Paweł Moskal
MESON2012 12th International Workshop on Meson Production, Properties
and Interaction, Cracow, Poland, 31 May - 5 June 2012
Jagiellonian University, Cracow, Poland on behalf and for the WASA-at-COSY Collaboration
Studies of the eta meson decays with the WASA detector at COSY
WASA-at-COSY
searches for the phenomena beyond the applicability of
Standard Model of Particle Physics
Since nothing is more pleasurable than to falsify the theory !!
I thought… the scientific theories were not the digest of observation,but that they were inventions-conjectures boldly put forward for trialto be eliminated if they clashed with observation … David Hume
production and decay of the meson
Production:• test of charge symmetry • search for the eta-mesic nuclei• studies of ABC effect – new resonance?• hadronic interactions …
Decays: • test of discrete symmetries• search for dark matter boson• contributing to the study of aμ
• test of QCD anomalies• test of CHPT …
production and decay of the meson
Production:• test of charge symmetry • search for the eta-mesic nuclei• studies of ABC effect – new resonance?• hadronic interactions …
Decays: • test of discrete symmetries• search for dark matter boson• contributing to the study of aμ
• test of QCD anomalies• test of CHPT …
decay: meson C P CP +1 -1 -1
All strong and electromagentic decays are forbidden in a first order
In SM weak decays are expected to occur at 10-13
PRECISE TESTS OF DISCRETE SYMMETRIES
violates P and CP
violates G and ( I or C )
0γ , 00γ violates C
γγγ violates C etc…
Second order EM γγ is forbidden in a massless quarks limits
C() = +1 , P() =-1; C(0) = +1 , P(0) =-1
WASA-at-COSY
109 mesons on discs
this presentation is based on
~ 3 · 107
WASA
• polarised and unpolarised proton and deuteron beams
• stochastic and electron cooling
• momentum range: 600 – 3700 MeV/c
• meson production up to (1020)
WASA-at-COSY pp pp pd 3He
WASA-at-COSY pp pp pd 3He
WASA-at-COSY pp pp pd 3He
WASA-at-COSY pp pp pd 3He
Today charged modes
- γ does not if L(+- ) = 1
00γ violates C
Phys. Lett. B707 (2012) 243 - Christoph Redmer, PhD thesis
- γ
L(- ) = 1
- γ
F. Stollenwerk, C. Hanhart, A. Kupść, U.G, Meissner, A. Wirzba,
Phys. Lett. B707 (2012) 184
factor of 100 more mesons collected by WASA-at-COSY
α = 1.89 ± 0.25± 0.59
Phys. Lett. B707 (2012) 243 Christoph Redmer, PhD thesis
suppresed by α- γ* -e+e-
- γ - γ* - e+e- - γ*
-e+e-
flavour conserving CP violation
CP conservation implies N(φ) = N(180 – φ)
π+
π-
e+
e-
φ
π+
π-
e+e-
180ᵒ - φ
IN PREPARATION ….
-e+e-
-e+e-
-γ
-e+e-
Daniel Coderre PhD thesis 2012
-e+e-
factor of 30 more mesons collected by WASA-at-COSY
γγ e+e-
Suppressed by α2 and by (me/m)2
10-9
Sensitive to hypothetical interactions from beyond the Standard Model
e+e- HADES Collaboration: < 5.6·10-6 at CL=90% ) Eur. J. Phys. A48 (2012) 64
Background: pp→pp+-, →e+e-, pp→p∆(1232)→pp[*→e+e-]based on 4.4 107 η mesonsBRlimit = 4.6×10−6 at CL 90% (preliminary)
factor of 20 more mesons collected by WASA-at-COSY
MMpp for →e+e- event candidates
Poster by Marcin Berłowski
γγ* γe+e-
Suppressed by α
The anomalous muon magnetic moment a = (g - 2)/2 = (116592080 ± 60)
10-11
from E821 at BNL
theory : a = aQED + a
weak + a
had
γ γ* γ e+e-
Meson transition Form Factors
FNAL experiment plans to improve this accuaracy to 0.14 ppm M. Hodana, PhD thesis, arXiv:1203.5756
η π p
Particle's charge radius:
based on 107 eta mesons
hadronic light-by-light scattering
factor of 100 more mesons collected by WASA-at-COSY
Suppressed by α
Suppressed by next factor of α 7 10-3 / 137 = 5 10-5
γγ* γe+e- γ*γ* e+e- e+e-
Oraz może pokazac e+e-e+e- wstepne na podstawie ….XXX* 10^7
KLOE
WASA-at-COSY
Neeee = 52 ± 13
factor of 30 more eta mesons on discs
γ*γ* e+e- e+e-
analysis: L. Yurev, P. Wurm
KLOE:
factor of 30 more mesons collected by WASA-at-COSY
π+π-π0
π+π-π0
factor of 30 more mesons collected by WASA-at-COSY
s1s2
s3
III
II
I
IV
VI
V
Poster by M. Zieliński
Oraz może pokazac e+e-e+e- wstepne na podstawie ….XXX* 10^7
CP
darkmatter
C
…
THANK YOU FOR YOUR ATTENTION
ABC effect in double pionic fusion - a new resonance?
Phys. Rev. Lett. 106 (2011) 242302
Plenary talk by Anette Pricking: Monaday, June 4th, 13:00-13:30 Posters by Mikhail Bashkanov and Tatiana Skorodko
Cross section for pn → dπ0π0
++
Search for THE ETA-MESIC NUCLEUS
η meson bound with nucleus via STRONG INTERACTION
η
N*N*
N* π+
Talk by Wojciech Krzemień, Session B 17:30, 31.05 Thursday Poster by Magdalena Skurzok
Dalitz decay ω→π0e+e−
Talk by 17:10-17:30 Farha Anjum Khan, Friday, June 1-st, Session B2
Missing Mass of pd → 3He X after π0e+e− selection
Oraz może pokazac e+e-e+e- wstepne na podstawie ….XXX* 10^7
THANK YOU FOR YOUR ATTENTION
13.6 ± 2.5 (stat) ± 1.2 (syst)%KTeV PRL 84 (2000) 408
-e+e-
10-3
10-12-10-15
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