# Presentation: 051959

## Fixed-Target Physics Results

- Recent Physics Results Highlights
-    KTeV (E832,E799), Hyper-CP,
-     NuTeV, NUSEA, DONUT,
-     E791, FOCUS, SELEX, E835

## The Precision Physics Frontier

- Easier things have been done already
- Need more statistics _and_ improved experimental techniques and/or specialized facilities/beams
- Precise comparisons or search for rare or forbidden processes

## CP and CPT Violation Studies

-   CP violation is one of the least tested part of SM
-   CP violation plays a role in matter/anti-matter asymmetry
-   Any CPT violation would also play a role

- KL semileptonic decay charge asymmetry from KTeV

- CP violation in mixing

- Compare to K

## KLe Asymmetry in KTeV

- Raw

## KLe Asymmetry in KTeV

- KLe Asymmetry in KTeV

- World Ave. L=(3.307  0.063)10-3

- Expect (3.32  0.03)10-3
- from K with only indirect CP viol.

- Take out direct CP contribution ()
- compare quantity that is sensitive to
- CPT violation in Ke3 and K2 decays:

- “K2 - Ke3” =

- The World’s best CPT limit on S = Q transitions

## CP and CPT with K

- CP and CPT with K

- KTeV

- NA48

- NA48+KTeV

- f.s. phase+CPT

- 2 contours

- E731

- E773

- KTeV published result for
-     direct CP violation

- World ave. Re()  = (16.6  6)  
-              (confidence level = 10%)

- KTeV has sensitivity to *Im*(/)
- which could show CPT violation:

- -3*Im*(/)   = 00 - +-
-     = 0.39 0.22(stat.) 0.45(syst.)

## CP Violation with HyperCP

- A = (-1.5  5.1(stat.)  4.8(syst.))  10-4

- Test CP violation everywhere - Related in quarks to CKM 

- If CP is conserved

- -  - 0 , 0  - p

- From 10% of 1999 data - expect from all data A = 1.4  10-4

| Theory | A | A |
| --- | --- | --- |
| Superweak | 0 | 0 |
| CKM (“SM”) | (-0.6 to 6.8)  10-5 | (-0.1 to 1)  10-5 |
| 2-Higgs |  -2  10-5 |  -3  10-4 |
| Left-Right |  5  10-4 |  10-4 |
| Supersymmetric |  1.9  10-3 |  10-4 |

## Rare decays with HyperCP

- Recently published Flavor changing decay K  +-

- B(K) = (9.8  1.0(stat.)  0.5(syst.))  10-8

- Specialized experiments are actually quite general:

- Resolves situation with 20% of data

## Electroweak Tests with Neutrinos

- Want precise EW tests other than with e+e- and at Z-pole

-  Sensitive to new physics (e.g. other than Z-exchange)
-  Test neutral-current neutrino couplings

- Reduce systematic uncertainties by comparing  with 

## Electroweak Tests with NuTeV

- Clean   and   beams using a SSQT beam line

-  Reduce systematics by comparing  and  (“ratio of ratios”)
-  Reduce systematics by reducing e background

- SM

- (NX)/(Nl-X)

- NuTeV sees a difference between
- neutrinos and antineutrinos compared
- to the SM:

-  Due to real difference in
-    interactions between  and -bar
- Or/And
-  Due to difference in asymmetries in
-    PDFs from QCD (LO vs NLO?)

- Knowledge of PDF is crucially important
- Need more - e.g. recent NuSea publication

## DONUT - a Start on  Studies?

- DONUT - a Start on  Studies?

- Long Decay

- Short Decay

- Study all Neutrinos!

-  Direct observation from
-   Phase I - Long decays
-  Now working on
-   Phase II - Short decays

- Totally automated
- scanning:

- Scanned tracks

- Non-penetrating and good
- quality track requirements

- Vertex requirements

- Advances in
- experimental
- techniques

## Charm - A Laboratory for Light Quarks

- Dalitz Plot analyses provides info on:
-  resonant substructure in decays
-  role of FSI in decays
-  Non-spectator contributions
- With higher statistics also provides:
-  study of light quark spectroscopy
-   in the scalar sector (JP = 0+)

- E791 Data
- D+K-++

-  I=0:    f0(600) or (500), f0(980), f0(1370),
-              f0(1500), f0(1710)
-  I=1/2: (800), K0*(1430)
-  I=1:    a0(980), a0(1450)

## Charm - A Laboratory for Light Quarks

- Without (800)

- With (800)

- E791 reports
- Evidence of
- (800) at
- Mass = 797  47 MeV/c2
- Width = 410  97 MeV/c2
-   (Produces better fit of
-     D+ K)
- And measures K0*(1430)
- Mass = 1459  9 MeV/c2
-   (PDG: 1412  6)
- Width= 175  17 MeV/c2
-   (PDG: 294  23)

- Also earlier publication on
- Evidence for a (500)

- Needs confirmation: FOCUS has  5-10 times more data on this

- Wu Ning (BES) reports evidence for (500) in J/+-, and (800) in J/K*K
-   (Hadron Spect. Feb 24-26 2003, Tokyo, Japan)

## Scalar Mesons and the Muon Anomaly

- Muon anomaly a = (g-2)/2

- Muon magnetic moment

- aexp - aSM = (2.7  1.1)  10-9

| (aexp) | 0.8  10-9 |
| --- | --- |
| (aQED) | 0.03  10-9 |
| (aEW) | 0.04  10-9 |
| (ahad,1) | 0.60.7  10-9 |
| (ahad, LOL) | 0.30.35  10-9 |

- Evaluation of contributions from scalar mesons
- Narison (‘03, hep-ph/0303004):

| aS had,1 | 0.031.3  10-9 |
| --- | --- |
| aSll | 01.1  10-9 |

- Uncertainty caused by uncertainty
- on widths of scalar mesons

- ahad,1

- aSll

- ahad, LOL

- (3.5  1.1)  10-9 (e+e-)
- (1.0  1.1)  10-9 ( decays)

- Also Dalitz analysis is an
- Important technique to understand

## Charm - Precision Vertexing

- Leading B-physics in vertexing

- Indications that systematics must be
- understood for all CP/mixing studies

- 2.7

- e.g.
- CLEO:
-   
- Lifetime

- Data

- MC

- Reconstructed mass

## Charm - Room for Surprises

- FOCUS has 7000 fully
- Reconstructed D-Dbars
- 325 previously (E687)

- Compared to Pythia5.6
- Pythia used everywhere

-  Events with
- only D-Dbar
- shows possible
-  “diffractive
-          charm”

- (3770)?

## Charm - Room for Surprises

- SELEX reported observation
- of  cc+  c+ K- +
- with 15.9 events and 6.1  0.5 bkgd
-    (reported as 6.3 and 1  10-6 prob.)
- Mass = 3519  1 MeV/c2
- Lifetime < 33 fs (90% CL)

-  Almost all cc from - beam!
-  20% of c comes from cc !
-    (from sample of 1630 c’s )

- What is the production mechanism?

## Charm - Room for Surprises

- FOCUS does not see cc+  c+ K- + from sample of 20,000 c’s

- FOCUS also searched in 20 other decay modes
- for cc+ and cc++ and do not observe any cc

|  | cc+  c+ K- + |  |
| --- | --- | --- |
| Experiment | FOCUS | SELEX |
| cc Events | < 2.21 @ 90%CL | 15.9 |
| Reconstructed c | 19444  262 | 1630 |
| Relative Efficiency | 5% | 11% |
| cc /c |  <0.23% @ 90%CL | 8.9% |
| SELEX Rel cc Prod
FOCUS      c | > 39 @ 90%CL |  |

- Could this be indicating a strange
-        production mechanism?

## E835 - Precision in pbar-p

- E835

- E835

- c0 Mass

- c0 Width

- Measures charmonium states in the pbar accumulator
-  Very fine energy/mass resolution
-  Can produce any spin-parity states directly

- New publication on c0 “10 times data”
-   plus improvement in pbar lattice

- Presents a challenge
- to Lattice QCD

- BES

- BES

- E835(‘97)

- E835(‘97)

## Summary

- From the report of the recent Fixed Target Analysis Review
- (Avi Yagil-CDF(Chair), Steve Brice-MiniBooNE, Bogdan Dobrescu-Theory,
- Doug Glenzinski-CDF, Wyatt Merrit-D0):
- “The committee was unanimously impressed with the physics output
- of fixed target experiments at Fermilab. These collaborations have
- produced and continue to produce world-class results of
- fundamental importance to High Energy Physics.”

- “The Fixed Target program at Fermilab is broad, deep and extremely
- productive...many of these datasets are unique and will not be
- superseded in the foreseeable future.”

## Summary II

- Improved experimental techniques and specialized accelerator facilities or beams
- are necessary to reach the precisions and scope to look for “New Physics”

- We should make sure these collaborations receive enough support
- to finish all the critical measurements, including but not limited to e.g.
-  / from KTeV from the full data set
-  CP violation analysis from the full HyperCP data set
-  Resolving the NuTeV /-bar discrepancy with the SM
- However we should not forget that some results can turn out to be more
- important than what one might at first expect, e.g. scalar mesons. There
- should be support in preserving the data and analysis legacy (e.g. via
- addition of new collaborators) to continue to reap these goldmines.
- For example FOCUS has 27 publications and 12 PhDs so far and
- expects additional 30-40 more publications and 14 more PhDs.

## Proceed to Backup Slides

## How HEP Publications on slide 2 are counted

-   Produced by Jeff Appel and Peter Cooper since 1990
-   Hand scanned 5 referred journals: PRL, PRD, Phy. Lett. B,
-     Nucl. Phys. B, and Zeit. fur Physik (later Eur. Phys. J.)
-   Individual physicists decided which HEP papers to include,
-     (experimental HEP results from US experiments - usually very
-     relatively few ambiguous papers.)
-    Hand scans augmented by SPIRES search
-    No attempt to be comprehensive, ignored non-US accelerators
-     with or without US participation, non-accelerator experiments,
-     theory, phenomenology, astrophysics and accelerator physics
-    Initiated by Jeff and Peter and carried out each year by them and
-      other members of the Fermilab scientific staff

## Theory - “Relating  with CKM ” 

- Bertolini, Sozzi

- Taken from recent talk from Ed. Blucher:

- Some optimism next round of lattice efforts could reach 10% level.
- Two recent lattice calculations (with similar approximations) find small, negative values for :
-              Re()=(  (RBC Collabor., stat. error only!)

## References for Scalar Mesons and Muon g-2

-  E791 publication referred to is PRL 89, 2002, 121801
-  BES data on (500) and (800) presented by Ning Wu at the
-    Int. Symp. on Hadron Spectroscopy, Chiral Symmetry and Relativistic
-    Description of Bound Systems, February 24-26, 2003,
-    Nihon University Kaikan, Ichigaya, Tokyo, Japan
- _[ ](http://aries.phys.cst.nihon-u.ac.jp/symp03/pdf/Wu.Ning.pdf)_          _[http://](http://aries.phys.cst.nihon-u.ac.jp/symp03/pdf/Wu.Ning.pdf)__[aries](http://aries.phys.cst.nihon-u.ac.jp/symp03/pdf/Wu.Ning.pdf)__[.phys.](http://aries.phys.cst.nihon-u.ac.jp/symp03/pdf/Wu.Ning.pdf)__[cst](http://aries.phys.cst.nihon-u.ac.jp/symp03/pdf/Wu.Ning.pdf)__[.](http://aries.phys.cst.nihon-u.ac.jp/symp03/pdf/Wu.Ning.pdf)__[nihon](http://aries.phys.cst.nihon-u.ac.jp/symp03/pdf/Wu.Ning.pdf)__[-u.ac.](http://aries.phys.cst.nihon-u.ac.jp/symp03/pdf/Wu.Ning.pdf)__[jp](http://aries.phys.cst.nihon-u.ac.jp/symp03/pdf/Wu.Ning.pdf)__[/symp03/](http://aries.phys.cst.nihon-u.ac.jp/symp03/pdf/Wu.Ning.pdf)__[pdf](http://aries.phys.cst.nihon-u.ac.jp/symp03/pdf/Wu.Ning.pdf)__[/Wu.](http://aries.phys.cst.nihon-u.ac.jp/symp03/pdf/Wu.Ning.pdf)__[Ning](http://aries.phys.cst.nihon-u.ac.jp/symp03/pdf/Wu.Ning.pdf)__[.](http://aries.phys.cst.nihon-u.ac.jp/symp03/pdf/Wu.Ning.pdf)__[pdf](http://aries.phys.cst.nihon-u.ac.jp/symp03/pdf/Wu.Ning.pdf)_
-  They find masses and widths consistent with E791 but the actual values
-    are model dependent

-  Data number on g-2 from C.S.Ozben et al., hep-ex/0211044 v3
-    (update to PRL 89, 2002, 101804)
-  Theory numbers from M.Davier, et al, hep-ph/0208177 v3, and
- S.Narison, hep-ph/0303004 v1

## More on Scalars in Charm: D+ K-++

- Right Sign
- Wrong Sign

- Data
- Fit
- charm bkg

- M(K (GeV/c2)

- events

- RS-WS

**WS**** Subtracted Plots**

- M(K (GeV/c2)

- 21,370events

- FOCUS K spectrum
- looks like everyone
- else’s, 100% K*(890),
- with much more data.

- However they see
- in the angular
- decay distributions
- evidence for a scalar
- interferring with the
- K*(890)

## More on Scalars from Charm: D+ K-++

- More on Scalars from Charm: D+ K-++

**Data****MC**

**HUGE****asymmetry!**

- FOCUS data can be
- explained by a
- scalar:
- Phys. Lett. B535,
- 43, 2002

## FOCUS decay modes for cc Search

- FOCUS efficiencies
- assume cc+ (cc++)
- lifetime of
- 0.2 ps (1.0 ps),
- a mass of 3.6 GeV/c2
- and production
- characteristics of a
- 3.6 GeV/c2 c
- in Pythia. See
- _[http://www-focus.](http://www-focus.fnal.gov/xicc/xicc_focus.html)_
- _[fnal](http://www-focus.fnal.gov/xicc/xicc_focus.html)__[.](http://www-focus.fnal.gov/xicc/xicc_focus.html)__[gov](http://www-focus.fnal.gov/xicc/xicc_focus.html)__[/](http://www-focus.fnal.gov/xicc/xicc_focus.html)__[xicc](http://www-focus.fnal.gov/xicc/xicc_focus.html)__[/](http://www-focus.fnal.gov/xicc/xicc_focus.html)_
- _[xicc](http://www-focus.fnal.gov/xicc/xicc_focus.html)__[_focus.html ](http://www-focus.fnal.gov/xicc/xicc_focus.html)_