAS on-Z Excess via gluino-Higgsino-singlino decay chains in the NMSSM
By Keisuke Harigaya, Masahiro Ibe, Teppei Kitahara.
[arXiv:1510.07691 [hep-ph]]. JHEP 1601 (2016) 030.

[11] Aspects of High-Scale Supersymmetry in a Singlet-Extended Model
By Teppei Kitahara.
[arXiv:1508.04810 [hep-ph]]. UTokyo Repository 1150220 (2015).
(doctoral thesis in the University of Tokyo)

[10] Prospects for Spin-1 Resonance Search at 13 TeV LHC and the ATLAS Diboson Excess
By Tomohiro Abe, Teppei Kitahara, Mihoko M. Nojiri.
[arXiv:1507.01681 [hep-ph]]. JHEP 1602 (2016) 084.

[9] Diquark bound states with a completely crossed ladder truncation
By Go Mishima, Ryusuke Jinno, Teppei Kitahara.
[arXiv:1502.05415 [nucl-th]]. Phys.Rev. D91 (2015) 076011.

[8] Towards a Scale Free Electroweak Baryogenesis
By Kazuya Ishikawa, Teppei Kitahara, Masahiro Takimoto.
[arXiv:1410.5432 [hep-ph]]. Phys.Rev. D91 (2015) no.5, 055004.

[7] Singlino Resonant Dark Matter and 125 GeV Higgs Boson in High-Scale Supersymmetry
By Kazuya Ishikawa, Teppei Kitahara, Masahiro Takimoto.
[arXiv:1405.7371 [hep-ph]]. Phys.Rev.Lett. 113 (2014) no.13, 131801.

[6] Future Prospects for Stau in Higgs Coupling to Di-photon
By Motoi Endo, Teppei Kitahara, Takahiro Yoshinaga.
[arXiv:1401.3748 [hep-ph]]. JHEP 1404 (2014) 139.

[5] Gauge invariant Barr-Zee type contributions to fermionic EDMs in the two-Higgs doublet models
By Tomohiro Abe, Junji Hisano, Teppei Kitahara, Kohsaku Tobioka.
[arXiv:1311.4704 [hep-ph]]. JHEP 1401 (2014) 106, Erratum: JHEP 1604 (2016) 161.

[4] Reconstructing Supersymmetric Contribution to Muon Anomalous Magnetic Dipole Moment at ILC
By Motoi Endo, Koichi Hamaguchi, Sho Iwamoto, Teppei Kitahara, Takeo Moroi.
[arXiv:1310.4496 [hep-ph]]. Phys.Lett. B728 (2014) 274-281.

[3] Probing Bino contribution to muon g-2
By Motoi Endo, Koichi Hamaguchi, Teppei Kitahara, Takahiro Yoshinaga.
[arXiv:1309.3065 [hep-ph]]. JHEP 1311 (2013) 013.

[2] Stau with Large Mass Difference and Enhancement of the Higgs to Diphoton Decay Rate in the MSSM
By Teppei Kitahara, Takahiro Yoshinaga.
[arXiv:1303.0461 [hep-ph]]. JHEP 1305 (2013) 035.

[1] Vacuum Stability Constraints on the Enhancement of the h → γ γ rate in the MSSM
By Teppei Kitahara.
[arXiv:1208.4792 [hep-ph]]. JHEP 1211 (2012) 021.



PRESENTATIONS

International Conference
[P] : Poster presentation

New physics implications of recent search for KL→πνν at KOTO, Invited talk, COST Workshop: Probing BSM physics at different scales, Magnus Haus, Berlin, Germany, January 2020

New physics implications of recent search for KL→πνν at KOTO experiment, Invited talk, 27th Regular Meeting of New Higgs Working Group, Osaka University, Japan, December 2019

Theory status and implications of R(D(*))  and polarization observables, Invited review talk, 18th International Conference on B-Physics at Frontier Machines (BEAUTY2019), Ljubljana, Slovenia, October 2019

Hunt for new physics in kaon decays, Invited talk, 2nd Workshop on Hadronic Contributions to New Physics Searches (HC2NP2019), Tenerife, Spain, September 2019

Lepton-flavor universality violation from soft-photon corrections to B semileptonic decays, Heavy-Quark Physics and Fundamental Symmetries: Interplay between theory and experiment, INT, University of Washington, USA, August 2019

Soft-photon corrections to semileptonic B-meson decays, Invited plenary talk, ANOMALIES 2019, IIT Hyderabad, India, July 2019

Unaccounted QED corrections in R(D(*)) ?, Invited lecture, GDR-InF workshop: QED corrections to (semi)leptonic B decays, LPNHE, Paris, July 2019

Soft-photon corrections to semileptonic decays of B-meson, Invited talk, 2019 NPKI workshop, Korea University, Korea, May 2019

Soft-photon corrections to B-meson semileptonic decays, Invited talk, 6th KEK Flavor Factory Workshop (KEK-FF 2019), KEK, Japan, February 2019

Kaon physics and connection to B  anomalies, Invited talk, High energy implications of flavor anomalies, CERN, Switzerland, October 2018

Effect of QED corrections on R (D ), 10Th International Workshop on the CKM Unitarity Triangle (CKM 2018), Heidelberg University, Germany, September 2018

Direct CP  Violation in Kaon, Lecture, Post FPCP 2018 Workshop, IIT Hyderabad, India, July 2018

Direct CP  Violation in K → μ+ μ- , Invited talk, 16th Conference on Flavor Physics and CP Violation (FPCP 2018), University of Hyderabad, India, July 2018

Kaon physics : theory view, Invited talk, Workshop on the physics of HL-LHC, and perspectives at HE-LHC, CERN, Switzerland, June 2018

The recent progress on direct CP  violation in the kaon system and probing new physics, Invited talk, The 3rd physics and applied physics seminar in Germany for Japanese researchers, Max-Planck-Institut für Astrophysik, Munich, Germany, June 2018

The recent developments on direct CP  violation in the kaon system and its connection to the upcoming K→πνν  measurements, Invited talk, Heavy Quarks and Leptons 2018 (HQL2018), Yamagata Terrsa, Yamagata, Japan, May 2018

Standard Model and New physics for ε'K, Invited talk, Flavour changing and conserving processes 2017 (FCCP2017), Villa Orlandi, Anacapri, Capri Island, Italy, September 2017

The ε'KK tension and supersymmetric interpretation, Invited talk, XIIth Meeting on B Physics. Tensions in Flavour measurements: a path toward Physics beyond the Standard Model, Centro Congressi Università di Napoli Federico II, Napoli, Italy, May 2017

Supersymmetry and CP  violation in kaon decays, Invited talk, Rare'N'Strange 2017: strange physics at LHCb, Universidade de Santiago de Compostela, Spain, April 2017

Epsilonprime and K to pi neutrino antineutrino correlations and new physics, MORIOND 2017 EW Session YSF, La Thuile, Italy, March 2017

[P] Supersymmetric explanation of CP  violation in K → π π  decays, MUTAG 2016, Helmholtz Institute Mainz, Germany, December 2016

Supersymmetric explanation of CP  violation in K → π π  decays, KAON2016 conference, University of Birmingham, England, September 2016

Interpretations of ε'KK in the MSSM, The annual Theory Meeting on Particle Physics Phenomenology 2016 (KEK-PH 2016), KEK, Japan, February 2016

Phenomenology of singlet extended supersymmetric model - Dark matter, Baryogenesis, Joint KEK Theory Fermilab Theory Workshop 2015, Fermilab, USA, August 2015

Reconstructing Supersymmetric Contribution to Muon Anomalous Magnetic Dipole Moment at ILC, Asian Linear Collider workshop 2015 (ALCW 2015), KEK, Japan, April 2015

Singlino Resonant Dark Matter in High-Scale nMSSM, The annual Theory Meeting on Particle Physics Phenomenology 2014 (KEK-PH 2014), KEK, Japan, October 2014

[P] Singlino Resonant Dark Matter and 125 GeV Higgs Boson in High-Scale Supersymmetry, Summer Institute 2014 -Phenomenology of Elementary Particles and Cosmology- (SI 2014), Fuji-Yoshida, Japan, August 2014

Future Prospects for Stau in Higgs Coupling to Di-photon, The 22nd International Conference on Supersymmetry and Unification of Fundamental Interactions (SUSY2014), University of Manchester, England, July 2014

Gauge invariant Barr-Zee type contributions to fermionic EDMs in the two-Higgs doublet models, Basis of the Universe with Revolutionary Ideas 2014 (BURI 2014), Toyama University, Japan, February 2014

Probing Bino Contribution to Muon g-2, SUSY: Model-building and Phenomenology, Kavli IPMU, Japan, December 2013

Gauge invariant Barr-Zee type contributions to fermionic EDMs in the 2HDMs, The annual Theory Meeting on Particle Physics Phenomenology 2013 FALL (KEK-PH 2013 FALL), KEK, Japan, October 2013

Vacuum Stability Constraints on the Enhancement of the Higgs to Diphoton Rate in the MSSM, The annual Theory Meeting on Particle Physics Phenomenology 2013 (KEK-PH 2013), KEK, Japan, March 2013

[P] Vacuum Stability Constraints on the Enhancement of the Higgs to Diphoton Rate in the MSSM, G-COE International Symposium on Physical Sciences Frontier, University of Tokyo, Japan, December 2012

National Conference
[P] : Poster presentation

Introduction to B physics (theory), Invited lecture, Flavor PhysicsWorkshop 2019, Osaka, Japan, November 2019

Probing new physics by precision measurements of kaon decays, Invited talk, The progress of the Particle Physics 2018 (PPP 2018), YITP, Japan, August 2018

Probing direct CP  violation in K → μ+ μ- , JPS 2018 Annual (73th) Meeting, Tokyo University of Science, Japan, March 2018

Improvements of theoretical prediction to the Δ S= 1 Kaon decay and effects from supersymmetric models, Award lecture, JPS 2018 Annual (73th) Meeting, Tokyo University of Science, Japan, March 2018

Supersymmetric explanation of CP  violation in K → π π  decays, The progress of the Particle Physics 2016 (PPP 2016), YITP, Japan, September 2016

Prospects for Spin-1 Resonance Search at 13TeV LHC and the ATLAS Diboson Excess, 4th New Physics Forum, ICRR, Japan, August 2015

Electroweak Baryogenesis at TeV scale and ILC, Summer camp on ILC accelerator and physics/detectors 2015, Hotel Tenbo, Ikaho, Japan, July 2015

Towards a Scale Free Electroweak Baryogenesis in the nMSSM, JPS 2015 Annual (70th) Meeting, Waseda University, Japan, March 2015

Diquark bound state using Bethe-Salpeter equation beyond ladder approximation, Invited talk, Beyond the Standard Model in Okinawa 2015, Okinawa Institute of Science and Technology, Japan, March 2015

Phenomenology of Singlino Resonant Dark Matter, Invited talk, Beyond the Standard Model in Okinawa 2015, Okinawa Institute of Science and Technology, Japan, March 2015

Singlino Resonant Dark Matter in High-Scale nMSSM, Invited talk, 2014 Tera-Scale Conference, Osaka University, Japan, November 2014

Singlino Resonant Dark Matter in High-Scale nMSSM, JPS 2014 Fall meetings, Saga University, Japan, September 2014

Singlino Resonant Dark Matter and 125 GeV Higgs Boson in High-Scale Supersymmetry, The progress of the Particle Physics 2014 (PPP 2014), YITP, Japan, July 2014

Reconstructing Supersymmetric Contribution to Muon Anomalous Magnetic Dipole Moment at ILC, JPS 2014 Annual (69th) Meeting, Tokai University, Japan, March 2014

Fermionic EDMs in the 2HDM with Z2 symmetry, JPS 2013 Fall meetings, Kochi University, Japan, September 2013

[P] Vacuum Stability and the Higgs to diphoton decay rate in the MSSM, The progress of the Particle Physics 2013 (PPP 2013), YITP, Japan, August 2013

Vacuum Stability Constraints on the Enhancement of the Higgs to Diphoton Rate in the MSSM, JPS 2013 Annual (68th) Meeting, Hiroshima University, Japan, March 2013

Vacuum Stability Constraints on the decay of the Higgs in the MSSM, GCOE 9th RA Meeting, Atami, Japan, February 2013

[P] Constraints on Higgs boson decay to two Photon from the vacuum metastability in the MSSM, Young Nuclear and Particle Physicist Group of Japan Summer School, Fuji-Yoshida, Japan, August, 2012

The Higgs Sector of the Next-to-MSSM, Young Nuclear and Particle Physicist Group of Japan Summer School, Shirahamaso Inn, Shiga, Japan, August 2011

Seminar Talks

Novel approach to neutron electric dipole moment search using weak measurement, Invited talk, Florida State University Seminar, online talk, April 2020

New physics implications of recent search for KL→πνν at KOTO experiment, Invited talk, INPAC-TDLI at SJTU Joint Seminar, online talk, March 2020

Novel approach to neutron electric dipole moment search using weak measurement, Invited talk, Joint particle physics seminars, Ben-Gurion University of the Negev, Israel, January 2020

CP violation in Kaon decays, Laboratoire d'Annecy-le-Vieux de Physique Théorique (LAPTh), CNRS, France, July 2019

CP violation in Kaon, Invited talk, Joint particle physics seminars, Hebrew University, Israel, November 2018

Soft-photon corrections to semileptonic B-meson decays, Invited talk, Particles and Fields Seminar, Ben-Gurion University of the Negev, Israel, November 2018

Soft-photon corrections to semileptonic B decays, University of Tokyo, Japan, August 2018

Soft-photon corrections to R (D ), KEK, Japan, March 2018

Direct CP  Violation in K → μ+ μ- , Nagoya University, Japan, January 2018

Tension of CP  Violation in the Kaon Decay and Supersymmetric Interpretation, Shinshu University, Japan, June 2017

Tension of CP  Violation in the Kaon Decay and Supersymmetric Interpretation, Niigata University, Japan, June 2017

Beryllium anomaly and its possible connection to Dark Sector, Theoretical Astroparticle Physics group seminar, KIT, Germany, February 2017

Recent progress on CP  violation in K → π π  decays in the SM and SUSY solution, Osaka University, Japan, August 2016

Recent progress on CP  violation in K → π π  decays in the SM and SUSY solution, Nagoya University, Japan, August 2016

Recent progress on CP  violation in K → π π  decays in the SM and SUSY solution, University of Tokyo, Japan, August 2016

Recent progress on CP  violation in K → π π  decays in the SM and SUSY solution, KEK, Japan, August 2016

Singlino Resonant Dark Matter and 125 GeV Higgs Boson in High-Scale Supersymmetry, Nagoya University, Japan, May 2015

Towards a scale free electroweak baryogenesis, Toyama University, Japan, May 2015

Gauge invariant Barr-Zee type contributions to fermionic EDMs in the 2HDMs, Tohoku University, Japan, November 2013

Stau with Large Mass Difference and Enhancement of the Higgs to Diphoton Decay Rate in the MSSM, Saitama University, Japan, May 2013



OUTREACH

Search for the Baryon asymmetry by EDM and New Physics, Elementary particle Cafe, Shinjuku, Japan, January 2014

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ADDITIONAL QUALIFICATIONS

Passing the First Level of the Test in Color Coordination authorized by the Japanese Ministry of Education, Culture, Sports, Science and Technology (1st Grade Color Coordinator certified by Color Test Institute)

Practical Mathematics Proficiency Test (Suken), 1st grade


SELECTED PUBLICATIONS

"New physics implications of recent search for KL→πνν  at KOTO"
By Teppei Kitahara, Takemichi Okui, Gilad Perez, Yotam Soreq, Kohsaku Tobioka.
Physical Review Letters 124 (2020) no.7, 071801
The KOTO experiment recently reported four candidate events in the signal region of KL→πνν  search, where the standard model only expects 0.10 ± 0.02 events. If confirmed, this requires physics beyond the standard model to enhance the signal. We examine various new physics interpretations of the result including these: (1) heavy new physics boosting the standard model signal, (2) reinterpretation of "νν" as a new light long-lived particle, or (3) reinterpretation of the whole signal as the production of a new light long-lived particle at the fixed target. We study the above explanations in the context of a generalized new physics Grossman-Nir bound coming from the K+→πνν  decay, bounded by data from the E949 and the NA62 experiments.


"Soft-Photon Corrections to B → D τ ν  Relative to B → D μ ν "
By Stefan de Boer, Teppei Kitahara, Ivan Nisandzic.
Physical Review Letters 120 (2018) no.26, 261804
We evaluate long-distance electromagnetic (QED) contributions to B0 → D+ τ- ν  and B- → D0 τ- ν  relative to B0 → D+ μ- ν  and B- → D0 μ- ν , respectively, in the standard model. We point out that the QED corrections to the ratios R (D+) and R (D0) are not negligible, contrary to the expectation that radiative corrections are almost canceled out in the ratio of the two branching fractions. The reason is that long-distance QED corrections depend on the masses and relative velocities of the daughter particles. We find that theoretical predictions for R (D+)τ/ μ and R (D0)τ/ μ can be amplified by ∼4% and ∼3%, respectively, for the soft-photon energy cut in range 20-40 MeV.


"Direct CP  Violation in K → μ+ μ- "
Giancarlo D'Ambrosio, Teppei Kitahara.
Physical Review Letters 119 (2017) no.20, 201802
A rare decay KL → μ+ μ-  has been measured precisely, while a rare decay KS → μ+ μ-  will be observed by an upgrade of the LHCb experiment. Although both processes are almost CP-conserving decays, we point out that an interference contribution between KL and KS in the kaon beam emerges from a genuine direct CP  violation. It is found that the interference contribution can change KS → μ+ μ-  standard-model predictions at O(60 %). We also stress that an unknown sign of A(KL → γ γ ) can be determined by a measurement of the interference, which can much reduce a theoretical uncertainty of B(KL → μ+ μ- ). We also investigate the interference in a new physics model, where the ε'KK tension is explained by an additional Z-penguin contribution.


"Singularity-free Next-to-leading Order Δ S= 1 Renormalization Group Evolution and ε'KK in the Standard Model and Beyond"
Teppei Kitahara, Ulrich Nierste, Paul Tremper.
Journal of High Energy Physics1612 (2016) 078
The standard analytic solution of the renormalization group (RG) evolution for the Δ S= 1 Wilson coefficients involves several singularities, which complicate analytic solutions. In this paper we derive a singularity-free solution of the next-to-leading order (NLO) RG equations, which greatly facilitates the calculation of ε'K, the measure of direct CP  violation in K → π π  decays. Using our new RG evolution and the latest lattice results for the hadronic matrix elements, we calculate the ratio ε'KK in the standard model at NLO to ε'KK=(1.06±5.07)×10−4, which is 2.8 σ below the experimental value.


"Supersymmetric Explanation of CP  Violation in K → π π  Decays"
Teppei Kitahara, Ulrich Nierste, Paul Tremper.
Physical Review Letters 117 (2016) no.9, 091802
Recent progress in the determination of hadronic matrix elements has revealed a tension between the measured value of ε'KK and the standard-model prediction. The well-understood indirect CP  violation encoded in the quantity εK typically precludes large new-physics contributions to ε'KK and challenges such an explanation of the discrepancy. We show that it is possible to cure the ε'KK anomaly in the Minimal Supersymmetric Standard Model with squark masses above 3 TeV without overshooting εK. This solution exploits two features of supersymmetry: the possibility of large isospin-breaking contributions (enhancing ε'K) and the Majorana nature of gluinos (permitting a suppression of εK). Our solution involves no fine-tuning of CP  phases or other parameters.


"Singlino Resonant Dark Matter and 125 GeV Higgs Boson in High-Scale Supersymmetry"
Kazuya Ishikawa, Teppei Kitahara, Masahiro Takimoto.
Physical Review Letters 113 (2014) no.13, 131801
We consider a singlino Dark Matter (DM) scenario in a singlet extension model of the Minimal Supersymmetric Standard Model, which is so-called the Nearly MSSM (nMSSM). We find that with high-scale supersymmetry breaking the singlino can obtain a sizable radiative correction to the mass, which opens a window for the DM scenario with resonant annihilation via the exchange of the Higgs boson. We show that the current DM relic abundance and the Higgs boson mass can be explained simultaneously. This scenario can be fully probed by XENON1T.


"Gauge invariant Barr-Zee type contributions to fermionic EDMs in the two-Higgs doublet models"
Tomohiro Abe, Junji Hisano, Teppei Kitahara, Kohsaku Tobioka.
Journal of High Energy Physics 1401 (2014) 106
We calculate all gauge invariant Barr-Zee type contributions to fermionic electric dipole moments (EDMs) in the two-Higgs doublet models (2HDM) with softly broken Z 2 symmetry. We calculate the effective couplings in a gauge invariant way by using the pinch technique. We make bounds on the parameter space in type-I, type-II, type-X, and type-Y 2HDMs. The electron and neutron EDMs are complementary to each other in discrimination of the 2HDMs. Type-II and type-X 2HDMs are strongly constrained by recent ACME experiment's result, and future experiments of electron and neutron EDMs may search O(10) TeV physics.

PICTURE

CONTACT

Email
teppeik@kmi.nagoya-u.ac.jp

Adress
E and S Building, Nagoya University,
Nagoya 464-8602,
Japan

Phone
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