Dr. Kenji Nishiwaki | Department of Physics


Dr. Kenji
Assistant Professor
Department of Physics
School of Natural Sciences (SNS)
Block-D, Shiv Nadar University
Profile Summary 

[Note: the link to our group website: https://hepsnu.weebly.com/ ]

Now is the time when we should contemplate future directions of phenomenology in particle physics seriously, because no direct and evident signal of new physics has been reported yet till today from the updated CERN Large Hadron Collider (LHC).

Due to the null result at the LHC, we should carefully consider how to probe new physics experimentally. In this regard, the physics associated with the flavors (differences coming from matter generations) is one of the most important directions. We can explore deviations from the standard scenario in measurements of precise experiments. I emphasize that their sensitivities can be much greater than those of the direct searches at the LHC. Indeed, several experimental results of finding such deviations have been already reported, and furthermore various experiments targeted at such deviations are ongoing/planned in the near future.

These probes will give us necessary data for unveiling the mechanism to generate differences in flavor, where the standard scenario cannot explain the origin; it just describes phenomena. Also, to pursue fascinating new scenarios which can address the origin in a reasonable matter is an important task.

Due to the above reasons, I believe that the topics associated with the flavors are especially important, and have been studying them in various points of view these days.

Educational Qualifications 
Bachelor of Science (in Physics)
Kobe University (in Kobe, Japan)
Master of Science (in Physics)
Kobe University (in Kobe, Japan)
Doctor of Science (Ph.D. in Physics)
Kobe University (in Kobe, Japan)
Work Experience 
Cooperative Postdoc Researcher ,
Department of Physics,
Kobe University (in Kobe, Japan)
Postdoctoral Fellow ,
Regional Center for Accelerator-based Particle Physics,
Harish-Chandra Research Institute (in Allahabad/Prayagraj)
Research Fellow ,
School of Physics,
Korea Institute for Advanced Study (in Seoul, South Korea)
Division of Theoretical Physics,
Rudjer Boskovic Institute (in Zagreb, Croatia)
Assistant Professor,
Department of Physics, School of Natural Sciences, Shiv Nadar University, Delhi-NCR
I currently work here
Teaching & Research Interests: 

Particle Physics Phenomenology (model building, flavor physics, collider physics, dark matter, wave-packet formulation for quantum scattering)


[Working Group]

- I am a member of the the New Higgs Working Group chaired by Prof. Shinya Kanemura (Osaka Univ.)

[Selected recent invitations for talks/lecture in last two years]

-    “Addressing B and K flavor anomalies in terms of vectorlike compositeness”,
Invited talk (15 mins) at Conference Anomalies 2019,
IIT Hyderabad, Hyderabad, India, 18 July 2019.

-    “Flavorful Vectorlike compositeness enjoys B & K anomalies; triggers Higgs mechanism”, Invited seminar (1 hour) at particle physics group of Roma Tre University,
Roma Tre University, Rome, Italy, 27 June 2019.

-    “Simultaneous explanation of K and B anomalies in vectorlike compositeness”,
Invited talk (30 mins) at Workshop on the Standard Model and Beyond (as a branch of Corfu Summer Institute, 18th Hellenic School and Workshops on Elementary Physics and Gravity), Corfu, Greece, 31 August 2018.

-    “Simultaneous Interpretation of K and B Anomalies in Vectorlike Compositeness”,
Invited talk (20 mins) at the 23rd Regular Meeting of New Higgs Working Group, Osaka University, Osaka, Japan, 24 August 2018.

-    “Simultaneous Interpretation of K and B Anomalies in Vectorlike Compositeness”,
Invited talk (30 mins) at APCTP-IBS-KISTI-KU 2018 LHC Physics Workshop @ Korea, Konkuk University, Seoul, Republic of Korea, 08 August 2018.

-    “Vector-like confinement visits RK(∗) flavor anomalies and more”,
Invited seminar (1 hour) at the particle physics group (Prof. Hyun Min Lee’s group),
Chung-Ang University, Seoul, Republic of Korea, 04 April 2018.

-    “RK(∗) anomaly comes from vector-like compositeness”,
Invited talk as an activity of the Working Groups I (collider physics)+II (flavor physics) at Workshop on High Energy Physics Phenomenology XV,
Indian Institute of Science Education and Research (IISER) Bhopal, Bhopal, India, 16 December 2017.

-    “What is behind the B-physics RD(∗)  anomaly?”,
Invited review talk at the workshop, The 7th KIAS Workshop on Particle Physics and
Cosmology and The 2nd KEK-NCTS-KIAS Workshop on Particle Physics Phenomenology,
KIAS, Seoul, Republic of Korea, 7 November 2017.

-    “Into the Flavor Physics: a crash course for recent anomalies”,
Two one-hour invited lectures as the 2nd Snail lecture at Yonsei University: RD, RD∗, RK, RK∗ anomalies,
Yonsei University, Seoul, Republic of Korea, 30 June 2017.

Scholarly Activity

[Summary of my publications in public databases]

Recent Publications:

  1. Yukihiro Fujimoto, Kouhei Hasegawa, Kenji Nishiwaki, Makoto Sakamoto, Kazunori Takenaga, "Dynamical generation of quark/lepton mass hierarchy in an extra dimension", PTEP 2019 (2019) 12, 123B02, arXiv:1905.11597 [hep-ph].
  2. Kenzo Ishikawa, Kenji Nishiwaki, Kin-ya Oda, "Scalar scattering amplitude in the Gaussian wave-packet formalism", PTEP 2020 (2020) 10, 103B04, arXiv:2006.14159 [hep-th].
  3. Kenzo Ishikawa, Kenji Nishiwaki, Kin-ya Oda, "New effect in wave-packet scatterings of quantum fields: Saddle points, Lefschetz thimbles, and Stokes phenomenon", arXiv:2102.12032 [hep-th].

Selected Publications (before SNU):

-    Shinya Matsuzaki, Kenji Nishiwaki, Kei Yamamoto, “Simultaneous interpretation of K and B anomalies in terms of chiral-flavorful vectors”,
Journal of High Energy Physics 1811 (2018) 164, arXiv:1806.02312 [hep-ph].

-    Yukihiro Fujimoto, Takashi Miura, Kenji Nishiwaki, and Makoto Sakamoto, “Dynamical generation of fermion mass hierarchy in an extra dimension”,
Physical. Review D97 (2018) 115039, arXiv:1709.05693 [hep-th].

-    Shinya Matsuzaki, Kenji Nishiwaki, and Ryoutaro Watanabe, “Phenomenology of flavorful composite vector bosons in light of B anomalies”,
Journal of High Energy Physics 1708 (2017) 145, arXiv:1706.01463 [hep-ph].

-    Béranger Dumont, Kenji Nishiwaki, and Ryoutaro Watanabe,
“LHC constraints and prospects for S1 scalar leptoquark explaining the B ̄ → D(∗)τν ̄ anomaly”,
Physical. Review D94 (2016) 034001, arXiv:1603.05248 [hep-ph].

-    Shinya Kanemura, Kenji Nishiwaki, Hiroshi Okada, Yuta Orikasa, Seong Chan Park, and Ryoutaro Watanabe,
“LHC 750 GeV diphoton excess in a radiative seesaw model”,
Progress of Theoretical and Experimental Physics 2016 no.12 (2016) 123B04, arXiv:1512.09048 [hep-ph].

-    Seungwon Baek, and Kenji Nishiwaki,
“Leptoquark explanation of h → μτ and muon (g − 2)”,
Physical. Review D93 (2016) 015002, arXiv:1509.07410 [hep-ph].

-    Tomo-hiro Abe, Yukihiro Fujimoto, Tatsuo Kobayashi, Takashi Miura, Kenji Nishiwaki, and Makoto Sakamoto,
“Operator analysis of physical states on magnetized T2/ZN orbifolds”,
Nuclear Physics B890 (2015) 442-480, arXiv:1409.5421 [hep-th].

-    Kenji Nishiwaki, Saurabh Niyogi, and Ambresh Shivaji,
“ttH Anomalous Coupling in Double Higgs Production”,
Journal of High Energy Physics 1404 (2014) 011, arXiv:1309.6907 [hep-ph].

-    Takuya Kakuda, Kenji Nishiwaki, Kin-ya Oda, and Ryoutaro Watanabe, “Universal extra dimensions after Higgs discovery”,
Physical. Review D88 (2013) 035007, arXiv:1305.1686 [hep-ph].

-    AseshKrishna Datta, Kenji Nishiwaki, and Saurabh Niyogi,
“Non-minimal Universal Extra Dimensions: The Strongly Interacting Sector at the Large Hadron Collider”,
Journal of High Energy Physics 1211 (2012) 154, arXiv:1206.3987 [hep-ph].