Belle II @ University of Florida

PI: John Yelton

US Belle II Science Readiness Briefing Jan 9-10 2019 Group Introduction PI: John Yelton, (member of Belle(II) for 4 years) still working the majority of the time on Belle analysis. Previously a long-time member of CLEO, and then on CMS (final student graduated 2018). Post-Doc: Igal Jaegle, was central to the BEAST II building/commissioning (moved from Hawaii->Florida). Is convener of the Dark Sector group (BELLE) and is very active the Belle II Dark Sector searches Graduate Students: Joseph McNeil, working on secondary and tertiary vertex finding using Belle II data Yefan Tao working on Dark Sector searches using B2BII (the interface which allows Belle data to be analyzed using Belle II software), combining Belle/BelleII data for maximum sensitivity

Jan 9-10 2019 US Belle II Science Readiness Briefing – Institution U. of Florida 2 Faculty Summary John Yelton. 100% (Belle + Belle II) (but presently mostly Belle). Papers published in the last 12 months: 0 “Measurement of Branching Fractions of Hadronic Decays of the c ”. Belle Collaboration (J. Yelton et al.), Phys. Rev. D97 032001 (2018). This details many new measurement of the branching fractions (including resonant 0 substructure) of the c 0 + - “Observation of Excited c Charmed in e e Collisions”. Belle Collaboration (J. Yelton et al.), Phys. Rev. D97 Rapid Communication (2018), 0351102. This confirms 4 out of the 5 peaks found by LHCb. Much of this work was done before the LHCb paper, but the statistics were not sufficient to claim discoveries, so it was only written up once we knew the masses and the widths of the . (27 citations) “Observation of an Excited - Baryon”. Belle Collaboration (J.Yelton et al.), Phys Rev. Lett. 121 052003 (2018). This details the first observation of an excited Omega baryon for several decades. (11 citations) “Editor’s Suggestion” by PRL In addition is a member of the internal referee committee for 4 papers (at this moment) as well as one of the committee of final language editing for Belle publications. Member of the HFLAV group.

Jan 9-10 2019 US Belle II Science Readiness Briefing – Institution U. of Florida 3 Postdoc Summary

Igal Jaeglé. 100% on Belle/Belle II Previously post-doc in Hawaii (5 years) Now in 4th year at Florida, and looking for a permanent position Has much experience in hardware/MC/data acquisition on the BEAST II. “First Measurement of Beam Backgrounds at SuperKEKB”. P.M.Lewis, I.Jaeglé, H.Nakayama et al, Nucl. Instrum. Meth. A914(2019) 69- 144. Paper on the TPC (part of the BEAST II system) in preparation. Convener of the Belle “Dark Sector” group, and co-author of several papers in various stages of preparation. e.g. “Search for Electrophilic Z/” analysis in internal committee ( one of 4 main authors)”

Jan 9-10 2019 US Belle II Science Readiness Briefing – Institution U. of Florida 4 Graduate Student Summary • Student: Joseph T. McNeil – Started on Belle II in 2016 – Working on in Belle II, including checking the Λ finding code, writing - and 0 finders and checking efficiencies in Phase II data and Phase III MC. – Running data-taking shifts – Running (very energetically!) software validation shifts – Passed UF oral qualifying exam

• Student: Yefan Tao – Started on Belle II in 2017 – Working on dark sector searches – Working on using B2BII code to analyze Belle data, which can then be added to Belle II data – Passed UF oral qualifying exam I have 2 grad students, but not enough funding for both students to be on RAs all the time Jan 9-10 2019 US Belle II Science Readiness Briefing – Institution U. of Florida 5 Belle II Activities Two main analysis/software thrusts in Belle II 1. Charmed Baryons and Hyperons 2. Dark Sector searches The two have the connection of secondary and tertiary vertices (beyond the standard reconstruction). Hyperons and charmed baryons (J. Yelton, J.T. McNeil) Although LHCb have high cross-sections for charmed baryon decays, they are not efficient at long-lived (e.g. Λ, , and ) detection. There is much physics to be done above the energies available at J-Lab, but not in the range of LHCb. We have a series of topics that are being analyzed in Belle, but will be continued in Belle II. These require good and standardized reconstruction. We are working on finding good Λ cuts for general users and standardized -, 0, +, - for charmed baryon and hyperon analyses John Yelton invited to be an organizer of charmed baryon studies within the physics group

Jan 9-10 2019 US Belle II Science Readiness Briefing – Institution U. of Florida 6 J.T. McNeil has presented: Belle vs Belle II Lambda Studies – Tracking Group and Physics Performance Meetings Phase II Lambda Efficiencies – Belle2 General Meeting Phase II -, 0 results – Physics General Meeting e.g. Phase II data (only 500 pb-1, and an incomplete experiment).

Jan 9-10 2019 US Belle II Science Readiness Briefing – Institution U. of Florida 7 Dark Sector Searches (I. Jaegle, Y. Tao) I Jaegle: Searching for Electrophilic Z’ (in committee, ready to go with Belle data: extendable to Belle II) also Dark A’ (Belle Note and waiting for committee). Debugging B2BII* software to allow combination of datasets. Limit-finding tutorial for B2GM, based on Belle Dark Sector Searches

Yefan Tao well defined thesis topic, using B2BII software “Search for Neutral Long-Lived Particles” (Previous analyses on smaller datasets has been done by BaBar and BES) Has implemented changes to MadGraph (for long-lived dark sector particles) in BASF2, and introduced new modules for secondary vertices for particles other than ππ and pπ. Target graduation date 2020.

*B2BII software works for most purposes, but not all information is accessible, particularly for those not working with skims.

Jan 9-10 2019 US Belle II Science Readiness Briefing – Institution U. of Florida 8 Personnel % Belle (II) Effort by FY FY18 FY19 FY20 FY21 J. Yelton* 95% 100% 100% 100% I. Jaegle** 100% 100% ->TBA TBA J.McNeil 70%**** 70% 100% 100% Y. Tao*** 70%**** 70% 100% - TBA 0% 0% 100% TOTAL FTEs: 3.4 3.4 4.0 4.0

*J. Yelton working on Belle analysis, but learning Belle II software. **I. Jaegle working on Belle and Belle II combined analyses. Will leave Florida by early 2020 at the latest. *** Y. Tao presently working on Belle data using B2BII software System and will look at Belle II as soon as that data is available **** Y. Tao and J. McNeil need to teach 1 semester/year to make the budget balance

Jan 9-10 2019 US Belle II Science Readiness Briefing – Institution U. of Florida 9 Personnel location by FY

FY18 FY19 FY20 FY21 J. Yelton UF UF UF UF I.Jaegle UF UF TBD TBD J. McNeil UF UF UF ? Y. Tao UF UF UF ?

Jan 9-10 2019 US Belle II Science Readiness Briefing – Institution U. of Florida 10 Conclusion Our physics interests are: 1. Charmed and Strange baryons + Dark Sector Recent achievements: J. Yelton – four first author papers published in last three years. (3 already noted, and,

in addition “Study of Excited States of the c”, Phys. Rev. D94 (2016), 31 citations) - three other analyses have reached the level of “Belle Notes” and have been presented at internal meetings - internal referee committee member for many analyses (4 complete, 4 continuing) - involved in planning for Belle II charmed baryon analyses, and overseeing hyperon reconstruction (J. McNeil) I. Jaegle – leader in the BEAST II commissioning hardware and software - convener of BELLE Dark Sector group. A primary author of two papers in the pipeline - phenomenological study of dark particles in Compton-like processes. (Unfortunately does not help BELLE II greatly, but has talked to several other collaborations) J. McNeil and Y. Tao. Both 4th Year Graduate Students and have developed code for themselves and others for Belle II (and Belle via B2BII).

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