hitlin physics case

Slide1: 

David Hitlin Super B Factory Workshop, Honolulu April 22, 2004

Making an effective case for a Super B Factory: 

Making an effective case for a Super B Factory Most of us at this Workshop are familiar with the measurement capabilities of a Super B Factory, comparisons with hadronic experiments, ………. (see MacFarlane, Yamauchi, …….. presentations) I will not, therefore go into these areas in detail The question I want to address is “What is the most effective way to make the case for a Super B Factory ?” and to motivate the investment of 0.5 Joint Strike Fighter planes in this goal Having demonstrated the consistency of tree-level Unitarity Triangle physics with the Standard Model, we now have a uniquely sharp tool to explore the details of New Physics that we trust will be unearthed at the LHC This is not, to the attendees of this Workshop, a particularly controversial point of view, but we have not yet succeeded in making the case clearly to the wider HEP community

EPP2010: 

EPP2010 The US National Academy of Sciences (Board on Physics and Astronomy) study on Elementary Particle Physics in the 21st Century (http://www7.nationalacademies.org/bpa/EPP2010.html) is underway, with a report expected in late 2005 or early 2006 Charge “Identify, articulate, and prioritize the scientific questions and opportunities that define elementary-particle physics Recommend a 15-year implementation plan with realistic, ordered priorities to realize these opportunities” The future of flavor physics in the US, as well as the participation of the US HEP community in flavor physics elsewhere, is crucially dependent on the outcome of this study We are attempting to communicate effectively with the committee, which consists of HEP and non-HEP physicists, as well as non-physicists How the recommendations of this report will be factored into DOE planning remains an open question

The real world: 

The real world When the EPP2010 Committee visited SLAC in January, Bob Cahn, at the invitation of the committee, gave a presentation on B physics He characterized the physics of Super B Factories as “shake the box” physics, and the physics of LHC as “open the box” physics

The real world: 

The real world When the EPP2010 Committee visited SLAC in January, Bob Cahn, at the invitation of the committee, gave a presentation on B physics He characterized the physics of Super B Factories as “shake the box” physics, and the physics of LHC as “open the box” physics This prompted committee member Harold Varmus, Nobel Laureate in Physiology or Medicine, 1989, to proclaim himself an “open the box kind of guy” Ironically, there seems to be great enthusiasm in the community and the EPP2010 Committee for the next generation of neutrino experiments, which is, of course, “shake the box” physics From this, and many other remarks, I conclude that although there is a very strong physics case for a Super B Factory, we have to this point not been particularly successful in convincing to the community What happened to the argument that virtual effects were a powerful tool, since they allow you to access very high scales? The question we must all urgently address, therefore, is how to educate the community that the physics that can be uniquely uncovered by measurements sensitive to virtual effects is important and worth a significant new investment

Vulnerabilities: 

Vulnerabilities At EPP2010 at SLAC, David Gross, Nobel Laureate in Physics, 2004, a panel member, remarked. rhetorically, “What have we ever learned from flavor physics?” Gross is also the author of The 25 Most Important Questions of Physics Question 7 - “The problems not solved by the Standard Model of particles: Particle types, masses and mixing, unification of forces ....” Question 8 – “The existence of supersymmetry: Does this framework for new physics appear at accessible energies?....” My answer: parity and CP violation, unitary symmetry, the existence of generations, the Standard Model, and, perhaps, the existence of physics beyond the SM For some reason, flavor physics (quark style) is passé, while flavor physics (neutrino style), is hot We have not effectively conveyed the importance and excitement of our achievements over the past several years, or the remaining potential of quark flavor physics at a Super B Factory

Vulnerabilities, continued: 

Vulnerabilities, continued Anomalous effects seen in by Belle/BABAR are intriguing, but … Effects are still in the 3+s range Belle /BABAR results on specific modes are not in detailed agreement There are non-negligible SM theory uncertainties in many modes Vulnerability will remain even if results in the next few years reach 4+s It is preferable to stress what can be achieved with the cleanest modes, and what is needed to measure them fKS (now) fKS 30 ab-1 Ciuchini, Franco, Martinelli, Masiero, & Silvestrini f23 mass insertion f13 mass insertion D ACP (J/ KS-p0KS) D ACP (J/ KS-fKS)

Vulnerabilities, continued: 

Vulnerabilities, continued Accelerator design performance is a very delicate issue The peak and integrated luminosity performance must be conservatively specified Parameters must withstand expert scrutiny Operating costs are important There is a trade-off between capital investment, operating costs and luminosity Performance must be sufficiently aggressive to promise important results within a few years of turn-on Evaluated on a comparable basis, KEK and SLAC concepts differ by factors of 2 to 3 This important difference is a subjective matter, but a vital one

Vulnerabilities, continued: 

Vulnerabilities, continued Too little, too late Many important results require ~50 ab-1 Most projects are expected to meet important new objectives within a few years of turn-on LHCb results that overlap with Super B will begin to appear in 2009/2010 Perhaps more important, discovery of SUSY is expected on this time scale It is crucial to have Super B results in time to promise a dialog with LHC A 50 ab-1 sample should be in hand as close to the middle of the next decade as is feasible

Strengths: 

Strengths We have a strong track record SLAC and KEK each built the current B Factories in a timely way, with reliable costing, have operated the facilities in a highly efficient manner and continue to improve performance We have done the physics we promised to do, exceeding all expectations We have made significant measurements and discoveries We have attracted (mostly favorable) newspaper and magazine coverage We have a strong and appropriate concern for Making conservative estimates ofthe precision of our measurements, including systematics, and The reliability of theoretical calculations We have done much (but not all) of the accelerator and detector R&D required to make proposals for a major upgrade that can build on our accomplishments and play an interesting part in the post-LHC New Physics conversation

Scenarios for the next decade: 

Scenarios for the next decade Evidence for SUSY (I will use SUSY to mean any kind of New Physics) will be found by ATLAS and CMS in the first few years of LHC operation LHCb will take data on the same time scale There will be an ILC, with first data in ~2020 Does a Super B Factory have a place in this context? It should have a place, but we have yet to find a sufficiently persuasive set of arguments to ensure this Super PEP-II is not currently part of SLAC’s long range plan  Tight budget constraints  Held hostage to ILC Super KEK-B is not currently part of KEK’s long range plan  Tight budget constraints  Held hostage to ILC

What can a Super B Factory bring to the party?: 

What can a Super B Factory bring to the party? Flavor physics, whether b, c or t decays, provides Sensitivity to New Physics (SUSY, extra dimensions, ……) New CP phases, non-Standard Wilson coefficients, …… Strong and unique constraints on models of SUSY breaking B(bsg) has already ruled out a host of New Physics models Super B specific measurements CPV in bs FCNC (Kll, Knn …...) LFV (t decays) Higgs mediation (B  Dtn, etc.) Precision CKM Unitarity Triangle parameters This is not news. How do we effectively demonstrate the impact of these measurements?

Scenarios for HEP in the next decade: 

Scenarios for HEP in the next decade LHC finds SUSY LHC turns on LHC doesn’t find SUSY We are here HEP What can the ILC say about SUSY-breaking models? What can a Super B Factory say about SUSY-breaking models?

What will we learn about SUSY from the LHC?: 

What will we learn about SUSY from the LHC? The first evidence for SUSY may be from inclusive distributions Example: mSUGRA with squark masses ~700 GeV

Exclusive studies are a game of edges and thresholds: 

Exclusive studies are a game of edges and thresholds If R parity is conserved, all SUSY particles decay to an invisible LSP , so there are no mass peaks. It is possible to identify particular decays and to measure their kinematic endpoints, allowing the determination of combinations of masses The three-body decay gives a dilepton endpoint at , while gives a triangular distribution with an endpoint at

Correlations allow model discrimination: 

Correlations allow model discrimination

Third generation squark signatures: 

Third generation squark signatures The main production mechanism is production and decay Example: mSUGRA with m0 = 100 GeV, m1/2 = 300 GeV, A0 = −300 GeV, tan β =10, sgn μ = + The decay chain is The M( ) endpoint can be used to measure a combination of the squark masses. The analysis requires as usual multiple hard jets and large ET plus two jets tagged as b’s, two other jets not tagged as b’s and consistent with

Opposite sign, same flavor distributions also yield Dm’s: 

Opposite sign, same flavor distributions also yield Dm’s

Slide20: 

There are also methods to get handles on combinations of the slepton mass, chargino masses, and perhaps, heavy gaugino masses and the spin

Ultimate precision on masses requires ILC: 

Ultimate precision on masses requires ILC LHC, by the mass difference and threshold methods, will measure SUSY masses to a precision of 5 to 10 GeV ILC, a decade or so later, will dramatically improve the errors slepton masses can be measured with a threshold scan to a precision ~100 MeV with 10 fb-1 per point

Combining LHC and ILC measurements (in >2020): 

Combining LHC and ILC measurements (in >2020) Can extract all SUSY parameters: example SPS1a Fittino

Squark mass matrix (d sector): 

Squark mass matrix (d sector) LHC Super B Factory A Super B Factory, early in the LHC era, can provide the means to eliminate potential models as well as unique information on CP phases

Can we integrate Super B information into the SUSY program?: 

Can we integrate Super B information into the SUSY program? There have been many interesting exercises (see, for example, the talks of Okada and Iijima on Wednesday) showing how, with improved precision, heavy quark and t measurements can uniquely discriminate between SUSY breaking models These studies relevant and persuasive We must find a mechanism to more effectively insert these approaches into the mainstream LHC/ILC conversation Is there a way, for example, to extend a global fitting program such as Fittino to incorporate information on new CP phases so that a global fit could do more than extract SUSY mass information?

The pattern of deviation from the SM values is diagnostic: 

The pattern of deviation from the SM values is diagnostic

A Super B Factory is a DNA chip for New Physics: 

A Super B Factory is a DNA chip for New Physics

A new workshop will begin this Fall: 

A new workshop will begin this Fall

Conclusions: What is needed to make the case (my opinion): 

Conclusions: What is needed to make the case (my opinion) My comments represent only my own point of view I have some (limited) understanding of the situation in the US and Europe I have even less understanding of the situation in Japan

Conclusions: What is needed to make the case (my opinion): 

Conclusions: What is needed to make the case (my opinion) A credible integrated luminosity capability approaching 10 ab-1/year An accelerator with an upgrade path, as with the current B Factories A detector that is conservatively designed and able to cope with background surprises and future luminosity upgrades A credible plan for gathering a data sample of 10’s of ab-1 that allows the marquee important measurements to be made on a time scale that is competitive with LHCb and relevant to clarifying SUSY discoveries An algorithm that there demonstrates the power of a real-time dialog between the LHC, a Super B Factory and, eventually, the ILC, would be a killer app We have made real progress on this – more is needed Discussions on forming a truly international collaboration on an appropriately scaled accelerator and detector This would, for example, facilitate an ICFA endorsement This could provide a critical mass of people and funding potential to convince the community that a Super B Factory should go forward