Re: d+ meson leptonic decay

Hi Ercan

The decay into tau+ neutrit is indeed not in the decay database.

However, the most recent PDG-listing
http://pdg.lbl.gov/2008/listings/s031.pdf
only gives an upper limit for the decay fraction. Thus, to my
understanding, it is not confirmed if it exists.

If you still want to study that channel, you can do it by sampling the
final state in a source routine and perform a separate simulation.

cheers
Stefan

On Wed, 3 Dec 2008, ercan pilicer wrote:

> hi again,
>
> thank you for your comment Stefan.
>
> i missed that point, i added DISCARD option and now so the simulation
> time took longer as expected.
>
> but still i can not see decayed tau+ particles in 1cm spherical vacuum
> when i see e+ and mu+ decay particles.
>
> btw, usrbin 1d histograms are exponential decays along R axes.
> except tau+.. it is empty.
>
> is there sth missing in the leptonic decay tables?
>
>
> ps. i see that there is problem in attached file. here i pasted it.
>
>
>
> TITLE
> leptonic decay
> GLOBAL 1000.0 0.0 0.0 0.0 1.
> BEAM 5.5 0.0 10000.0 D+
> BEAMPOS 0.0 0.0 0.0 0.0 0.0
> DEFAULTS
> PRECISIO
> PHYSICS 1. D+ D0BAR
> DECAYS
> PHOTONUC 1111. ALUMINUM @LASTMAT
> DISCARD -NEUTRIE -ANEUTRIE -NEUTRIM -ANEUTRIM -NEUTRIT -ANEUTRIT
> GEOBEGIN
> COMBNAME
> 0 0 simple sphrical geometry
> RPP exbox -5000.00 5000.00 -5000.00 5000.00 -5000.00 5000.00
> RPP inbox -50. 50. -50. 50. -50. 50.
> RCC bp1 0.00 0.00 -50. 0.00 0.00 20. 1.
> RCC bp2 0.00 0.00 -50. 0.00 0.00 20. 2.00
> RCC bp3 0.00 0.00 30.00 0.00 0.00 20. 1.
> RCC bp4 0.00 0.00 30.00 0.00 0.00 20. 2.00
> END
> bpl 5 +bp2 -bp1
> bpr 5 +bp4 -bp3
> invoid 5 +inbox -( +bp2 -bp1 ) -( +bp4 -bp3 )
> exvoid 5 +exbox -inbox
> END
> GEOEND
> ASSIGNMA BLCKHOLE exvoid
> ASSIGNMA VACUUM invoid
> ASSIGNMA BERYLLIU bpl
> ASSIGNMA BERYLLIU bpr
> SCORE BEAMPART
> USRBIN 11. BEAMPART -25. 1. 0.0
> 1.BPart
> USRBIN 0.0 0.0 -1. 100. 100. 100.&
> USRBIN 11. TAU+ -25. 1. 0.0
> 1.tau+
> USRBIN 0.0 0.0 -1. 100. 100. 100.&
> USRBIN 11. POSITRON -25. 1. 0.0
> 1.positrn
> USRBIN 0.0 0.0 -1. 100. 100. 100.&
> USRBIN 11. MUON+ -25. 1. 0.0
> 1.muon
> USRBIN 0.0 0.0 -1. 100. 100. 100.&
> USRBIN 11. NEUTRIE -26. 1. 0.0
> 1.eneut
> USRBIN 0.0 0.0 -1. 100. 100. 100.&
> USRBIN 11. NEUTRIM -26. 1. 0.0
> 1.mneut
> USRBIN 0.0 0.0 -1. 100. 100. 100.&
> USRBIN 11. NEUTRIT -26. 1. 0.0
> 1.tneut
> USRBIN 0.0 0.0 -1. 100. 100. 100.&
> RANDOMIZ 1.0
> START 1D5 9999999.0
> STOP
>
>
>
> On Tue, 2008-12-02 at 16:01 +0100, Stefan Roesler wrote:
> > Hi Ercan
> >
> > Did you un-discard the neutrino-transport? See the Manual under DISCARD:
> >
> > 3) Neutrinos are always discarded by default, to avoid useless
> > tracking. To force neutrinos (or other particles) to be NOT
> > discarded, make their particle number or name to be preceded by a
> > minus sign. In that case, however, remember that:
> > - no neutrino cross sections are available for transport in FLUKA:
> > these particles are just tracked through the geometry until they
> > escape. Boundary crossing and tracklength density can however be
> > scored if requested
> > - if neutrinos are not discarded, their transport threshold is set
> > = 0. by default. This value can be changed (by option PART-THR),
> > but it must be kept in mind that the energy of any neutrino
> > produced below the threshold WILL BE DEPOSITED LOCALLY, generating
> > a likely bias in dose calculations.
> >
> > cheers
> > Stefan
> >
> >
> > On Mon, 1 Dec 2008, ercan pilicer wrote:
> >
> > > dear all
> > >
> > > i try to obtain and check if there is a leptonic decay for d+ meson by;
> > >
> > > d+ --> e- + e_neutrino
> > > d+ --> muon- + muon_neutrino
> > > d+ --> tau- + tau_neutrino
> > >
> > > but i can not see produced tau+.
> > >
> > > am i making a physical mistake in my input card?
> > >
> > > ciao
> > > e.
> > >
> > >
> > >
> > > --=20
> > > =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
> > > =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D
> > > ()".'."() Ercan Pilicer
> > > ( (T) ) Uludag University, Turkey
> > > (=C3=B6) (=C3=B6) High Energy Physics Department
> > > =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
> > > =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D
> > >
> > >
> > >
> > > TITLE
> > > TAC Detector
> > > GLOBAL 1000.0 0.0 0.0 0.0 1.
> > > PHOTONUC 1111. ALUMINUM @LASTMAT
> > > DEFAULTS PRECI=
> > > SIO
> > > BEAM -2.25 0.0 10000.0 D+
> > > BEAMPOS 0.0 0.0 0.0 0.0 0.0
> > > PHYSICS 1. PROTON @LASTPAR DECAY=
> > > S
> > > GEOBEGIN COMBN=
> > > AME
> > > 0 0 TAC Charm factory geometry
> > > RPP exbox -5000.00 5000.00 -5000.00 5000.00 -5000.00 5000.00
> > > RPP inbox -50. 50. -50. 50. -50. 50.
> > > RCC bp1 0.00 0.00 -50. 0.00 0.00 20. 1.
> > > RCC bp2 0.00 0.00 -50. 0.00 0.00 20. 2.00
> > > RCC bp3 0.00 0.00 30.00 0.00 0.00 20. 1.
> > > RCC bp4 0.00 0.00 30.00 0.00 0.00 20. 2.00
> > > END
> > > bpl 5 +bp2 -bp1
> > > bpr 5 +bp4 -bp3
> > > invoid 5 +inbox -( +bp2 -bp1 ) -( +bp4 -bp3 )
> > > exvoid 5 +exbox -inbox
> > > END
> > > GEOEND
> > > ASSIGNMA BLCKHOLE exvoid
> > > ASSIGNMA VACUUM invoid
> > > ASSIGNMA BERYLLIU bpl
> > > ASSIGNMA BERYLLIU bpr
> > > SCORE BEAMPART
> > > USRBIN 11. BEAMPART -25. 1. 0.0 1.BPart
> > > USRBIN 0.0 0.0 -1. 100. 100. 100.&
> > > USRBIN 11. TAU+ -25. 1. 0.0 1.tau+
> > > USRBIN 0.0 0.0 -1. 100. 100. 100.&
> > > USRBIN 11. ELECTRON -25. 1. 0.0 1.elect=
> > > rn
> > > USRBIN 0.0 0.0 -1. 100. 100. 100.&
> > > USRBIN 11. MUON+ -25. 1. 0.0 1.muon
> > > USRBIN 0.0 0.0 -1. 100. 100. 100.&
> > > RANDOMIZ 1.0
> > > START 1D5 9999999.0
> > > STOP
> > >
> > > --=3D-F6VTZKr3ixBvd0XMTw5C--
> > >
> > >
> >
>

-- 
___________________________________
Stefan Roesler
CERN, SC/RP
CH-1211 Geneva 23
Switzerland
Phone:  +41-22-7679891
Fax:    +41-22-7669639
E-mail: Stefan.Roesler_at_cern.ch